pthread_mutex_init(3thr)pthread_mutex_init(3thr)Namepthread_mutex_init - Creates a mutex
Syntax
#include <pthread.h>
int pthread_mutex_init (mutex, attr)
pthread_mutex_t *mutex;
pthread_mutexattr_t attr;
Arguments
mutex Mutex created.
attr Mutex attributes object that defines the characteristics of the
created mutex. If you specify pthread_mutexattr_default,
default attributes are used.
Description
This routine creates a mutex. A mutex (mutual exclusion) is a synchro‐
nization object that allows multiple threads to serialize their access
to shared data.
The mutex is created and initialized to the unlocked state.
The created mutex is not automatically deallocated because it is con‐
sidered shared among multiple threads if the thread that called this
routine terminates.
Return Values
If an error condition occurs, this routine returns -1, the mutex is not
initialized, and the contents of mutex are undefined. This routine
sets errno to the corresponding error value. Possible return values
are as follows.
Return Error Description
0 Successful comple‐
tion.
-1 [EAGAIN] The system lacks
the necessary
resources to ini‐
tialize another
mutex.
The system-imposed
limit on the total
number of mutexes
under execution by
a singled user is
exceeded.
-1 [ENOMEM] Insufficient memory
exists to initial‐
ize the mutex.
pthread_mutex_init(3thr)
