diff options
Diffstat (limited to 'lib/libc_r/uthread/uthread_sig.c')
| -rw-r--r-- | lib/libc_r/uthread/uthread_sig.c | 1165 |
1 files changed, 0 insertions, 1165 deletions
diff --git a/lib/libc_r/uthread/uthread_sig.c b/lib/libc_r/uthread/uthread_sig.c deleted file mode 100644 index 7f700b2..0000000 --- a/lib/libc_r/uthread/uthread_sig.c +++ /dev/null @@ -1,1165 +0,0 @@ -/* - * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au> - * 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. 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 JOHN BIRRELL 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. - * - * $FreeBSD$ - */ -#include <sys/param.h> -#include <sys/types.h> -#include <sys/signalvar.h> -#include <signal.h> -#include <errno.h> -#include <fcntl.h> -#include <unistd.h> -#include <setjmp.h> -#include <string.h> -#include <pthread.h> -#include "pthread_private.h" - -/* Prototypes: */ -static void thread_sig_add(struct pthread *pthread, int sig, int has_args); -static void thread_sig_check_state(struct pthread *pthread, int sig); -static struct pthread *thread_sig_find(int sig); -static void thread_sig_handle_special(int sig); -static void thread_sigframe_add(struct pthread *thread, int sig, - int has_args); -static void thread_sigframe_save(struct pthread *thread, - struct pthread_signal_frame *psf); -static void thread_sig_invoke_handler(int sig, siginfo_t *info, - ucontext_t *ucp, int unblock); - -/*#define DEBUG_SIGNAL*/ -#ifdef DEBUG_SIGNAL -#define DBG_MSG stdout_debug -#else -#define DBG_MSG(x...) -#endif - -#if defined(_PTHREADS_INVARIANTS) -#define SIG_SET_ACTIVE() _sig_in_handler = 1 -#define SIG_SET_INACTIVE() _sig_in_handler = 0 -#else -#define SIG_SET_ACTIVE() -#define SIG_SET_INACTIVE() -#endif - -void -_thread_sig_handler(int sig, siginfo_t *info, ucontext_t *ucp) -{ - struct pthread *curthread = _get_curthread(); - struct pthread *pthread, *pthread_h; - int in_sched = _thread_kern_in_sched; - char c; - sigset_t sigset; - - if (ucp == NULL) - PANIC("Thread signal handler received null context"); - DBG_MSG("Got signal %d, current thread %p\n", sig, curthread); - - /* Check if an interval timer signal: */ - if (sig == _SCHED_SIGNAL) { - /* Update the scheduling clock: */ - gettimeofday((struct timeval *)&_sched_tod, NULL); - _sched_ticks++; - - if (in_sched != 0) { - /* - * The scheduler is already running; ignore this - * signal. - */ - } - /* - * Check if the scheduler interrupt has come when - * the currently running thread has deferred thread - * signals. - */ - else if (curthread->sig_defer_count > 0) - curthread->yield_on_sig_undefer = 1; - else { - /* Schedule the next thread: */ - _thread_kern_sched(ucp); - - /* - * This point should not be reached, so abort the - * process: - */ - 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 ((in_sched != 0) || (curthread->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. - */ - if (_queue_signals != 0) { - ssize_t wgot; - do { - wgot = __sys_write(_thread_kern_pipe[1], &c, - 1); - } while (wgot < 0 && errno == EINTR); - if (wgot < 0 && errno != EAGAIN) { - PANIC("Failed to queue signal"); - } - DBG_MSG("Got signal %d, queueing to kernel pipe\n", sig); - } - if (_thread_sigq[sig - 1].blocked == 0) { - DBG_MSG("Got signal %d, adding to _thread_sigq\n", sig); - /* - * Do not block this signal; it will be blocked - * when the pending signals are run down. - */ - /* _thread_sigq[sig - 1].blocked = 1; */ - - /* - * Queue the signal, saving siginfo and sigcontext - * (ucontext). - * - * XXX - Do we need to copy siginfo and ucp? - */ - _thread_sigq[sig - 1].signo = sig; - if (info != NULL) - memcpy(&_thread_sigq[sig - 1].siginfo, info, - sizeof(*info)); - memcpy(&_thread_sigq[sig - 1].uc, ucp, sizeof(*ucp)); - - /* Indicate that there are queued signals: */ - _thread_sigq[sig - 1].pending = 1; - _sigq_check_reqd = 1; - } - /* These signals need special handling: */ - else if (sig == SIGCHLD || sig == SIGTSTP || - sig == SIGTTIN || sig == SIGTTOU) { - _thread_sigq[sig - 1].pending = 1; - _thread_sigq[sig - 1].signo = sig; - _sigq_check_reqd = 1; - } - else - DBG_MSG("Got signal %d, ignored.