Mercurial > urweb
view src/c/queue.c @ 1361:7a436b6267ab
Fix soundness bug in Effectize, where it missed some functions that might have effectful RPCs
author | Adam Chlipala <adam@chlipala.net> |
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date | Thu, 23 Dec 2010 18:07:05 -0500 |
parents | 452b14d88a10 |
children |
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#include "config.h" #include <stdlib.h> #include <pthread.h> typedef struct node { int fd; struct node *next; } *node; static node front = NULL, back = NULL; static int empty() { return front == NULL; } static void enqueue(int fd) { node n = malloc(sizeof(struct node)); n->fd = fd; n->next = NULL; if (back) back->next = n; else front = n; back = n; } static int dequeue() { int ret = front->fd; node n = front->next; free(front); front = n; if (!front) back = NULL; return ret; } static pthread_mutex_t queue_mutex = PTHREAD_MUTEX_INITIALIZER; static pthread_cond_t queue_cond = PTHREAD_COND_INITIALIZER; int uw_dequeue() { int sock; pthread_mutex_lock(&queue_mutex); while (empty()) pthread_cond_wait(&queue_cond, &queue_mutex); sock = dequeue(); pthread_mutex_unlock(&queue_mutex); return sock; } void uw_enqueue(int new_fd) { pthread_mutex_lock(&queue_mutex); enqueue(new_fd); pthread_cond_broadcast(&queue_cond); pthread_mutex_unlock(&queue_mutex); }