diff options
Diffstat (limited to 'lib/libpthread')
25 files changed, 1851 insertions, 1440 deletions
diff --git a/lib/libpthread/thread/Makefile.inc b/lib/libpthread/thread/Makefile.inc index 16799cf..22e9548 100644 --- a/lib/libpthread/thread/Makefile.inc +++ b/lib/libpthread/thread/Makefile.inc @@ -1,4 +1,4 @@ -# $Id: Makefile.inc,v 1.16 1998/09/30 06:36:55 jb Exp $ +# $Id: Makefile.inc,v 1.17 1999/03/23 05:07:54 jb Exp $ # uthread sources .PATH: ${.CURDIR}/uthread @@ -73,8 +73,8 @@ SRCS+= \ uthread_once.c \ uthread_open.c \ uthread_pipe.c \ + uthread_poll.c \ uthread_priority_queue.c \ - uthread_queue.c \ uthread_read.c \ uthread_readv.c \ uthread_recvfrom.c \ diff --git a/lib/libpthread/thread/thr_close.c b/lib/libpthread/thread/thr_close.c index 7e21853..4f55b0a 100644 --- a/lib/libpthread/thread/thr_close.c +++ b/lib/libpthread/thread/thr_close.c @@ -29,7 +29,9 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * + * $Id$ */ +#include <errno.h> #include <stdlib.h> #include <unistd.h> #include <fcntl.h> @@ -45,12 +47,21 @@ close(int fd) int ret; int status; struct stat sb; + struct fd_table_entry *entry; - /* Lock the file descriptor while the file is closed: */ - if ((ret = _FD_LOCK(fd, FD_RDWR, NULL)) == 0) { - /* Get file descriptor status. */ - _thread_sys_fstat(fd, &sb); - + if ((fd == _thread_kern_pipe[0]) || (fd == _thread_kern_pipe[1])) { + /* + * Don't allow silly programs to close the kernel pipe. + */ + errno = EBADF; + ret = -1; + } + /* + * Lock the file descriptor while the file is closed and get + * the file descriptor status: + */ + else if (((ret = _FD_LOCK(fd, FD_RDWR, NULL)) == 0) && + ((ret = _thread_sys_fstat(fd, &sb)) == 0)) { /* * Check if the file should be left as blocking. * @@ -78,11 +89,14 @@ close(int fd) _thread_sys_fcntl(fd, F_SETFL, flags & ~O_NONBLOCK); } + /* XXX: Assumes well behaved threads. */ + /* XXX: Defer real close to avoid race condition */ + entry = _thread_fd_table[fd]; + _thread_fd_table[fd] = NULL; + free(entry); + /* Close the file descriptor: */ ret = _thread_sys_close(fd); - - free(_thread_fd_table[fd]); - _thread_fd_table[fd] = NULL; } return (ret); } diff --git a/lib/libpthread/thread/thr_cond.c b/lib/libpthread/thread/thr_cond.c index e0360dd..bacfb72 100644 --- a/lib/libpthread/thread/thr_cond.c +++ b/lib/libpthread/thread/thr_cond.c @@ -29,6 +29,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * + * $Id$ */ #include <stdlib.h> #include <errno.h> @@ -44,6 +45,28 @@ static inline pthread_t cond_queue_deq(pthread_cond_t); static inline void cond_queue_remove(pthread_cond_t, pthread_t); static inline void cond_queue_enq(pthread_cond_t, pthread_t); +/* Reinitialize a condition variable to defaults. */ +int +_cond_reinit(pthread_cond_t * cond) +{ + int ret = 0; + + if (cond == NULL) + ret = EINVAL; + else if (*cond == NULL) + ret = pthread_cond_init(cond, NULL); + else { + /* + * Initialize the condition variable structure: + */ + TAILQ_INIT(&(*cond)->c_queue); + (*cond)->c_flags = COND_FLAGS_INITED; + (*cond)->c_type = COND_TYPE_FAST; + (*cond)->c_mutex = NULL; + memset(&(*cond)->lock, 0, sizeof((*cond)->lock)); + } + return (ret); +} int pthread_cond_init(pthread_cond_t * cond, const pthread_condattr_t * cond_attr) @@ -146,6 +169,9 @@ pthread_cond_wait(pthread_cond_t * cond, pthread_mutex_t * mutex) */ else if (*cond != NULL || (rval = pthread_cond_init(cond,NULL)) == 0) { + /* Lock the condition variable structure: */ + _SPINLOCK(&(*cond)->lock); + /* * If the condvar was statically allocated, properly * initialize the tail queue. @@ -155,9 +181,6 @@ pthread_cond_wait(pthread_cond_t * cond, pthread_mutex_t * mutex) (*cond)->c_flags |= COND_FLAGS_INITED; } - /* Lock the condition variable structure: */ - _SPINLOCK(&(*cond)->lock); - /* Process according to condition variable type: */ switch ((*cond)->c_type) { /* Fast condition variable: */ @@ -247,6 +270,9 @@ pthread_cond_timedwait(pthread_cond_t * cond, pthread_mutex_t * mutex, */ else if (*cond != NULL || (rval = pthread_cond_init(cond,NULL)) == 0) { + /* Lock the condition variable structure: */ + _SPINLOCK(&(*cond)->lock); + /* * If the condvar was statically allocated, properly * initialize the tail queue. @@ -256,10 +282,6 @@ pthread_cond_timedwait(pthread_cond_t * cond, pthread_mutex_t * mutex, (*cond)->c_flags |= COND_FLAGS_INITED; } - - /* Lock the condition variable structure: */ - _SPINLOCK(&(*cond)->lock); - /* Process according to condition variable type: */ switch ((*cond)->c_type) { /* Fast condition variable: */ @@ -375,6 +397,12 @@ pthread_cond_signal(pthread_cond_t * cond) if (cond == NULL || *cond == NULL) rval = EINVAL; else { + /* + * Defer signals to protect the scheduling queues + * from access by the signal handler: + */ + _thread_kern_sig_defer(); + /* Lock the condition variable structure: */ _SPINLOCK(&(*cond)->lock); @@ -409,6 +437,12 @@ pthread_cond_signal(pthread_cond_t * cond) /* Unlock the condition variable structure: */ _SPINUNLOCK(&(*cond)->lock); + + /* + * Undefer and handle pending signals, yielding if + * necessary: + */ + _thread_kern_sig_undefer(); } /* Return the completion status: */ @@ -425,14 +459,10 @@ pthread_cond_broadcast(pthread_cond_t * cond) rval = EINVAL; else { /* - * Guard against preemption by a scheduling signal. - * A change of thread state modifies the waiting - * and priority queues. In addition, we must assure - * that all threads currently waiting on the condition - * variable are signaled and are not timedout by a - * scheduling signal that causes a preemption. + * Defer signals to protect the scheduling queues + * from access by the signal handler: */ - _thread_kern_sched_defer(); + _thread_kern_sig_defer(); /* Lock the condition variable structure: */ _SPINLOCK(&(*cond)->lock); @@ -468,9 +498,11 @@ pthread_cond_broadcast(pthread_cond_t * cond) /* Unlock the condition variable structure: */ _SPINUNLOCK(&(*cond)->lock); - /* Reenable preemption and yield if necessary. + /* + * Undefer and handle pending signals, yielding if + * necessary: */ - _thread_kern_sched_undefer(); + _thread_kern_sig_undefer(); } /* Return the completion status: */ @@ -488,7 +520,7 @@ cond_queue_deq(pthread_cond_t cond) if ((pthread = TAILQ_FIRST(&cond->c_queue)) != NULL) { TAILQ_REMOVE(&cond->c_queue, pthread, qe); - pthread->flags &= ~PTHREAD_FLAGS_QUEUED; + pthread->flags &= ~PTHREAD_FLAGS_IN_CONDQ; } return(pthread); @@ -507,9 +539,9 @@ cond_queue_remove(pthread_cond_t cond, pthread_t pthread) * guard against removing the thread from the queue if * it isn't in the queue. */ - if (pthread->flags & PTHREAD_FLAGS_QUEUED) { + if (pthread->flags & PTHREAD_FLAGS_IN_CONDQ) { TAILQ_REMOVE(&cond->c_queue, pthread, qe); - pthread->flags &= ~PTHREAD_FLAGS_QUEUED; + pthread->flags &= ~PTHREAD_FLAGS_IN_CONDQ; } } @@ -535,6 +567,6 @@ cond_queue_enq(pthread_cond_t cond, pthread_t pthread) tid = TAILQ_NEXT(tid, qe); TAILQ_INSERT_BEFORE(tid, pthread, qe); } - pthread->flags |= PTHREAD_FLAGS_QUEUED; + pthread->flags |= PTHREAD_FLAGS_IN_CONDQ; } #endif diff --git a/lib/libpthread/thread/thr_create.c b/lib/libpthread/thread/thr_create.c index 438e527..f5e0b63 100644 --- a/lib/libpthread/thread/thr_create.c +++ b/lib/libpthread/thread/thr_create.c @@ -29,6 +29,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * + * $Id$ */ #include <errno.h> #include <stdlib.h> @@ -171,7 +172,7 @@ pthread_create(pthread_t * thread, const pthread_attr_t * attr, new_thread->inherited_priority = 0; /* Initialise the join queue for the new thread: */ - _thread_queue_init(&(new_thread->join_queue)); + TAILQ_INIT(&(new_thread->join_queue)); /* Initialize the mutex queue: */ TAILQ_INIT(&new_thread->mutexq); @@ -179,46 +180,39 @@ pthread_create(pthread_t * thread, const pthread_attr_t * attr, /* Initialise hooks in the thread structure: */ new_thread->specific_data = NULL; new_thread->cleanup = NULL; - new_thread->queue = NULL; - new_thread->qnxt = NULL; new_thread->flags = 0; + new_thread->poll_data.nfds = 0; + new_thread->poll_data.fds = NULL; - /* Lock the thread list: */ - _lock_thread_list(); + /* + * Defer signals to protect the scheduling queues + * from access by the signal handler: + */ + _thread_kern_sig_defer(); /* * Check if the garbage collector thread * needs to be started. */ - f_gc = (_thread_link_list == _thread_initial); + f_gc = (TAILQ_FIRST(&_thread_list) == _thread_initial); /* Add the thread to the linked list of all threads: */ - new_thread->nxt = _thread_link_list; - _thread_link_list = new_thread; - - /* Unlock the thread list: */ - _unlock_thread_list(); - - /* - * Guard against preemption by a scheduling signal. - * A change of thread state modifies the waiting - * and priority queues. - */ - _thread_kern_sched_defer(); + TAILQ_INSERT_HEAD(&_thread_list, new_thread, tle); if (pattr->suspend == PTHREAD_CREATE_SUSPENDED) { new_thread->state = PS_SUSPENDED; PTHREAD_WAITQ_INSERT(new_thread); - } else { + } + else { new_thread->state = PS_RUNNING; PTHREAD_PRIOQ_INSERT_TAIL(new_thread); } /* - * Reenable preemption and yield if a scheduling - * signal occurred while in the critical region. + * Undefer and handle pending signals, yielding + * if necessary. */ - _thread_kern_sched_undefer(); + _thread_kern_sig_undefer(); /* Return a pointer to the thread structure: */ (*thread) = new_thread; diff --git a/lib/libpthread/thread/thr_detach.c b/lib/libpthread/thread/thr_detach.c index 05da832..73a58de2 100644 --- a/lib/libpthread/thread/thr_detach.c +++ b/lib/libpthread/thread/thr_detach.c @@ -29,6 +29,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * + * $Id$ */ #include <errno.h> #ifdef _THREAD_SAFE @@ -53,23 +54,25 @@ pthread_detach(pthread_t pthread) pthread->attr.flags |= PTHREAD_DETACHED; /* - * Guard against preemption by a scheduling signal. - * A change of thread state modifies the waiting - * and priority queues. + * Defer signals to protect the scheduling queues from + * access by the signal handler: */ - _thread_kern_sched_defer(); + _thread_kern_sig_defer(); /* Enter a loop to bring all threads off the join queue: */ - while ((next_thread = _thread_queue_deq(&pthread->join_queue)) != NULL) { + while ((next_thread = TAILQ_FIRST(&pthread->join_queue)) != NULL) { + /* Remove the thread from the queue: */ + TAILQ_REMOVE(&pthread->join_queue, next_thread, qe); + /* Make the thread run: */ PTHREAD_NEW_STATE(next_thread,PS_RUNNING); } /* - * Reenable preemption and yield if a scheduling signal - * occurred while in the critical region. + * Undefer and handle pending signals, yielding if a + * scheduling signal occurred while in the critical region. */ - _thread_kern_sched_undefer(); + _thread_kern_sig_undefer(); } else /* Return an error: */ rval = EINVAL; diff --git a/lib/libpthread/thread/thr_exit.c b/lib/libpthread/thread/thr_exit.c index c54dbda..a5f706d 100644 --- a/lib/libpthread/thread/thr_exit.c +++ b/lib/libpthread/thread/thr_exit.c @@ -29,6 +29,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * + * $Id$ */ #include <errno.h> #include <unistd.h> @@ -92,7 +93,12 @@ _thread_exit(char *fname, int lineno, char *string) _thread_sys_write(2, s, strlen(s)); /* Force this process to exit: */ + /* XXX - Do we want abort to be conditional on _PTHREADS_INVARIANTS? */ +#if defined(_PTHREADS_INVARIANTS) + abort(); +#else _exit(1); +#endif } void @@ -129,22 +135,24 @@ pthread_exit(void *status) } /* - * Guard against preemption by a scheduling signal. A change of - * thread state modifies the waiting and priority queues. + * Defer signals to protect the scheduling queues from access + * by the signal handler: */ - _thread_kern_sched_defer(); + _thread_kern_sig_defer(); /* Check if there are any threads joined to this one: */ - while ((pthread = _thread_queue_deq(&(_thread_run->join_queue))) != NULL) { + while ((pthread = TAILQ_FIRST(&(_thread_run->join_queue))) != NULL) { + /* Remove the thread from the queue: */ + TAILQ_REMOVE(&_thread_run->join_queue, pthread, qe); + /* Wake the joined thread and let it detach this thread: */ PTHREAD_NEW_STATE(pthread,PS_RUNNING); } /* - * Reenable preemption and yield if a scheduling signal - * occurred while in the critical region. + * Undefer and handle pending signals, yielding if necessary: */ - _thread_kern_sched_undefer(); + _thread_kern_sig_undefer(); /* * Lock the garbage collector mutex to ensure that the garbage @@ -154,8 +162,21 @@ pthread_exit(void *status) PANIC("Cannot lock gc mutex"); /* Add this thread to the list of dead threads. */ - _thread_run->nxt_dead = _thread_dead; - _thread_dead = _thread_run; + TAILQ_INSERT_HEAD(&_dead_list, _thread_run, dle); + + /* + * Defer signals to protect the scheduling queues from access + * by the signal handler: + */ + _thread_kern_sig_defer(); + + /* Remove this thread from the thread list: */ + TAILQ_REMOVE(&_thread_list, _thread_run, tle); + + /* + * Undefer and handle pending signals, yielding if necessary: + */ + _thread_kern_sig_undefer(); /* * Signal the garbage collector thread that there is something diff --git a/lib/libpthread/thread/thr_find_thread.c b/lib/libpthread/thread/thr_find_thread.c index e4a59a0..a010a7e 100644 --- a/lib/libpthread/thread/thr_find_thread.c +++ b/lib/libpthread/thread/thr_find_thread.c @@ -29,6 +29,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * + * $Id$ */ #include <errno.h> #ifdef _THREAD_SAFE @@ -46,20 +47,20 @@ _find_thread(pthread_t pthread) /* Invalid thread: */ return(EINVAL); - /* Lock the thread list: */ - _lock_thread_list(); - - /* Point to the first thread in the list: */ - pthread1 = _thread_link_list; + /* + * Defer signals to protect the thread list from access + * by the signal handler: + */ + _thread_kern_sig_defer(); - /* Search for the thread to join to: */ - while (pthread1 != NULL && pthread1 != pthread) { - /* Point to the next thread: */ - pthread1 = pthread1->nxt; + /* Search for the specified thread: */ + TAILQ_FOREACH(pthread1, &_thread_list, tle) { + if (pthread == pthread1) + break; } - /* Unlock the thread list: */ - _unlock_thread_list(); + /* Undefer and handle pending signals, yielding if necessary: */ + _thread_kern_sig_undefer(); /* Return zero if the thread exists: */ return ((pthread1 != NULL) ? 