thrqueue.c is a blob of C which provides a thread-safe queue, allowing you to pass void pointers between pthreads easily.

Producer threads enqueue items and optionally block if the work queue is too long. Worker threads dequeue items and block if there is no work to be done.

An example test program is included in the source code. Basic operation:

// gcc -Wall -std=c99 -pthread -o test test.c thrqueue.c
#include <stdio.h>
#include <pthread.h>
#include "thrqueue.h"

struct Queue *q;
void *worker(void *args) {
        char *work;
        while ((work = queue_deq(q)))
                printf("Got: '%s'\n", work);

        return NULL;

int main(void) {
        q = queue_init();
        queue_limit(q, 10); // no more than 10 pending items

        pthread_t worker_thread;
        pthread_create(&worker_thread, NULL, worker, NULL);

        // Feed workers work, blocking if workers fall behind
        char *foo = "moo";
        for (int i=0; i < 20; i++)
                queue_enq(q, foo);

        // Signal workers to quit
        queue_enq(q, NULL);

        // Wait for workers to exit, then free the queue
        pthread_join(worker_thread, NULL);

        return 0;
Listing of /files/c/thrqueue/
FilenameFilesizeLast Modified
thrqueue.c6.39k2009-02-19 01:02
thrqueue.h0.76k2009-02-19 11:02