\n", sig); - } - /* - * The signal handlers should have been installed so that they - * cannot be interrupted by other signals. - */ - else if (_thread_sigq[sig - 1].blocked == 0) { - /* - * The signal is not blocked; handle the signal. - * - * Ignore subsequent occurrences of this signal - * until the current signal is handled: - */ - _thread_sigq[sig - 1].blocked = 1; - - /* This signal will be handled; clear the pending flag: */ - _thread_sigq[sig - 1].pending = 0; - - /* - * Save siginfo and sigcontext (ucontext). - * - * XXX - Do we need to copy siginfo and ucp? - */ - _thread_sigq[sig - 1].signo = sig; - - if (info != NULL) - memcpy(&_thread_sigq[sig - 1].siginfo, info, - sizeof(*info)); - memcpy(&_thread_sigq[sig - 1].uc, ucp, sizeof(*ucp)); - SIG_SET_ACTIVE(); - - /* Handle special signals: */ - thread_sig_handle_special(sig); - - pthread_h = NULL; - if ((pthread = thread_sig_find(sig)) == NULL) - DBG_MSG("No thread to handle signal %d\n", sig); - else if (pthread == curthread) { - /* Call the signal handler for the current thread: */ - thread_sig_invoke_handler(sig, info, ucp, 2); - - /* - * Set the process signal mask in the context; it - * could have changed by the handler. - */ - ucp->uc_sigmask = _process_sigmask; - - /* - * The signal mask was restored; check for any - * pending signals: - */ - sigset = curthread->sigpend; - SIGSETOR(sigset, _process_sigpending); - SIGSETNAND(sigset, curthread->sigmask); - if (SIGNOTEMPTY(sigset)) - curthread->check_pending = 1; - - /* Resume the interrupted thread: */ - __sys_sigreturn(ucp); - } else { - DBG_MSG("Got signal %d, adding frame to thread %p\n", - sig, pthread); - - /* Setup the target thread to receive the signal: */ - thread_sig_add(pthread, sig, /*has_args*/ 1); - - /* Take a peek at the next ready to run thread: */ - pthread_h = PTHREAD_PRIOQ_FIRST(); - DBG_MSG("Finished adding frame, head of prio list %p\n", - pthread_h); - } - SIG_SET_INACTIVE(); - - /* - * Switch to a different context if the currently running - * thread takes a signal, or if another thread takes a - * signal and the currently running thread is not in a - * signal handler. - */ - if ((pthread_h != NULL) && - (pthread_h->active_priority > curthread->active_priority)) { - /* Enter the kernel scheduler: */ - _thread_kern_sched(ucp); - } - } - else { - SIG_SET_ACTIVE(); - thread_sig_handle_special(sig); - SIG_SET_INACTIVE(); - } -} - -static void -thread_sig_invoke_handler(int sig, siginfo_t *info, ucontext_t *ucp, - int unblock) - { - struct pthread *curthread = _get_curthread(); - void (*sigfunc)(int, siginfo_t *, void *); - int saved_seqno; - sigset_t saved_sigmask; - - /* Invoke the signal handler without going through the scheduler: - */ - DBG_MSG("Got signal %d, calling handler for current thread %p\n", - sig, curthread); - - /* Save the threads signal mask: */ - saved_sigmask = curthread->sigmask; - saved_seqno = curthread->sigmask_seqno; - - /* Setup the threads signal mask: */ - SIGSETOR(curthread->sigmask, _thread_sigact[sig - 1].sa_mask); - sigaddset(&curthread->sigmask, sig); - - if (unblock > 0) { - /* - * Unblock the signal and