0:ESRCH); @@ -83,13 +84,10 @@ _find_dead_thread(pthread_t pthread) if (pthread_mutex_lock(&_gc_mutex) != 0) PANIC("Cannot lock gc mutex"); - /* Point to the first thread in the list: */ - pthread1 = _thread_dead; - - /* Search for the thread to join to: */ - while (pthread1 != NULL && pthread1 != pthread) { - /* Point to the next thread: */ - pthread1 = pthread1->nxt_dead; + /* Search for the specified thread: */ + TAILQ_FOREACH(pthread1, &_dead_list, dle) { + if (pthread1 == pthread) + break; } /* Unlock the garbage collector mutex: */ diff --git a/lib/libpthread/thread/thr_fork.c b/lib/libpthread/thread/thr_fork.c index 5582c1e..8d3322e 100644 --- a/lib/libpthread/thread/thr_fork.c +++ b/lib/libpthread/thread/thr_fork.c @@ -29,6 +29,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * + * $Id$ */ #include <errno.h> #include <string.h> @@ -44,10 +45,13 @@ fork(void) int i, flags; pid_t ret; pthread_t pthread; - pthread_t pthread_next; + pthread_t pthread_save; - /* Lock the thread list: */ - _lock_thread_list(); + /* + * Defer signals to protect the scheduling queues from access + * by the signal handler: + */ + _thread_kern_sig_defer(); /* Fork a new process: */ if ((ret = _thread_sys_fork()) != 0) { @@ -88,45 +92,79 @@ fork(void) else if (_thread_sys_fcntl(_thread_kern_pipe[1], F_SETFL, flags | O_NONBLOCK) == -1) { /* Abort this application: */ abort(); + } + /* Reinitialize the GC mutex: */ + else if (_mutex_reinit(&_gc_mutex) != 0) { + /* Abort this application: */ + PANIC("Cannot initialize GC mutex for forked process"); + } + /* Reinitialize the GC condition variable: */ + else if (_cond_reinit(&_gc_cond) != 0) { + /* Abort this application: */ + PANIC("Cannot initialize GC condvar for forked process"); + } /* Initialize the ready queue: */ - } else if (_pq_init(&_readyq, PTHREAD_MIN_PRIORITY, - PTHREAD_MAX_PRIORITY) != 0) { + else if (_pq_init(&_readyq) != 0) { /* Abort this application: */ - PANIC("Cannot allocate priority ready queue."); + PANIC("Cannot initialize priority ready queue."); } else { - /* Point to the first thread in the list: */ - pthread = _thread_link_list; - /* * Enter a loop to remove all threads other than * the running thread from the thread list: */ + pthread = TAILQ_FIRST(&_thread_list); while (pthread != NULL) { - pthread_next = pthread->nxt; - if (pthread == _thread_run) { - _thread_link_list = pthread; - pthread->nxt = NULL; - } else { - if (pthread->attr.stackaddr_attr == - NULL && pthread->stack != NULL) + /* Save the thread to be freed: */ + pthread_save = pthread; + + /* + * Advance to the next thread before + * destroying the current thread: + */ + pthread = TAILQ_NEXT(pthread, dle); + + /* Make sure this isn't the running thread: */ + if (pthread_save != _thread_run) { + /* Remove this thread from the list: */ + TAILQ_REMOVE(&_thread_list, + pthread_save, tle); + + if (pthread_save->attr.stackaddr_attr == + NULL && pthread_save->stack != NULL) /* * Free the stack of the * dead thread: */ - free(pthread->stack); + free(pthread_save->stack); - if (pthread->specific_data != NULL) - free(pthread->specific_data); + if (pthread_save->specific_data != NULL) + free(pthread_save->specific_data); - free(pthread); - } + if (pthread_save->poll_data.fds != NULL) + free(pthread_save->poll_data.fds); - /* Point to the next thread: */ - pthread = pthread_next; + free(pthread_save); + } } - /* Re-init the waiting queues. */ + /* Re-init the dead thread list: */ + TAILQ_INIT(&_dead_list); + + /* Re-init the waiting and work queues. */ TAILQ_INIT(&_waitingq); + TAILQ_INIT(&_workq); + + /* Re-init the threads mutex queue: */ + TAILQ_INIT(&_thread_run->mutexq); + + /* No spinlocks yet: */ + _spinblock_count = 0; + + /* Don't queue signals yet: */ + _queue_signals = 0; + + /* Initialize signal handling: */ + _thread_sig_init(); /* Initialize the scheduling switch hook routine: */ _sched_switch_hook = NULL; @@ -147,15 +185,17 @@ fork(void) _thread_fd_table[i]->w_lockcount = 0;; /* Initialise the read/write queues: */ - _thread_queue_init(&_thread_fd_table[i]->r_queue); - _thread_queue_init(&_thread_fd_table[i]->w_queue); + TAILQ_INIT(&_thread_fd_table[i]->r_queue); + TAILQ_INIT(&_thread_fd_table[i]->w_queue); } } } } - /* Unock the thread list: */ - _unlock_thread_list(); + /* + * Undefer and handle pending signals, yielding if necessary: + */ + _thread_kern_sig_undefer(); /* Return the process ID: */ return (ret); diff --git a/lib/libpthread/thread/thr_gc.c b/lib/libpthread/thread/thr_gc.c index 510c51f..e29e29b 100644 --- a/lib/libpthread/thread/thr_gc.c +++ b/lib/libpthread/thread/thr_gc.c @@ -29,7 +29,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * - * $Id: uthread_gc.c,v 1.2 1998/09/30 19:17:51 dt Exp $ + * $Id: uthread_gc.c,v 1.3 1999/03/23 05:07:55 jb Exp $ * * Garbage collector thread. Frees memory allocated for dead threads. * @@ -74,20 +74,26 @@ _thread_gc(pthread_addr_t arg) /* Dump thread info to file. */ _thread_dump_info(); - /* Lock the thread list: */ - _lock_thread_list(); + /* + * Defer signals to protect the scheduling queues from + * access by the signal handler: + */ + _thread_kern_sig_defer(); /* Check if this is the last running thread: */ - if (_thread_link_list == _thread_run && - _thread_link_list->nxt == NULL) + if (TAILQ_FIRST(&_thread_list) == _thread_run && + TAILQ_NEXT(_thread_run, tle) == NULL) /* * This is the last thread, so it can exit * now. */ f_done = 1; - /* Unlock the thread list: */ - _unlock_thread_list(); + /* + * Undefer and handle pending signals, yielding if + * necessary: + */ + _thread_kern_sig_undefer(); /* * Lock the garbage collector mutex which ensures that @@ -100,48 +106,24 @@ _thread_gc(pthread_addr_t arg) p_stack = NULL; pthread_cln = NULL; - /* Point to the first dead thread (if there are any): */ - pthread = _thread_dead; - - /* There is no previous dead thread: */ - pthread_prv = NULL; - /* * Enter a loop to search for the first dead thread that * has memory to free. */ - while (p_stack == NULL && pthread_cln == NULL && - pthread != NULL) { - /* Save a pointer to the next thread: */ - pthread_nxt = pthread->nxt_dead; - + for (pthread = TAILQ_FIRST(&_dead_list); + p_stack == NULL && pthread_cln == NULL && pthread != NULL; + pthread = TAILQ_NEXT(pthread, dle)) { /* Check if the initial thread: */ - if (pthread == _thread_initial) + if (pthread == _thread_initial) { /* Don't destroy the initial thread. */ - pthread_prv = pthread; - + } /* * Check if this thread has detached: */ else if ((pthread->attr.flags & PTHREAD_DETACHED) != 0) { - /* - * Check if there is no previous dead - * thread: - */ - if (pthread_prv == NULL) - /* - * The dead thread is at the head - * of the list: - */ - _thread_dead = pthread_nxt; - else - /* - * The dead thread is not at the - * head of the list: - */ - pthread_prv->nxt_dead = - pthread->nxt_dead; + /* Remove this thread from the dead list: */ + TAILQ_REMOVE(&_dead_list, pthread, dle); /* * Check if the stack was not specified by @@ -162,14 +144,12 @@ _thread_gc(pthread_addr_t arg) * be freed outside the locks: */ pthread_cln = pthread; + } else { /* * This thread has not detached, so do - * not destroy it: - */ - pthread_prv = pthread; - - /* + * not destroy it. + * * Check if the stack was not specified by * the caller to pthread_create and has not * been destroyed yet: @@ -189,9 +169,6 @@ _thread_gc(pthread_addr_t arg) pthread->stack = NULL; } } - - /* Point to the next thread: */ - pthread = pthread_nxt; } /* @@ -229,52 +206,12 @@ _thread_gc(pthread_addr_t arg) */ if (p_stack != NULL) free(p_stack); - if (pthread_cln != NULL) { - /* Lock the thread list: */ - _lock_thread_list(); - - /* - * Check if the thread is at the head of the - * linked list. - */ - if (_thread_link_list == pthread_cln) - /* There is no previous thread: */ - _thread_link_list = pthread_cln->nxt; - else { - /* Point to the first thread in the list: */ - pthread = _thread_link_list; - - /* - * Enter a loop to find the thread in the - * linked list before the thread that is - * about to be freed. - */ - while (pthread != NULL && - pthread->nxt != pthread_cln) - /* Point to the next thread: */ - pthread = pthread->nxt; - - /* Check that a previous thread was found: */ - if (pthread != NULL) { - /* - * Point the previous thread to - * the one after the thread being - * freed: - */ - pthread->nxt = pthread_cln->nxt; - } - } - - /* Unlock the thread list: */ - _unlock_thread_list(); - + if (pthread_cln != NULL) /* * Free the memory allocated for the thread * structure. */ free(pthread_cln); - } - } return (NULL); } diff --git a/lib/libpthread/thread/thr_info.c b/lib/libpthread/thread/thr_info.c index d2d97da..8c0787a 100644 --- a/lib/libpthread/thread/thr_info.c +++ b/lib/libpthread/thread/thr_info.c @@ -29,6 +29,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * + * $Id$ */ #include <stdio.h> #include <fcntl.h> @@ -55,6 +56,7 @@ static const struct s_thread_info thread_info[] = { {PS_FDR_WAIT , "Waiting for read"}, {PS_FDW_WAIT , "Waiting for write"}, {PS_FILE_WAIT , "Waiting for FILE lock"}, + {PS_POLL_WAIT , "Waiting on poll"}, {PS_SELECT_WAIT , "Waiting on select"}, {PS_SLEEP_WAIT , "Sleeping"}, {PS_WAIT_WAIT , "Waiting process"}, @@ -108,8 +110,7 @@ _thread_dump_info(void) _thread_sys_write(fd, s, strlen(s)); /* Enter a loop to report each thread in the global list: */ - for (pthread = _thread_link_list; pthread != NULL; - pthread = pthread->nxt) { + TAILQ_FOREACH(pthread, &_thread_list, tle) { /* Find the state: */ for (j = 0; j < (sizeof(thread_info) / sizeof(struct s_thread_info)) - 1; j++) @@ -214,8 +215,29 @@ _thread_dump_info(void) _thread_sys_write(fd, s, strlen(s)); } + /* Output a header for threads in the work queue: */ + strcpy(s, "\n\n=============\nTHREADS IN WORKQ\n\n"); + _thread_sys_write(fd, s, strlen(s)); + + /* Enter a loop to report each thread in the waiting queue: */ + TAILQ_FOREACH (pthread, &_workq, qe) { + /* Find the state: */ + for (j = 0; j < (sizeof(thread_info) / + sizeof(struct s_thread_info)) - 1; j++) + if (thread_info[j].state == pthread->state) + break; + /* Output a record for the current thread: */ + snprintf(s, sizeof(s), + "--------------------\nThread %p (%s) prio %3d state %s [%s:%d]\n", + pthread, (pthread->name == NULL) ? + "":pthread->name, pthread->base_priority, + thread_info[j].name, + pthread->fname,pthread->lineno); + _thread_sys_write(fd, s, strlen(s)); + } + /* Check if there are no dead threads: */ - if (_thread_dead == NULL) { + if (TAILQ_FIRST(&_dead_list) == NULL) { /* Output a record: */ strcpy(s, "\n\nTHERE ARE NO DEAD THREADS\n"); _thread_sys_write(fd, s, strlen(s)); @@ -228,8 +250,7 @@ _thread_dump_info(void) * Enter a loop to report each thread in the global * dead thread list: */ - for (pthread = _thread_dead; pthread != NULL; - pthread = pthread->nxt_dead) { + TAILQ_FOREACH(pthread, &_dead_list, dle) { /* Output a record for the current thread: */ snprintf(s, sizeof(s), "Thread %p prio %3d [%s:%d]\n", diff --git a/lib/libpthread/thread/thr_init.c b/lib/libpthread/thread/thr_init.c index e4411ce..d470301 100644 --- a/lib/libpthread/thread/thr_init.c +++ b/lib/libpthread/thread/thr_init.c @@ -29,6 +29,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * + * $Id$ */ /* Allocate space for global thread variables here: */ @@ -39,7 +40,9 @@ #include <string.h> #include <fcntl.h> #include <paths.h> +#include <poll.h> #include <unistd.h> +#include <sys/sysctl.h> #include <sys/time.h> #include <sys/ttycom.h> #ifdef _THREAD_SAFE @@ -81,6 +84,9 @@ _thread_init(void) int fd; int flags; int i; + int len; + int mib[2]; + struct clockinfo clockinfo; struct sigaction act; /* Check if this function has already been called: */ @@ -147,8 +153,8 @@ _thread_init(void) /* Abort this application: */ PANIC("Cannot get kernel write pipe flags"); } - /* Initialize the ready queue: */ - else if (_pq_init(&_readyq, PTHREAD_MIN_PRIORITY, PTHREAD_MAX_PRIORITY) != 0) { + /* Allocate and initialize the ready queue: */ + else if (_pq_alloc(&_readyq, PTHREAD_MIN_PRIORITY, PTHREAD_MAX_PRIORITY) != 0) { /* Abort this application: */ PANIC("Cannot allocate priority ready queue."); } @@ -165,8 +171,9 @@ _thread_init(void) _thread_kern_thread.flags = PTHREAD_FLAGS_PRIVATE; memset(_thread_initial, 0, sizeof(struct pthread)); - /* Initialize the waiting queue: */ + /* Initialize the waiting and work queues: */ TAILQ_INIT(&_waitingq); + TAILQ_INIT(&_workq); /* Initialize the scheduling switch hook routine: */ _sched_switch_hook = NULL; @@ -186,23 +193,23 @@ _thread_init(void) _thread_initial->state = PS_RUNNING; /* Initialise the queue: */ - _thread_queue_init(&(_thread_initial->join_queue)); + TAILQ_INIT(&(_thread_initial->join_queue)); /* Initialize the owned mutex queue and count: */ TAILQ_INIT(&(_thread_initial->mutexq)); _thread_initial->priority_mutex_count = 0; /* Initialise the rest of the fields: */ - _thread_initial->sched_defer_count = 0; - _thread_initial->yield_on_sched_undefer = 0; + _thread_initial->poll_data.nfds = 0; + _thread_initial->poll_data.fds = NULL; + _thread_initial->sig_defer_count = 0; + _thread_initial->yield_on_sig_undefer = 0; _thread_initial->specific_data = NULL; _thread_initial->cleanup = NULL; - _thread_initial->queue = NULL; - _thread_initial->qnxt = NULL; - _thread_initial->nxt = NULL; _thread_initial->flags = 0; _thread_initial->error = 0; - _thread_link_list = _thread_initial; + TAILQ_INIT(&_thread_list); + TAILQ_INSERT_HEAD(&_thread_list, _thread_initial, tle); _thread_run = _thread_initial; /* Initialise the global signal action structure: */ @@ -210,6 +217,9 @@ _thread_init(void) act.sa_handler = (void (*) ()) _thread_sig_handler; act.sa_flags = 0; + /* Initialize signal handling: */ + _thread_sig_init(); + /* Enter a loop to get the existing signal status: */ for (i = 1; i < NSIG; i++) { /* Check for signals which cannot be trapped: */ @@ -241,6 +251,13 @@ _thread_init(void) PANIC("Cannot initialise signal handler"); } + /* Get the kernel clockrate: */ + mib[0] = CTL_KERN; + mib[1] = KERN_CLOCKRATE; + len = sizeof (struct clockinfo); + if (sysctl(mib, 2, &clockinfo, &len, NULL, 0) == 0) + _clock_res_nsec = clockinfo.tick * 1000; + /* Get the table size: */ if ((_thread_dtablesize = getdtablesize()) < 0) { /* @@ -256,6 +273,14 @@ _thread_init(void) * table, so abort this process. */ PANIC("Cannot allocate memory for file descriptor table"); + } + /* Allocate memory for the pollfd table: */ + if ((_thread_pfd_table = (struct pollfd *) malloc(sizeof(struct pollfd) * _thread_dtablesize)) == NULL) { + /* + * Cannot allocate memory for the file descriptor + * table, so abort this process. + */ + PANIC("Cannot allocate memory for pollfd table"); } else { /* * Enter a loop to initialise the file descriptor @@ -265,6 +290,14 @@ _thread_init(void) /* Initialise the file descriptor table: */ _thread_fd_table[i] = NULL; } + + /* Initialize stdio file descriptor table entries: */ + if ((_thread_fd_table_init(0) != 0) || + (_thread_fd_table_init(1) != 0) || + (_thread_fd_table_init(2) != 0)) { + PANIC("Cannot initialize stdio file descriptor " + "table entries"); + } } } diff --git a/lib/libpthread/thread/thr_join.c b/lib/libpthread/thread/thr_join.c index 2043b76..f36d7f7 100644 --- a/lib/libpthread/thread/thr_join.c +++ b/lib/libpthread/thread/thr_join.c @@ -29,6 +29,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * + * $Id$ */ #include <errno.h> #ifdef _THREAD_SAFE @@ -71,7 +72,7 @@ pthread_join(pthread_t pthread, void **thread_return) /* Check if the thread is not dead: */ else if (pthread->state != PS_DEAD) { /* Add the running thread to the join queue: */ - _thread_queue_enq(&(pthread->join_queue), _thread_run); + TAILQ_INSERT_TAIL(&(pthread->join_queue), _thread_run, qe); /* Schedule the next thread: */ _thread_kern_sched_state(PS_JOIN, __FILE__, __LINE__); diff --git a/lib/libpthread/thread/thr_kern.c b/lib/libpthread/thread/thr_kern.c index f1e97f9..8718906 100644 --- a/lib/libpthread/thread/thr_kern.c +++ b/lib/libpthread/thread/thr_kern.c @@ -29,10 +29,11 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * - * $Id: uthread_kern.c,v 1.17 1999/05/07 07:59:44 jasone Exp $ + * $Id: uthread_kern.c,v 1.16 1999/03/23 05:07:56 jb Exp $ * */ #include <errno.h> +#include <poll.h> #include <stdlib.h> #include <stdarg.h> #include <string.h> @@ -51,7 +52,10 @@ /* Static function prototype definitions: */ static void -_thread_kern_select(int wait_reqd); +_thread_kern_poll(int wait_reqd); + +static void +dequeue_signals(void); static inline void thread_run_switch_hook(pthread_t thread_out, pthread_t thread_in); @@ -62,14 +66,12 @@ _thread_kern_sched(struct sigcontext * scp) #ifndef __alpha__ char *fdata; #endif - pthread_t pthread; - pthread_t pthread_h = NULL; + pthread_t pthread, pthread_h = NULL; pthread_t last_thread = NULL; struct itimerval itimer; - struct timespec ts; - struct timespec ts1; - struct timeval tv; - struct timeval tv1; + struct timespec ts, ts1; + struct timeval tv, tv1; + int i, set_timer = 0; /* * Flag the pthread kernel as executing scheduler code @@ -111,6 +113,7 @@ __asm__("fnsave %0": :"m"(*fdata)); /* Run the installed switch hook: */ thread_run_switch_hook(_last_user_thread, _thread_run); } + return; } else /* Flag the jump buffer was the last state saved: */ @@ -127,238 +130,208 @@ __asm__("fnsave %0": :"m"(*fdata)); * either a sigreturn (if the state was saved as a sigcontext) or a * longjmp (if the state was saved by a setjmp). */ - while (_thread_link_list != NULL) { + while (!