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author | Jakub Jelinek <jakub@redhat.com> | 2007-07-12 18:26:36 +0000 |
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committer | Jakub Jelinek <jakub@redhat.com> | 2007-07-12 18:26:36 +0000 |
commit | 0ecb606cb6cf65de1d9fc8a919bceb4be476c602 (patch) | |
tree | 2ea1f8305970753e4a657acb2ccc15ca3eec8e2c /linuxthreads/mutex.c | |
parent | 7d58530341304d403a6626d7f7a1913165fe2f32 (diff) | |
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2.5-18.1
Diffstat (limited to 'linuxthreads/mutex.c')
-rw-r--r-- | linuxthreads/mutex.c | 362 |
1 files changed, 0 insertions, 362 deletions
diff --git a/linuxthreads/mutex.c b/linuxthreads/mutex.c deleted file mode 100644 index d5f7a335cc..0000000000 --- a/linuxthreads/mutex.c +++ /dev/null @@ -1,362 +0,0 @@ -/* Linuxthreads - a simple clone()-based implementation of Posix */ -/* threads for Linux. */ -/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) */ -/* */ -/* This program is free software; you can redistribute it and/or */ -/* modify it under the terms of the GNU Library General Public License */ -/* as published by the Free Software Foundation; either version 2 */ -/* of the License, or (at your option) any later version. */ -/* */ -/* This program is distributed in the hope that it will be useful, */ -/* but WITHOUT ANY WARRANTY; without even the implied warranty of */ -/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */ -/* GNU Library General Public License for more details. */ - -/* Mutexes */ - -#include <bits/libc-lock.h> -#include <errno.h> -#include <sched.h> -#include <stddef.h> -#include <limits.h> -#include "pthread.h" -#include "internals.h" -#include "spinlock.h" -#include "queue.h" -#include "restart.h" - -int __pthread_mutex_init(pthread_mutex_t * mutex, - const pthread_mutexattr_t * mutex_attr) -{ - __pthread_init_lock(&mutex->__m_lock); - mutex->__m_kind = - mutex_attr == NULL ? PTHREAD_MUTEX_TIMED_NP : mutex_attr->__mutexkind; - mutex->__m_count = 0; - mutex->__m_owner = NULL; - return 0; -} -strong_alias (__pthread_mutex_init, pthread_mutex_init) -hidden_def (__pthread_mutex_init) - -int __pthread_mutex_destroy(pthread_mutex_t * mutex) -{ - switch (mutex->__m_kind) { - case PTHREAD_MUTEX_ADAPTIVE_NP: - case PTHREAD_MUTEX_RECURSIVE_NP: - if ((mutex->__m_lock.__status & 1) != 0) - return EBUSY; - return 0; - case PTHREAD_MUTEX_ERRORCHECK_NP: - case PTHREAD_MUTEX_TIMED_NP: - if (mutex->__m_lock.__status != 0) - return EBUSY; - return 0; - default: - return EINVAL; - } -} -strong_alias (__pthread_mutex_destroy, pthread_mutex_destroy) -hidden_def (__pthread_mutex_destroy) - -int __pthread_mutex_trylock(pthread_mutex_t * mutex) -{ - pthread_descr self; - int retcode; - - switch(mutex->__m_kind) { - case PTHREAD_MUTEX_ADAPTIVE_NP: - retcode = __pthread_trylock(&mutex->__m_lock); - return retcode; - case PTHREAD_MUTEX_RECURSIVE_NP: - self = thread_self(); - if (mutex->__m_owner == self) { - mutex->__m_count++; - return 0; - } - retcode = __pthread_trylock(&mutex->__m_lock); - if (retcode == 0) { - mutex->__m_owner = self; - mutex->__m_count = 0; - } - return retcode; - case PTHREAD_MUTEX_ERRORCHECK_NP: - retcode = __pthread_alt_trylock(&mutex->__m_lock); - if (retcode == 0) { - mutex->__m_owner = thread_self(); - } - return retcode; - case PTHREAD_MUTEX_TIMED_NP: - retcode = __pthread_alt_trylock(&mutex->__m_lock); - return retcode; - default: - return EINVAL; - } -} -strong_alias (__pthread_mutex_trylock, pthread_mutex_trylock) -hidden_def (__pthread_mutex_trylock) - -int __pthread_mutex_lock(pthread_mutex_t * mutex) -{ - pthread_descr self; - - switch(mutex->__m_kind) { - case PTHREAD_MUTEX_ADAPTIVE_NP: - __pthread_lock(&mutex->__m_lock, NULL); - return 