diff options
Diffstat (limited to 'lib/libpthread/thread/thr_create.c')
| -rw-r--r-- | lib/libpthread/thread/thr_create.c | 327 |
1 files changed, 327 insertions, 0 deletions
diff --git a/lib/libpthread/thread/thr_create.c b/lib/libpthread/thread/thr_create.c new file mode 100644 index 0000000..430869e --- /dev/null +++ b/lib/libpthread/thread/thr_create.c @@ -0,0 +1,327 @@ +/* + * 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. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by John Birrell. + * 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 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 <errno.h> +#include <stdlib.h> +#include <string.h> +#include <fcntl.h> +#include <unistd.h> +#include <stddef.h> +#include <sys/time.h> +#include <sys/param.h> +#include <sys/mman.h> +#ifdef _THREAD_SAFE +#include <machine/reg.h> +#include <pthread.h> +#include "pthread_private.h" +#include "libc_private.h" + +static u_int64_t next_uniqueid = 1; + +#define OFF(f) offsetof(struct pthread, f) +int _thread_next_offset = OFF(tle.tqe_next); +int _thread_uniqueid_offset = OFF(uniqueid); +int _thread_state_offset = OFF(state); +int _thread_name_offset = OFF(name); +int _thread_ctxtype_offset = OFF(ctxtype); +int _thread_ctx_offset = OFF(ctx); +#undef OFF + +int _thread_PS_RUNNING_value = PS_RUNNING; +int _thread_PS_DEAD_value = PS_DEAD; +int _thread_CTX_JB_NOSIG_value = CTX_JB_NOSIG; +int _thread_CTX_JB_value = CTX_JB; +int _thread_CTX_SJB_value = CTX_SJB; +int _thread_CTX_UC_value = CTX_UC; + +int +pthread_create(pthread_t * thread, const pthread_attr_t * attr, + void *(*start_routine) (void *), void *arg) +{ + struct itimerval itimer; + int f_gc = 0; + int ret = 0; + pthread_t gc_thread; + pthread_t new_thread; + pthread_attr_t pattr; + void *stack; + + /* + * Locking functions in libc are required when there are + * threads other than the initial thread. + */ + __isthreaded = 1; + + /* Allocate memory for the thread structure: */ + if ((new_thread = (pthread_t) malloc(sizeof(struct pthread))) == NULL) { + /* Insufficient memory to create a thread: */ + ret = EAGAIN; + } else { + /* Check if default thread attributes are required: */ + if (attr == NULL || *attr == NULL) { + /* Use the default thread attributes: */ + pattr = &pthread_attr_default; + } else { + pattr = *attr; + } + /* Check if a stack was specified in the thread attributes: */ + if ((stack = pattr->stackaddr_attr) != NULL) { + } + /* Allocate memory for a default-size stack: */ + else if (pattr->stacksize_attr == PTHREAD_STACK_DEFAULT) { + struct stack *spare_stack; + + /* Allocate or re-use a default-size stack. */ + + /* + * Use the garbage collector mutex for synchronization + * of the spare stack list. + */ + if (pthread_mutex_lock(&_gc_mutex) != 0) + PANIC("Cannot lock gc mutex"); + + if ((spare_stack = SLIST_FIRST(&_stackq)) != NULL) { + /* Use the spare stack. */ + SLIST_REMOVE_HEAD(&_stackq, qe); + + /* Unlock the garbage collector mutex. */ + if (pthread_mutex_unlock(&_gc_mutex) != 0) + PANIC("Cannot unlock gc mutex"); + + stack = sizeof(struct stack) + + (void *) spare_stack + - PTHREAD_STACK_DEFAULT; + } else { + /* Allocate a new stack. */ + stack = _next_stack + PTHREAD_STACK_GUARD; + + /* + * Even if stack allocation fails, we don't want + * to try to use this location again, so + * unconditionally decrement _next_stack. Under + * normal operating conditions, the most likely + * reason for an mmap() error is a stack + * overflow of the adjacent thread stack. + */ + _next_stack -= (PTHREAD_STACK_DEFAULT + + PTHREAD_STACK_GUARD); + + /* Unlock the garbage collector mutex. */ + if (pthread_mutex_unlock(&_gc_mutex) != 0) + PANIC("Cannot unlock gc mutex"); + + /* Stack: */ + if (mmap(stack, PTHREAD_STACK_DEFAULT, + PROT_READ | PROT_WRITE, MAP_STACK, + -1, 0) == MAP_FAILED) { + ret = EAGAIN; + free(new_thread); + } + } + } + /* + * The user wants a stack of a particular size. Lets hope they + * really know what they want, and simply malloc the stack. + */ + else if ((stack = (void *) malloc(pattr->stacksize_attr)) + == NULL) { + /* Insufficient memory to create a thread: */ + ret = EAGAIN; + free(new_thread); + } + + /* Check for