(TAILQ_EMPTY(&_thread_list))) { /* Get the current time of day: */ gettimeofday(&tv, NULL); TIMEVAL_TO_TIMESPEC(&tv, &ts); /* - * Poll file descriptors to update the state of threads - * waiting on file I/O where data may be available: + * Protect the scheduling queues from access by the signal + * handler. */ - _thread_kern_select(0); + _queue_signals = 1; - /* - * Define the maximum time before a scheduling signal - * is required: - */ - itimer.it_value.tv_sec = 0; - itimer.it_value.tv_usec = TIMESLICE_USEC; - - /* - * The interval timer is not reloaded when it - * times out. The interval time needs to be - * calculated every time. - */ - itimer.it_interval.tv_sec = 0; - itimer.it_interval.tv_usec = 0; - - /* - * Enter a loop to look for sleeping threads that are ready - * or timedout. While we're at it, also find the smallest - * timeout value for threads waiting for a time. - */ - _waitingq_check_reqd = 0; /* reset flag before loop */ - TAILQ_FOREACH(pthread, &_waitingq, pqe) { - /* Check if this thread is ready: */ - if (pthread->state == PS_RUNNING) { - PTHREAD_WAITQ_REMOVE(pthread); - PTHREAD_PRIOQ_INSERT_TAIL(pthread); - } + if (_thread_run != &_thread_kern_thread) { /* - * Check if this thread is blocked by an - * atomic lock: + * This thread no longer needs to yield the CPU. + */ + _thread_run->yield_on_sig_undefer = 0; + + /* + * Save the current time as the time that the thread + * became inactive: */ - else if (pthread->state == PS_SPINBLOCK) { + _thread_run->last_inactive.tv_sec = tv.tv_sec; + _thread_run->last_inactive.tv_usec = tv.tv_usec; + + /* + * Place the currently running thread into the + * appropriate queue(s). + */ + switch (_thread_run->state) { + case PS_DEAD: /* - * If the lock is available, let - * the thread run. + * Dead threads are not placed in any queue: */ - if (pthread->data.spinlock->access_lock == 0) { - PTHREAD_NEW_STATE(pthread,PS_RUNNING); - } + break; - /* Check if this thread is to timeout: */ - } else if (pthread->state == PS_COND_WAIT || - pthread->state == PS_SLEEP_WAIT || - pthread->state == PS_FDR_WAIT || - pthread->state == PS_FDW_WAIT || - pthread->state == PS_SELECT_WAIT) { - /* Check if this thread is to wait forever: */ - if (pthread->wakeup_time.tv_sec == -1) { - } + case PS_RUNNING: /* - * Check if this thread is to wakeup - * immediately or if it is past its wakeup - * time: + * Runnable threads can't be placed in the + * priority queue until after waiting threads + * are polled (to preserve round-robin + * scheduling). */ - else if ((pthread->wakeup_time.tv_sec == 0 && - pthread->wakeup_time.tv_nsec == 0) || - (ts.tv_sec > pthread->wakeup_time.tv_sec) || - ((ts.tv_sec == pthread->wakeup_time.tv_sec) && - (ts.tv_nsec >= pthread->wakeup_time.tv_nsec))) { - /* - * Check if this thread is waiting on - * select: - */ - if (pthread->state == PS_SELECT_WAIT) { - /* - * The select has timed out, so - * zero the file descriptor - * sets: - */ - FD_ZERO(&pthread->data.select_data->readfds); - FD_ZERO(&pthread->data.select_data->writefds); - FD_ZERO(&pthread->data.select_data->exceptfds); - pthread->data.select_data->nfds = 0; - } + if ((_thread_run->slice_usec != -1) && + (_thread_run->attr.sched_policy != SCHED_FIFO)) { /* - * Return an error as an interrupted - * wait: + * Accumulate the number of microseconds that + * this thread has run for: */ - _thread_seterrno(pthread, EINTR); + _thread_run->slice_usec += + (_thread_run->last_inactive.tv_sec - + _thread_run->last_active.tv_sec) * 1000000 + + _thread_run->last_inactive.tv_usec - + _thread_run->last_active.tv_usec; + + /* Check for time quantum exceeded: */ + if (_thread_run->slice_usec > TIMESLICE_USEC) + _thread_run->slice_usec = -1; + } + break; - /* - * Flag the timeout in the thread - * structure: - */ - pthread->timeout = 1; + /* + * States which do not depend on file descriptor I/O + * operations or timeouts: + */ + case PS_DEADLOCK: + case PS_FDLR_WAIT: + case PS_FDLW_WAIT: + case PS_FILE_WAIT: + case PS_JOIN: + case PS_MUTEX_WAIT: + case PS_SIGSUSPEND: + case PS_SIGTHREAD: + case PS_SIGWAIT: + case PS_SUSPENDED: + case PS_WAIT_WAIT: + /* No timeouts for these states: */ + _thread_run->wakeup_time.tv_sec = -1; + _thread_run->wakeup_time.tv_nsec = -1; - /* - * Change the threads state to allow - * it to be restarted: - */ - PTHREAD_NEW_STATE(pthread,PS_RUNNING); - } else { - /* - * Calculate the time until this thread - * is ready, allowing for the clock - * resolution: - */ - ts1.tv_sec = pthread->wakeup_time.tv_sec - - ts.tv_sec; - ts1.tv_nsec = pthread->wakeup_time.tv_nsec - - ts.tv_nsec + CLOCK_RES_NSEC; + /* Restart the time slice: */ + _thread_run->slice_usec = -1; - /* - * Check for underflow of the - * nanosecond field: - */ - if (ts1.tv_nsec < 0) { - /* - * Allow for the underflow - * of the nanosecond field: - */ - ts1.tv_sec--; - ts1.tv_nsec += 1000000000; - } - /* - * Check for overflow of the nanosecond - * field: - */ - if (ts1.tv_nsec >= 1000000000) { - /* - * Allow for the overflow of - * the nanosecond field: - */ - ts1.tv_sec++; - ts1.tv_nsec -= 1000000000; - } - /* - * Convert the timespec structure - * to a timeval structure: - */ - TIMESPEC_TO_TIMEVAL(&tv1, &ts1); + /* Insert into the waiting queue: */ + PTHREAD_WAITQ_INSERT(_thread_run); + break; - /* - * Check if the thread will be ready - * sooner than the earliest ones found - * so far: - */ - if (timercmp(&tv1, &itimer.it_value, <)) { - /* - * Update the time value: - */ - itimer.it_value.tv_sec = tv1.tv_sec; - itimer.it_value.tv_usec = tv1.tv_usec; - } - } + /* States which can timeout: */ + case PS_COND_WAIT: + case PS_SLEEP_WAIT: + /* Restart the time slice: */ + _thread_run->slice_usec = -1; + + /* Insert into the waiting queue: */ + PTHREAD_WAITQ_INSERT(_thread_run); + break; + + /* States that require periodic work: */ + case PS_SPINBLOCK: + /* No timeouts for this state: */ + _thread_run->wakeup_time.tv_sec = -1; + _thread_run->wakeup_time.tv_nsec = -1; + + /* Increment spinblock count: */ + _spinblock_count++; + /* fall through */ + case PS_FDR_WAIT: + case PS_FDW_WAIT: + case PS_POLL_WAIT: + case PS_SELECT_WAIT: + /* Restart the time slice: */ + _thread_run->slice_usec = -1; + + /* Insert into the waiting queue: */ + PTHREAD_WAITQ_INSERT(_thread_run); + + /* Insert into the work queue: */ + PTHREAD_WORKQ_INSERT(_thread_run); } } - /* Check if there is a current thread: */ - if (_thread_run != &_thread_kern_thread) { - /* - * This thread no longer needs to yield the CPU. - */ - _thread_run->yield_on_sched_undefer = 0; + /* Unprotect the scheduling queues: */ + _queue_signals = 0; - /* - * Save the current time as the time that the thread - * became inactive: - */ - _thread_run->last_inactive.tv_sec = tv.tv_sec; - _thread_run->last_inactive.tv_usec = tv.tv_usec; + /* + * Poll file descriptors to update the state of threads + * waiting on file I/O where data may be available: + */ + _thread_kern_poll(0); + + /* Protect the scheduling queues: */ + _queue_signals = 1; + /* + * Wake up threads that have timedout. This has to be + * done after polling in case a thread does a poll or + * select with zero time. + */ + PTHREAD_WAITQ_SETACTIVE(); + while (((pthread = TAILQ_FIRST(&_waitingq)) != NULL) && + (pthread->wakeup_time.tv_sec != -1) && + (((pthread->wakeup_time.tv_sec == 0) && + (pthread->wakeup_time.tv_nsec == 0)) || + (pthread->wakeup_time.tv_sec < ts.tv_sec) || + ((pthread->wakeup_time.tv_sec == ts.tv_sec) && + (pthread->wakeup_time.tv_nsec <= ts.tv_nsec)))) { + switch (pthread->state) { + case PS_POLL_WAIT: + case PS_SELECT_WAIT: + /* Return zero file descriptors ready: */ + pthread->data.poll_data->nfds = 0; + /* fall through */ + default: + /* + * Remove this thread from the waiting queue + * (and work queue if necessary) and place it + * in the ready queue. + */ + PTHREAD_WAITQ_CLEARACTIVE(); + if (pthread->flags & PTHREAD_FLAGS_IN_WORKQ) + PTHREAD_WORKQ_REMOVE(pthread); + PTHREAD_NEW_STATE(pthread, PS_RUNNING); + PTHREAD_WAITQ_SETACTIVE(); + break; + } /* - * Accumulate the number of microseconds that this - * thread has run for: + * Flag the timeout in the thread structure: */ - if ((_thread_run->slice_usec != -1) && - (_thread_run->attr.sched_policy != SCHED_FIFO)) { - _thread_run->slice_usec += - (_thread_run->last_inactive.tv_sec - - _thread_run->last_active.tv_sec) * 1000000 + - _thread_run->last_inactive.tv_usec - - _thread_run->last_active.tv_usec; - - /* Check for time quantum exceeded: */ - if (_thread_run->slice_usec > TIMESLICE_USEC) - _thread_run->slice_usec = -1; - } - if (_thread_run->state == PS_RUNNING) { - if (_thread_run->slice_usec == -1) { - /* - * The thread exceeded its time - * quantum or it yielded the CPU; - * place it at the tail of the - * queue for its priority. - */ - PTHREAD_PRIOQ_INSERT_TAIL(_thread_run); - } else { - /* - * The thread hasn't exceeded its - * interval. Place it at the head - * of the queue for its priority. - */ - PTHREAD_PRIOQ_INSERT_HEAD(_thread_run); - } - } - else if (_thread_run->state == PS_DEAD) { + pthread->timeout = 1; + } + PTHREAD_WAITQ_CLEARACTIVE(); + + /* + * Check if there is a current runnable thread that isn't + * already in the ready queue: + */ + if ((_thread_run != &_thread_kern_thread) && + (_thread_run->state == PS_RUNNING) && + ((_thread_run->flags & PTHREAD_FLAGS_IN_PRIOQ) == 0)) { + if (_thread_run->slice_usec == -1) { /* - * Don't add dead threads to the waiting - * queue, because when they're reaped, it - * will corrupt the queue. + * The thread exceeded its time + * quantum or it yielded the CPU; + * place it at the tail of the + * queue for its priority. */ - } - else { + PTHREAD_PRIOQ_INSERT_TAIL(_thread_run); + } else { /* - * This thread has changed state and needs - * to be placed in the waiting queue. + * The thread hasn't exceeded its + * interval. Place it at the head + * of the queue for its priority. */ - PTHREAD_WAITQ_INSERT(_thread_run); - - /* Restart the time slice: */ - _thread_run->slice_usec = -1; + PTHREAD_PRIOQ_INSERT_HEAD(_thread_run); } } /* * Get the highest priority thread in the ready queue. */ - pthread_h = PTHREAD_PRIOQ_FIRST; + pthread_h = PTHREAD_PRIOQ_FIRST(); /* Check if there are no threads ready to run: */ if (pthread_h == NULL) { @@ -369,18 +342,84 @@ __asm__("fnsave %0": :"m"(*fdata)); */ _thread_run = &_thread_kern_thread; + /* Unprotect the scheduling queues: */ + _queue_signals = 0; + /* * There are no threads ready to run, so wait until * something happens that changes this condition: */ - _thread_kern_select(1); - } else { + _thread_kern_poll(1); + } + else { + /* Remove the thread from the ready queue: */ + PTHREAD_PRIOQ_REMOVE(pthread_h); + + /* Get first thread on the waiting list: */ + pthread = TAILQ_FIRST(&_waitingq); + + /* Check to see if there is more than one thread: */ + if (pthread_h != TAILQ_FIRST(&_thread_list) || + TAILQ_NEXT(pthread_h, tle) != NULL) + set_timer = 1; + else + set_timer = 0; + + /* Unprotect the scheduling queues: */ + _queue_signals = 0; + + /* + * Check for signals queued while the scheduling + * queues were protected: + */ + while (_sigq_check_reqd != 0) { + /* Clear before handling queued signals: */ + _sigq_check_reqd = 0; + + /* Protect the scheduling queues again: */ + _queue_signals = 1; + + dequeue_signals(); + + /* + * Check for a higher priority thread that + * became runnable due to signal handling. + */ + if (((pthread = PTHREAD_PRIOQ_FIRST()) != NULL) && + (pthread->active_priority > pthread_h->active_priority)) { + /* + * Insert the lower priority thread + * at the head of its priority list: + */ + PTHREAD_PRIOQ_INSERT_HEAD(pthread_h); + + /* Remove the thread from the ready queue: */ + PTHREAD_PRIOQ_REMOVE(pthread); + + /* There's a new thread in town: */ + pthread_h = pthread; + } + + /* Get first thread on the waiting list: */ + pthread = TAILQ_FIRST(&_waitingq); + + /* + * Check to see if there is more than one + * thread: + */ + if (pthread_h != TAILQ_FIRST(&_thread_list) || + TAILQ_NEXT(pthread_h, tle) != NULL) + set_timer = 1; + else + set_timer = 0; + + /* Unprotect the scheduling queues: */ + _queue_signals = 0; + } + /* Make the selected thread the current thread: */ _thread_run = pthread_h; - /* Remove the thread from the ready queue. */ - PTHREAD_PRIOQ_REMOVE(_thread_run); - /* * Save the current time as the time that the thread * became active: @@ -389,6 +428,76 @@ __asm__("fnsave %0": :"m"(*fdata)); _thread_run->last_active.tv_usec = tv.tv_usec; /* + * Define the maximum time before a scheduling signal + * is required: + */ + itimer.it_value.tv_sec = 0; + itimer.it_value.tv_usec = TIMESLICE_USEC; + + /* + * The interval timer is not reloaded when it + * times out. The interval time needs to be + * calculated every time. + */ + itimer.it_interval.tv_sec = 0; + itimer.it_interval.tv_usec = 0; + + /* Get first thread on the waiting list: */ + if ((pthread != NULL) && + (pthread->wakeup_time.tv_sec != -1)) { + /* + * Calculate the time until this thread + * is ready, allowing for the clock + * resolution: + */ + ts1.tv_sec = pthread->wakeup_time.tv_sec + - ts.tv_sec; + ts1.tv_nsec = pthread->wakeup_time.tv_nsec + - ts.tv_nsec + _clock_res_nsec; + + /* + * Check for underflow of the nanosecond field: + */ + if (ts1.tv_nsec < 0) { + /* + * Allow for the underflow of the + * nanosecond field: + */ + ts1.tv_sec--; + ts1.tv_nsec += 1000000000; + } + /* + * Check for overflow of the nanosecond field: + */ + if (ts1.tv_nsec >= 1000000000) { + /* + * Allow for the overflow of the + * nanosecond field: + */ + ts1.tv_sec++; + ts1.tv_nsec -= 1000000000; + } + /* + * Convert the timespec structure to a + * timeval structure: + */ + TIMESPEC_TO_TIMEVAL(&tv1, &ts1); + + /* + * Check if the thread will be ready + * sooner than the earliest ones found + * so far: + */ + if (timercmp(&tv1, &itimer.it_value, <)) { + /* + * Update the time value: + */ + itimer.it_value.tv_sec = tv1.tv_sec; + itimer.it_value.tv_usec = tv1.tv_usec; + } + } + + /* * Check if this thread is running for the first time * or running again after using its full time slice * allocation: @@ -399,7 +508,7 @@ __asm__("fnsave %0": :"m"(*fdata)); } /* Check if there is more than one thread: */ - if (_thread_run != _thread_link_list || _thread_run->nxt != NULL) { + if (set_timer != 0) { /* * Start the interval timer for the * calculated time interval: @@ -462,6 +571,19 @@ __asm__("fnsave %0": :"m"(*fdata)); void _thread_kern_sched_state(enum pthread_state state, char *fname, int lineno) { + /* + * Flag the pthread kernel as executing scheduler code + * to avoid a scheduler signal from interrupting this + * execution and calling the scheduler again. + */ + _thread_kern_in_sched = 1; + + /* + * Prevent the signal handler from fiddling with this thread + * before its state is set and is placed into the proper queue. + */ + _queue_signals = 1; + /* Change the state of the current thread: */ _thread_run->state = state; _thread_run->fname = fname; @@ -476,6 +598,20 @@ void _thread_kern_sched_state_unlock(enum pthread_state state, spinlock_t *lock, char *fname, int lineno) { + /* + * Flag the pthread kernel as executing scheduler code + * to avoid a scheduler signal from interrupting this + * execution and calling the scheduler again. + */ + _thread_kern_in_sched = 1; + + /* + * Prevent the signal handler from fiddling with this thread + * before its state is set and it is placed into the proper + * queue(s). + */ + _queue_signals = 1; + /* Change the state of the current thread: */ _thread_run->state = state; _thread_run->fname = fname; @@ -489,384 +625,193 @@ _thread_kern_sched_state_unlock(enum pthread_state state, } static void -_thread_kern_select(int wait_reqd) +_thread_kern_poll(int wait_reqd) { char bufr[128]; - fd_set fd_set_except; - fd_set fd_set_read; - fd_set fd_set_write; int count = 0; - int count_dec; - int found_one; - int i; - int nfds = -1; - int settimeout; - pthread_t pthread; + int i, found; + int kern_pipe_added = 0; + int nfds = 0; + int timeout_ms = 0; + struct pthread *pthread, *pthread_next; ssize_t num; struct timespec ts; - struct timespec ts1; - struct timeval *p_tv; struct timeval tv; - struct timeval tv1; - - /* Zero the file descriptor sets: */ - FD_ZERO(&fd_set_read); - FD_ZERO(&fd_set_write); - FD_ZERO(&fd_set_except); /* Check if the caller wants to wait: */ - if (wait_reqd) { - /* - * Add the pthread kernel pipe file descriptor to the read - * set: - */ - FD_SET(_thread_kern_pipe[0], &fd_set_read); - nfds = _thread_kern_pipe[0]; - + if (wait_reqd == 0) { + timeout_ms = 0; + } + else { /* Get the current time of day: */ gettimeofday(&tv, NULL); TIMEVAL_TO_TIMESPEC(&tv, &ts); + + _queue_signals = 1; + pthread = TAILQ_FIRST(&_waitingq); + _queue_signals = 0; + + if ((pthread == NULL) || (pthread->wakeup_time.tv_sec == -1)) { + /* + * Either there are no threads in the waiting queue, + * or there are no threads that can timeout. + */ + timeout_ms = INFTIM; + } + else { + /* + * Calculate the time left for the next thread to + * timeout allowing for the clock resolution: + */ + timeout_ms = ((pthread->wakeup_time.tv_sec - ts.tv_sec) * + 1000) + ((pthread->wakeup_time.tv_nsec - ts.tv_nsec + + _clock_res_nsec) / 1000000); + /* + * Don't allow negative timeouts: + */ + if (timeout_ms < 0) + timeout_ms = 0; + } } - /* Initialise the time value structure: */ - tv.tv_sec = 0; - tv.tv_usec = 0; + + /* Protect the scheduling queues: */ + _queue_signals = 1; /* - * Enter a loop to process threads waiting on either file descriptors - * or times: + * Check to see if the signal queue needs to be walked to look + * for threads awoken by a signal while in the scheduler. Only + * do this if a wait is specified; otherwise, the waiting queue + * will be checked after the zero-timed _poll. */ - _waitingq_check_reqd = 0; /* reset flag before loop */ - TAILQ_FOREACH (pthread, &_waitingq, pqe) { - /* Assume that this state does not time out: */ - settimeout = 0; + while ((_sigq_check_reqd != 0) && (timeout_ms != 0)) { + /* Reset flag before handling queued signals: */ + _sigq_check_reqd = 0; + + dequeue_signals(); - /* Process according to thread state: */ - switch (pthread->state) { /* - * States which do not depend on file descriptor I/O - * operations or timeouts: + * Check for a thread that became runnable due to + * a signal: */ - case PS_DEAD: - case PS_DEADLOCK: - case PS_FDLR_WAIT: - case PS_FDLW_WAIT: - case PS_FILE_WAIT: - case PS_JOIN: - case PS_MUTEX_WAIT: - case PS_SIGTHREAD: - case PS_SIGWAIT: - case PS_STATE_MAX: - case PS_WAIT_WAIT: - case PS_SUSPENDED: - /* Nothing to do here. */ - break; - - case PS_RUNNING: + if (PTHREAD_PRIOQ_FIRST() != NULL) { /* - * A signal occurred and made this thread ready - * while in the scheduler or while the scheduling - * queues were protected. + * Since there is at least one runnable thread, + * disable the wait. */ - PTHREAD_WAITQ_REMOVE(pthread); - PTHREAD_PRIOQ_INSERT_TAIL(pthread); - break; + timeout_ms = 0; + } + } - /* File descriptor read wait: */ - case PS_FDR_WAIT: - /* Add the file descriptor to the read set: */ - FD_SET(pthread->data.fd.fd, &fd_set_read); + /* + * Form the poll table: + */ + nfds = 0; + if (timeout_ms != 0) { + /* Add the kernel pipe to the poll table: */ + _thread_pfd_table[nfds].fd = _thread_kern_pipe[0]; + _thread_pfd_table[nfds].events = POLLRDNORM; + _thread_pfd_table[nfds].revents = 0; + nfds++; + kern_pipe_added = 1; + } + PTHREAD_WAITQ_SETACTIVE(); + TAILQ_FOREACH(pthread, &_workq, qe) { + switch (pthread->state) { + case PS_SPINBLOCK: /* - * Check if this file descriptor is greater than any - * of those seen so far: + * If the lock is available, let the thread run. */ - if (pthread->data.fd.fd > nfds) { - /* Remember this file descriptor: */ - nfds = pthread->data.fd.fd; + if (pthread->data.spinlock->access_lock == 0) { + PTHREAD_WAITQ_CLEARACTIVE(); + PTHREAD_WORKQ_REMOVE(pthread); + PTHREAD_NEW_STATE(pthread,PS_RUNNING); + PTHREAD_WAITQ_SETACTIVE(); + /* One less thread in a spinblock state: */ + _spinblock_count--; } - /* Increment the file descriptor count: */ - count++; + break; - /* This state can time out: */ - settimeout = 1; + /* File descriptor read wait: */ + case PS_FDR_WAIT: + /* Limit number of polled files to table size: */ + if (nfds < _thread_dtablesize) { + _thread_pfd_table[nfds].events = POLLRDNORM; + _thread_pfd_table[nfds].fd = pthread->data.fd.fd; + nfds++; + } break; /* File descriptor write wait: */ case PS_FDW_WAIT: - /* Add the file descriptor to the write set: */ - FD_SET(pthread->data.fd.fd, &fd_set_write); - - /* - * Check if this file descriptor is greater than any - * of those seen so far: - */ - if (pthread->data.fd.fd > nfds) { - /* Remember this file descriptor: */ - nfds = pthread->data.fd.fd; + /* Limit number of polled files to table size: */ + if (nfds < _thread_dtablesize) { + _thread_pfd_table[nfds].events = POLLWRNORM; + _thread_pfd_table[nfds].fd = pthread->data.fd.fd; + nfds++; } - /* Increment the file descriptor count: */ - count++; - - /* This state can time out: */ - settimeout = 1; break; - /* States that time out: */ - case PS_SLEEP_WAIT: - case PS_COND_WAIT: - /* Flag a timeout as required: */ - settimeout = 1; - break; - - /* Select wait: */ + /* File descriptor poll or select wait: */ + case PS_POLL_WAIT: case PS_SELECT_WAIT: - /* - * Enter a loop to process each file descriptor in - * the thread-specific file descriptor sets: - */ - for (i = 0; i < pthread->data.select_data->nfds; i++) { - /* - * Check if this file descriptor is set for - * exceptions: - */ - if (FD_ISSET(i, &pthread->data.select_data->exceptfds)) { - /* - * Add the file descriptor to the - * exception set: - */ - FD_SET(i, &fd_set_except); - - /* - * Increment the file descriptor - * count: - */ - count++; - - /* - * Check if this file descriptor is - * greater than any of those seen so - * far: - */ - if (i > nfds) { - /* - * Remember this file - * descriptor: - */ - nfds = i; - } - } - /* - * Check if this file descriptor is set for - * write: - */ - if (FD_ISSET(i, &pthread->data.select_data->writefds)) { - /* - * Add the file descriptor to the - * write set: - */ - FD_SET(i, &fd_set_write); - - /* - * Increment the file descriptor - * count: - */ - count++; - - /* - * Check if this file descriptor is - * greater than any of those seen so - * far: - */ - if (i > nfds) { - /* - * Remember this file - * descriptor: - */ - nfds = i; - } - } - /* - * Check if this file descriptor is set for - * read: - */ - if (FD_ISSET(i, &pthread->data.select_data->readfds)) { - /* - * Add the file descriptor to the - * read set: - */ - FD_SET(i, &fd_set_read); - - /* - * Increment the file descriptor - * count: - */ - count++; - - /* - * Check if this file descriptor is - * greater than any of those seen so - * far: - */ - if (i > nfds) { - /* - * Remember this file - * descriptor: - */ - nfds = i; - } + /* Limit number of polled files to table size: */ + if (pthread->data.poll_data->nfds + nfds < + _thread_dtablesize) { + for (i = 0; i < pthread->data.poll_data->nfds; i++) { + _thread_pfd_table[nfds + i].fd = + pthread->data.poll_data->fds[i].fd; + _thread_pfd_table[nfds + i].events = + pthread->data.poll_data->fds[i].events; } + nfds += pthread->data.poll_data->nfds; } - - /* This state can time out: */ - settimeout = 1; break; - } - - /* - * Check if the caller wants to wait and if the thread state - * is one that times out: - */ - if (wait_reqd && settimeout) { - /* Check if this thread wants to wait forever: */ - if (pthread->wakeup_time.tv_sec == -1) { - } - /* Check if this thread doesn't want to wait at all: */ - else if (pthread->wakeup_time.tv_sec == 0 && - pthread->wakeup_time.tv_nsec == 0) { - /* Override the caller's request to wait: */ - wait_reqd = 0; - } else { - /* - * Calculate the time until this thread is - * ready, allowing for the clock resolution: - */ - ts1.tv_sec = pthread->wakeup_time.tv_sec - ts.tv_sec; - ts1.tv_nsec = pthread->wakeup_time.tv_nsec - ts.tv_nsec + - CLOCK_RES_NSEC; - - /* - * Check for underflow of the nanosecond - * field: - */ - if (ts1.tv_nsec < 0) { - /* - * Allow for the underflow of the - * nanosecond field: - */ - ts1.tv_sec--; - ts1.tv_nsec += 1000000000; - } - /* - * Check for overflow of the nanosecond - * field: - */ - if (ts1.tv_nsec >= 1000000000) { - /* - * Allow for the overflow of the - * nanosecond field: - */ - ts1.tv_sec++; - ts1.tv_nsec -= 1000000000; - } - /* - * Convert the timespec structure to a - * timeval structure: - */ - TIMESPEC_TO_TIMEVAL(&tv1, &ts1); - /* - * Check if no time value has been found yet, - * or if the thread will be ready sooner that - * the earliest one found so far: - */ - if ((tv.tv_sec == 0 && tv.tv_usec == 0) || timercmp(&tv1, &tv, <)) { - /* Update the time value: */ - tv.tv_sec = tv1.tv_sec; - tv.tv_usec = tv1.tv_usec; - } - } + /* Other states do not depend on file I/O. */ + default: + break; } } + PTHREAD_WAITQ_CLEARACTIVE(); - /* Check if the caller wants to wait: */ - if (wait_reqd) { - /* Check if no threads were found with timeouts: */ - if (tv.tv_sec == 0 && tv.tv_usec == 0) { - /* Wait forever: */ - p_tv = NULL; - } else { - /* - * Point to the time value structure which contains - * the earliest time that a thread will be ready: - */ - p_tv = &tv; - } + /* + * Wait for a file descriptor to be ready for read, write, or + * an exception, or a timeout to occur: + */ + count = _thread_sys_poll(_thread_pfd_table, nfds, timeout_ms); + if (kern_pipe_added != 0) /* - * Flag the pthread kernel as in a select. This is to avoid - * the window between the next statement that unblocks - * signals and the select statement which follows. + * Remove the pthread kernel pipe file descriptor + * from the pollfd table: */ - _thread_kern_in_select = 1; + nfds = 1; + else + nfds = 0; + /* + * Check if it is possible that there are bytes in the kernel + * read pipe waiting to be read: + */ + if (count < 0 || ((kern_pipe_added != 0) && + (_thread_pfd_table[0].revents & POLLRDNORM))) { /* - * Wait for a file descriptor to be ready for read, write, or - * an exception, or a timeout to occur: + * If the kernel read pipe was included in the + * count: */ - count = _thread_sys_select(nfds + 1, &fd_set_read, &fd_set_write, &fd_set_except, p_tv); + if (count > 0) { + /* Decrement the count of file descriptors: */ + count--; + } - /* Reset the kernel in select flag: */ - _thread_kern_in_select = 0; + if (_sigq_check_reqd != 0) { + /* Reset flag before handling signals: */ + _sigq_check_reqd = 0; - /* - * Check if it is possible that there are bytes in the kernel - * read pipe waiting to be read: - */ - if (count < 0 || FD_ISSET(_thread_kern_pipe[0], &fd_set_read)) { - /* - * Check if the kernel read pipe was included in the - * count: - */ - if (count > 0) { - /* - * Remove the kernel read pipe from the - * count: - */ - FD_CLR(_thread_kern_pipe[0], &fd_set_read); - - /* Decrement the count of file descriptors: */ - count--; - } - /* - * Enter a loop to read (and trash) bytes from the - * pthread kernel pipe: - */ - while ((num = _thread_sys_read(_thread_kern_pipe[0], bufr, sizeof(bufr))) > 0) { - /* - * The buffer read contains one byte per - * signal and each byte is the signal number. - * This data is not used, but the fact that - * the signal handler wrote to the pipe *is* - * used to cause the _select call - * to complete if the signal occurred between - * the time when signals were unblocked and - * the _select select call being - * made. - */ - } + dequeue_signals(); } } - /* Check if there are file descriptors to poll: */ - else if (count > 0) { - /* - * Point to the time value structure which has been zeroed so - * that the call to _select will not wait: - */ - p_tv = &tv; - - /* Poll file descrptors without wait: */ - count = _thread_sys_select(nfds + 1, &fd_set_read, &fd_set_write, &fd_set_except, p_tv); - } /* * Check if any file descriptors are ready: @@ -875,301 +820,133 @@ _thread_kern_select(int wait_reqd) /* * Enter a loop to look for threads waiting on file * descriptors that are flagged as available by the - * _select syscall: + * _poll syscall: */ - TAILQ_FOREACH (pthread, &_waitingq, pqe) { - /* Process according to thread state: */ + PTHREAD_WAITQ_SETACTIVE(); + TAILQ_FOREACH(pthread, &_workq, qe) { switch (pthread->state) { - /* - * States which do not depend on file - * descriptor I/O operations: - */ - case PS_COND_WAIT: - case PS_DEAD: - case PS_DEADLOCK: - case PS_FDLR_WAIT: - case PS_FDLW_WAIT: - case PS_FILE_WAIT: - case PS_JOIN: - case PS_MUTEX_WAIT: - case PS_SIGWAIT: - case PS_SLEEP_WAIT: - case PS_WAIT_WAIT: - case PS_SIGTHREAD: - case PS_STATE_MAX: - case PS_SUSPENDED: - /* Nothing to do here. */ - break; - - case PS_RUNNING: + case PS_SPINBLOCK: /* - * A signal occurred and made this thread - * ready while in the scheduler. + * If the lock is available, let the thread run. */ - PTHREAD_WAITQ_REMOVE(pthread); - PTHREAD_PRIOQ_INSERT_TAIL(pthread); - break; + if (pthread->data.spinlock->access_lock == 0) { + PTHREAD_WAITQ_CLEARACTIVE(); + PTHREAD_WORKQ_REMOVE(pthread); + PTHREAD_NEW_STATE(pthread,PS_RUNNING); + PTHREAD_WAITQ_SETACTIVE(); - /* File descriptor read wait: */ - case PS_FDR_WAIT: - /* - * Check if the file descriptor is available - * for read: - */ - if (FD_ISSET(pthread->data.fd.fd, &fd_set_read)) { /* - * Change the thread state to allow - * it to read from the file when it - * is scheduled next: + * One less thread in a spinblock state: */ - pthread->state = PS_RUNNING; + _spinblock_count--; + } + break; - /* - * Remove it from the waiting queue - * and add it to the ready queue: - */ - PTHREAD_WAITQ_REMOVE(pthread); - PTHREAD_PRIOQ_INSERT_TAIL(pthread); + /* File descriptor read wait: */ + case PS_FDR_WAIT: + if ((nfds < _thread_dtablesize) && + (_thread_pfd_table[nfds].revents & POLLRDNORM)) { + PTHREAD_WAITQ_CLEARACTIVE(); + PTHREAD_WORKQ_REMOVE(pthread); + PTHREAD_NEW_STATE(pthread,PS_RUNNING); + PTHREAD_WAITQ_SETACTIVE(); } + nfds++; break; /* File descriptor write wait: */ case PS_FDW_WAIT: - /* - * Check if the file descriptor is available - * for write: - */ - if (FD_ISSET(pthread->data.fd.fd, &fd_set_write)) { - /* - * Change the thread state to allow - * it to write to the file when it is - * scheduled next: - */ - pthread->state = PS_RUNNING; - - /* - * Remove it from the waiting queue - * and add it to the ready queue: - */ - PTHREAD_WAITQ_REMOVE(pthread); - PTHREAD_PRIOQ_INSERT_TAIL(pthread); + if ((nfds < _thread_dtablesize) && + (_thread_pfd_table[nfds].revents & POLLWRNORM)) { + PTHREAD_WAITQ_CLEARACTIVE(); + PTHREAD_WORKQ_REMOVE(pthread); + PTHREAD_NEW_STATE(pthread,PS_RUNNING); + PTHREAD_WAITQ_SETACTIVE(); } + nfds++; break; - /* Select wait: */ + /* File descriptor poll or select wait: */ + case PS_POLL_WAIT: case PS_SELECT_WAIT: - /* - * Reset the flag that indicates if a file - * descriptor is ready for some type of - * operation: - */ - count_dec = 0; - - /* - * Enter a loop to search though the - * thread-specific select file descriptors - * for the first descriptor that is ready: - */ - for (i = 0; i < pthread->data.select_data->nfds && count_dec == 0; i++) { + if (pthread->data.poll_data->nfds + nfds < + _thread_dtablesize) { /* - * Check if this file descriptor does - * not have an exception: + * Enter a loop looking for I/O + * readiness: */ - if (FD_ISSET(i, &pthread->data.select_data->exceptfds) && FD_ISSET(i, &fd_set_except)) { - /* - * Flag this file descriptor - * as ready: - */ - count_dec = 1; - } - /* - * Check if this file descriptor is - * not ready for write: - */ - if (FD_ISSET(i, &pthread->data.select_data->writefds) && FD_ISSET(i, &fd_set_write)) { - /* - * Flag this file descriptor - * as ready: - */ - count_dec = 1; + found = 0; + for (i = 0; i < pthread->data.poll_data->nfds; i++) { + if (_thread_pfd_table[nfds + i].revents != 0) { + pthread->data.poll_data->fds[i].revents = + _thread_pfd_table[nfds + i].revents; + found++; + } } - /* - * Check if this file descriptor is - * not ready for read: - */ - if (FD_ISSET(i, &pthread->data.select_data->readfds) && FD_ISSET(i, &fd_set_read)) { - /* - * Flag this file descriptor - * as ready: - */ - count_dec = 1; + + /* Increment before destroying: */ + nfds += pthread->data.poll_data->nfds; + + if (found != 0) { + pthread->data.poll_data->nfds = found; + PTHREAD_WAITQ_CLEARACTIVE(); + PTHREAD_WORKQ_REMOVE(pthread); + PTHREAD_NEW_STATE(pthread,PS_RUNNING); + PTHREAD_WAITQ_SETACTIVE(); } } + else + nfds += pthread->data.poll_data->nfds; + break; + /* Other states do not depend on file I/O. */ + default: + break; + } + } + PTHREAD_WAITQ_CLEARACTIVE(); + } + else if (_spinblock_count != 0) { + /* + * Enter a loop to look for threads waiting on a spinlock + * that is now available. + */ + PTHREAD_WAITQ_SETACTIVE(); + TAILQ_FOREACH(pthread, &_workq, qe) { + if (pthread->state == PS_SPINBLOCK) { /* - * Check if any file descriptors are ready - * for the current thread: + * If the lock is available, let the thread run. */ - if (count_dec) { - /* - * Reset the count of file - * descriptors that are ready for - * this thread: - */ - found_one = 0; - - /* - * Enter a loop to search though the - * thread-specific select file - * descriptors: - */ - for (i = 0; i < pthread->data.select_data->nfds; i++) { - /* - * Reset the count of - * operations for which the - * current file descriptor is - * ready: - */ - count_dec = 0; - - /* - * Check if this file - * descriptor is selected for - * exceptions: - */ - if (FD_ISSET(i, &pthread->data.select_data->exceptfds)) { - /* - * Check if this file - * descriptor has an - * exception: - */ - if (FD_ISSET(i, &fd_set_except)) { - /* - * Increment - * the count - * for this - * file: - */ - count_dec++; - } else { - /* - * Clear the - * file - * descriptor - * in the - * thread-spec - * ific file - * descriptor - * set: - */ - FD_CLR(i, &pthread->data.select_data->exceptfds); - } - } - /* - * Check if this file - * descriptor is selected for - * write: - */ - if (FD_ISSET(i, &pthread->data.select_data->writefds)) { - /* - * Check if this file - * descriptor is - * ready for write: - */ - if (FD_ISSET(i, &fd_set_write)) { - /* - * Increment - * the count - * for this - * file: - */ - count_dec++; - } else { - /* - * Clear the - * file - * descriptor - * in the - * thread-spec - * ific file - * descriptor - * set: - */ - FD_CLR(i, &pthread->data.select_data->writefds); - } - } - /* - * Check if this file - * descriptor is selected for - * read: - */ - if (FD_ISSET(i, &pthread->data.select_data->readfds)) { - /* - * Check if this file - * descriptor is - * ready for read: - */ - if (FD_ISSET(i, &fd_set_read)) { - /* - * Increment - * the count - * for this - * file: - */ - count_dec++; - } else { - /* - * Clear the - * file - * descriptor - * in the - * thread-spec - * ific file - * descriptor - * set: - */ - FD_CLR(i, &pthread->data.select_data->readfds); - } - } - /* - * Check if the current file - * descriptor is ready for - * any one of the operations: - */ - if (count_dec > 0) { - /* - * Increment the - * count of file - * descriptors that - * are ready for the - * current thread: - */ - found_one++; - } - } - - /* - * Return the number of file - * descriptors that are ready: - */ - pthread->data.select_data->nfds = found_one; - - /* - * Change the state of the current - * thread to run: - */ - pthread->state = PS_RUNNING; + if (pthread->data.spinlock->access_lock == 0) { + PTHREAD_WAITQ_CLEARACTIVE(); + PTHREAD_WORKQ_REMOVE(pthread); + PTHREAD_NEW_STATE(pthread,PS_RUNNING); + PTHREAD_WAITQ_SETACTIVE(); /* - * Remove it from the waiting queue - * and add it to the ready queue: + * One less thread in a spinblock state: */ - PTHREAD_WAITQ_REMOVE(pthread); - PTHREAD_PRIOQ_INSERT_TAIL(pthread); + _spinblock_count--; } - break; } } + PTHREAD_WAITQ_CLEARACTIVE(); + } + + /* Unprotect the scheduling queues: */ + _queue_signals = 0; + + while (_sigq_check_reqd != 0) { + /* Handle queued signals: */ + _sigq_check_reqd = 0; + + /* Protect the scheduling queues: */ + _queue_signals = 1; + + dequeue_signals(); + + /* Unprotect the scheduling queues: */ + _queue_signals = 0; } /* Nothing to return. */ @@ -1219,59 +996,101 @@ _thread_kern_set_timeout(struct timespec * timeout) } void -_thread_kern_sched_defer(void) +_thread_kern_sig_defer(void) { - /* Allow scheduling deferral to be recursive. */ - _thread_run->sched_defer_count++; + /* Allow signal deferral to be recursive. */ + _thread_run->sig_defer_count++; } void -_thread_kern_sched_undefer(void) +_thread_kern_sig_undefer(void) { pthread_t pthread; int need_resched = 0; /* * Perform checks to yield only if we are about to undefer - * scheduling. + * signals. */ - if (_thread_run->sched_defer_count == 1) { + if (_thread_run->sig_defer_count > 1) { + /* Decrement the signal deferral count. */ + _thread_run->sig_defer_count--; + } + else if (_thread_run->sig_defer_count == 1) { + /* Reenable signals: */ + _thread_run->sig_defer_count = 0; + /* - * Check if the waiting queue needs to be examined for - * threads that are now ready: + * Check if there are queued signals: */ - while (_waitingq_check_reqd != 0) { - /* Clear the flag before checking the waiting queue: */ - _waitingq_check_reqd = 0; - - TAILQ_FOREACH(pthread, &_waitingq, pqe) { - if (pthread->state == PS_RUNNING) { - PTHREAD_WAITQ_REMOVE(pthread); - PTHREAD_PRIOQ_INSERT_TAIL(pthread); - } + while (_sigq_check_reqd != 0) { + /* Defer scheduling while we process queued signals: */ + _thread_run->sig_defer_count = 1; + + /* Clear the flag before checking the signal queue: */ + _sigq_check_reqd = 0; + + /* Dequeue and handle signals: */ + dequeue_signals(); + + /* + * Avoiding an unnecessary check to reschedule, check + * to see if signal handling caused a higher priority + * thread to become ready. + */ + if ((need_resched == 0) && + (((pthread = PTHREAD_PRIOQ_FIRST()) != NULL) && + (pthread->active_priority > _thread_run->active_priority))) { + need_resched = 1; } + + /* Reenable signals: */ + _thread_run->sig_defer_count = 0; } - /* - * We need to yield if a thread change of state caused a - * higher priority thread to become ready, or if a - * scheduling signal occurred while preemption was disabled. - */ - if ((((pthread = PTHREAD_PRIOQ_FIRST) != NULL) && - (pthread->active_priority > _thread_run->active_priority)) || - (_thread_run->yield_on_sched_undefer != 0)) { - _thread_run->yield_on_sched_undefer = 0; - need_resched = 1; + /* Yield the CPU if necessary: */ + if (need_resched || _thread_run->yield_on_sig_undefer != 0) { + _thread_run->yield_on_sig_undefer = 0; + _thread_kern_sched(NULL); } } +} - if (_thread_run->sched_defer_count > 0) { - /* Decrement the scheduling deferral count. */ - _thread_run->sched_defer_count--; +static void +dequeue_signals(void) +{ + char bufr[128]; + int i, num; - /* Yield the CPU if necessary: */ - if (need_resched) - _thread_kern_sched(NULL); + /* + * Enter a loop to read and handle queued signals from the + * pthread kernel pipe: + */ + while (((num = _thread_sys_read(_thread_kern_pipe[0], bufr, + sizeof(bufr))) > 0) || (num == -1 && errno == EINTR)) { + /* + * The buffer read contains one byte per signal and + * each byte is the signal number. + */ + for (i = 0; i < num; i++) { + if ((int) bufr[i] == _SCHED_SIGNAL) { + /* + * Scheduling signals shouldn't ever be + * queued; just ignore it for now. + */ + } + else { + /* Handle this signal: */ + _thread_sig_handle((int) bufr[i], NULL); + } + } + } + if ((num < 0) && (errno != EAGAIN)) { + /* + * The only error we should expect is if there is + * no data to read. + */ + PANIC("Unable to read from thread kernel pipe"); } } diff --git a/lib/libpthread/thread/thr_kill.c b/lib/libpthread/thread/thr_kill.c index c729179..f5bb6e2 100644 --- a/lib/libpthread/thread/thr_kill.c +++ b/lib/libpthread/thread/thr_kill.c @@ -29,6 +29,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * + * $Id$ */ #include <errno.h> #include <signal.h> @@ -46,18 +47,18 @@ pthread_kill(pthread_t pthread, int sig) /* Invalid signal: */ ret = EINVAL; - /* Ignored signals get dropped on the floor. */ - else if (_thread_sigact[sig - 1].sa_handler == SIG_IGN) - ret = 0; - - /* Find the thread in the list of active threads: */ - else if ((ret = _find_thread(pthread)) == 0) { + /* + * Ensure the thread is in the list of active threads, and the + * signal is valid (signal 0 specifies error checking only) and + * not being ignored: + */ + else if (((ret = _find_thread(pthread)) == 0) && (sig > 0) && + (_thread_sigact[sig - 1].sa_handler != SIG_IGN)) { /* - * Guard against preemption by a scheduling signal. - * A change of thread state modifies the waiting - * and priority queues. + * Defer signals to protect the scheduling queues from + * access by the signal handler: */ - _thread_kern_sched_defer(); + _thread_kern_sig_defer(); switch (pthread->state) { case PS_SIGSUSPEND: @@ -90,15 +91,19 @@ pthread_kill(pthread_t pthread, int sig) sigaddset(&pthread->sigpend,sig); break; - case PS_SELECT_WAIT: case PS_FDR_WAIT: case PS_FDW_WAIT: + case PS_POLL_WAIT: case PS_SLEEP_WAIT: + case PS_SELECT_WAIT: if (!sigismember(&pthread->sigmask, sig) && (_thread_sigact[sig - 1].sa_handler != SIG_IGN)) { /* Flag the operation as interrupted: */ pthread->interrupted = 1; + if (pthread->flags & PTHREAD_FLAGS_IN_WORKQ) + PTHREAD_WORKQ_REMOVE(pthread); + /* Change the state of the thread to run: */ PTHREAD_NEW_STATE(pthread,PS_RUNNING); @@ -116,11 +121,43 @@ pthread_kill(pthread_t pthread, int sig) break; } + + /* + * Check that a custom handler is installed + * and if the signal is not blocked: + */ + if (_thread_sigact[sig - 1].sa_handler != SIG_DFL && + _thread_sigact[sig - 1].sa_handler != SIG_IGN && + sigismember(&pthread->sigpend, sig) && + !sigismember(&pthread->sigmask, sig)) { + pthread_t pthread_saved = _thread_run; + + /* Current thread inside critical region? */ + if (_thread_run->sig_defer_count > 0) + pthread->sig_defer_count++; + + _thread_run = pthread; + + /* Clear the pending signal: */ + sigdelset(&pthread->sigpend, sig); + + /* + * Dispatch the signal via the custom signal + * handler: + */ + (*(_thread_sigact[sig - 1].sa_handler))(sig); + + _thread_run = pthread_saved; + + if (_thread_run->sig_defer_count > 0) + pthread->sig_defer_count--; + } + /* - * Reenable preemption and yield if a scheduling signal - * occurred while in the critical region. + * Undefer and handle pending signals, yielding if + * necessary: */ - _thread_kern_sched_undefer(); + _thread_kern_sig_undefer(); } /* Return the completion status: */ diff --git a/lib/libpthread/thread/thr_mutex.c b/lib/libpthread/thread/thr_mutex.c index fa9c8cf..c967b46 100644 --- a/lib/libpthread/thread/thr_mutex.c +++ b/lib/libpthread/thread/thr_mutex.c @@ -29,6 +29,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * + * $Id$ */ #include <stdlib.h> #include <errno.h> @@ -39,6 +40,25 @@ #include <pthread.h> #include "pthread_private.h" +#if defined(_PTHREADS_INVARIANTS) +#define _MUTEX_INIT_LINK(m) do { \ + (m)->m_qe.tqe_prev = NULL; \ + (m)->m_qe.tqe_next = NULL; \ +} while (0) +#define _MUTEX_ASSERT_IS_OWNED(m) do { \ + if ((m)->m_qe.tqe_prev == NULL) \ + PANIC("mutex is not on list"); \ +} while (0) +#define _MUTEX_ASSERT_NOT_OWNED(m) do { \ + if (((m)->m_qe.tqe_prev != NULL) || \ + ((m)->m_qe.tqe_next != NULL)) \ + PANIC("mutex is on list"); \ +} while (0) +#else +#define _MUTEX_INIT_LINK(m) +#define _MUTEX_ASSERT_IS_OWNED(m) +#define _MUTEX_ASSERT_NOT_OWNED(m) +#endif /* * Prototypes @@ -55,6 +75,34 @@ static inline void mutex_queue_enq(pthread_mutex_t, pthread_t); static spinlock_t static_init_lock = _SPINLOCK_INITIALIZER; +/* Reinitialize a mutex to defaults. */ +int +_mutex_reinit(pthread_mutex_t * mutex) +{ + int ret = 0; + + if (mutex == NULL) + ret = EINVAL; + else if (*mutex == NULL) + ret = pthread_mutex_init(mutex, NULL); + else { + /* + * Initialize the mutex structure: + */ + (*mutex)->m_type = PTHREAD_MUTEX_DEFAULT; + (*mutex)->m_protocol = PTHREAD_PRIO_NONE; + TAILQ_INIT(&(*mutex)->m_queue); + (*mutex)->m_owner = NULL; + (*mutex)->m_data.m_count = 0; + (*mutex)->m_flags = MUTEX_FLAGS_INITED; + (*mutex)->m_refcount = 0; + (*mutex)->m_prio = 0; + (*mutex)->m_saved_prio = 0; + _MUTEX_INIT_LINK(*mutex); + memset(&(*mutex)->lock, 0, sizeof((*mutex)->lock)); + } + return (ret); +} int pthread_mutex_init(pthread_mutex_t * mutex, @@ -138,6 +186,7 @@ pthread_mutex_init(pthread_mutex_t * mutex, else pmutex->m_prio = 0; pmutex->m_saved_prio = 0; + _MUTEX_INIT_LINK(pmutex); memset(&pmutex->lock, 0, sizeof(pmutex->lock)); *mutex = pmutex; } else { @@ -147,7 +196,7 @@ pthread_mutex_init(pthread_mutex_t * mutex, } } /* Return the completion status: */ - return (ret); + return(ret); } int @@ -177,6 +226,7 @@ pthread_mutex_destroy(pthread_mutex_t * mutex) * Free the memory allocated for the mutex * structure: */ + _MUTEX_ASSERT_NOT_OWNED(*mutex); free(*mutex); /* @@ -222,28 +272,24 @@ pthread_mutex_trylock(pthread_mutex_t * mutex) */ else if (*mutex != NULL || (ret = init_static(mutex)) == 0) { /* + * Defer signals to protect the scheduling queues from + * access by the signal handler: + */ + _thread_kern_sig_defer(); + + /* Lock the mutex structure: */ + _SPINLOCK(&(*mutex)->lock); + + /* * If the mutex was statically allocated, properly * initialize the tail queue. */ if (((*mutex)->m_flags & MUTEX_FLAGS_INITED) == 0) { TAILQ_INIT(&(*mutex)->m_queue); + _MUTEX_INIT_LINK(*mutex); (*mutex)->m_flags |= MUTEX_FLAGS_INITED; } - /* - * Guard against being preempted by a scheduling signal. - * To support priority inheritence mutexes, we need to - * maintain lists of mutex ownerships for each thread as - * well as lists of waiting threads for each mutex. In - * order to propagate priorities we need to atomically - * walk these lists and cannot rely on a single mutex - * lock to provide protection against modification. - */ - _thread_kern_sched_defer(); - - /* Lock the mutex structure: */ - _SPINLOCK(&(*mutex)->lock); - /* Process according to mutex type: */ switch ((*mutex)->m_protocol) { /* Default POSIX mutex: */ @@ -254,6 +300,7 @@ pthread_mutex_trylock(pthread_mutex_t * mutex) (*mutex)->m_owner = _thread_run; /* Add to the list of owned mutexes: */ + _MUTEX_ASSERT_NOT_OWNED(*mutex); TAILQ_INSERT_TAIL(&_thread_run->mutexq, (*mutex), m_qe); } else if ((*mutex)->m_owner == _thread_run) @@ -282,6 +329,7 @@ pthread_mutex_trylock(pthread_mutex_t * mutex) _thread_run->inherited_priority; /* Add to the list of owned mutexes: */ + _MUTEX_ASSERT_NOT_OWNED(*mutex); TAILQ_INSERT_TAIL(&_thread_run->mutexq, (*mutex), m_qe); } else if ((*mutex)->m_owner == _thread_run) @@ -317,6 +365,7 @@ pthread_mutex_trylock(pthread_mutex_t * mutex) (*mutex)->m_prio; /* Add to the list of owned mutexes: */ + _MUTEX_ASSERT_NOT_OWNED(*mutex); TAILQ_INSERT_TAIL(&_thread_run->mutexq, (*mutex), m_qe); } else if ((*mutex)->m_owner == _thread_run) @@ -337,10 +386,10 @@ pthread_mutex_trylock(pthread_mutex_t * mutex) _SPINUNLOCK(&(*mutex)->lock); /* - * Renable preemption and yield if a scheduling signal - * arrived while in the critical region: + * Undefer and handle pending signals, yielding if + * necessary: */ - _thread_kern_sched_undefer(); + _thread_kern_sig_undefer(); } /* Return the completion status: */ @@ -361,28 +410,24 @@ pthread_mutex_lock(pthread_mutex_t * mutex) */ else if (*mutex != NULL || (ret = init_static(mutex)) == 0) { /* + * Defer signals to protect the scheduling queues from + * access by the signal handler: + */ + _thread_kern_sig_defer(); + + /* Lock the mutex structure: */ + _SPINLOCK(&(*mutex)->lock); + + /* * If the mutex was statically allocated, properly * initialize the tail queue. */ if (((*mutex)->m_flags & MUTEX_FLAGS_INITED) == 0) { TAILQ_INIT(&(*mutex)->m_queue); (*mutex)->m_flags |= MUTEX_FLAGS_INITED; + _MUTEX_INIT_LINK(*mutex); } - /* - * Guard against being preempted by a scheduling signal. - * To support priority inheritence mutexes, we need to - * maintain lists of mutex ownerships for each thread as - * well as lists of waiting threads for each mutex. In - * order to propagate priorities we need to atomically - * walk these lists and cannot rely on a single mutex - * lock to provide protection against modification. - */ - _thread_kern_sched_defer(); - - /* Lock the mutex structure: */ - _SPINLOCK(&(*mutex)->lock); - /* Process according to mutex type: */ switch ((*mutex)->m_protocol) { /* Default POSIX mutex: */ @@ -392,6 +437,7 @@ pthread_mutex_lock(pthread_mutex_t * mutex) (*mutex)->m_owner = _thread_run; /* Add to the list of owned mutexes: */ + _MUTEX_ASSERT_NOT_OWNED(*mutex); TAILQ_INSERT_TAIL(&_thread_run->mutexq, (*mutex), m_qe); @@ -419,12 +465,6 @@ pthread_mutex_lock(pthread_mutex_t * mutex) /* Lock the mutex structure again: */ _SPINLOCK(&(*mutex)->lock); - - /* - * This thread is no longer waiting for - * the mutex: - */ - _thread_run->data.mutex = NULL; } break; @@ -449,6 +489,7 @@ pthread_mutex_lock(pthread_mutex_t * mutex) (*mutex)->m_prio; /* Add to the list of owned mutexes: */ + _MUTEX_ASSERT_NOT_OWNED(*mutex); TAILQ_INSERT_TAIL(&_thread_run->mutexq, (*mutex), m_qe); @@ -481,12 +522,6 @@ pthread_mutex_lock(pthread_mutex_t * mutex) /* Lock the mutex structure again: */ _SPINLOCK(&(*mutex)->lock); - - /* - * This thread is no longer waiting for - * the mutex: - */ - _thread_run->data.mutex = NULL; } break; @@ -519,6 +554,7 @@ pthread_mutex_lock(pthread_mutex_t * mutex) (*mutex)->m_prio; /* Add to the list of owned mutexes: */ + _MUTEX_ASSERT_NOT_OWNED(*mutex); TAILQ_INSERT_TAIL(&_thread_run->mutexq, (*mutex), m_qe); } else if ((*mutex)->m_owner == _thread_run) @@ -556,12 +592,6 @@ pthread_mutex_lock(pthread_mutex_t * mutex) */ ret = _thread_run->error; _thread_run->error = 0; - - /* - * This thread is no longer waiting for - * the mutex: - */ - _thread_run->data.mutex = NULL; } break; @@ -576,10 +606,10 @@ pthread_mutex_lock(pthread_mutex_t * mutex) _SPINUNLOCK(&(*mutex)->lock); /* - * Renable preemption and yield if a scheduling signal - * arrived while in the critical region: + * Undefer and handle pending signals, yielding if + * necessary: */ - _thread_kern_sched_undefer(); + _thread_kern_sig_undefer(); } /* Return the completion status: */ @@ -683,15 +713,10 @@ mutex_unlock_common(pthread_mutex_t * mutex, int add_reference) ret = EINVAL; } else { /* - * Guard against being preempted by a scheduling signal. - * To support priority inheritence mutexes, we need to - * maintain lists of mutex ownerships for each thread as - * well as lists of waiting threads for each mutex. In - * order to propagate priorities we need to atomically - * walk these lists and cannot rely on a single mutex - * lock to provide protection against modification. + * Defer signals to protect the scheduling queues