/* 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 "task.h"

#include "uv.h"

#include <stdio.h>

#include <stdlib.h>

#define NUM_PINGS               (1000 * 1000)

#define ACCESS_ONCE(type, var)  (*(volatile type*) &(var))

static unsigned int callbacks;

static volatile int done;

static const char running[] = "running";

static const char stop[]    = "stop";

static const char stopped[] = "stopped";

static void async_cb(uv_async_t* handle) {

  if (++callbacks == NUM_PINGS) {

    /* Tell the pummel thread to stop. */

    ACCESS_ONCE(const char*, handle->data) = stop;

    /* Wait for the pummel thread to acknowledge that it has stoppped. */

    while (ACCESS_ONCE(const char*, handle->data) != stopped)

      uv_sleep(0);

    uv_close((uv_handle_t*) handle, NULL);

  }

}

static void pummel(void* arg) {

  uv_async_t* handle = (uv_async_t*) arg;

  while (ACCESS_ONCE(const char*, handle->data) == running)

    uv_async_send(handle);

  /* Acknowledge that we've seen handle->data change. */

  ACCESS_ONCE(const char*, handle->data) = stopped;

}

static int test_async_pummel(int nthreads) {

  uv_thread_t* tids;

  uv_async_t handle;

  uint64_t time;

  int i;

  tids = calloc(nthreads, sizeof(tids[0]));

  ASSERT(tids != NULL);

  ASSERT(0 == uv_async_init(uv_default_loop(), &handle, async_cb));

  ACCESS_ONCE(const char*, handle.data) = running;

  for (i = 0; i < nthreads; i++)

    ASSERT(0 == uv_thread_create(tids + i, pummel, &handle));

  time = uv_hrtime();

  ASSERT(0 == uv_run(uv_default_loop(), UV_RUN_DEFAULT));

  time = uv_hrtime() - time;

  done = 1;

  for (i = 0; i < nthreads; i++)

    ASSERT(0 == uv_thread_join(tids + i));

  printf("async_pummel_%d: %s callbacks in %.2f seconds (%s/sec)\n",

         nthreads,

         fmt(callbacks),

         time / 1e9,

         fmt(callbacks / (time / 1e9)));

  free(tids);

  MAKE_VALGRIND_HAPPY();

  return 0;

}

BENCHMARK_IMPL(async_pummel_1) {

  return test_async_pummel(1);

}

BENCHMARK_IMPL(async_pummel_2) {

  return test_async_pummel(2);

}

BENCHMARK_IMPL(async_pummel_4) {

  return test_async_pummel(4);

}

BENCHMARK_IMPL(async_pummel_8) {

  return test_async_pummel(8);

}