Standard C Library Functions pthread_mutex_init(3C)
NAME
pthread_mutex_init, pthread_mutex_destroy - initialize or
destroy a mutexSYNOPSIS
cc -mt [ flag... ] file... -lpthread [ library... ]
#include
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;
DESCRIPTION
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 initialization, the state of the mutex becomes initialized and unlocked. Except for robust mutexes, 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, ineffect, uninitialized. A destroyed mutex object can be re-
initialized using pthread_mutex_init(); the results of oth-
erwise 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, themacro PTHREAD_MUTEX_INITIALIZER can be used to initialize
mutexes that are statically allocated. The effect is equivalent to dynamic initialization by a call topthread_mutex_init() with parameter attr specified as NULL,
except that no error checks are performed.SunOS 5.11 Last change: 11 Nov 2008 1
Standard C Library Functions pthread_mutex_init(3C)
RETURN VALUES
If successful, the pthread_mutex_init() and
pthread_mutex_destroy() functions return 0. Otherwise, an
error number is returned to indicate the error.ERRORS
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 a robust
mutex previously initialized but not yet des-
troyed. See pthread_mutexattr_setrobust(3C).
EINVAL An attempt was detected to re-initialize a robust
mutex previously initialized with a different set of attributes. Seepthread_mutexattr_setrobust(3C).
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 objectreferenced by mutex while it is locked or refer-
enced (for example, while being used in apthread_cond_wait(3C) or
pthread_cond_timedwait(3C)) by another thread.
SunOS 5.11 Last change: 11 Nov 2008 2
Standard C Library Functions pthread_mutex_init(3C)
EINVAL The value specified by mutex is invalid.ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Interface Stability | Committed ||_____________________________|_____________________________|
| MT-Level | MT-Safe |
|_____________________________|_____________________________|
| Standard | See standards(5). ||_____________________________|_____________________________|
SEE ALSO
pthread_cond_wait(3C), pthread_mutex_lock(3C),
pthread_mutexattr_setprioceiling(3C),
pthread_mutexattr_setprotocol(3C),
pthread_mutexattr_setpshared(3C),
pthread_mutexattr_setrobust(3C),
pthread_mutexattr_settype(3C), attributes(5), mutex(5),
standards(5)SunOS 5.11 Last change: 11 Nov 2008 3