diff options
author | Eric Andersen <andersen@codepoet.org> | 2002-02-20 09:18:50 +0000 |
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committer | Eric Andersen <andersen@codepoet.org> | 2002-02-20 09:18:50 +0000 |
commit | e356ea321c8098cf1a83a67e27d64c44de08a298 (patch) | |
tree | 8be9273fb8f0e6acab47a9e09552cfbea5400b31 /libpthread/linuxthreads/mutex.c | |
parent | 07ebf927b17572d92e785533d6e8ac1668cc57c6 (diff) |
Merge in the pthread library. This is the linuxthreads library taken from
glibc 2.1.3 and ported to work with uClibc by Stefan Soucek and Erik Andersen
(me). Stefan has hacked things up such that linuxthreads runs on MMU-less
systems (tested only on arm-nommu). Erik cleaned things up and made it work
properly as a shared library.
-Erik
Diffstat (limited to 'libpthread/linuxthreads/mutex.c')
-rw-r--r-- | libpthread/linuxthreads/mutex.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/libpthread/linuxthreads/mutex.c b/libpthread/linuxthreads/mutex.c new file mode 100644 index 000000000..2217a504e --- /dev/null +++ b/libpthread/linuxthreads/mutex.c @@ -0,0 +1,201 @@ +/* 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. */ + +/* changes for uClibc: remove strong_alias'es and define the real symbol */ + +/* Mutexes */ + +#include <errno.h> +#include <sched.h> +#include <stddef.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_FAST_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) +{ + if (mutex->__m_lock.__status != 0) return EBUSY; + return 0; +} +//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_FAST_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_trylock(&mutex->__m_lock); + if (retcode == 0) { + mutex->__m_owner = thread_self(); + } + 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_FAST_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_lock(&mutex->__m_lock, self); + mutex->__m_owner = self; + return 0; + default: + return EINVAL; + } +} +//strong_alias (__pthread_mutex_lock, pthread_mutex_lock) + +int pthread_mutex_unlock(pthread_mutex_t * mutex) +{ + switch (mutex->__m_kind) { + case PTHREAD_MUTEX_FAST_NP: + __pthread_unlock(&mutex->__m_lock); + return 0; + case PTHREAD_MUTEX_RECURSIVE_NP: + 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_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_FAST_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_FAST_NP + && kind != PTHREAD_MUTEX_RECURSIVE_NP + && kind != PTHREAD_MUTEX_ERRORCHECK_NP) + return EINVAL; + attr->__mutexkind = kind; + return 0; +} +weak_alias (__pthread_mutexattr_settype, pthread_mutexattr_settype) +weak_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) +weak_alias (__pthread_mutexattr_gettype, __pthread_mutexattr_getkind_np) +weak_alias (__pthread_mutexattr_getkind_np, pthread_mutexattr_getkind_np) + +/* Once-only execution */ + +static pthread_mutex_t once_masterlock = PTHREAD_MUTEX_INITIALIZER; +static pthread_cond_t once_finished = PTHREAD_COND_INITIALIZER; + +enum { NEVER = 0, IN_PROGRESS = 1, DONE = 2 }; + +int pthread_once(pthread_once_t * once_control, void (*init_routine)(void)) +{ + /* Test without locking first for speed */ + if (*once_control == DONE) return 0; + /* Lock and test again */ + pthread_mutex_lock(&once_masterlock); + /* If init_routine is being called from another routine, wait until + it completes. */ + while (*once_control == 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; + pthread_mutex_unlock(&once_masterlock); + init_routine(); + pthread_mutex_lock(&once_masterlock); + *once_control = DONE; + pthread_cond_broadcast(&once_finished); + } + pthread_mutex_unlock(&once_masterlock); + return 0; +} +//strong_alias (__pthread_once, pthread_once) |