/* 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.

 */

/* This test does not pretend to be cross-platform. */

#ifndef _WIN32

#include "uv.h"

#include "task.h"

#include <errno.h>

#include <signal.h>

#include <stdarg.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

/* The value of NUM_SIGNAL_HANDLING_THREADS is not arbitrary; it needs to be a

 * multiple of three for reasons that will become clear when you scroll down.

 * We're basically creating three different thread groups.  The total needs

 * to be divisible by three in order for the numbers in the final check to

 * match up.

 */

#define NUM_SIGNAL_HANDLING_THREADS 24

#define NUM_LOOP_CREATING_THREADS 10

enum signal_action {

  ONLY_SIGUSR1,

  ONLY_SIGUSR2,

  SIGUSR1_AND_SIGUSR2

};

static uv_sem_t sem;

static uv_mutex_t counter_lock;

static volatile int stop = 0;

static volatile int signal1_cb_counter = 0;

static volatile int signal2_cb_counter = 0;

static volatile int loop_creation_counter = 0;

static void increment_counter(volatile int* counter) {

  uv_mutex_lock(&counter_lock);

  ++(*counter);

  uv_mutex_unlock(&counter_lock);

}

static void signal1_cb(uv_signal_t* handle, int signum) {

  ASSERT(signum == SIGUSR1);

  increment_counter(&signal1_cb_counter);

  uv_signal_stop(handle);

}

static void signal2_cb(uv_signal_t* handle, int signum) {

  ASSERT(signum == SIGUSR2);

  increment_counter(&signal2_cb_counter);

  uv_signal_stop(handle);

}

static void signal_handling_worker(void* context) {

  enum signal_action action;

  uv_signal_t signal1a;

  uv_signal_t signal1b;

  uv_signal_t signal2;

  uv_loop_t loop;

  int r;

  action = (enum signal_action) (uintptr_t) context;

  ASSERT(0 == uv_loop_init(&loop);;

  /* Setup the signal watchers and start them. */

  if (action == ONLY_SIGUSR1 || action == SIGUSR1_AND_SIGUSR2) {

    r = uv_signal_init(&loop, &signal1a);

    ASSERT(r == 0);

    r = uv_signal_start(&signal1a, signal1_cb, SIGUSR1);

    ASSERT(r == 0);

    r = uv_signal_init(&loop, &signal1b);

    ASSERT(r == 0);

    r = uv_signal_start(&signal1b, signal1_cb, SIGUSR1);

    ASSERT(r == 0);

  }

  if (action == ONLY_SIGUSR2 || action == SIGUSR1_AND_SIGUSR2) {

    r = uv_signal_init(&loop, &signal2);

    ASSERT(r == 0);

    r = uv_signal_start(&signal2, signal2_cb, SIGUSR2);

    ASSERT(r == 0);

  }

  /* Signal watchers are now set up. */

  uv_sem_post(&sem);

  /* Wait for all signals. The signal callbacks stop the watcher, so uv_run

   * will return when all signal watchers caught a signal.

   */

  r = uv_run(&loop, UV_RUN_DEFAULT);

  ASSERT(r == 0);

  /* Restart the signal watchers. */

  if (action == ONLY_SIGUSR1 || action == SIGUSR1_AND_SIGUSR2) {

    r = uv_signal_start(&signal1a, signal1_cb, SIGUSR1);

    ASSERT(r == 0);

    r = uv_signal_start(&signal1b, signal1_cb, SIGUSR1);

    ASSERT(r == 0);

  }

  if (action == ONLY_SIGUSR2 || action == SIGUSR1_AND_SIGUSR2) {

    r = uv_signal_start(&signal2, signal2_cb, SIGUSR2);

    ASSERT(r == 0);

  }

  /* Wait for signals once more. */

  uv_sem_post(&sem);

  r = uv_run(&loop, UV_RUN_DEFAULT);

  ASSERT(r == 0);

  /* Close the watchers. */

  if (action == ONLY_SIGUSR1 || action == SIGUSR1_AND_SIGUSR2) {

    uv_close((uv_handle_t*) &signal1a, NULL);

    uv_close((uv_handle_t*) &signal1b, NULL);

  }

  if (action == ONLY_SIGUSR2 || action == SIGUSR1_AND_SIGUSR2) {

    uv_close((uv_handle_t*) &signal2, NULL);

  }

  /* Wait for the signal watchers to close. */

  r = uv_run(&loop, UV_RUN_DEFAULT);

  ASSERT(r == 0);

  uv_loop_close(&loop);

}

static void signal_unexpected_cb(uv_signal_t* handle, int signum) {

  ASSERT(0 && "signal_unexpected_cb should never be called");

}

static void loop_creating_worker(void* context) {

  (void) context;

  do {

    uv_loop_t *loop;

    uv_signal_t signal;

    int r;

    loop = malloc(sizeof(*loop));

