diff options
Diffstat (limited to 'linuxthreads/semaphore.c')
-rw-r--r-- | linuxthreads/semaphore.c | 307 |
1 files changed, 0 insertions, 307 deletions
diff --git a/linuxthreads/semaphore.c b/linuxthreads/semaphore.c deleted file mode 100644 index 017539e176..0000000000 --- a/linuxthreads/semaphore.c +++ /dev/null @@ -1,307 +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. */ - -/* Semaphores a la POSIX 1003.1b */ - -#include <errno.h> -#include "pthread.h" -#include "semaphore.h" -#include "internals.h" -#include "spinlock.h" -#include "restart.h" -#include "queue.h" -#include <shlib-compat.h> -#include <not-cancel.h> - -int __new_sem_init(sem_t *sem, int pshared, unsigned int value) -{ - if (value > SEM_VALUE_MAX) { - errno = EINVAL; - return -1; - } - if (pshared) { - errno = ENOSYS; - return -1; - } - __pthread_init_lock(&sem->__sem_lock); - sem->__sem_value = value; - sem->__sem_waiting = NULL; - return 0; -} - -/* Function called by pthread_cancel to remove the thread from - waiting inside __new_sem_wait. */ - -static int new_sem_extricate_func(void *obj, pthread_descr th) -{ - volatile pthread_descr self = thread_self(); - sem_t *sem = obj; - int did_remove = 0; - - __pthread_lock(&sem->__sem_lock, self); - did_remove = remove_from_queue(&sem->__sem_waiting, th); - __pthread_unlock(&sem->__sem_lock); - - return did_remove; -} - -int __new_sem_wait(sem_t * sem) -{ - volatile pthread_descr self = thread_self(); - pthread_extricate_if extr; - int already_canceled = 0; - int spurious_wakeup_count; - - /* Set up extrication interface */ - extr.pu_object = sem; - extr.pu_extricate_func = new_sem_extricate_func; - - __pthread_lock(&sem->__sem_lock, self); - if (sem->__sem_value > 0) { - sem->__sem_value--; - __pthread_unlock(&sem->__sem_lock); - return 0; - } - /* Register extrication interface */ - THREAD_SETMEM(self, p_sem_avail, 0); - __pthread_set_own_extricate_if(self, &extr); - /* Enqueue only if not already cancelled. */ - if (!(THREAD_GETMEM(self, p_canceled) - && THREAD_GETMEM(self, p_cancelstate) == PTHREAD_CANCEL_ENABLE)) - enqueue(&sem->__sem_waiting, self); - else - already_canceled = 1; - __pthread_unlock(&sem->__sem_lock); - - if (already_canceled) { - __pthread_set_own_extricate_if(self, 0); - __pthread_do_exit(PTHREAD_CANCELED, CURRENT_STACK_FRAME); - } - - /* Wait for sem_post or cancellation, or fall through if already canceled */ - spurious_wakeup_count = 0; - while (1) - { - suspend(self); - if (THREAD_GETMEM(self, p_sem_avail) == 0 - && (THREAD_GETMEM(self, p_woken_by_cancel) == 0 - || THREAD_GETMEM(self, p_cancelstate) != PTHREAD_CANCEL_ENABLE)) - { - /* Count resumes that don't belong to us. */ - spurious_wakeup_count++; - continue; - } - break; - } - __pthread_set_own_extricate_if(self, 0); - - /* Terminate only if the wakeup came from cancellation. */ - /* Otherwise ignore cancellation because we got the semaphore. */ - - if (THREAD_GETMEM(self, p_woken_by_cancel) - && THREAD_GETMEM(self, p_cancelstate) == PTHREAD_CANCEL_ENABLE) { - THREAD_SETMEM(self, p_woken_by_cancel, 0); - __pthread_do_exit(PTHREAD_CANCELED, CURRENT_STACK_FRAME); - } - /* We got the semaphore */ - return 0; -} - -int __new_sem_trywait(sem_t * sem) -{ - int retval; - - __pthread_lock(&sem->__sem_lock, NULL); - if (sem->__sem_value == 0) { - errno = EAGAIN; - retval = -1; - } else { - sem->__sem_value--; - retval = 0; - } - __pthread_unlock(&sem->__sem_lock); - return retval; -} - -int __new_sem_post(sem_t * sem) -{ - pthread_descr self = thread_self(); - pthread_descr th; - struct pthread_request request; - - if (THREAD_GETMEM(self, p_in_sighandler) == NULL) { - __pthread_lock(&sem->__sem_lock, self); - if (sem->__sem_waiting == NULL) { - if (sem->__sem_value >= SEM_VALUE_MAX) { - /* Overflow */ - errno = ERANGE; - __pthread_unlock(&sem->__sem_lock); - return -1; - } - sem->__sem_value++; - __pthread_unlock(&sem->__sem_lock); - } else { - th = dequeue(&sem->__sem_waiting); - __pthread_unlock(&sem->__sem_lock); - th->p_sem_avail = 1; - WRITE_MEMORY_BARRIER(); - restart(th); - } - } else { - /* If we're in signal handler, delegate post operation to - the thread manager. */ - if (__pthread_manager_request < 0) { - if (__pthread_initialize_manager() < 0) { - errno = EAGAIN; - return -1; - } - } - request.req_kind = REQ_POST; - request.req_args.post = sem; - TEMP_FAILURE_RETRY(write_not_cancel(__pthread_manager_request, - (char *) &request, sizeof(request))); - } - return 0; -} - -int __new_sem_getvalue(sem_t * sem, int * sval) -{ - *sval = sem->__sem_value; - return 0; -} - -int __new_sem_destroy(sem_t * sem) -{ - if (sem->__sem_waiting != NULL) { - __set_errno (EBUSY); - return -1; - } - return 0; -} - -sem_t *sem_open(const char *name, int oflag, ...) -{ - __set_errno (ENOSYS); - return SEM_FAILED; -} - -int sem_close(sem_t *sem) -{ - __set_errno (ENOSYS); - return -1; -} - -int sem_unlink(const char *name) -{ - __set_errno (ENOSYS); - return -1; -} - -int sem_timedwait(sem_t *sem, const struct timespec *abstime) -{ - pthread_descr self = thread_self(); - pthread_extricate_if extr; - int already_canceled = 0; - int spurious_wakeup_count; - - __pthread_lock(&sem->__sem_lock, self); - if (sem->__sem_value > 0) { - --sem->__sem_value; - __pthread_unlock(&sem->__sem_lock); - return 0; - } - - if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000) { - /* The standard requires that if the function would block and the - time value is illegal, the function returns with an error. */ - __pthread_unlock(&sem->__sem_lock); - __set_errno (EINVAL); - return -1; - } - - /* Set up extrication interface */ - extr.pu_object = sem; - extr.pu_extricate_func = new_sem_extricate_func; - - /* Register extrication interface */ - THREAD_SETMEM(self, p_sem_avail, 0); - __pthread_set_own_extricate_if(self, &extr); - /* Enqueue only if not already cancelled. */ - if (!(THREAD_GETMEM(self, p_canceled) - && THREAD_GETMEM(self, p_cancelstate) == PTHREAD_CANCEL_ENABLE)) - enqueue(&sem->__sem_waiting, self); - else - already_canceled = 1; - __pthread_unlock(&sem->__sem_lock); - - if (already_canceled) { - __pthread_set_own_extricate_if(self, 0); - __pthread_do_exit(PTHREAD_CANCELED, CURRENT_STACK_FRAME); - } - - spurious_wakeup_count = 0; - while (1) - { - if (timedsuspend(self, abstime) == 0) { - int was_on_queue; - - /* __pthread_lock will queue back any spurious restarts that - may happen to it. */ - - __pthread_lock(&sem->__sem_lock, self); - was_on_queue = remove_from_queue(&sem->__sem_waiting, self); - __pthread_unlock(&sem->__sem_lock); - - if (was_on_queue) { - __pthread_set_own_extricate_if(self, 0); - __set_errno (ETIMEDOUT); - return -1; - } - - /* Eat the outstanding restart() from the signaller */ - suspend(self); - } - - if (THREAD_GETMEM(self, p_sem_avail) == 0 - && (THREAD_GETMEM(self, p_woken_by_cancel) == 0 - || THREAD_GETMEM(self, p_cancelstate) != PTHREAD_CANCEL_ENABLE)) - { - /* Count resumes that don't belong to us. */ - spurious_wakeup_count++; - continue; - } - break; - } - - __pthread_set_own_extricate_if(self, 0); - - /* Terminate only if the wakeup came from cancellation. */ - /* Otherwise ignore cancellation because we got the semaphore. */ - - if (THREAD_GETMEM(self, p_woken_by_cancel) - && THREAD_GETMEM(self, p_cancelstate) == PTHREAD_CANCEL_ENABLE) { - THREAD_SETMEM(self, p_woken_by_cancel, 0); - __pthread_do_exit(PTHREAD_CANCELED, CURRENT_STACK_FRAME); - } - /* We got the semaphore */ - return 0; -} - - -versioned_symbol (libpthread, __new_sem_init, sem_init, GLIBC_2_1); -versioned_symbol (libpthread, __new_sem_wait, sem_wait, GLIBC_2_1); -versioned_symbol (libpthread, __new_sem_trywait, sem_trywait, GLIBC_2_1); -versioned_symbol (libpthread, __new_sem_post, sem_post, GLIBC_2_1); -versioned_symbol (libpthread, __new_sem_getvalue, sem_getvalue, GLIBC_2_1); -versioned_symbol (libpthread, __new_sem_destroy, sem_destroy, GLIBC_2_1); |