Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

(sunos section 3c)
man page for pthread_mutex_init

pthread_mutex_init(3C)													    pthread_mutex_init(3C)

NAME
pthread_mutex_init, pthread_mutex_destroy - initialize or destroy a mutex SYNOPSIS
cc -mt [ flag... ] file... -lpthread [ library... ] #include <pthread.h> int pthread_mutex_init(pthread_mutex_t *restrict mutex, const pthread_mutexattr_t *restrict attr); int pthread_mutex_destroy(pthread_mutex_t *mutex); pthread_mutex_t mutex= PTHREAD_MUTEX_INITIALIZER The pthread_mutex_init() function initializes the mutex referenced by mutex with attributes specified by attr. If attr is NULL, the default mutex attributes are used; the effect is the same as passing the address of a default mutex attributes object. Upon successful ini- tialization, the state of the mutex becomes initialized and unlocked. Attempting to initialize an already initialized mutex results in undefined behavior. The pthread_mutex_destroy() function destroys the mutex object referenced by mutex; the mutex object becomes, in effect, uninitialized. A destroyed mutex object can be re-initialized using pthread_mutex_init(); the results of otherwise referencing the object after it has been destroyed are undefined. It is safe to destroy an initialized mutex that is unlocked. Attempting to destroy a locked mutex results in undefined behavior. In cases where default mutex attributes are appropriate, the macro PTHREAD_MUTEX_INITIALIZER can be used to initialize mutexes that are statically allocated. The effect is equivalent to dynamic initialization by a call to pthread_mutex_init() with parameter attr specified as NULL, except that no error checks are performed. If successful, the pthread_mutex_init() and pthread_mutex_destroy() functions return 0. Otherwise, an error number is returned to indicate the error. The pthread_mutex_init() function will fail if: EAGAIN The system lacked the necessary resources (other than memory) to initialize another mutex. EBUSY An attempt was detected to re-initialize the object referenced by mutex, a robust mutex previously initialized but not yet destroyed. EINVAL The value specified by attr has not been initialized using pthread_mutexattr_init(3C). EINVAL An attempt was made to initialize mutex to be robust and not PTHREAD_PRIO_INHERIT. EINVAL An attempt was made to initalize mutex to be PTHREAD_PRIO_INHERIT or PTHREAD_PRIO_PROTECT and the type of the mutex to be PTHREAD_MUTEX_ERRORCHECK or PTHREAD_MUTEX_RECURSIVE. EINVAL An attpemt was made to initalize mutex to be PTHREAD_PROCESS_SHARED and the type of the mutex to be PTHREAD_MUTEX_RECUR- SIVE. EINVAL The process-shared attribute associated with attr is invalid. ENOMEM Insufficient memory exists to initialize the mutex. EPERM The caller does not have the privilege to perform the operation. The pthread_mutex_init() function may fail if: EBUSY An attempt was detected to re-initialize the object referenced by mutex, a mutex previously initialized but not yet destroyed. EINVAL The value specified by attr or mutex is invalid. The pthread_mutex_destroy() function may fail if: EBUSY An attempt was detected to destroy the object referenced by mutex while it is locked or referenced (for example, while being used in a pthread_cond_wait(3C) or pthread_cond_timedwait(3C)) by another thread. EINVAL The value specified by mutex is invalid. See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ |MT-Level |MT-Safe | +-----------------------------+-----------------------------+ pthread_cond_timedwait(3C), pthread_cond_wait(3C), pthread_mutex_getprioceiling(3C), pthread_mutex_lock(3C), pthread_mutex_unlock(3C), pthread_mutex_setprioceiling(3C), pthread_mutex_trylock(3C), pthread_mutexattr_init(3C), pthread_mutexattr_getpshared(3C), pthread_mutex- attr_setpshared(3C) attributes(5), mutex(5), standards(5) 23 Mar 2005 pthread_mutex_init(3C)
Test Your Knowledge in Science: Mathematics
Difficulty: Medium
Zero factorial is equal to zero.
True or False?

Featured Tech Videos