0; - case PTHREAD_MUTEX_RECURSIVE_NP: - self = thread_self(); - if (mutex->__m_owner == self) { - mutex->__m_count++; - return 0; - } - __pthread_lock(&mutex->__m_lock, self); - mutex->__m_owner = self; - mutex->__m_count = 0; - return 0; - case PTHREAD_MUTEX_ERRORCHECK_NP: - self = thread_self(); - if (mutex->__m_owner == self) return EDEADLK; - __pthread_alt_lock(&mutex->__m_lock, self); - mutex->__m_owner = self; - return 0; - case PTHREAD_MUTEX_TIMED_NP: - __pthread_alt_lock(&mutex->__m_lock, NULL); - return 0; - default: - return EINVAL; - } -} -strong_alias (__pthread_mutex_lock, pthread_mutex_lock) -hidden_def (__pthread_mutex_lock) - -int __pthread_mutex_timedlock (pthread_mutex_t *mutex, - const struct timespec *abstime) -{ - pthread_descr self; - int res; - - if (__builtin_expect (abstime->tv_nsec, 0) < 0 - || __builtin_expect (abstime->tv_nsec, 0) >= 1000000000) - return EINVAL; - - switch(mutex->__m_kind) { - case PTHREAD_MUTEX_ADAPTIVE_NP: - __pthread_lock(&mutex->__m_lock, NULL); - return 0; - case PTHREAD_MUTEX_RECURSIVE_NP: - self = thread_self(); - if (mutex->__m_owner == self) { - mutex->__m_count++; - return 0; - } - __pthread_lock(&mutex->__m_lock, self); - mutex->__m_owner = self; - mutex->__m_count = 0; - return 0; - case PTHREAD_MUTEX_ERRORCHECK_NP: - self = thread_self(); - if (mutex->__m_owner == self) return EDEADLK; - res = __pthread_alt_timedlock(&mutex->__m_lock, self, abstime); - if (res != 0) - { - mutex->__m_owner = self; - return 0; - } - return ETIMEDOUT; - case PTHREAD_MUTEX_TIMED_NP: - /* Only this type supports timed out lock. */ - return (__pthread_alt_timedlock(&mutex->__m_lock, NULL, abstime) - ? 0 : ETIMEDOUT); - default: - return EINVAL; - } -} -strong_alias (__pthread_mutex_timedlock, pthread_mutex_timedlock) - -int __pthread_mutex_unlock(pthread_mutex_t * mutex) -{ - switch (mutex->__m_kind) { - case PTHREAD_MUTEX_ADAPTIVE_NP: - __pthread_unlock(&mutex->__m_lock); - return 0; - case PTHREAD_MUTEX_RECURSIVE_NP: - if (mutex->__m_owner != thread_self()) - return EPERM; - if (mutex->__m_count > 0) { - mutex->__m_count--; - return 0; - } - mutex->__m_owner = NULL; - __pthread_unlock(&mutex->__m_lock); - return 0; - case PTHREAD_MUTEX_ERRORCHECK_NP: - if (mutex->__m_owner != thread_self() || mutex->__m_lock.__status == 0) - return EPERM; - mutex->__m_owner = NULL; - __pthread_alt_unlock(&mutex->__m_lock); - return 0; - case PTHREAD_MUTEX_TIMED_NP: - __pthread_alt_unlock(&mutex->__m_lock); - return 0; - default: - return EINVAL; - } -} -strong_alias (__pthread_mutex_unlock, pthread_mutex_unlock) -hidden_def (__pthread_mutex_unlock) - -int __pthread_mutexattr_init(pthread_mutexattr_t *attr) -{ - attr->__mutexkind = PTHREAD_MUTEX_TIMED_NP; - return 0; -} -strong_alias (__pthread_mutexattr_init, pthread_mutexattr_init) - -int __pthread_mutexattr_destroy(pthread_mutexattr_t *attr) -{ - return 0; -} -strong_alias (__pthread_mutexattr_destroy, pthread_mutexattr_destroy) - -int __pthread_mutexattr_settype(pthread_mutexattr_t *attr, int kind) -{ - if (kind != PTHREAD_MUTEX_ADAPTIVE_NP - && kind != PTHREAD_MUTEX_RECURSIVE_NP - && kind != PTHREAD_MUTEX_ERRORCHECK_NP - && kind != PTHREAD_MUTEX_TIMED_NP) - return EINVAL; - attr->__mutexkind = kind; - return 0; -} -weak_alias (__pthread_mutexattr_settype, pthread_mutexattr_settype) -strong_alias ( __pthread_mutexattr_settype, __pthread_mutexattr_setkind_np) -weak_alias (__pthread_mutexattr_setkind_np, pthread_mutexattr_setkind_np) - -int __pthread_mutexattr_gettype(const pthread_mutexattr_t *attr, int *kind) -{ - *kind = attr->__mutexkind; - return 0; -} -weak_alias (__pthread_mutexattr_gettype, pthread_mutexattr_gettype) -strong_alias (__pthread_mutexattr_gettype, __pthread_mutexattr_getkind_np) -weak_alias (__pthread_mutexattr_getkind_np, pthread_mutexattr_getkind_np) - -int __pthread_mutexattr_getpshared (const pthread_mutexattr_t *attr, - int *pshared) -{ - *pshared = PTHREAD_PROCESS_PRIVATE; - return 0; -} -weak_alias (__pthread_mutexattr_getpshared, pthread_mutexattr_getpshared) - -int __pthread_mutexattr_setpshared (pthread_mutexattr_t *attr, int pshared) -{ - if (pshared != PTHREAD_PROCESS_PRIVATE && pshared != PTHREAD_PROCESS_SHARED) - return EINVAL; - - /* For now it is not possible to shared a conditional variable. */ - if (pshared != PTHREAD_PROCESS_PRIVATE) - return ENOSYS; - - return 0; -} -weak_alias (__pthread_mutexattr_setpshared, pthread_mutexattr_setpshared) - -/* Once-only execution */ - -static pthread_mutex_t once_masterlock = PTHREAD_MUTEX_INITIALIZER; -static pthread_cond_t once_finished = PTHREAD_COND_INITIALIZER; -static int fork_generation = 0; /* Child process increments this after fork. */ - -enum { NEVER = 0, IN_PROGRESS = 1, DONE = 2 }; - -/* If a thread is canceled while calling the init_routine out of - pthread once, this handler will reset the once_control variable - to the NEVER state. */ - -static void pthread_once_cancelhandler(void *arg) -{ - pthread_once_t *once_control = arg; - - pthread_mutex_lock(&once_masterlock); - *once_control = NEVER; - pthread_mutex_unlock(&once_masterlock); - pthread_cond_broadcast(&once_finished); -} - -int __pthread_once(pthread_once_t * once_control, void (*init_routine)(void)) -{ - /* flag for doing the condition broadcast outside of mutex */ - int state_changed; - - /* Test without locking first for speed */ - if (*once_control == DONE) { - READ_MEMORY_BARRIER(); - return 0; - } - /* Lock and test again */ - - state_changed = 0; - - pthread_mutex_lock(&once_masterlock); - - /* If this object was left in an IN_PROGRESS state in a parent - process (indicated by stale generation field), reset it to NEVER. */ - if ((*once_control & 3) == IN_PROGRESS && (*once_control & ~3) != fork_generation) - *once_control = NEVER; - - /* If init_routine is being called from another routine, wait until - it completes. */ - while ((*once_control & 3) == IN_PROGRESS) { - pthread_cond_wait(&once_finished, &once_masterlock); - } - /* Here *once_control is stable and either NEVER or DONE. */ - if (*once_control == NEVER) { - *once_control = IN_PROGRESS | fork_generation; - pthread_mutex_unlock(&once_masterlock); - pthread_cleanup_push(pthread_once_cancelhandler, once_control); - init_routine(); - pthread_cleanup_pop(0); - pthread_mutex_lock(&once_masterlock); - WRITE_MEMORY_BARRIER(); - *once_control = DONE; - state_changed = 1; - } - pthread_mutex_unlock(&once_masterlock); - - if (state_changed) - pthread_cond_broadcast(&once_finished); - - return 0; -} -strong_alias (__pthread_once, pthread_once) - -/* - * Handle the state of the pthread_once mechanism across forks. The - * once_masterlock is acquired in the parent process prior to a fork to ensure - * that no thread is in the critical region protected by the lock. After the - * fork, the lock is released. In the child, the lock and the condition - * variable are simply reset. The child also increments its generation - * counter which lets pthread_once calls detect stale IN_PROGRESS states - * and reset them back to NEVER. - */ - -void __pthread_once_fork_prepare(void) -{ - pthread_mutex_lock(&once_masterlock); -} - -void __pthread_once_fork_parent(void) -{ - pthread_mutex_unlock(&once_masterlock); -} - -void __pthread_once_fork_child(void) -{ - pthread_mutex_init(&once_masterlock, NULL); - pthread_cond_init(&once_finished, NULL); - if (fork_generation <= INT_MAX - 4) - fork_generation += 4; /* leave least significant two bits zero */ - else - fork_generation = 0; -} |