restore the process signal - * mask in case we don't return from the handler: - */ - _thread_sigq[sig - 1].blocked = 0; - if (unblock > 1) - __sys_sigprocmask(SIG_SETMASK, &_process_sigmask, - NULL); - } - - /* - * Check that a custom handler is installed and if - * the signal is not blocked: - */ - sigfunc = _thread_sigact[sig - 1].sa_sigaction; - if (((__sighandler_t *)sigfunc != SIG_DFL) && - ((__sighandler_t *)sigfunc != SIG_IGN)) { - if (((_thread_sigact[sig - 1].sa_flags & SA_SIGINFO) != 0) || - (info == NULL)) - (*(sigfunc))(sig, info, ucp); - else - (*(sigfunc))(sig, (void*)(intptr_t)info->si_code, ucp); - } - /* - * Only restore the signal mask if it hasn't been changed by the - * application during invocation of the signal handler: - */ - if (curthread->sigmask_seqno == saved_seqno) - curthread->sigmask = saved_sigmask; -} - -/* - * Find a thread that can handle the signal. - */ -struct pthread * -thread_sig_find(int sig) -{ - struct pthread *curthread = _get_curthread(); - int handler_installed; - struct pthread *pthread, *pthread_next; - struct pthread *suspended_thread, *signaled_thread; - - DBG_MSG("Looking for thread to handle signal %d\n", sig); - /* Check if the signal requires a dump of thread information: */ - if (sig == SIGINFO) { - /* Dump thread information to file: */ - _thread_dump_info(); - - /* Unblock this signal to allow further dumps: */ - _thread_sigq[sig - 1].blocked = 0; - } - /* Check if an interval timer signal: */ - else if (sig == _SCHED_SIGNAL) { - /* - * This shouldn't ever occur (should this panic?). - */ - } else { - /* - * Enter a loop to look for threads that have the signal - * unmasked. POSIX specifies that a thread in a sigwait - * will get the signal over any other threads. Second - * preference will be threads in a sigsuspend. Third - * preference will be the current thread. If none of the - * above, then the signal is delivered to the first thread - * that is found. Note that if a custom handler is not - * installed, the signal only affects threads in sigwait. - */ - suspended_thread = NULL; - if ((curthread != &_thread_kern_thread) && - !sigismember(&curthread->sigmask, sig)) - signaled_thread = curthread; - else - signaled_thread = NULL; - if ((_thread_sigact[sig - 1].sa_handler == SIG_IGN) || - (_thread_sigact[sig - 1].sa_handler == SIG_DFL)) - handler_installed = 0; - else - handler_installed = 1; - - 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_NEW_STATE(pthread,PS_RUNNING); - /* - * A signal handler is not invoked for threads - * in sigwait. Clear the blocked and pending - * flags. - */ - _thread_sigq[sig - 1].blocked = 0; - _thread_sigq[sig - 1].pending = 0; - - /* Return the signal number: */ - pthread->signo = sig; - - /* - * POSIX doesn't doesn't specify which thread - * will get the signal if there are multiple - * waiters, so we give it to the first thread - * we find. - * - * Do not attempt to deliver this signal - * to other threads and do not add the signal - * to the process pending set. - */ - return (NULL); - } - else if ((handler_installed != 0) && - !sigismember(&pthread->sigmask, sig) && - ((pthread->flags & PTHREAD_FLAGS_SUSPENDED) == 0)) { - if (pthread->state == PS_SIGSUSPEND) { - if (suspended_thread == NULL) - suspended_thread = pthread; - } else if (signaled_thread == NULL) - signaled_thread = pthread; - } - } - - /* - * Only perform wakeups and signal delivery if there is a - * custom handler installed: - */ - if (handler_installed == 0) { - /* - * There is no handler installed. Unblock the - * signal so that if a handler _is_ installed, any - * subsequent signals can be handled. - */ - _thread_sigq[sig - 1].blocked = 0; - } else { - /* - * If we didn't find a thread in the waiting queue, - * check the all threads queue: - */ - if (suspended_thread == NULL && - signaled_thread == NULL) { - /* - * Enter a loop to look for other threads - * capable of receiving the signal: - */ - TAILQ_FOREACH(pthread, &_thread_list, tle) { - if (!sigismember(&pthread->sigmask, - sig)) { - signaled_thread = pthread; - break; - } - } - } - - if (suspended_thread == NULL && - signaled_thread == NULL) - /* - * Add it to the set of signals pending - * on the process: - */ - sigaddset(&_process_sigpending, sig); - else { - /* - * We only deliver the signal to one thread; - * give preference to the suspended thread: - */ - if (suspended_thread != NULL) - pthread = suspended_thread; - else - pthread = signaled_thread; - return (pthread); - } - } - } - - /* Returns nothing. */ - return (NULL); -} - -void -_thread_sig_check_pending(struct pthread *pthread) -{ - sigset_t sigset; - int i; - - /* - * Check if there are pending signals for the running - * thread or process that aren't blocked: - */ - sigset = pthread->sigpend; - SIGSETOR(sigset, _process_sigpending); - SIGSETNAND(sigset, pthread->sigmask); - if (SIGNOTEMPTY(sigset)) { - for (i = 1; i < NSIG; i++) { - if (sigismember(&sigset, i) != 0) { - if (sigismember(&pthread->sigpend, i) != 0) - thread_sig_add(pthread, i, - /*has_args*/ 0); - else { - thread_sig_add(pthread, i, - /*has_args*/ 1); - sigdelset(&_process_sigpending, i); - } - } - } - } -} - -/* - * This can only be called from the kernel scheduler. It assumes that - * all thread contexts are saved and that a signal frame can safely be - * added to any user thread. - */ -void -_thread_sig_handle_pending(void) -{ - struct pthread *pthread; - int i, sig; - - PTHREAD_ASSERT(_thread_kern_in_sched != 0, - "_thread_sig_handle_pending called from outside kernel schedule"); - /* - * Check the array of pending signals: - */ - for (i = 0; i < NSIG; i++) { - if (_thread_sigq[i].pending != 0) { - /* This signal is no longer pending. */ - _thread_sigq[i].pending = 0; - - sig = _thread_sigq[i].signo; - - /* Some signals need special handling: */ - thread_sig_handle_special(sig); - - if (_thread_sigq[i].blocked == 0) { - /* - * Block future signals until this one - * is handled: - */ - _thread_sigq[i].blocked = 1; - - if ((pthread = thread_sig_find(sig)) != NULL) { - /* - * Setup the target thread to receive - * the signal: - */ - thread_sig_add(pthread, sig, - /*has_args*/ 1); - } - } - } - } -} - -static void -thread_sig_handle_special(int sig) -{ - struct pthread *pthread, *pthread_next; - int i; - - switch (sig) { - case SIGCHLD: - /* - * Go through the file list and set all files - * to non-blocking again in case the child - * set some of them to block. Sigh. - */ - for (i = 0; i < _thread_dtablesize; i++) { - /* Check if this file is used: */ - if (_thread_fd_table[i] != NULL) { - /* - * Set the file descriptor to non-blocking: - */ - __sys_fcntl(i, F_SETFL, - _thread_fd_getflags(i) | O_NONBLOCK); - } - } - /* - * Enter a loop to wake up all threads waiting - * for a process to complete: - */ - 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 this thread is waiting for a child - * process to complete, wake it up: - */ - if (pthread->state == PS_WAIT_WAIT) { - /* Make the thread runnable: */ - PTHREAD_NEW_STATE(pthread,PS_RUNNING); - - /* Return the signal number: */ - pthread->signo = sig; - } - } - break; - - /* - * POSIX says that pending SIGCONT signals are - * discarded when one of these signals occurs. - */ - case SIGTSTP: - case SIGTTIN: - case SIGTTOU: - /* - * Enter