a091d823ad
1. fast simple type mutex.
2. __thread tls works.
3. asynchronous cancellation works ( using signal ).
4. thread synchronization is fully based on umtx, mainly, condition
variable and other synchronization objects were rewritten by using
umtx directly. those objects can be shared between processes via
shared memory, it has to change ABI which does not happen yet.
5. default stack size is increased to 1M on 32 bits platform, 2M for
64 bits platform.
As the result, some mysql super-smack benchmarks show performance is
improved massivly.
Okayed by: jeff, mtm, rwatson, scottl
223 lines
6.7 KiB
C
223 lines
6.7 KiB
C
/*
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* Copyright (c) 2005 David Xu <davidxu@freebsd.org>
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* Copyright (c) 2003 Daniel Eischen <deischen@freebsd.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Neither the name of the author nor the names of any co-contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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/*
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* Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by John Birrell.
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* 4. Neither the name of the author nor the names of any co-contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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*/
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#include <errno.h>
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#include <string.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <pthread.h>
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#include <spinlock.h>
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#include "libc_private.h"
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#include "thr_private.h"
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__weak_reference(_pthread_atfork, pthread_atfork);
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int
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_pthread_atfork(void (*prepare)(void), void (*parent)(void),
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void (*child)(void))
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{
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struct pthread *curthread;
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struct pthread_atfork *af;
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_thr_check_init();
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if ((af = malloc(sizeof(struct pthread_atfork))) == NULL)
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return (ENOMEM);
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curthread = _get_curthread();
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af->prepare = prepare;
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af->parent = parent;
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af->child = child;
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THR_UMTX_LOCK(curthread, &_thr_atfork_lock);
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TAILQ_INSERT_TAIL(&_thr_atfork_list, af, qe);
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THR_UMTX_UNLOCK(curthread, &_thr_atfork_lock);
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return (0);
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}
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/*
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* For a while, allow libpthread to work with a libc that doesn't
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* export the malloc lock.
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*/
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#pragma weak __malloc_lock
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__weak_reference(_fork, fork);
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pid_t
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_fork(void)
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{
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static umtx_t inprogress;
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static int waiters;
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umtx_t tmp;
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struct pthread *curthread;
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struct pthread_atfork *af;
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pid_t ret;
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int errsave;
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int unlock_malloc;
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if (!_thr_is_inited())
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return (__sys_fork());
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curthread = _get_curthread();
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/*
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* Block all signals until we reach a safe point.
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*/
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_thr_signal_block(curthread);
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THR_UMTX_LOCK(curthread, &_thr_atfork_lock);
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tmp = inprogress;
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while (tmp) {
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waiters++;
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THR_UMTX_UNLOCK(curthread, &_thr_atfork_lock);
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_thr_umtx_wait(&inprogress, tmp, NULL);
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THR_UMTX_LOCK(curthread, &_thr_atfork_lock);
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waiters--;
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tmp = inprogress;
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}
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inprogress = 1;
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/* Unlock mutex, allow new hook to be added during executing hooks. */
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THR_UMTX_UNLOCK(curthread, &_thr_atfork_lock);
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/* Run down atfork prepare handlers. */
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TAILQ_FOREACH_REVERSE(af, &_thr_atfork_list, atfork_head, qe) {
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if (af->prepare != NULL)
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af->prepare();
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}
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/*
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* Try our best to protect memory from being corrupted in
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* child process because another thread in malloc code will
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* simply be kill by fork().
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*/
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if ((_thr_isthreaded() != 0) && (__malloc_lock != NULL)) {
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unlock_malloc = 1;
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_spinlock(__malloc_lock);
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} else {
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unlock_malloc = 0;
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}
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/* Fork a new process: */
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if ((ret = __sys_fork()) == 0) {
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/* Child process */
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errsave = errno;
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inprogress = 0;
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curthread->cancelflags &= ~THR_CANCEL_NEEDED;
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/*
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* Thread list will be reinitialized, and later we call
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* _libpthread_init(), it will add us back to list.
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*/
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curthread->tlflags &= ~(TLFLAGS_IN_TDLIST | TLFLAGS_DETACHED);
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/* child is a new kernel thread. */
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thr_self(&curthread->tid);
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/* clear other threads locked us. */
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_thr_umtx_init(&curthread->lock);
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_thr_umtx_init(&_thr_atfork_lock);
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_thr_setthreaded(0);
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/* reinitialize libc spinlocks, this includes __malloc_lock. */
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_thr_spinlock_init();
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_mutex_fork(curthread);
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/* reinitalize library. */
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_libpthread_init(curthread);
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/* Ready to continue, unblock signals. */
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_thr_signal_unblock(curthread);
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/* Run down atfork child handlers. */
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TAILQ_FOREACH(af, &_thr_atfork_list, qe) {
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if (af->child != NULL)
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af->child();
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}
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} else {
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/* Parent process */
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errsave = errno;
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if (unlock_malloc)
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_spinunlock(__malloc_lock);
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/* Ready to continue, unblock signals. */
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_thr_signal_unblock(curthread);
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/* Run down atfork parent handlers. */
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TAILQ_FOREACH(af, &_thr_atfork_list, qe) {
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if (af->parent != NULL)
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af->parent();
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}
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THR_UMTX_LOCK(curthread, &_thr_atfork_lock);
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inprogress = 0;
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if (waiters)
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_thr_umtx_wake(&inprogress, waiters);
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THR_UMTX_UNLOCK(curthread, &_thr_atfork_lock);
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}
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errno = errsave;
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/* Return the process ID: */
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return (ret);
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}
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