From a9f5aa1cc96fc2c71f19a9c3e9dcbee0e78f83ca Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Tue, 15 Nov 2005 03:13:04 +0000 Subject: rename current stable linuxthreads to linuxthreads.old to prepare for import of latest glibc version --- libpthread/linuxthreads.old/mutex.c | 356 ++++++++++++++++++++++++++++++++++++ 1 file changed, 356 insertions(+) create mode 100644 libpthread/linuxthreads.old/mutex.c (limited to 'libpthread/linuxthreads.old/mutex.c') diff --git a/libpthread/linuxthreads.old/mutex.c b/libpthread/linuxthreads.old/mutex.c new file mode 100644 index 000000000..7cc344fac --- /dev/null +++ b/libpthread/linuxthreads.old/mutex.c @@ -0,0 +1,356 @@ +/* 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 +#include +#include +#include +#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) + +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) + +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) + +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) + +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) + +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; +} -- cgit v1.2.3