Multithreaded Programming Guide

`pthread_mutexattr_init` Syntax

int pthread_mutexattr_init(pthread_mutexattr_t *mattr);

#include <pthread.h>

pthread_mutexattr_t mattr;
int ret;

/* initialize an attribute to default value */
ret = pthread_mutexattr_init(&mattr);

mattr is an opaque type that contains a system-allocated attribute object. See Table 4–2 for information about the attributes in the mattr object.

Before a mutex attribute object can be reinitialized, the object must first be destroyed by a call to pthread_mutexattr_destroy(3C). The pthread_mutexattr_init() call results in the allocation of an opaque object. If the object is not destroyed, a memory leak results.

Table 4–2 Default Attribute Values for mattr


Attribute	Value	Result
`pshared`	`PTHREAD_PROCESS_PRIVATE`	The initialized mutex can be used within a process. Only those threads created by the same process can operate on the mutex.
`type`	`PTHREAD_MUTEX_DEFAULT`	The Solaris Pthreads implementation maps `PTHREAD_MUTEX_DEFAULT` to `PTHREAD_MUTEX_NORMAL`, which does not detect deadlock.
`protocol`	`PTHREAD_PRIO_NONE`	Thread priority and scheduling are not affected by the priority of the mutex owned by the thread.
`prioceiling`	–	The `prioceiling` value is drawn from the existing priority range for the `SCHED_FIFO` policy, as returned by the `sched_get_priority_min()` and `sched_get_priority_max()` functions. This priority range is determined by the Solaris version on which the mutex is created.
`robustness`	`PTHREAD_MUTEX_STALLED_NP`	When the owner of a mutex dies, all future calls to `pthread_mutex_lock()` for this mutex will be blocked from progress.

pthread_mutexattr_init Syntax

`pthread_mutexattr_init` Syntax