    ASSERT(loop != NULL);

    ASSERT(0 == uv_loop_init(loop));

    r = uv_signal_init(loop, &signal);

    ASSERT(r == 0);

    r = uv_signal_start(&signal, signal_unexpected_cb, SIGTERM);

    ASSERT(r == 0);

    uv_close((uv_handle_t*) &signal, NULL);

    r = uv_run(loop, UV_RUN_DEFAULT);

    ASSERT(r == 0);

    uv_loop_close(loop);

    free(loop);

    increment_counter(&loop_creation_counter);

  } while (!stop);

}

TEST_IMPL(signal_multiple_loops) {

#if defined(__CYGWIN__) || defined(__MSYS__)

  /* FIXME: This test needs more investigation.  Somehow the `read` in

     uv__signal_lock fails spuriously with EACCES or even EAGAIN even

     though it is supposed to be blocking.  Also the test hangs during

     thread setup occasionally.  */

  RETURN_SKIP("FIXME: This test needs more investigation on Cygwin");

#endif

  uv_thread_t loop_creating_threads[NUM_LOOP_CREATING_THREADS];

  uv_thread_t signal_handling_threads[NUM_SIGNAL_HANDLING_THREADS];

  enum signal_action action;

  sigset_t sigset;

  int i;

  int r;

  r = uv_sem_init(&sem, 0);

  ASSERT(r == 0);

  r = uv_mutex_init(&counter_lock);

  ASSERT(r == 0);

  /* Create a couple of threads that create a destroy loops continuously. */

  for (i = 0; i < NUM_LOOP_CREATING_THREADS; i++) {

    r = uv_thread_create(&loop_creating_threads[i],

                         loop_creating_worker,

                         NULL);

    ASSERT(r == 0);

  }

  /* Create a couple of threads that actually handle signals. */

  for (i = 0; i < NUM_SIGNAL_HANDLING_THREADS; i++) {

    switch (i % 3) {

      case 0: action = ONLY_SIGUSR1; break;

      case 1: action = ONLY_SIGUSR2; break;

      case 2: action = SIGUSR1_AND_SIGUSR2; break;

    }

    r = uv_thread_create(&signal_handling_threads[i],

                         signal_handling_worker,

                         (void*) (uintptr_t) action);

    ASSERT(r == 0);

  }

  /* Wait until all threads have started and set up their signal watchers. */

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

    uv_sem_wait(&sem);

  r = kill(getpid(), SIGUSR1);

  ASSERT(r == 0);

  r = kill(getpid(), SIGUSR2);

  ASSERT(r == 0);

  /* Wait for all threads to handle these signals. */

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

    uv_sem_wait(&sem);

  /* Block all signals to this thread, so we are sure that from here the signal

   * handler runs in another thread. This is more likely to catch thread and

   * signal safety issues if there are any.

   */

  sigfillset(&sigset);

  pthread_sigmask(SIG_SETMASK, &sigset, NULL);

  r = kill(getpid(), SIGUSR1);

  ASSERT(r == 0);

  r = kill(getpid(), SIGUSR2);

  ASSERT(r == 0);

  /* Wait for all signal handling threads to exit. */

  for (i = 0; i < NUM_SIGNAL_HANDLING_THREADS; i++) {

    r = uv_thread_join(&signal_handling_threads[i]);

    ASSERT(r == 0);

  }

  /* Tell all loop creating threads to stop. */

  stop = 1;

  /* Wait for all loop creating threads to exit. */

  for (i = 0; i < NUM_LOOP_CREATING_THREADS; i++) {

    r = uv_thread_join(&loop_creating_threads[i]);

    ASSERT(r == 0);

  }

  uv_sem_destroy(&sem);

  printf("signal1_cb calls: %d\n", signal1_cb_counter);

  printf("signal2_cb calls: %d\n", signal2_cb_counter);

  printf("loops created and destroyed: %d\n", loop_creation_counter);

  /* The division by three reflects the fact that we spawn three different

   * thread groups of (NUM_SIGNAL_HANDLING_THREADS / 3) threads each.

   */

  ASSERT(signal1_cb_counter == 8 * (NUM_SIGNAL_HANDLING_THREADS / 3));

  ASSERT(signal2_cb_counter == 4 * (NUM_SIGNAL_HANDLING_THREADS / 3));

  /* We don't know exactly how much loops will be created and destroyed, but at

   * least there should be 1 for every loop creating thread.

   */

  ASSERT(loop_creation_counter >= NUM_LOOP_CREATING_THREADS);

  MAKE_VALGRIND_HAPPY();

  return 0;

}

#else

typedef int file_has_no_tests; /* ISO C forbids an empty translation unit. */

#endif /* !_WIN32 */