test-semaphore.c

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/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
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 * The above copyright notice and this permission notice shall be included in
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#include "uv.h"
#include "task.h"
 
#include <stdlib.h>
#include <string.h>
 
typedef struct {
  uv_mutex_t mutex;
  uv_sem_t sem;
  int delay;
  volatile int posted;
} worker_config;
 
 
static void worker(void* arg) {
  worker_config* c = arg;
 
  if (c->delay)
    uv_sleep(c->delay);
 
  uv_mutex_lock(&c->mutex);
  ASSERT(c->posted == 0);
  uv_sem_post(&c->sem);
  c->posted = 1;
  uv_mutex_unlock(&c->mutex);
}
 
 
TEST_IMPL(semaphore_1) {
  uv_thread_t thread;
  worker_config wc;
 
  memset(&wc, 0, sizeof(wc));
 
  ASSERT(0 == uv_sem_init(&wc.sem, 0));
  ASSERT(0 == uv_mutex_init(&wc.mutex));
  ASSERT(0 == uv_thread_create(&thread, worker, &wc));
 
  uv_sleep(100);
  uv_mutex_lock(&wc.mutex);
  ASSERT(wc.posted == 1);
  uv_sem_wait(&wc.sem); /* should not block */
  uv_mutex_unlock(&wc.mutex); /* ergo, it should be ok to unlock after wait */
 
  ASSERT(0 == uv_thread_join(&thread));
  uv_mutex_destroy(&wc.mutex);
  uv_sem_destroy(&wc.sem);
 
  return 0;
}
 
 
TEST_IMPL(semaphore_2) {
  uv_thread_t thread;
  worker_config wc;
 
  memset(&wc, 0, sizeof(wc));
  wc.delay = 100;
 
  ASSERT(0 == uv_sem_init(&wc.sem, 0));
  ASSERT(0 == uv_mutex_init(&wc.mutex));
  ASSERT(0 == uv_thread_create(&thread, worker, &wc));
 
  uv_sem_wait(&wc.sem);
 
  ASSERT(0 == uv_thread_join(&thread));
  uv_mutex_destroy(&wc.mutex);
  uv_sem_destroy(&wc.sem);
 
  return 0;
}
 
 
TEST_IMPL(semaphore_3) {
  uv_sem_t sem;
 
  ASSERT(0 == uv_sem_init(&sem, 3));
  uv_sem_wait(&sem); /* should not block */
  uv_sem_wait(&sem); /* should not block */
  ASSERT(0 == uv_sem_trywait(&sem));
  ASSERT(UV_EAGAIN == uv_sem_trywait(&sem));
 
  uv_sem_post(&sem);
  ASSERT(0 == uv_sem_trywait(&sem));
  ASSERT(UV_EAGAIN == uv_sem_trywait(&sem));
 
  uv_sem_destroy(&sem);
 
  return 0;
}