/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to

 * deal in the Software without restriction, including without limitation the

 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or

 * sell copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS

 * IN THE SOFTWARE.

 */

#include "uv.h"

#include "task.h"

#include <stdio.h>

#include <stdlib.h>

static uv_thread_t thread;

static uv_mutex_t mutex;

static uv_prepare_t prepare;

static uv_async_t async;

static volatile int async_cb_called;

static int prepare_cb_called;

static int close_cb_called;

static void thread_cb(void *arg) {

  int n;

  int r;

  for (;;) {

    uv_mutex_lock(&mutex);

    n = async_cb_called;

    uv_mutex_unlock(&mutex);

    if (n == 3) {

      break;

    }

    r = uv_async_send(&async);

    ASSERT(r == 0);

    /* Work around a bug in Valgrind.

     *

     * Valgrind runs threads not in parallel but sequentially, i.e. one after

     * the other. It also doesn't preempt them, instead it depends on threads

     * yielding voluntarily by making a syscall.

     *

     * That never happens here: the pipe that is associated with the async

     * handle is written to once but that's too early for Valgrind's scheduler

     * to kick in. Afterwards, the thread busy-loops, starving the main thread.

     * Therefore, we yield.

     *

     * This behavior has been observed with Valgrind 3.7.0 and 3.9.0.

     */

    uv_sleep(0);

  }

}

static void close_cb(uv_handle_t* handle) {

  ASSERT(handle != NULL);

  close_cb_called++;

}

static void async_cb(uv_async_t* handle) {

  int n;

  ASSERT(handle == &async);

  uv_mutex_lock(&mutex);

  n = ++async_cb_called;

  uv_mutex_unlock(&mutex);

  if (n == 3) {

    uv_close((uv_handle_t*)&async, close_cb);

    uv_close((uv_handle_t*)&prepare, close_cb);

  }

}

static void prepare_cb(uv_prepare_t* handle) {

  int r;

  ASSERT(handle == &prepare);

  if (prepare_cb_called++)

    return;

  r = uv_thread_create(&thread, thread_cb, NULL);

  ASSERT(r == 0);

  uv_mutex_unlock(&mutex);

}

TEST_IMPL(async) {

  int r;

  r = uv_mutex_init(&mutex);

  ASSERT(r == 0);

  uv_mutex_lock(&mutex);

  r = uv_prepare_init(uv_default_loop(), &prepare);

  ASSERT(r == 0);

  r = uv_prepare_start(&prepare, prepare_cb);

  ASSERT(r == 0);

  r = uv_async_init(uv_default_loop(), &async, async_cb);

  ASSERT(r == 0);

  r = uv_run(uv_default_loop(), UV_RUN_DEFAULT);

  ASSERT(r == 0);

  ASSERT(prepare_cb_called > 0);

  ASSERT(async_cb_called == 3);

  ASSERT(close_cb_called == 2);

  ASSERT(0 == uv_thread_join(&thread));

  MAKE_VALGRIND_HAPPY();

  return 0;

}