a loop to discard pending SIGCONT - * signals: - */ - TAILQ_FOREACH(pthread, &_thread_list, tle) { - sigdelset(&pthread->sigpend, SIGCONT); - } - break; - - default: - break; - } -} - -/* - * Perform thread specific actions in response to a signal. - * This function is only called if there is a handler installed - * for the signal, and if the target thread has the signal - * unmasked. - */ -static void -thread_sig_add(struct pthread *pthread, int sig, int has_args) -{ - int restart; - int suppress_handler = 0; - int thread_is_active = 0; - - restart = _thread_sigact[sig - 1].sa_flags & SA_RESTART; - - /* Make sure this signal isn't still in the pending set: */ - sigdelset(&pthread->sigpend, sig); - - /* - * Process according to thread state: - */ - switch (pthread->state) { - /* - * States which do not change when a signal is trapped: - */ - case PS_DEAD: - case PS_DEADLOCK: - case PS_STATE_MAX: - case PS_SIGTHREAD: - /* - * You can't call a signal handler for threads in these - * states. - */ - suppress_handler = 1; - break; - - /* - * States which do not need any cleanup handling when signals - * occur: - */ - case PS_RUNNING: - /* - * Remove the thread from the queue before changing its - * priority: - */ - if ((pthread->flags & PTHREAD_FLAGS_IN_PRIOQ) != 0) - PTHREAD_PRIOQ_REMOVE(pthread); - else - /* - * This thread is running; avoid placing it in - * the run queue: - */ - thread_is_active = 1; - break; - - case PS_SUSPENDED: - break; - - case PS_SPINBLOCK: - /* Remove the thread from the workq and waitq: */ - PTHREAD_WORKQ_REMOVE(pthread); - PTHREAD_WAITQ_REMOVE(pthread); - /* Make the thread runnable: */ - PTHREAD_SET_STATE(pthread, PS_RUNNING); - break; - - case PS_SIGWAIT: - /* The signal handler is not called for threads in SIGWAIT. */ - suppress_handler = 1; - /* Wake up the thread if the signal is blocked. */ - if (sigismember(pthread->data.sigwait, sig)) { - /* Change the state of the thread to run: */ - PTHREAD_NEW_STATE(pthread, PS_RUNNING); - - /* Return the signal number: */ - pthread->signo = sig; - } else - /* Increment the pending signal count. */ - sigaddset(&pthread->sigpend, sig); - break; - - /* - * The wait state is a special case due to the handling of - * SIGCHLD signals. - */ - case PS_WAIT_WAIT: - if (sig == SIGCHLD) { - /* Change the state of the thread to run: */ - PTHREAD_WAITQ_REMOVE(pthread); - PTHREAD_SET_STATE(pthread, PS_RUNNING); - - /* Return the signal number: */ - pthread->signo = sig; - } - else { - /* - * Mark the thread as interrupted only if the - * restart flag is not set on the signal action: - */ - if (restart == 0) - pthread->interrupted = 1; - PTHREAD_WAITQ_REMOVE(pthread); - PTHREAD_SET_STATE(pthread, PS_RUNNING); - } - break; - - /* - * States which cannot be interrupted but still require the - * signal handler to run: - */ - case PS_COND_WAIT: - case PS_MUTEX_WAIT: - /* - * Remove the thread from the wait queue. It will - * be added back to the wait queue once all signal - * handlers have been invoked. - */ - PTHREAD_WAITQ_REMOVE(pthread); - break; - - case PS_JOIN: - /* - * Remove the thread from the wait queue. It will - * be added back to the wait queue once all signal - * handlers have been invoked. - */ - PTHREAD_WAITQ_REMOVE(pthread); - /* Make the thread runnable: */ - PTHREAD_SET_STATE(pthread, PS_RUNNING); - break; - - /* - * States which are interruptible but may need to be removed - * from queues before any signal handler is called. - * - * XXX - We may not need to handle this condition, but will - * mark it as a potential problem. - */ - case PS_FDLR_WAIT: - case PS_FDLW_WAIT: - case PS_FILE_WAIT: - if (restart == 0) - pthread->interrupted = 1; - /* - * Remove the thread from the wait queue. Our - * signal handler hook will remove this thread - * from the fd or file queue before invoking - * the actual handler. - */ - PTHREAD_WAITQ_REMOVE(pthread); - break; - - /* - * States which are interruptible: - */ - case PS_FDR_WAIT: - case PS_FDW_WAIT: - if (restart == 0) { - /* - * Flag the operation as interrupted and - * set the state to running: - */ - pthread->interrupted = 1; - PTHREAD_SET_STATE(pthread, PS_RUNNING); - } - PTHREAD_WORKQ_REMOVE(pthread); - PTHREAD_WAITQ_REMOVE(pthread); - break; - - case PS_POLL_WAIT: - case PS_SELECT_WAIT: - case PS_SLEEP_WAIT: - /* - * Unmasked signals always cause poll, select, and sleep - * to terminate early, regardless of SA_RESTART: - */ - pthread->interrupted = 1; - /* Remove threads in poll and select from the workq: */ - if ((pthread->flags & PTHREAD_FLAGS_IN_WORKQ) != 0) - PTHREAD_WORKQ_REMOVE(pthread); - PTHREAD_WAITQ_REMOVE(pthread); - PTHREAD_SET_STATE(pthread, PS_RUNNING); - break; - - case PS_SIGSUSPEND: - PTHREAD_WAITQ_REMOVE(pthread); - PTHREAD_SET_STATE(pthread, PS_RUNNING); - break; - } - - if (suppress_handler == 0) { - /* Setup a signal frame and save the current threads state: */ - thread_sigframe_add(pthread, sig, has_args); - - /* - * Signals are deferred until just before the threads - * signal handler is invoked: - */ - pthread->sig_defer_count = 1; - - /* Make sure the thread is runnable: */ - if (pthread->state != PS_RUNNING) - PTHREAD_SET_STATE(pthread, PS_RUNNING); - /* - * The thread should be removed from all scheduling - * queues at this point. Raise the priority and place - * the thread in the run queue. It is also possible - * for a signal to be sent to a suspended thread, - * mostly via pthread_kill(). If a thread is suspended, - * don't insert it into the priority queue; just set - * its state to suspended and it will run the signal - * handler when it is resumed. - */ - pthread->active_priority |= PTHREAD_SIGNAL_PRIORITY; - if ((pthread->flags & PTHREAD_FLAGS_SUSPENDED) != 0) - PTHREAD_SET_STATE(pthread, PS_SUSPENDED); - else if (thread_is_active == 0) - PTHREAD_PRIOQ_INSERT_TAIL(pthread); - } -} - -static void -thread_sig_check_state(struct pthread *pthread, int sig) -{ - /* - * Process according to thread state: - */ - switch (pthread->state) { - /* - * States which do not change when a signal is trapped: - */ - case PS_DEAD: - case PS_DEADLOCK: - case PS_STATE_MAX: - case PS_SIGTHREAD: - case PS_RUNNING: - case PS_SUSPENDED: - case PS_SPINBLOCK: - case PS_COND_WAIT: - case PS_JOIN: - case PS_MUTEX_WAIT: - break; - - case PS_SIGWAIT: - /* Wake up the thread if the signal is blocked. */ - if (sigismember(pthread->data.sigwait, sig)) { - /* Change the state of the thread to run: */ - PTHREAD_NEW_STATE(pthread, PS_RUNNING); - - /* Return the signal number: */ - pthread->signo = sig; - } else - /* Increment the pending signal count. */ - sigaddset(&pthread->sigpend, sig); - break; - - /* - * The wait state is a special case due to the handling of - * SIGCHLD signals. - */ - case PS_WAIT_WAIT: - if (sig == SIGCHLD) { - /* - * Remove the thread from the wait queue and - * make it runnable: - */ - PTHREAD_NEW_STATE(pthread, PS_RUNNING); - - /* Return the signal number: */ - pthread->signo = sig; - } - break; - - case PS_FDLR_WAIT: - case PS_FDLW_WAIT: - case PS_SIGSUSPEND: - case PS_SLEEP_WAIT: - /* - * Remove the thread from the wait queue and make it - * runnable: - */ - PTHREAD_NEW_STATE(pthread, PS_RUNNING); - - /* Flag the operation as interrupted: */ - pthread->interrupted = 1; - break; - - /* - * These