pthread_cond_destroy

Synopsis

#include <pthread.h>

int pthread_cond_destroy(pthread_cond_t *cond);

int pthread_cond_init(pthread_cond_t *restrict cond,
                      const pthread_condattr_t *restrict attr);

pthread_cond_t cond = PTHREAD_COND_INITIALIZER;

Status

Implemented

Conformance

IEEE Std 1003.1-2017

Description

The pthread_cond_destroy() function shall destroy the given condition variable specified by cond; the object becomes, in effect, uninitialized. An implementation may cause pthread_cond_destroy() to set the object referenced by cond to an invalid value. A destroyed condition variable object can be reinitialized using pthread_cond_init(); the results of otherwise referencing the object after it has been destroyed are undefined.

It shall be safe to destroy an initialized condition variable upon which no threads are currently blocked. Attempting to destroy a condition variable upon which other threads are currently blocked results in undefined behavior.

The pthread_cond_init() function shall initialize the condition variable referenced by cond with attributes referenced by attr. If attr is NULL, the default condition variable attributes shall be used; the effect is the same as passing the address of a default condition variable attributes object. Upon successful initialization, the state of the condition variable shall become initialized.

Attempting to initialize an already initialized condition variable results in undefined behavior.

In cases where default condition variable attributes are appropriate, the macro PTHREAD_COND_INITIALIZER can be used to initialize condition variables. The effect shall be equivalent to dynamic initialization by a call to pthread_cond_init() with parameter attr specified as NULL, except that no error checks are performed.

The behavior is undefined if the value specified by the cond argument to pthread_cond_destroy() does not refer to an initialized condition variable.

The behavior is undefined if the value specified by the attr argument to pthread_cond_init() does not refer to an initialized condition variable attributes object.

Return value

If successful, the pthread_cond_destroy() and pthread_cond_init() functions shall return zero; otherwise, an error number shall be returned to indicate the error.

Errors

The pthread_cond_init() function shall fail if:

• EAGAIN - The system lacked the necessary resources (other than memory) to initialize another condition variable.

• ENOMEM - Insufficient memory exists to initialize the condition variable.

These functions shall not return an error code of EINTR.

POSIX deviations

No POSIX deviations discovered.