errors: */ + if (ret != 0) { + } else { + /* Initialise the thread structure: */ + memset(new_thread, 0, sizeof(struct pthread)); + new_thread->slice_usec = -1; + new_thread->stack = stack; + new_thread->start_routine = start_routine; + new_thread->arg = arg; + + new_thread->cancelflags = PTHREAD_CANCEL_ENABLE | + PTHREAD_CANCEL_DEFERRED; + + /* + * Write a magic value to the thread structure + * to help identify valid ones: + */ + new_thread->magic = PTHREAD_MAGIC; + + /* Initialise the thread for signals: */ + new_thread->sigmask = _thread_run->sigmask; + new_thread->sigmask_seqno = 0; + + /* Initialize the signal frame: */ + new_thread->curframe = NULL; + + /* Initialise the jump buffer: */ + _setjmp(new_thread->ctx.jb); + + /* + * Set up new stack frame so that it looks like it + * returned from a longjmp() to the beginning of + * _thread_start(). + */ + SET_RETURN_ADDR_JB(new_thread->ctx.jb, _thread_start); + + /* The stack starts high and builds down: */ + SET_STACK_JB(new_thread->ctx.jb, + (long)new_thread->stack + pattr->stacksize_attr + - sizeof(double)); + + /* Initialize the rest of the frame: */ + new_thread->ctxtype = CTX_JB_NOSIG; + + /* Copy the thread attributes: */ + memcpy(&new_thread->attr, pattr, sizeof(struct pthread_attr)); + + /* + * Check if this thread is to inherit the scheduling + * attributes from its parent: + */ + if (new_thread->attr.flags & PTHREAD_INHERIT_SCHED) { + /* Copy the scheduling attributes: */ + new_thread->base_priority = + _thread_run->base_priority & + ~PTHREAD_SIGNAL_PRIORITY; + new_thread->attr.prio = + _thread_run->base_priority & + ~PTHREAD_SIGNAL_PRIORITY; + new_thread->attr.sched_policy = + _thread_run->attr.sched_policy; + } else { + /* + * Use just the thread priority, leaving the + * other scheduling attributes as their + * default values: + */ + new_thread->base_priority = + new_thread->attr.prio; + } + new_thread->active_priority = new_thread->base_priority; + new_thread->inherited_priority = 0; + + /* Initialise the join queue for the new thread: */ + TAILQ_INIT(&(new_thread->join_queue)); + + /* Initialize the mutex queue: */ + TAILQ_INIT(&new_thread->mutexq); + + /* Initialise hooks in the thread structure: */ + new_thread->specific_data = NULL; + new_thread->cleanup = NULL; + new_thread->flags = 0; + new_thread->poll_data.nfds = 0; + new_thread->poll_data.fds = NULL; + new_thread->continuation = NULL; + + /* + * Defer signals to protect the scheduling queues + * from access by the signal handler: + */ + _thread_kern_sig_defer(); + + /* + * Initialise the unique id which GDB uses to + * track threads. + */ + new_thread->uniqueid = next_uniqueid++; + + /* + * Check if the garbage collector thread + * needs to be started. + */ + f_gc = (TAILQ_FIRST(&_thread_list) == _thread_initial); + + /* Add the thread to the linked list of all threads: */ + TAILQ_INSERT_HEAD(&_thread_list, new_thread, tle); + + if (pattr->suspend == PTHREAD_CREATE_SUSPENDED) + new_thread->state = PS_SUSPENDED; + else { + new_thread->state = PS_RUNNING; + PTHREAD_PRIOQ_INSERT_TAIL(new_thread); + } + + /* + * Undefer and handle pending signals, yielding + * if necessary. + */ + _thread_kern_sig_undefer(); + + /* Return a pointer to the thread structure: */ + (*thread) = new_thread; + + if (f_gc != 0) { + /* Install the scheduling timer: */ + itimer.it_interval.tv_sec = 0; + itimer.it_interval.tv_usec = _clock_res_usec; + itimer.it_value = itimer.it_interval; + if (setitimer(_ITIMER_SCHED_TIMER, &itimer, + NULL) != 0) + PANIC("Cannot set interval timer"); + } + + /* Schedule the new user thread: */ + _thread_kern_sched(NULL); + + /* + * Start a garbage collector thread + * if necessary. + */ + if (f_gc && pthread_create(&gc_thread,NULL, + _thread_gc,NULL) != 0) + PANIC("Can't create gc thread"); + + } + } + + /* Return the status: */ + return (ret); +} + +void +_thread_start(void) +{ + /* We just left the scheduler via longjmp: */ + _thread_kern_in_sched = 0; + + /* Run the current thread's start routine with argument: */ + pthread_exit(_thread_run->start_routine(_thread_run->arg)); + + /* This point should never be reached. */ + PANIC("Thread has resumed after exit"); +} +#endif |