states are additionally in the work queue: - */ - case PS_FDR_WAIT: - case PS_FDW_WAIT: - case PS_FILE_WAIT: - case PS_POLL_WAIT: - case PS_SELECT_WAIT: - /* - * Remove the thread from the wait and work queues, and - * make it runnable: - */ - PTHREAD_WORKQ_REMOVE(pthread); - PTHREAD_NEW_STATE(pthread, PS_RUNNING); - - /* Flag the operation as interrupted: */ - pthread->interrupted = 1; - break; - } -} - -/* - * Send a signal to a specific thread (ala pthread_kill): - */ -void -_thread_sig_send(struct pthread *pthread, int sig) -{ - struct pthread *curthread = _get_curthread(); - - /* Check for signals whose actions are SIG_DFL: */ - if (_thread_sigact[sig - 1].sa_handler == SIG_DFL) { - /* - * Check to see if a temporary signal handler is - * installed for sigwaiters: - */ - if (_thread_dfl_count[sig] == 0) - /* - * Deliver the signal to the process if a handler - * is not installed: - */ - kill(getpid(), sig); - /* - * Assuming we're still running after the above kill(), - * make any necessary state changes to the thread: - */ - thread_sig_check_state(pthread, sig); - } - /* - * Check that the signal is not being ignored: - */ - else if (_thread_sigact[sig - 1].sa_handler != SIG_IGN) { - if (pthread->state == PS_SIGWAIT && - sigismember(pthread->data.sigwait, sig)) { - /* Change the state of the thread to run: */ - PTHREAD_NEW_STATE(pthread, PS_RUNNING); - - /* Return the signal number: */ - pthread->signo = sig; - } else if (sigismember(&pthread->sigmask, sig)) - /* Add the signal to the pending set: */ - sigaddset(&pthread->sigpend, sig); - else if (pthread == curthread) - /* Call the signal handler for the current thread: */ - thread_sig_invoke_handler(sig, NULL, NULL, 0); - else { - /* Protect the scheduling queues: */ - _thread_kern_sig_defer(); - /* - * Perform any state changes due to signal - * arrival: - */ - thread_sig_add(pthread, sig, /* has args */ 0); - /* Unprotect the scheduling queues: */ - _thread_kern_sig_undefer(); - } - } -} - -/* - * User thread signal handler wrapper. - * - * thread - current running thread - */ -void -_thread_sig_wrapper(void) -{ - struct pthread_signal_frame *psf; - struct pthread *thread = _get_curthread(); - - /* Get the current frame and state: */ - psf = thread->curframe; - thread->curframe = NULL; - PTHREAD_ASSERT(psf != NULL, "Invalid signal frame in signal handler"); - - /* - * We're coming from the kernel scheduler; clear the in - * scheduler flag: - */ - _thread_kern_in_sched = 0; - - /* Check the threads previous state: */ - if (psf->saved_state.psd_state != PS_RUNNING) { - /* - * Do a little cleanup handling for those threads in - * queues before calling the signal handler. Signals - * for these threads are temporarily blocked until - * after cleanup handling. - */ - switch (psf->saved_state.psd_state) { - case PS_FDLR_WAIT: - case PS_FDLW_WAIT: - _fd_lock_backout(thread); - psf->saved_state.psd_state = PS_RUNNING; - break; - - case PS_COND_WAIT: - _cond_wait_backout(thread); - psf->saved_state.psd_state = PS_RUNNING; - break; - - case PS_MUTEX_WAIT: - _mutex_lock_backout(thread); - psf->saved_state.psd_state = PS_RUNNING; - break; - - default: - break; - } - } - - /* - * Lower the priority before calling the handler in case - * it never returns (longjmps back): - */ - thread->active_priority &= ~PTHREAD_SIGNAL_PRIORITY; - - /* - * Reenable interruptions without checking for the need to - * context switch: - */ - thread->sig_defer_count = 0; - - /* - * Dispatch the signal via the custom signal handler: - */ - if (psf->sig_has_args == 0) - thread_sig_invoke_handler(psf->signo, NULL, NULL, 1); - else - thread_sig_invoke_handler(psf->signo, &psf->siginfo, &psf->uc, - 1); - - /* - * Call the kernel scheduler to safely restore the frame and - * schedule the next thread: - */ - _thread_kern_sched_frame(psf); -} - -static void -thread_sigframe_add(struct pthread *thread, int sig, int has_args) -{ - struct pthread_signal_frame *psf = NULL; - unsigned long stackp; - - /* Get the top of the threads stack: */ - stackp = GET_STACK_JB(thread->ctx.jb); - -#if !defined(__ia64__) - /* - * Leave a little space on the stack and round down to the - * nearest aligned word: - */ -#if defined(__amd64__) - stackp -= 128; /* Skip over 128 byte red-zone */ -#endif - stackp -= sizeof(double); -#if defined(__amd64__) - stackp &= ~0xFUL; -#else - stackp &= ~0x3UL; -#endif -#endif - - /* Allocate room on top of the stack for a new signal frame: */ - stackp -= sizeof(struct pthread_signal_frame); -#if defined(__ia64__) || defined(__amd64__) - stackp &= ~0xFUL; -#endif - - psf = (struct pthread_signal_frame *) stackp; - - /* Save the current context in the signal frame: */ - thread_sigframe_save(thread, psf); - - /* Set handler specific information: */ - psf->sig_has_args = has_args; - psf->signo = sig; - if (has_args) { - /* Copy the signal handler arguments to the signal frame: */ - memcpy(&psf->uc, &_thread_sigq[psf->signo - 1].uc, - sizeof(psf->uc)); - memcpy(&psf->siginfo, &_thread_sigq[psf->signo - 1].siginfo, - sizeof(psf->siginfo)); - } - - /* Setup the signal mask: */ - SIGSETOR(thread->sigmask, _thread_sigact[sig - 1].sa_mask); - sigaddset(&thread->sigmask, sig); - - /* Set up the new frame: */ - thread->curframe = psf; - thread->flags &= PTHREAD_FLAGS_PRIVATE | PTHREAD_FLAGS_TRACE | - PTHREAD_FLAGS_IN_SYNCQ; - /* - * Set up the context: - */ -#if !defined(__ia64__) - stackp -= sizeof(double); -#if defined(__amd64__) - stackp &= ~0xFUL; -#endif -#endif - _setjmp(thread->ctx.jb); -#if !defined(__ia64__) - SET_STACK_JB(thread->ctx.jb, stackp); -#else - UPD_STACK_JB(thread->ctx.jb, stackp - 16); -#endif - SET_RETURN_ADDR_JB(thread->ctx.jb, _thread_sig_wrapper); -} - -void -_thread_sigframe_restore(struct pthread *thread, - struct pthread_signal_frame *psf) -{ - memcpy(&thread->ctx, &psf->ctx, sizeof(thread->ctx)); - /* - * Only restore the signal mask if it hasn't been changed - * by the application during invocation of the signal handler: - */ - if (thread->sigmask_seqno == psf->saved_state.psd_sigmask_seqno) - thread->sigmask = psf->saved_state.psd_sigmask; - thread->curframe = psf->saved_state.psd_curframe; - thread->wakeup_time = psf->saved_state.psd_wakeup_time; - thread->data = psf->saved_state.psd_wait_data; - thread->state = psf->saved_state.psd_state; - thread->flags = psf->saved_state.psd_flags; - thread->interrupted = psf->saved_state.psd_interrupted; - thread->signo = psf->saved_state.psd_signo; - thread->sig_defer_count = psf->saved_state.psd_sig_defer_count; -} - -static void -thread_sigframe_save(struct pthread *thread, struct pthread_signal_frame *psf) -{ - memcpy(&psf->ctx, &thread->ctx, sizeof(thread->ctx)); - psf->saved_state.psd_sigmask = thread->sigmask; - psf->saved_state.psd_curframe = thread->curframe; - psf->saved_state.psd_wakeup_time = thread->wakeup_time; - psf->saved_state.psd_wait_data = thread->data; - psf->saved_state.psd_state = thread->state; - psf->saved_state.psd_flags = thread->flags & - (PTHREAD_FLAGS_PRIVATE | PTHREAD_FLAGS_TRACE); - psf->saved_state.psd_interrupted = thread->interrupted; - psf->saved_state.psd_sigmask_seqno = thread->sigmask_seqno; - psf->saved_state.psd_signo = thread->signo; - psf->saved_state.psd_sig_defer_count = thread->sig_defer_count; -} - |