from + * access by the signal handler: */ - _thread_kern_sched_defer(); + _thread_kern_sig_defer(); /* Lock the mutex structure: */ _SPINLOCK(&(*mutex)->lock); @@ -723,8 +748,10 @@ mutex_unlock_common(pthread_mutex_t * mutex, int add_reference) (*mutex)->m_data.m_count = 0; /* Remove the mutex from the threads queue. */ + _MUTEX_ASSERT_IS_OWNED(*mutex); TAILQ_REMOVE(&(*mutex)->m_owner->mutexq, (*mutex), m_qe); + _MUTEX_INIT_LINK(*mutex); /* * Get the next thread from the queue of @@ -738,6 +765,19 @@ mutex_unlock_common(pthread_mutex_t * mutex, int add_reference) */ PTHREAD_NEW_STATE((*mutex)->m_owner, PS_RUNNING); + + /* + * Add the mutex to the threads list of + * owned mutexes: + */ + TAILQ_INSERT_TAIL(&(*mutex)->m_owner->mutexq, + (*mutex), m_qe); + + /* + * The owner is no longer waiting for + * this mutex: + */ + (*mutex)->m_owner->data.mutex = NULL; } } break; @@ -784,8 +824,10 @@ mutex_unlock_common(pthread_mutex_t * mutex, int add_reference) _thread_run->priority_mutex_count--; /* Remove the mutex from the threads queue. */ + _MUTEX_ASSERT_IS_OWNED(*mutex); TAILQ_REMOVE(&(*mutex)->m_owner->mutexq, (*mutex), m_qe); + _MUTEX_INIT_LINK(*mutex); /* * Get the next thread from the queue of threads @@ -891,8 +933,10 @@ mutex_unlock_common(pthread_mutex_t * mutex, int add_reference) _thread_run->priority_mutex_count--; /* Remove the mutex from the threads queue. */ + _MUTEX_ASSERT_IS_OWNED(*mutex); TAILQ_REMOVE(&(*mutex)->m_owner->mutexq, - (*mutex), m_qe); + (*mutex), m_qe); + _MUTEX_INIT_LINK(*mutex); /* * Enter a loop to find a waiting thread whose @@ -913,6 +957,11 @@ mutex_unlock_common(pthread_mutex_t * mutex, int add_reference) (*mutex)->m_owner->error = EINVAL; PTHREAD_NEW_STATE((*mutex)->m_owner, PS_RUNNING); + /* + * The thread is no longer waiting for + * this mutex: + */ + (*mutex)->m_owner->data.mutex = NULL; } /* Check for a new owner: */ @@ -978,10 +1027,10 @@ mutex_unlock_common(pthread_mutex_t * mutex, int add_reference) _SPINUNLOCK(&(*mutex)->lock); /* - * Renable preemption and yield if a scheduling signal - * arrived while in the critical region: + * Undefer and handle pending signals, yielding if + * necessary: */ - _thread_kern_sched_undefer(); + _thread_kern_sig_undefer(); } /* Return the completion status: */ @@ -990,11 +1039,11 @@ mutex_unlock_common(pthread_mutex_t * mutex, int add_reference) /* - * This function is called when a change in base priority occurs - * for a thread that is thread holding, or waiting for, a priority - * protection or inheritence mutex. A change in a threads base - * priority can effect changes to active priorities of other threads - * and to the ordering of mutex locking by waiting threads. + * This function is called when a change in base priority occurs for + * a thread that is holding or waiting for a priority protection or + * inheritence mutex. A change in a threads base priority can effect + * changes to active priorities of other threads and to the ordering + * of mutex locking by waiting threads. * * This must be called while thread scheduling is deferred. */ @@ -1231,8 +1280,7 @@ mutex_rescan_owned (pthread_t pthread, pthread_mutex_t mutex) * If this thread is in the priority queue, it must be * removed and reinserted for its new priority. */ - if ((pthread != _thread_run) && - (pthread->state == PS_RUNNING)) { + if (pthread->flags & PTHREAD_FLAGS_IN_PRIOQ) { /* * Remove the thread from the priority queue * before changing its priority: diff --git a/lib/libpthread/thread/thr_poll.c b/lib/libpthread/thread/thr_poll.c new file mode 100644 index 0000000..a54d023 --- /dev/null +++ b/lib/libpthread/thread/thr_poll.c @@ -0,0 +1,95 @@ +/* + * Copyright (c) 1999 Daniel Eischen <eischen@vigrid.com> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by Daniel Eischen. + * 4. Neither the name of the author nor the names of any co-contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY DANIEL EISCHEN AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $Id$ + */ +#include <unistd.h> +#include <errno.h> +#include <string.h> +#include <poll.h> +#include <sys/types.h> +#include <sys/time.h> +#include <sys/fcntl.h> +#ifdef _THREAD_SAFE +#include <pthread.h> +#include "pthread_private.h" + + +int +poll(struct pollfd *fds, unsigned int nfds, int timeout) +{ + struct timespec ts; + int numfds = nfds; + int i, ret = 0, found = 0; + struct pthread_poll_data data; + + if (numfds > _thread_dtablesize) { + numfds = _thread_dtablesize; + } + /* Check if a timeout was specified: */ + if (timeout == INFTIM) { + /* Wait for ever: */ + _thread_kern_set_timeout(NULL); + } else if (timeout != 0) { + /* Convert the timeout in msec to a timespec: */ + ts.tv_sec = timeout / 1000; + ts.tv_nsec = (timeout % 1000) * 1000; + + /* Set the wake up time: */ + _thread_kern_set_timeout(&ts); + } + + if (((ret = _thread_sys_poll(fds, numfds, 0)) == 0) && (timeout != 0)) { + data.nfds = numfds; + data.fds = fds; + + /* + * Clear revents in case of a timeout which leaves fds + * unchanged: + */ + for (i = 0; i < numfds; i++) { + fds[i].revents = 0; + } + + _thread_run->data.poll_data = &data; + _thread_run->interrupted = 0; + _thread_kern_sched_state(PS_POLL_WAIT, __FILE__, __LINE__); + if (_thread_run->interrupted) { + errno = EINTR; + ret = -1; + } else { + ret = data.nfds; + } + } + + return (ret); +} +#endif diff --git a/lib/libpthread/thread/thr_priority_queue.c b/lib/libpthread/thread/thr_priority_queue.c index 516a1e0..0a00a9d3 100644 --- a/lib/libpthread/thread/thr_priority_queue.c +++ b/lib/libpthread/thread/thr_priority_queue.c @@ -29,6 +29,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * + * $Id$ */ #include <stdlib.h> #include <sys/queue.h> @@ -40,9 +41,51 @@ /* Prototypes: */ static void pq_insert_prio_list(pq_queue_t *pq, int prio); +#if defined(_PTHREADS_INVARIANTS) + +static int _pq_active = 0; + +#define _PQ_IN_SCHEDQ (PTHREAD_FLAGS_IN_PRIOQ | PTHREAD_FLAGS_IN_WAITQ | PTHREAD_FLAGS_IN_WORKQ) + +#define _PQ_SET_ACTIVE() _pq_active = 1 +#define _PQ_CLEAR_ACTIVE() _pq_active = 0 +#define _PQ_ASSERT_ACTIVE(msg) do { \ + if (_pq_active == 0) \ + PANIC(msg); \ +} while (0) +#define _PQ_ASSERT_INACTIVE(msg) do { \ + if (_pq_active != 0) \ + PANIC(msg); \ +} while (0) +#define _PQ_ASSERT_IN_WAITQ(thrd, msg) do { \ + if (((thrd)->flags & PTHREAD_FLAGS_IN_WAITQ) == 0) \ + PANIC(msg); \ +} while (0) +#define _PQ_ASSERT_IN_PRIOQ(thrd, msg) do { \ + if (((thrd)->flags & PTHREAD_FLAGS_IN_PRIOQ) == 0) \ + PANIC(msg); \ +} while (0) +#define _PQ_ASSERT_NOT_QUEUED(thrd, msg) do { \ + if ((thrd)->flags & _PQ_IN_SCHEDQ) \ + PANIC(msg); \ +} while (0) + +#else + +#define _PQ_SET_ACTIVE() +#define _PQ_CLEAR_ACTIVE() +#define _PQ_ASSERT_ACTIVE(msg) +#define _PQ_ASSERT_INACTIVE(msg) +#define _PQ_ASSERT_IN_WAITQ(thrd, msg) +#define _PQ_ASSERT_IN_PRIOQ(thrd, msg) +#define _PQ_ASSERT_NOT_QUEUED(thrd, msg) +#define _PQ_CHECK_PRIO() + +#endif + int -_pq_init(pq_queue_t *pq, int minprio, int maxprio) +_pq_alloc(pq_queue_t *pq, int minprio, int maxprio) { int i, ret = 0; int prioslots = maxprio - minprio + 1; @@ -56,8 +99,26 @@ _pq_init(pq_queue_t *pq, int minprio, int maxprio) ret = -1; else { + /* Remember the queue size: */ + pq->pq_size = prioslots; + + ret = _pq_init(pq); + + } + return (ret); +} + +int +_pq_init(pq_queue_t *pq) +{ + int i, ret = 0; + + if ((pq == NULL) || (pq->pq_lists == NULL)) + ret = -1; + + else { /* Initialize the queue for each priority slot: */ - for (i = 0; i < prioslots; i++) { + for (i = 0; i < pq->pq_size; i++) { TAILQ_INIT(&pq->pq_lists[i].pl_head); pq->pq_lists[i].pl_prio = i; pq->pq_lists[i].pl_queued = 0; @@ -65,9 +126,7 @@ _pq_init(pq_queue_t *pq, int minprio, int maxprio) /* Initialize the priority queue: */ TAILQ_INIT(&pq->pq_queue); - - /* Remember the queue size: */ - pq->pq_size = prioslots; + _PQ_CLEAR_ACTIVE(); } return (ret); } @@ -77,7 +136,27 @@ _pq_remove(pq_queue_t *pq, pthread_t pthread) { int prio = pthread->active_priority; + /* + * Make some assertions when debugging is enabled: + */ + _PQ_ASSERT_INACTIVE("_pq_remove: pq_active"); + _PQ_SET_ACTIVE(); + _PQ_ASSERT_IN_PRIOQ(pthread, "_pq_remove: Not in priority queue"); + + /* + * Remove this thread from priority list. Note that if + * the priority list becomes empty, it is not removed + * from the priority queue because another thread may be + * added to the priority list (resulting in a needless + * removal/insertion). Priority lists are only removed + * from the priority queue when _pq_first is called. + */ TAILQ_REMOVE(&pq->pq_lists[prio].pl_head, pthread, pqe); + + /* This thread is now longer in the priority queue. */ + pthread->flags &= ~PTHREAD_FLAGS_IN_PRIOQ; + + _PQ_CLEAR_ACTIVE(); } @@ -86,10 +165,23 @@ _pq_insert_head(pq_queue_t *pq, pthread_t pthread) { int prio = pthread->active_priority; + /* + * Make some assertions when debugging is enabled: + */ + _PQ_ASSERT_INACTIVE("_pq_insert_head: pq_active"); + _PQ_SET_ACTIVE(); + _PQ_ASSERT_NOT_QUEUED(pthread, + "_pq_insert_head: Already in priority queue"); + TAILQ_INSERT_HEAD(&pq->pq_lists[prio].pl_head, pthread, pqe); if (pq->pq_lists[prio].pl_queued == 0) /* Insert the list into the priority queue: */ pq_insert_prio_list(pq, prio); + + /* Mark this thread as being in the priority queue. */ + pthread->flags |= PTHREAD_FLAGS_IN_PRIOQ; + + _PQ_CLEAR_ACTIVE(); } @@ -98,10 +190,23 @@ _pq_insert_tail(pq_queue_t *pq, pthread_t pthread) { int prio = pthread->active_priority; + /* + * Make some assertions when debugging is enabled: + */ + _PQ_ASSERT_INACTIVE("_pq_insert_tail: pq_active"); + _PQ_SET_ACTIVE(); + _PQ_ASSERT_NOT_QUEUED(pthread, + "_pq_insert_tail: Already in priority queue"); + TAILQ_INSERT_TAIL(&pq->pq_lists[prio].pl_head, pthread, pqe); if (pq->pq_lists[prio].pl_queued == 0) /* Insert the list into the priority queue: */ pq_insert_prio_list(pq, prio); + + /* Mark this thread as being in the priority queue. */ + pthread->flags |= PTHREAD_FLAGS_IN_PRIOQ; + + _PQ_CLEAR_ACTIVE(); } @@ -111,6 +216,12 @@ _pq_first(pq_queue_t *pq) pq_list_t *pql; pthread_t pthread = NULL; + /* + * Make some assertions when debugging is enabled: + */ + _PQ_ASSERT_INACTIVE("_pq_first: pq_active"); + _PQ_SET_ACTIVE(); + while (((pql = TAILQ_FIRST(&pq->pq_queue)) != NULL) && (pthread == NULL)) { if ((pthread = TAILQ_FIRST(&pql->pl_head)) == NULL) { @@ -124,6 +235,8 @@ _pq_first(pq_queue_t *pq) pql->pl_queued = 0; } } + + _PQ_CLEAR_ACTIVE(); return (pthread); } @@ -134,9 +247,14 @@ pq_insert_prio_list(pq_queue_t *pq, int prio) pq_list_t *pql; /* + * Make some assertions when debugging is enabled: + */ + _PQ_ASSERT_ACTIVE("pq_insert_prio_list: pq_active"); + + /* * The priority queue is in descending priority order. Start at * the beginning of the queue and find the list before which the - * new list should to be inserted. + * new list should be inserted. */ pql = TAILQ_FIRST(&pq->pq_queue); while ((pql != NULL) && (pql->pl_prio > prio)) @@ -152,4 +270,66 @@ pq_insert_prio_list(pq_queue_t *pq, int prio) pq->pq_lists[prio].pl_queued = 1; } +#if defined(_PTHREADS_INVARIANTS) +void +_waitq_insert(pthread_t pthread) +{ + pthread_t tid; + + /* + * Make some assertions when debugging is enabled: + */ + _PQ_ASSERT_INACTIVE("_waitq_insert: pq_active"); + _PQ_SET_ACTIVE(); + _PQ_ASSERT_NOT_QUEUED(pthread, "_waitq_insert: Already in queue"); + + if (pthread->wakeup_time.tv_sec == -1) + TAILQ_INSERT_TAIL(&_waitingq, pthread, pqe); + else { + tid = TAILQ_FIRST(&_waitingq); + while ((tid != NULL) && (tid->wakeup_time.tv_sec != -1) && + ((tid->wakeup_time.tv_sec < pthread->wakeup_time.tv_sec) || + ((tid->wakeup_time.tv_sec == pthread->wakeup_time.tv_sec) && + (tid->wakeup_time.tv_nsec <= pthread->wakeup_time.tv_nsec)))) + tid = TAILQ_NEXT(tid, pqe); + if (tid == NULL) + TAILQ_INSERT_TAIL(&_waitingq, pthread, pqe); + else + TAILQ_INSERT_BEFORE(tid, pthread, pqe); + } + pthread->flags |= PTHREAD_FLAGS_IN_WAITQ; + + _PQ_CLEAR_ACTIVE(); +} + +void +_waitq_remove(pthread_t pthread) +{ + /* + * Make some assertions when debugging is enabled: + */ + _PQ_ASSERT_INACTIVE("_waitq_remove: pq_active"); + _PQ_SET_ACTIVE(); + _PQ_ASSERT_IN_WAITQ(pthread, "_waitq_remove: Not in queue"); + + TAILQ_REMOVE(&_waitingq, pthread, pqe); + pthread->flags &= ~PTHREAD_FLAGS_IN_WAITQ; + + _PQ_CLEAR_ACTIVE(); +} + +void +_waitq_setactive(void) +{ + _PQ_ASSERT_INACTIVE("_waitq_setactive: pq_active"); + _PQ_SET_ACTIVE(); +} + +void +_waitq_clearactive(void) +{ + _PQ_ASSERT_ACTIVE("_waitq_clearactive: ! pq_active"); + _PQ_CLEAR_ACTIVE(); +} +#endif #endif diff --git a/lib/libpthread/thread/thr_private.h b/lib/libpthread/thread/thr_private.h index 6cacb27..036ea80 100644 --- a/lib/libpthread/thread/thr_private.h +++ b/lib/libpthread/thread/thr_private.h @@ -31,6 +31,7 @@ * * Private thread definitions for the uthread kernel. * + * $Id$ */ #ifndef _PTHREAD_PRIVATE_H @@ -68,33 +69,88 @@ /* - * Priority queue manipulation macros: + * Priority queue manipulation macros (using pqe link): */ #define PTHREAD_PRIOQ_INSERT_HEAD(thrd) _pq_insert_head(&_readyq,thrd) #define PTHREAD_PRIOQ_INSERT_TAIL(thrd) _pq_insert_tail(&_readyq,thrd) #define PTHREAD_PRIOQ_REMOVE(thrd) _pq_remove(&_readyq,thrd) -#define PTHREAD_PRIOQ_FIRST _pq_first(&_readyq) +#define PTHREAD_PRIOQ_FIRST() _pq_first(&_readyq) /* - * Waiting queue manipulation macros: + * Waiting queue manipulation macros (using pqe link): */ -#define PTHREAD_WAITQ_INSERT(thrd) TAILQ_INSERT_TAIL(&_waitingq,thrd,pqe) +#if defined(_PTHREADS_INVARIANTS) +#define PTHREAD_WAITQ_REMOVE(thrd) _waitq_remove(thrd) +#define PTHREAD_WAITQ_INSERT(thrd) _waitq_insert(thrd) +#define PTHREAD_WAITQ_CLEARACTIVE() _waitq_clearactive() +#define PTHREAD_WAITQ_SETACTIVE() _waitq_setactive() +#else #define PTHREAD_WAITQ_REMOVE(thrd) TAILQ_REMOVE(&_waitingq,thrd,pqe) +#define PTHREAD_WAITQ_INSERT(thrd) do { \ + if ((thrd)->wakeup_time.tv_sec == -1) \ + TAILQ_INSERT_TAIL(&_waitingq,thrd,pqe); \ + else { \ + pthread_t tid = TAILQ_FIRST(&_waitingq); \ + while ((tid != NULL) && (tid->wakeup_time.tv_sec != -1) && \ + ((tid->wakeup_time.tv_sec < (thrd)->wakeup_time.tv_sec) || \ + ((tid->wakeup_time.tv_sec == (thrd)->wakeup_time.tv_sec) && \ + (tid->wakeup_time.tv_nsec <= (thrd)->wakeup_time.tv_nsec)))) \ + tid = TAILQ_NEXT(tid, pqe); \ + if (tid == NULL) \ + TAILQ_INSERT_TAIL(&_waitingq,thrd,pqe); \ + else \ + TAILQ_INSERT_BEFORE(tid,thrd,pqe); \ + } \ +} while (0) +#define PTHREAD_WAITQ_CLEARACTIVE() +#define PTHREAD_WAITQ_SETACTIVE() +#endif + +/* + * Work queue manipulation macros (using qe link): + */ +#define PTHREAD_WORKQ_INSERT(thrd) do { \ + TAILQ_INSERT_TAIL(&_workq,thrd,qe); \ + (thrd)->flags |= PTHREAD_FLAGS_IN_WORKQ; \ +} while (0) +#define PTHREAD_WORKQ_REMOVE(thrd) do { \ + TAILQ_REMOVE(&_workq,thrd,qe); \ + (thrd)->flags &= ~PTHREAD_FLAGS_IN_WORKQ; \ +} while (0) + /* * State change macro without scheduling queue change: */ -#define PTHREAD_SET_STATE(thrd, newstate) { \ +#define PTHREAD_SET_STATE(thrd, newstate) do { \ (thrd)->state = newstate; \ (thrd)->fname = __FILE__; \ (thrd)->lineno = __LINE__; \ -} +} while (0) /* * State change macro with scheduling queue change - This must be * called with preemption deferred (see thread_kern_sched_[un]defer). */ -#define PTHREAD_NEW_STATE(thrd, newstate) { \ +#if defined(_PTHREADS_INVARIANTS) +#define PTHREAD_NEW_STATE(thrd, newstate) do { \ + if (_thread_kern_new_state != 0) \ + PANIC("Recursive PTHREAD_NEW_STATE"); \ + _thread_kern_new_state = 1; \ + if ((thrd)->state != newstate) { \ + if ((thrd)->state == PS_RUNNING) { \ + PTHREAD_PRIOQ_REMOVE(thrd); \ + PTHREAD_WAITQ_INSERT(thrd); \ + } else if (newstate == PS_RUNNING) { \ + PTHREAD_WAITQ_REMOVE(thrd); \ + PTHREAD_PRIOQ_INSERT_TAIL(thrd); \ + } \ + } \ + _thread_kern_new_state = 0; \ + PTHREAD_SET_STATE(thrd, newstate); \ +} while (0) +#else +#define PTHREAD_NEW_STATE(thrd, newstate) do { \ if ((thrd)->state != newstate) { \ if ((thrd)->state == PS_RUNNING) { \ PTHREAD_PRIOQ_REMOVE(thrd); \ @@ -105,7 +161,8 @@ } \ } \ PTHREAD_SET_STATE(thrd, newstate); \ -} +} while (0) +#endif /* * Define the signals to be used for scheduling. @@ -119,15 +176,6 @@ #endif /* - * Queue definitions. - */ -struct pthread_queue { - struct pthread *q_next; - struct pthread *q_last; - void *q_data; -}; - -/* * Priority queues. * * XXX It'd be nice if these were contained in uthread_priority_queue.