Multithreaded Programming Guide

pthread_condattr_setpshared Syntax

int pthread_condattr_setpshared(pthread_condattr_t *cattr, int pshared);
#include <pthread.h> 
pthread_condattr_t cattr; 
int ret; 

/* all processes */ 
ret = pthread_condattr_setpshared(&cattr, PTHREAD_PROCESS_SHARED); 

/* within a process */ 
ret = pthread_condattr_setpshared(&cattr, PTHREAD_PROCESS_PRIVATE);

A condition variable created with the pshared attribute set in shared memory to PTHREAD_PROCESS_SHARED, can be shared among threads from more than one process.

If the mutex pshared attribute is set to PTHREAD_PROCESS_PRIVATE, only those threads created by the same process can operate on the mutex. PTHREAD_PROCESS_PRIVATE is the default value. PTHREAD_PROCESS_PRIVATE behaves like a local condition variable. The behavior of PTHREAD_PROCESS_SHARED is equivalent to a global condition variable.