/* Copyright The libuv project and 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 <string.h>

/*

 * The idea behind the test is as follows.

 * Certain handle types are stored in a queue internally.

 * Extra care should be taken for removal of a handle from the queue while iterating over the queue.

 * (i.e., QUEUE_REMOVE() called within QUEUE_FOREACH())

 * This usually happens when someone closes or stops a handle from within its callback.

 * So we need to check that we haven't screwed the queue on close/stop.

 * To do so we do the following (for each handle type):

 *  1. Create and start 3 handles (#0, #1, and #2).

 *

 *     The queue after the start() calls:

 *     ..=> [queue head] <=> [handle] <=> [handle #1] <=> [handle] <=..

 *

 *  2. Trigger handles to fire (for uv_idle_t, uv_prepare_t, and uv_check_t there is nothing to do).

 *

 *  3. In the callback for the first-executed handle (#0 or #2 depending on handle type)

 *     stop the handle and the next one (#1).

 *     (for uv_idle_t, uv_prepare_t, and uv_check_t callbacks are executed in the reverse order as they are start()'ed,

 *     so callback for handle #2 will be called first)

 *

 *     The queue after the stop() calls:

 *                                correct foreach "next"  |

 *                                                       \/

 *     ..=> [queue head] <==============================> [handle] <=..

 *          [          ] <-  [handle] <=> [handle #1]  -> [      ]

 *                                       /\

 *                  wrong foreach "next"  |

 *

 *  4. The callback for handle #1 shouldn't be called because the handle #1 is stopped in the previous step.

 *     However, if QUEUE_REMOVE() is not handled properly within QUEUE_FOREACH(), the callback _will_ be called.

 */

static const unsigned first_handle_number_idle     = 2;

static const unsigned first_handle_number_prepare  = 2;

static const unsigned first_handle_number_check    = 2;

#ifdef __linux__

static const unsigned first_handle_number_fs_event = 0;

#endif

#define DEFINE_GLOBALS_AND_CBS(name, ...)                                     \

  static uv_##name##_t (name)[3];                                             \

  static unsigned name##_cb_calls[3];                                         \

                                                                              \

  static void name##2_cb(__VA_ARGS__) {                                       \

    ASSERT(handle == &(name)[2]);                                             \

    if (first_handle_number_##name == 2) {                                    \

      uv_close((uv_handle_t*)&(name)[2], NULL);                               \

      uv_close((uv_handle_t*)&(name)[1], NULL);                               \

    }                                                                         \

    name##_cb_calls[2]++;                                                     \

  }                                                                           \

                                                                              \

  static void name##1_cb(__VA_ARGS__) {                                       \

    ASSERT(handle == &(name)[1]);                                             \

    ASSERT(0 && "Shouldn't be called" && (&name[0]));                         \

  }                                                                           \

                                                                              \

  static void name##0_cb(__VA_ARGS__) {                                       \

    ASSERT(handle == &(name)[0]);                                             \

    if (first_handle_number_##name == 0) {                                    \

      uv_close((uv_handle_t*)&(name)[0], NULL);                               \

      uv_close((uv_handle_t*)&(name)[1], NULL);                               \

    }                                                                         \

    name##_cb_calls[0]++;                                                     \

  }                                                                           \

                                                                              \

  static const uv_##name##_cb name##_cbs[] = {                                \

    name##0_cb,                                                               \

    name##1_cb,                                                               \

    name##2_cb,                                                               \

  };

#define INIT_AND_START(name, loop)                                            \

  do {                                                                        \

    size_t i;                                                                 \

    for (i = 0; i < ARRAY_SIZE(name); i++) {                                  \

      int r;                                                                  \

      r = uv_##name##_init((loop), &(name)[i]);                               \

      ASSERT(r == 0);                                                         \

                                                                              \

      r = uv_##name##_start(&(name)[i], name##_cbs[i]);                       \

      ASSERT(r == 0);                                                         \

    }                                                                         \

  } while (0)

#define END_ASSERTS(name)                                                     \

  do {                                                                        \

    ASSERT(name##_cb_calls[0] == 1);                                          \

    ASSERT(name##_cb_calls[1] == 0);                                          \

    ASSERT(name##_cb_calls[2] == 1);                                          \

  } while (0)

DEFINE_GLOBALS_AND_CBS(idle, uv_idle_t* handle)

DEFINE_GLOBALS_AND_CBS(prepare, uv_prepare_t* handle)

DEFINE_GLOBALS_AND_CBS(check, uv_check_t* handle)

#ifdef __linux__

DEFINE_GLOBALS_AND_CBS(fs_event,

                       uv_fs_event_t* handle,

                       const char* filename,

                       int events,

                       int status)

static const char watched_dir[] = ".";

static uv_timer_t timer;

static unsigned helper_timer_cb_calls;

static void init_and_start_fs_events(uv_loop_t* loop) {

  size_t i;

  for (i = 0; i < ARRAY_SIZE(fs_event); i++) {

    int r;

    r = uv_fs_event_init(loop, &fs_event[i]);

    ASSERT(r == 0);

    r = uv_fs_event_start(&fs_event[i],

                          (uv_fs_event_cb)fs_event_cbs[i],

                          watched_dir,

                          0);

    ASSERT(r == 0);

  }

}

static void helper_timer_cb(uv_timer_t* thandle) {

  int r;

  uv_fs_t fs_req;

  /* fire all fs_events */

  r = uv_fs_utime(thandle->loop, &fs_req, watched_dir, 0, 0, NULL);

  ASSERT(r == 0);

  ASSERT(fs_req.result == 0);

  ASSERT(fs_req.fs_type == UV_FS_UTIME);

  ASSERT(strcmp(fs_req.path, watched_dir) == 0);

  uv_fs_req_cleanup(&fs_req);

  helper_timer_cb_calls++;

}

#endif

TEST_IMPL(queue_foreach_delete) {

  uv_loop_t* loop;

  int r;

  loop = uv_default_loop();

  INIT_AND_START(idle,    loop);

  INIT_AND_START(prepare, loop);

  INIT_AND_START(check,   loop);

#ifdef __linux__

  init_and_start_fs_events(loop);

  /* helper timer to trigger async and fs_event callbacks */

  r = uv_timer_init(loop, &timer;;

  ASSERT(r == 0);

  r = uv_timer_start(&timer, helper_timer_cb, 0, 0);

  ASSERT(r == 0);

#endif

  r = uv_run(loop, UV_RUN_NOWAIT);

  ASSERT(r == 1);

  END_ASSERTS(idle);

  END_ASSERTS(prepare);

  END_ASSERTS(check);

#ifdef __linux__

  ASSERT(helper_timer_cb_calls == 1);

#endif

  MAKE_VALGRIND_HAPPY();

  return 0;

}