Subj : linux, pthreads and message queues, thread safe
To   : comp.programming.threads
From : smoog5
Date : Mon May 16 2005 12:27 am

Hi

Are message queues (msgrcv, msgsnd) thread safe in linux pthreads?

For example:

int k1, k2;

void *thread_main(void *k) {
    for (;;) {
        //each thread uses unique message type (for example pid 
        //of external process)

        //thread receives messages from other processes
        msgrcv(k1, ...);
        [...]
        //thread sends message to other processes
        msgsnd(k2, ...);
        [...]
    }

int main(int argc, char **argv) {
    k1 = msgget(KEY_1, IPC_CREAT);
    k2 = msgget(KEY_2, IPC_CREAT);

    pthread_t threads[10];
    for (int i = 0; i < 10; i++)
        pthread_create(&threads[i], thread_main, ...);
    
    /* do something in infinite loop */
}

Does it works?

.