Professional Multicore Programming: Design and Implementation for C++ Developers

Name

NAME

pthread_cond_destroy, pthread_cond_init — destroy and initialize condition variables

SYNOPSIS

THR #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;

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.

Only cond itself may be used for performing synchronization. The result of referring to copies of cond in calls to pthread_cond_wait ...