[ch]. @@ -147,14 +195,9 @@ typedef struct pq_queue { /* - * Static queue initialization values. - */ -#define PTHREAD_QUEUE_INITIALIZER { NULL, NULL, NULL } - -/* * TailQ initialization values. */ -#define TAILQ_INITIALIZER { NULL, NULL } +#define TAILQ_INITIALIZER { NULL, NULL } /* * Mutex definitions. @@ -257,7 +300,7 @@ struct pthread_cond_attr { * Static cond initialization values. */ #define PTHREAD_COND_STATIC_INITIALIZER \ - { COND_TYPE_FAST, PTHREAD_QUEUE_INITIALIZER, NULL, NULL, \ + { COND_TYPE_FAST, TAILQ_INITIALIZER, NULL, NULL, \ 0, _SPINLOCK_INITIALIZER } /* @@ -303,12 +346,6 @@ struct pthread_attr { #define CLOCK_RES_NSEC 10000000 /* - * Number of microseconds between incremental priority updates for - * threads that are ready to run, but denied being run. - */ -#define INC_PRIO_USEC 500000 - -/* * Time slice period in microseconds. */ #define TIMESLICE_USEC 100000 @@ -345,6 +382,7 @@ enum pthread_state { PS_FDR_WAIT, PS_FDW_WAIT, PS_FILE_WAIT, + PS_POLL_WAIT, PS_SELECT_WAIT, PS_SLEEP_WAIT, PS_WAIT_WAIT, @@ -377,8 +415,8 @@ struct fd_table_entry { * state of the lock on the file descriptor. */ spinlock_t lock; - struct pthread_queue r_queue; /* Read queue. */ - struct pthread_queue w_queue; /* Write queue. */ + TAILQ_HEAD(, pthread) r_queue; /* Read queue. */ + TAILQ_HEAD(, pthread) w_queue; /* Write queue. */ struct pthread *r_owner; /* Ptr to thread owning read lock. */ struct pthread *w_owner; /* Ptr to thread owning write lock. */ char *r_fname; /* Ptr to read lock source file name */ @@ -390,11 +428,9 @@ struct fd_table_entry { int flags; /* Flags used in open. */ }; -struct pthread_select_data { +struct pthread_poll_data { int nfds; - fd_set readfds; - fd_set writefds; - fd_set exceptfds; + struct pollfd *fds; }; union pthread_wait_data { @@ -406,7 +442,7 @@ union pthread_wait_data { short branch; /* Line number, for debugging. */ char *fname; /* Source file name for debugging.*/ } fd; - struct pthread_select_data * select_data; + struct pthread_poll_data * poll_data; spinlock_t *spinlock; }; @@ -427,15 +463,11 @@ struct pthread { */ spinlock_t lock; - /* - * Pointer to the next thread in the thread linked list. - */ - struct pthread *nxt; + /* Queue entry for list of all threads: */ + TAILQ_ENTRY(pthread) tle; - /* - * Pointer to the next thread in the dead thread linked list. - */ - struct pthread *nxt_dead; + /* Queue entry for list of dead threads: */ + TAILQ_ENTRY(pthread) dle; /* * Thread start routine, argument, stack pointer and thread @@ -514,25 +546,25 @@ struct pthread { */ int error; - /* Join queue for waiting threads: */ - struct pthread_queue join_queue; + /* Join queue head and link for waiting threads: */ + TAILQ_HEAD(join_head, pthread) join_queue; /* - * The current thread can belong to only one scheduling queue - * at a time (ready or waiting queue). It can also belong to - * a queue of threads waiting on mutexes or condition variables. - * Use pqe for the scheduling queue link (both ready and waiting), - * and qe for other links (mutexes and condition variables). + * The current thread can belong to only one scheduling queue at + * a time (ready or waiting queue). It can also belong to (only) + * one of: * - * Pointer to queue (if any) on which the current thread is waiting. + * o A queue of threads waiting for a mutex + * o A queue of threads waiting for a condition variable + * o A queue of threads waiting for another thread to terminate + * (the join queue above) + * o A queue of threads waiting for a file descriptor lock + * o A queue of threads needing work done by the kernel thread + * (waiting for a spinlock or file I/O) * - * XXX The queuing should be changed to use the TAILQ entry below. - * XXX For the time being, it's hybrid. + * Use pqe for the scheduling queue link (both ready and waiting), + * and qe for other links. */ - struct pthread_queue *queue; - - /* Pointer to next element in queue. */ - struct pthread *qnxt; /* Priority queue entry for this thread: */ TAILQ_ENTRY(pthread) pqe; @@ -544,6 +576,11 @@ struct pthread { union pthread_wait_data data; /* + * Allocated for converting select into poll. + */ + struct pthread_poll_data poll_data; + + /* * Set to TRUE if a blocking operation was * interrupted by a signal: */ @@ -553,23 +590,26 @@ struct pthread { int signo; /* - * Set to non-zero when this thread has deferred thread - * scheduling. We allow for recursive deferral. + * Set to non-zero when this thread has deferred signals. + * We allow for recursive deferral. */ - int sched_defer_count; + int sig_defer_count; /* * Set to TRUE if this thread should yield after undeferring - * thread scheduling. + * signals. */ - int yield_on_sched_undefer; + int yield_on_sig_undefer; /* Miscellaneous data. */ int flags; #define PTHREAD_FLAGS_PRIVATE 0x0001 #define PTHREAD_EXITING 0x0002 -#define PTHREAD_FLAGS_QUEUED 0x0004 /* in queue (qe is used) */ -#define PTHREAD_FLAGS_TRACE 0x0008 +#define PTHREAD_FLAGS_IN_CONDQ 0x0004 /* in condition queue using qe link*/ +#define PTHREAD_FLAGS_IN_WORKQ 0x0008 /* in work queue using qe link */ +#define PTHREAD_FLAGS_IN_WAITQ 0x0010 /* in waiting queue using pqe link*/ +#define PTHREAD_FLAGS_IN_PRIOQ 0x0020 /* in priority queue using pqe link*/ +#define PTHREAD_FLAGS_TRACE 0x0040 /* for debugging purposes */ /* * Base priority is the user setable and retrievable priority @@ -592,7 +632,7 @@ struct pthread { /* * Active priority is always the maximum of the threads base * priority and inherited priority. When there is a change - * in either the real or inherited priority, the active + * in either the base or inherited priority, the active * priority must be recalculated. */ char active_priority; @@ -649,10 +689,10 @@ SCLASS struct pthread * volatile _thread_single ; #endif -/* Ptr to the first thread in the thread linked list: */ -SCLASS struct pthread * volatile _thread_link_list +/* List of all threads: */ +SCLASS TAILQ_HEAD(, pthread) _thread_list #ifdef GLOBAL_PTHREAD_PRIVATE -= NULL; += TAILQ_HEAD_INITIALIZER(_thread_list); #else ; #endif @@ -661,7 +701,7 @@ SCLASS struct pthread * volatile _thread_link_list * Array of kernel pipe file descriptors that are used to ensure that * no signals are missed in calls to _select. */ -SCLASS int _thread_kern_pipe[2] +SCLASS int _thread_kern_pipe[2] #ifdef GLOBAL_PTHREAD_PRIVATE = { -1, @@ -670,7 +710,7 @@ SCLASS int _thread_kern_pipe[2] #else ; #endif -SCLASS int _thread_kern_in_select +SCLASS int volatile _queue_signals #ifdef GLOBAL_PTHREAD_PRIVATE = 0; #else @@ -692,9 +732,9 @@ SCLASS struct timeval kern_inc_prio_time #endif /* Dead threads: */ -SCLASS struct pthread * volatile _thread_dead +SCLASS TAILQ_HEAD(, pthread) _dead_list #ifdef GLOBAL_PTHREAD_PRIVATE -= NULL; += TAILQ_HEAD_INITIALIZER(_dead_list); #else ; #endif @@ -747,6 +787,14 @@ SCLASS struct fd_table_entry **_thread_fd_table ; #endif +/* Table for polling file descriptors: */ +SCLASS struct pollfd *_thread_pfd_table +#ifdef GLOBAL_PTHREAD_PRIVATE += NULL; +#else +; +#endif + SCLASS const int dtablecount #ifdef GLOBAL_PTHREAD_PRIVATE = 4096/sizeof(struct fd_table_entry); @@ -760,6 +808,13 @@ SCLASS int _thread_dtablesize /* Descriptor table size. */ ; #endif +SCLASS int _clock_res_nsec /* Clock resolution in nsec. */ +#ifdef GLOBAL_PTHREAD_PRIVATE += CLOCK_RES_NSEC; +#else +; +#endif + /* Garbage collector mutex and condition variable. */ SCLASS pthread_mutex_t _gc_mutex #ifdef GLOBAL_PTHREAD_PRIVATE @@ -783,8 +838,20 @@ struct sigaction _thread_sigact[NSIG]; SCLASS pq_queue_t _readyq; SCLASS TAILQ_HEAD(, pthread) _waitingq; -/* Indicates that the waitingq now has threads ready to run. */ -SCLASS volatile int _waitingq_check_reqd +/* + * Work queue: + */ +SCLASS TAILQ_HEAD(, pthread) _workq; + +/* Tracks the number of threads blocked while waiting for a spinlock. */ +SCLASS volatile int _spinblock_count +#ifdef GLOBAL_PTHREAD_PRIVATE += 0 +#endif +; + +/* Indicates that the signal queue needs to be checked. */ +SCLASS volatile int _sigq_check_reqd #ifdef GLOBAL_PTHREAD_PRIVATE = 0 #endif @@ -797,6 +864,13 @@ SCLASS pthread_switch_routine_t _sched_switch_hook #endif ; +/* Used for _PTHREADS_INVARIANTS checking. */ +SCLASS int _thread_kern_new_state +#ifdef GLOBAL_PTHREAD_PRIVATE += 0 +#endif +; + /* Undefine the storage class specifier: */ #undef SCLASS @@ -825,18 +899,23 @@ int _thread_fd_lock(int, int, struct timespec *); int _thread_fd_lock_debug(int, int, struct timespec *,char *fname,int lineno); void _dispatch_signals(void); void _thread_signal(pthread_t, int); -void _lock_thread(void); -void _lock_thread_list(void); -void _unlock_thread(void); -void _unlock_thread_list(void); int _mutex_cv_lock(pthread_mutex_t *); int _mutex_cv_unlock(pthread_mutex_t *); +int _mutex_reinit(pthread_mutex_t *); void _mutex_notify_priochange(struct pthread *); -int _pq_init(struct pq_queue *pq, int, int); +int _cond_reinit(pthread_cond_t *); +int _pq_alloc(struct pq_queue *, int, int); +int _pq_init(struct pq_queue *); void _pq_remove(struct pq_queue *pq, struct pthread *); void _pq_insert_head(struct pq_queue *pq, struct pthread *); void _pq_insert_tail(struct pq_queue *pq, struct pthread *); struct pthread *_pq_first(struct pq_queue *pq); +#if defined(_PTHREADS_INVARIANTS) +void _waitq_insert(pthread_t pthread); +void _waitq_remove(pthread_t pthread); +void _waitq_setactive(void); +void _waitq_clearactive(void); +#endif void _thread_exit(char *, int, char *); void _thread_fd_unlock(int, int); void _thread_fd_unlock_debug(int, int, char *, int); @@ -849,18 +928,15 @@ void _thread_kern_sched_state(enum pthread_state,char *fname,int lineno); void _thread_kern_sched_state_unlock(enum pthread_state state, spinlock_t *lock, char *fname, int lineno); void _thread_kern_set_timeout(struct timespec *); -void _thread_kern_sched_defer(void); -void _thread_kern_sched_undefer(void); +void _thread_kern_sig_defer(void); +void _thread_kern_sig_undefer(void); void _thread_sig_handler(int, int, struct sigcontext *); +void _thread_sig_handle(int, struct sigcontext *); +void _thread_sig_init(void); void _thread_start(void); void _thread_start_sig_handler(void); void _thread_seterrno(pthread_t,int); -void _thread_queue_init(struct pthread_queue *); -void _thread_queue_enq(struct pthread_queue *, struct pthread *); -int _thread_queue_remove(struct pthread_queue *, struct pthread *); int _thread_fd_table_init(int fd); -struct pthread *_thread_queue_get(struct pthread_queue *); -struct pthread *_thread_queue_deq(struct pthread_queue *); pthread_addr_t _thread_gc(pthread_addr_t); /* #include <signal.h> */ @@ -1036,6 +1112,11 @@ pid_t _thread_sys_waitpid(pid_t, int *, int); pid_t _thread_sys_wait3(int *, int, struct rusage *); pid_t _thread_sys_wait4(pid_t, int *, int, struct rusage *); #endif + +/* #include <poll.h> */ +#ifdef _SYS_POLL_H_ +int _thread_sys_poll(struct pollfd *, unsigned, int); +#endif __END_DECLS #endif /* !_PTHREAD_PRIVATE_H */ diff --git a/lib/libpthread/thread/thr_resume_np.c b/lib/libpthread/thread/thr_resume_np.c index 885a457..b12baba 100644 --- a/lib/libpthread/thread/thr_resume_np.c +++ b/lib/libpthread/thread/thr_resume_np.c @@ -29,6 +29,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * + * $Id$ */ #include <errno.h> #ifdef _THREAD_SAFE @@ -46,20 +47,19 @@ pthread_resume_np(pthread_t thread) /* The thread exists. Is it suspended? */ if (thread->state != PS_SUSPENDED) { /* - * Guard against preemption by a scheduling signal. - * A change of thread state modifies the waiting - * and priority queues. + * Defer signals to protect the scheduling queues + * from access by the signal handler: */ - _thread_kern_sched_defer(); + _thread_kern_sig_defer(); /* Allow the thread to run. */ PTHREAD_NEW_STATE(thread,PS_RUNNING); /* - * Reenable preemption and yield if a scheduling - * signal occurred while in the critical region. + * Undefer and handle pending signals, yielding if + * necessary: */ - _thread_kern_sched_undefer(); + _thread_kern_sig_undefer(); } } return(ret); diff --git a/lib/libpthread/thread/thr_select.c b/lib/libpthread/thread/thr_select.c index 6d7d7dc..c2f86c5 100644 --- a/lib/libpthread/thread/thr_select.c +++ b/lib/libpthread/thread/thr_select.c @@ -29,10 +29,13 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * + * $Id$ */ #include <unistd.h> #include <errno.h> +#include <poll.h> #include <string.h> +#include <sys/param.h> #include <sys/types.h> #include <sys/time.h> #include <sys/fcntl.h> @@ -44,12 +47,10 @@ int select(int numfds, fd_set * readfds, fd_set * writefds, fd_set * exceptfds, struct timeval * timeout) { - fd_set read_locks, write_locks, rdwr_locks; struct timespec ts; - struct timeval zero_timeout = {0, 0}; - int i, ret = 0, got_all_locks = 1; - int f_wait = 1; - struct pthread_select_data data; + int i, ret = 0, f_wait = 1; + int pfd_index, got_one = 0, fd_count = 0; + struct pthread_poll_data data; if (numfds > _thread_dtablesize) { numfds = _thread_dtablesize; @@ -68,112 +69,129 @@ select(int numfds, fd_set * readfds, fd_set * writefds, _thread_kern_set_timeout(NULL); } - FD_ZERO(&read_locks); - FD_ZERO(&write_locks); - FD_ZERO(&rdwr_locks); - - /* lock readfds */ + /* Count the number of file descriptors to be polled: */ if (readfds || writefds || exceptfds) { for (i = 0; i < numfds; i++) { - if ((readfds && (FD_ISSET(i, readfds))) || (exceptfds && FD_ISSET(i, exceptfds))) { - if (writefds && FD_ISSET(i, writefds)) { - if ((ret = _FD_LOCK(i, FD_RDWR, NULL)) != 0) { - got_all_locks = 0; - break; - } - FD_SET(i, &rdwr_locks); - } else { - if ((ret = _FD_LOCK(i, FD_READ, NULL)) != 0) { - got_all_locks = 0; - break; - } - FD_SET(i, &read_locks); - } - } else { - if (writefds && FD_ISSET(i, writefds)) { - if ((ret = _FD_LOCK(i, FD_WRITE, NULL)) != 0) { - got_all_locks = 0; - break; - } - FD_SET(i, &write_locks); - } + if ((readfds && FD_ISSET(i, readfds)) || + (exceptfds && FD_ISSET(i, exceptfds)) || + (writefds && FD_ISSET(i, writefds))) { + fd_count++; } } } - if (got_all_locks) { - data.nfds = numfds; - FD_ZERO(&data.readfds); - FD_ZERO(&data.writefds); - FD_ZERO(&data.exceptfds); - if (readfds != NULL) { - memcpy(&data.readfds, readfds, sizeof(data.readfds)); - } - if (writefds != NULL) { - memcpy(&data.writefds, writefds, sizeof(data.writefds)); + + /* + * Allocate memory for poll data if it hasn't already been + * allocated or if previously allocated memory is insufficient. + */ + if ((_thread_run->poll_data.fds == NULL) || + (_thread_run->poll_data.nfds < fd_count)) { + data.fds = (struct pollfd *) realloc(_thread_run->poll_data.fds, + sizeof(struct pollfd) * MAX(128, fd_count)); + if (data.fds == NULL) { + errno = ENOMEM; + ret = -1; } - if (exceptfds != NULL) { - memcpy(&data.exceptfds, exceptfds, sizeof(data.exceptfds)); + else { + /* + * Note that the threads poll data always + * indicates what is allocated, not what is + * currently being polled. + */ + _thread_run->poll_data.fds = data.fds; + _thread_run->poll_data.nfds = MAX(128, fd_count); } - if ((ret = _thread_sys_select(data.nfds, &data.readfds, &data.writefds, &data.exceptfds, &zero_timeout)) == 0 && f_wait) { - data.nfds = numfds; - FD_ZERO(&data.readfds); - FD_ZERO(&data.writefds); - FD_ZERO(&data.exceptfds); - if (readfds != NULL) { - memcpy(&data.readfds, readfds, sizeof(data.readfds)); + } + if (ret == 0) { + /* Setup the wait data. */ + data.fds = _thread_run->poll_data.fds; + data.nfds = fd_count; + + /* + * Setup the array of pollfds. Optimize this by + * running the loop in reverse and stopping when + * the number of selected file descriptors is reached. + */ + for (i = numfds - 1, pfd_index = fd_count - 1; + (i >= 0) && (pfd_index >= 0); i--) { + data.fds[pfd_index].events = 0; + if (readfds && FD_ISSET(i, readfds)) { + data.fds[pfd_index].events = POLLRDNORM; } - if (writefds != NULL) { - memcpy(&data.writefds, writefds, sizeof(data.writefds)); + if (exceptfds && FD_ISSET(i, exceptfds)) { + data.fds[pfd_index].events |= POLLRDBAND; } - if (exceptfds != NULL) { - memcpy(&data.exceptfds, exceptfds, sizeof(data.exceptfds)); + if (writefds && FD_ISSET(i, writefds)) { + data.fds[pfd_index].events |= POLLWRNORM; + } + if (data.fds[pfd_index].events != 0) { + /* + * Set the file descriptor to be polled and + * clear revents in case of a timeout which + * leaves fds unchanged: + */ + data.fds[pfd_index].fd = i; + data.fds[pfd_index].revents = 0; + pfd_index--; } - _thread_run->data.select_data = &data; + } + if (((ret = _thread_sys_poll(data.fds, data.nfds, 0)) == 0) && + (f_wait != 0)) { + _thread_run->data.poll_data = &data; _thread_run->interrupted = 0; _thread_kern_sched_state(PS_SELECT_WAIT, __FILE__, __LINE__); if (_thread_run->interrupted) { errno = EINTR; + data.nfds = 0; ret = -1; } else ret = data.nfds; } } - /* clean up the locks */ - for (i = 0; i < numfds; i++) - if (FD_ISSET(i, &read_locks)) - _FD_UNLOCK(i, FD_READ); - for (i = 0; i < numfds; i++) - if (FD_ISSET(i, &rdwr_locks)) - _FD_UNLOCK(i, FD_RDWR); - for (i = 0; i < numfds; i++) - if (FD_ISSET(i, &write_locks)) - _FD_UNLOCK(i, FD_WRITE); if (ret >= 0) { - if (readfds != NULL) { - for (i = 0; i < numfds; i++) { - if (FD_ISSET(i, readfds) && - !FD_ISSET(i, &data.readfds)) { - FD_CLR(i, readfds); + numfds = 0; + for (i = 0; i < fd_count; i++) { + /* + * Check the results of the poll and clear + * this file descriptor from the fdset if + * the requested event wasn't ready. + */ + got_one = 0; + if (readfds != NULL) { + if (FD_ISSET(data.fds[i].fd, readfds)) { + if (data.fds[i].revents & (POLLIN | + POLLRDNORM)) + got_one = 1; + else + FD_CLR(data.fds[i].fd, readfds); } } - } - if (writefds != NULL) { - for (i = 0; i < numfds; i++) { - if (FD_ISSET(i, writefds) && - !FD_ISSET(i, &data.writefds)) { - FD_CLR(i, writefds); + if (writefds != NULL) { + if (FD_ISSET(data.fds[i].fd, writefds)) { + if (data.fds[i].revents & (POLLOUT | + POLLWRNORM | POLLWRBAND)) + got_one = 1; + else + FD_CLR(data.fds[i].fd, + writefds); } } - } - if (exceptfds != NULL) { - for (i = 0; i < numfds; i++) { - if (FD_ISSET(i, exceptfds) && - !FD_ISSET(i, &data.exceptfds)) { - FD_CLR(i, exceptfds); + if (exceptfds != NULL) { + if (FD_ISSET(data.fds[i].fd, exceptfds)) { + if (data.fds[i].revents & (POLLRDBAND | + POLLPRI | POLLHUP | POLLERR | + POLLNVAL)) + got_one = 1; + else + FD_CLR(data.fds[i].fd, + exceptfds); } } + if (got_one) + numfds++; } + ret = numfds; } return (ret); diff --git a/lib/libpthread/thread/thr_setschedparam.c b/lib/libpthread/thread/thr_setschedparam.c index 93635da..1ba0e20 100644 --- a/lib/libpthread/thread/thr_setschedparam.c +++ b/lib/libpthread/thread/thr_setschedparam.c @@ -29,6 +29,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * + * $Id$ */ #include <errno.h> #include <sys/param.h> @@ -50,10 +51,10 @@ pthread_setschedparam(pthread_t pthread, int policy, struct sched_param *param) /* Find the thread in the list of active threads: */ else if ((ret = _find_thread(pthread)) == 0) { /* - * Guard against being preempted by a scheduling - * signal: + * Defer signals to protect the scheduling queues from + * access by the signal handler: */ - _thread_kern_sched_defer(); + _thread_kern_sig_defer(); if (param->sched_priority != pthread->base_priority) { /* @@ -61,8 +62,7 @@ pthread_setschedparam(pthread_t pthread, int policy, struct sched_param *param) * queue before any adjustments are made to its * active priority: */ - if ((pthread != _thread_run) && - (pthread->state == PS_RUNNING)) { + if ((pthread->flags & PTHREAD_FLAGS_IN_PRIOQ) != 0) { in_readyq = 1; old_prio = pthread->active_priority; PTHREAD_PRIOQ_REMOVE(pthread); @@ -103,10 +103,10 @@ pthread_setschedparam(pthread_t pthread, int policy, struct sched_param *param) pthread->attr.sched_policy = policy; /* - * Renable preemption and yield if a scheduling signal - * arrived while in the critical region: + * Undefer and handle pending signals, yielding if + * necessary: */ - _thread_kern_sched_undefer(); + _thread_kern_sig_undefer(); } return(ret); } diff --git a/lib/libpthread/thread/thr_sig.c b/lib/libpthread/thread/thr_sig.c index e51d949..ac475a4 100644 --- a/lib/libpthread/thread/thr_sig.c +++ b/lib/libpthread/thread/thr_sig.c @@ -29,6 +29,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * + * $Id$ */ #include <signal.h> #include <fcntl.h> @@ -38,107 +39,51 @@ #include <pthread.h> #include "pthread_private.h" -/* - * State change macro for signal handler: - */ -#define PTHREAD_SIG_NEW_STATE(thrd, newstate) { \ - if ((_thread_run->sched_defer_count == 0) && \ - (_thread_kern_in_sched == 0)) { \ - PTHREAD_NEW_STATE(thrd, newstate); \ - } else { \ - _waitingq_check_reqd = 1; \ - PTHREAD_SET_STATE(thrd, newstate); \ - } \ -} - /* Static variables: */ -static int volatile yield_on_unlock_thread = 0; -static spinlock_t thread_link_list_lock = _SPINLOCK_INITIALIZER; - -/* Lock the thread list: */ -void -_lock_thread_list() -{ - /* Lock the thread list: */ - _SPINLOCK(&thread_link_list_lock); -} +static spinlock_t signal_lock = _SPINLOCK_INITIALIZER; +unsigned int pending_sigs[NSIG]; +unsigned int handled_sigs[NSIG]; +int volatile check_pending = 0; -/* Lock the thread list: */ +/* Initialize signal handling facility: */ void -_unlock_thread_list() +_thread_sig_init(void) { - /* Unlock the thread list: */ - _SPINUNLOCK(&thread_link_list_lock); - - /* - * Check if a scheduler interrupt occurred while the thread - * list was locked: - */ - if (yield_on_unlock_thread) { - /* Reset the interrupt flag: */ - yield_on_unlock_thread = 0; + int i; - /* This thread has overstayed it's welcome: */ - sched_yield(); + /* Clear pending and handled signal counts: */ + for (i = 1; i < NSIG; i++) { + pending_sigs[i - 1] = 0; + handled_sigs[i - 1] = 0; } + + /* Clear the lock: */ + signal_lock.access_lock = 0; } void _thread_sig_handler(int sig, int code, struct sigcontext * scp) { - char c; - int i; - pthread_t pthread; - - /* - * Check if the pthread kernel has unblocked signals (or is about to) - * and was on its way into a _select when the current - * signal interrupted it: - */ - if (_thread_kern_in_select) { - /* Cast the signal number to a character variable: */ - c = sig; - - /* - * Write the signal number to the kernel pipe so that it will - * be ready to read when this signal handler returns. This - * means that the _select call will complete - * immediately. - */ - _thread_sys_write(_thread_kern_pipe[1], &c, 1); - } - /* Check if the signal requires a dump of thread information: */ - if (sig == SIGINFO) - /* Dump thread information to file: */ - _thread_dump_info(); + char c; + int i; /* Check if an interval timer signal: */ - else if (sig == _SCHED_SIGNAL) { - /* Check if the scheduler interrupt has come at an - * unfortunate time which one of the threads is - * modifying the thread list: - */ - if (thread_link_list_lock.access_lock) + if (sig == _SCHED_SIGNAL) { + if (_thread_kern_in_sched != 0) { /* - * Set a flag so that the thread that has - * the lock yields when it unlocks the - * thread list: + * The scheduler is already running; ignore this + * signal. */ - yield_on_unlock_thread = 1; - + } /* * Check if the scheduler interrupt has come when * the currently running thread has deferred thread - * scheduling. + * signals. */ - else if (_thread_run->sched_defer_count) - _thread_run->yield_on_sched_undefer = 1; + else if (_thread_run->sig_defer_count > 0) + _thread_run->yield_on_sig_undefer = 1; - /* - * Check if the kernel has not been interrupted while - * executing scheduler code: - */ - else if (!_thread_kern_in_sched) { + else { /* * Schedule the next thread. This function is not * expected to return because it will do a longjmp @@ -152,6 +97,72 @@ _thread_sig_handler(int sig, int code, struct sigcontext * scp) */ PANIC("Returned to signal function from scheduler"); } + } + /* + * Check if the kernel has been interrupted while the scheduler + * is accessing the scheduling queues or if there is a currently + * running thread that has deferred signals. + */ + else if ((_queue_signals != 0) || ((_thread_kern_in_sched == 0) && + (_thread_run->sig_defer_count > 0))) { + /* Cast the signal number to a character variable: */ + c = sig; + + /* + * Write the signal number to the kernel pipe so that it will + * be ready to read when this signal handler returns. + */ + _thread_sys_write(_thread_kern_pipe[1], &c, 1); + + /* Indicate that there are queued signals in the pipe. */ + _sigq_check_reqd = 1; + } + else { + if (_atomic_lock(&signal_lock.access_lock)) { + /* There is another signal handler running: */ + pending_sigs[sig - 1]++; + check_pending = 1; + } + else { + /* It's safe to handle the signal now. */ + _thread_sig_handle(sig, scp); + + /* Reset the pending and handled count back to 0: */ + pending_sigs[sig - 1] = 0; + handled_sigs[sig - 1] = 0; + + signal_lock.access_lock = 0; + } + + /* Enter a loop to process pending signals: */ + while ((check_pending != 0) && + (_atomic_lock(&signal_lock.access_lock) == 0)) { + check_pending = 0; + for (i = 1; i < NSIG; i++) { + if (pending_sigs[i - 1] > handled_sigs[i - 1]) + _thread_sig_handle(i, scp); + } + signal_lock.access_lock = 0; + } + } +} + +void +_thread_sig_handle(int sig, struct sigcontext * scp) +{ + int i; + pthread_t pthread, pthread_next; + + /* Check if the signal requires a dump of thread information: */ + if (sig == SIGINFO) + /* Dump thread information to file: */ + _thread_dump_info(); + + /* Check if an interval timer signal: */ + else if (sig == _SCHED_SIGNAL) { + /* + * This shouldn't ever occur (should this panic?). + */ } else { /* Check if a child has terminated: */ if (sig == SIGCHLD) { @@ -183,10 +194,9 @@ _thread_sig_handler(int sig, int code, struct sigcontext * scp) * Enter a loop to discard pending SIGCONT * signals: */ - for (pthread = _thread_link_list; - pthread != NULL; - pthread = pthread->nxt) + TAILQ_FOREACH(pthread, &_thread_list, tle) { sigdelset(&pthread->sigpend,SIGCONT); + } } /* @@ -196,11 +206,18 @@ _thread_sig_handler(int sig, int code, struct sigcontext * scp) * if there are multiple waiters, we'll give it to the * first one we find. */ - TAILQ_FOREACH(pthread, &_waitingq, pqe) { + for (pthread = TAILQ_FIRST(&_waitingq); + pthread != NULL; pthread = pthread_next) { + /* + * Grab the next thread before possibly destroying + * the link entry. + */ + pthread_next = TAILQ_NEXT(pthread, pqe); + if ((pthread->state == PS_SIGWAIT) && sigismember(pthread->data.sigwait, sig)) { /* Change the state of the thread to run: */ - PTHREAD_SIG_NEW_STATE(pthread,PS_RUNNING); + PTHREAD_NEW_STATE(pthread,PS_RUNNING); /* Return the signal number: */ pthread->signo = sig; @@ -219,10 +236,13 @@ _thread_sig_handler(int sig, int code, struct sigcontext * scp) * Enter a loop to process each thread in the linked * list: */ - for (pthread = _thread_link_list; pthread != NULL; - pthread = pthread->nxt) { + TAILQ_FOREACH(pthread, &_thread_list, tle) { pthread_t pthread_saved = _thread_run; + /* Current thread inside critical region? */ + if (_thread_run->sig_defer_count > 0) + pthread->sig_defer_count++; + _thread_run = pthread; _thread_signal(pthread,sig); @@ -232,6 +252,10 @@ _thread_sig_handler(int sig, int code, struct sigcontext * scp) */ _dispatch_signals(); _thread_run = pthread_saved; + + /* Current thread inside critical region? */ + if (_thread_run->sig_defer_count > 0) + pthread->sig_defer_count--; } } @@ -284,7 +308,7 @@ _thread_signal(pthread_t pthread, int sig) pthread->interrupted = 1; /* Change the state of the thread to run: */ - PTHREAD_SIG_NEW_STATE(pthread,PS_RUNNING); + PTHREAD_NEW_STATE(pthread,PS_RUNNING); /* Return the signal number: */ pthread->signo = sig; @@ -296,6 +320,7 @@ _thread_signal(pthread_t pthread, int sig) */ case PS_FDR_WAIT: case PS_FDW_WAIT: + case PS_POLL_WAIT: case PS_SLEEP_WAIT: case PS_SELECT_WAIT: if (sig != SIGCHLD || @@ -303,8 +328,11 @@ _thread_signal(pthread_t pthread, int sig) /* Flag the operation as interrupted: */ pthread->interrupted = 1; + if (pthread->flags & PTHREAD_FLAGS_IN_WORKQ) + PTHREAD_WORKQ_REMOVE(pthread); + /* Change the state of the thread to run: */ - PTHREAD_SIG_NEW_STATE(pthread,PS_RUNNING); + PTHREAD_NEW_STATE(pthread,PS_RUNNING); /* Return the signal number: */ pthread->signo = sig; @@ -319,7 +347,7 @@ _thread_signal(pthread_t pthread, int sig) if (!sigismember(&pthread->sigmask, sig) && _thread_sigact[sig - 1].sa_handler != SIG_DFL) { /* Change the state of the thread to run: */ - PTHREAD_SIG_NEW_STATE(pthread,PS_RUNNING); + PTHREAD_NEW_STATE(pthread,PS_RUNNING); /* Return the signal number: */ pthread->signo = sig; diff --git a/lib/libpthread/thread/thr_sigaction.c b/lib/libpthread/thread/thr_sigaction.c index 73a3b21..ed390d1 100644 --- a/lib/libpthread/thread/thr_sigaction.c +++ b/lib/libpthread/thread/thr_sigaction.c @@ -29,6 +29,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * + * $Id$ */ #include <signal.h> #include <errno.h> @@ -77,6 +78,9 @@ sigaction(int sig, const struct sigaction * act, struct sigaction * oact) gact.sa_mask = act->sa_mask; gact.sa_flags = 0; + /* Ensure the scheduling signal is masked: */ + sigaddset(&gact.sa_mask, _SCHED_SIGNAL); + /* * Check if the signal handler is being set to * the default or ignore handlers: diff --git a/lib/libpthread/thread/thr_sigwait.c b/lib/libpthread/thread/thr_sigwait.c index 98a5359..6c7d8d3 100644 --- a/lib/libpthread/thread/thr_sigwait.c +++ b/lib/libpthread/thread/thr_sigwait.c @@ -29,6 +29,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * + * $Id$ */ #include <signal.h> #include <errno.h> @@ -41,7 +42,7 @@ sigwait(const sigset_t * set, int *sig) { int ret = 0; int i; - sigset_t tempset; + sigset_t tempset, waitset; struct sigaction act; /* @@ -51,17 +52,23 @@ sigwait(const sigset_t * set, int *sig) act.sa_flags = SA_RESTART; act.sa_mask = *set; + /* Ensure the scheduling signal is masked: */ + sigaddset(&act.sa_mask, _SCHED_SIGNAL); + /* - * These signals can't be waited on. + * Initialize the set of signals that will be waited on: */ - sigdelset(&act.sa_mask, SIGKILL); - sigdelset(&act.sa_mask, SIGSTOP); - sigdelset(&act.sa_mask, _SCHED_SIGNAL); - sigdelset(&act.sa_mask, SIGCHLD); - sigdelset(&act.sa_mask, SIGINFO); + waitset = *set; + + /* These signals can't be waited on. */ + sigdelset(&waitset, SIGKILL); + sigdelset(&waitset, SIGSTOP); + sigdelset(&waitset, _SCHED_SIGNAL); + sigdelset(&waitset, SIGCHLD); + sigdelset(&waitset, SIGINFO); /* Check to see if a pending signal is in the wait mask. */ - if (tempset = (_thread_run->sigpend & act.sa_mask)) { + if (tempset = (_thread_run->sigpend & waitset)) { /* Enter a loop to find a pending signal: */ for (i = 1; i < NSIG; i++) { if (sigismember (&tempset, i)) @@ -81,17 +88,17 @@ sigwait(const sigset_t * set, int *sig) * Enter a loop to find the signals that are SIG_DFL. For * these signals we must install a dummy signal handler in * order for the kernel to pass them in to us. POSIX says - * that the application must explicitly install a dummy + * that the _application_ must explicitly install a dummy * handler for signals that are SIG_IGN in order to sigwait * on them. Note that SIG_IGN signals are left in the * mask because a subsequent sigaction could enable an * ignored signal. */ for (i = 1; i < NSIG; i++) { - if (sigismember(&act.sa_mask, i)) { - if (_thread_sigact[i - 1].sa_handler == SIG_DFL) - if (_thread_sys_sigaction(i,&act,NULL) != 0) - ret = -1; + if (sigismember(&waitset, i) && + (_thread_sigact[i - 1].sa_handler == SIG_DFL)) { + if (_thread_sys_sigaction(i,&act,NULL) != 0) + ret = -1; } } if (ret == 0) { @@ -101,7 +108,7 @@ sigwait(const sigset_t * set, int *sig) * mask is independent of the threads signal mask * and requires separate storage. */ - _thread_run->data.sigwait = &act.sa_mask; + _thread_run->data.sigwait = &waitset; /* Wait for a signal: */ _thread_kern_sched_state(PS_SIGWAIT, __FILE__, __LINE__); @@ -119,7 +126,7 @@ sigwait(const sigset_t * set, int *sig) /* Restore the sigactions: */ act.sa_handler = SIG_DFL; for (i = 1; i < NSIG; i++) { - if (sigismember(&act.sa_mask, i) && + if (sigismember(&waitset, i) && (_thread_sigact[i - 1].sa_handler == SIG_DFL)) { if (_thread_sys_sigaction(i,&act,NULL) != 0) ret = -1; diff --git a/lib/libpthread/thread/thr_suspend_np.c b/lib/libpthread/thread/thr_suspend_np.c index 6a6eaf4..02943bb 100644 --- a/lib/libpthread/thread/thr_suspend_np.c +++ b/lib/libpthread/thread/thr_suspend_np.c @@ -29,6 +29,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * + * $Id$ */ #include <errno.h> #ifdef _THREAD_SAFE @@ -52,20 +53,19 @@ pthread_suspend_np(pthread_t thread) } /* - * Guard against preemption by a scheduling signal. - * A change of thread state modifies the waiting - * and priority queues. + * Defer signals to protect the scheduling queues from + * access by the signal handler: */ - _thread_kern_sched_defer(); + _thread_kern_sig_defer(); /* Suspend the thread. */ PTHREAD_NEW_STATE(thread,PS_SUSPENDED); /* - * Reenable preemption and yield if a scheduling signal - * occurred while in the critical region. + * Undefer and handle pending signals, yielding if + * necessary: */ - _thread_kern_sched_undefer(); + _thread_kern_sig_undefer(); } return(ret); } |
