/* 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 <assert.h>

#include <errno.h>

#include <limits.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#if defined(_MSC_VER) || defined(__MINGW64_VERSION_MAJOR)

#include <crtdbg.h>

#endif

#include "uv.h"

#include "internal.h"

#include "queue.h"

#include "handle-inl.h"

#include "heap-inl.h"

#include "req-inl.h"

/* uv_once initialization guards */

static uv_once_t uv_init_guard_ = UV_ONCE_INIT;

#if defined(_DEBUG) && (defined(_MSC_VER) || defined(__MINGW64_VERSION_MAJOR))

/* Our crt debug report handler allows us to temporarily disable asserts

 * just for the current thread.

 */

UV_THREAD_LOCAL int uv__crt_assert_enabled = TRUE;

static int uv__crt_dbg_report_handler(int report_type, char *message, int *ret_val) {

  if (uv__crt_assert_enabled || report_type != _CRT_ASSERT)

    return FALSE;

  if (ret_val) {

    /* Set ret_val to 0 to continue with normal execution.

     * Set ret_val to 1 to trigger a breakpoint.

    */

    if(IsDebuggerPresent())

      *ret_val = 1;

    else

      *ret_val = 0;

  }

  /* Don't call _CrtDbgReport. */

  return TRUE;

}

#else

UV_THREAD_LOCAL int uv__crt_assert_enabled = FALSE;

#endif

#if !defined(__MINGW32__) || __MSVCRT_VERSION__ >= 0x800

static void uv__crt_invalid_parameter_handler(const wchar_t* expression,

    const wchar_t* function, const wchar_t * file, unsigned int line,

    uintptr_t reserved) {

  /* No-op. */

}

#endif

static uv_loop_t** uv__loops;

static int uv__loops_size;

static int uv__loops_capacity;

#define UV__LOOPS_CHUNK_SIZE 8

static uv_mutex_t uv__loops_lock;

static void uv__loops_init(void) {

  uv_mutex_init(&uv__loops_lock);

}

static int uv__loops_add(uv_loop_t* loop) {

  uv_loop_t** new_loops;

  int new_capacity, i;

  uv_mutex_lock(&uv__loops_lock);

  if (uv__loops_size == uv__loops_capacity) {

    new_capacity = uv__loops_capacity + UV__LOOPS_CHUNK_SIZE;

    new_loops = uv__realloc(uv__loops, sizeof(uv_loop_t*) * new_capacity);

    if (!new_loops)

      goto failed_loops_realloc;

    uv__loops = new_loops;

    for (i = uv__loops_capacity; i < new_capacity; ++i)

      uv__loops[i] = NULL;

    uv__loops_capacity = new_capacity;

  }

  uv__loops[uv__loops_size] = loop;

  ++uv__loops_size;

  uv_mutex_unlock(&uv__loops_lock);

  return 0;

failed_loops_realloc:

  uv_mutex_unlock(&uv__loops_lock);

  return ERROR_OUTOFMEMORY;

}

static void uv__loops_remove(uv_loop_t* loop) {

  int loop_index;

  int smaller_capacity;

  uv_loop_t** new_loops;

  uv_mutex_lock(&uv__loops_lock);

  for (loop_index = 0; loop_index < uv__loops_size; ++loop_index) {

    if (uv__loops[loop_index] == loop)

      break;

  }

  /* If loop was not found, ignore */

  if (loop_index == uv__loops_size)

    goto loop_removed;

  uv__loops[loop_index] = uv__loops[uv__loops_size - 1];

  uv__loops[uv__loops_size - 1] = NULL;

  --uv__loops_size;

  if (uv__loops_size == 0) {

    uv__loops_capacity = 0;

    uv__free(uv__loops);

    uv__loops = NULL;

    goto loop_removed;

  }

  /* If we didn't grow to big skip downsizing */

  if (uv__loops_capacity < 4 * UV__LOOPS_CHUNK_SIZE)

    goto loop_removed;

  /* Downsize only if more than half of buffer is free */

  smaller_capacity = uv__loops_capacity / 2;

  if (uv__loops_size >= smaller_capacity)

    goto loop_removed;

  new_loops = uv__realloc(uv__loops, sizeof(uv_loop_t*) * smaller_capacity);

  if (!new_loops)

    goto loop_removed;

  uv__loops = new_loops;

  uv__loops_capacity = smaller_capacity;

loop_removed:

  uv_mutex_unlock(&uv__loops_lock);

}

void uv__wake_all_loops(void) {

  int i;

  uv_loop_t* loop;

  uv_mutex_lock(&uv__loops_lock);

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

    loop = uv__loops[i];

    assert(loop);

    if (loop->iocp != INVALID_HANDLE_VALUE)

      PostQueuedCompletionStatus(loop->iocp, 0, 0, NULL);

  }

  uv_mutex_unlock(&uv__loops_lock);

}

static void uv_init(void) {

  /* Tell Windows that we will handle critical errors. */

  SetErrorMode(SEM_FAILCRITICALERRORS | SEM_NOGPFAULTERRORBOX |

               SEM_NOOPENFILEERRORBOX);

  /* Tell the CRT to not exit the application when an invalid parameter is

   * passed. The main issue is that invalid FDs will trigger this behavior.

   */

#if !defined(__MINGW32__) || __MSVCRT_VERSION__ >= 0x800

  _set_invalid_parameter_handler(uv__crt_invalid_parameter_handler);

#endif

  /* We also need to setup our debug report handler because some CRT

   * functions (eg _get_osfhandle) raise an assert when called with invalid

   * FDs even though they return the proper error code in the release build.

   */

#if defined(_DEBUG) && (defined(_MSC_VER) || defined(__MINGW64_VERSION_MAJOR))

  _CrtSetReportHook(uv__crt_dbg_report_handler);

#endif

  /* Initialize tracking of all uv loops */

  uv__loops_init();

  /* Fetch winapi function pointers. This must be done first because other

   * initialization code might need these function pointers to be loaded.

   */

  uv_winapi_init();

  /* Initialize winsock */

  uv_winsock_init();

  /* Initialize FS */

  uv_fs_init();

  /* Initialize signal stuff */

  uv_signals_init();

  /* Initialize console */

  uv_console_init();

  /* Initialize utilities */

  uv__util_init();

  /* Initialize system wakeup detection */

  uv__init_detect_system_wakeup();

}

int uv_loop_init(uv_loop_t* loop) {

  uv__loop_internal_fields_t* lfields;

  struct heap* timer_heap;

  int err;

  /* Initialize libuv itself first */

  uv__once_init();

  /* Create an I/O completion port */

  loop->iocp = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 1);

  if (loop->iocp == NULL)

    return uv_translate_sys_error(GetLastError());

  lfields = (uv__loop_internal_fields_t*) uv__calloc(1, sizeof(*lfields));

  if (lfields == NULL)

    return UV_ENOMEM;

  loop->internal_fields = lfields;

  err = uv_mutex_init(&lfields->loop_metrics.lock);

  if (err)

    goto fail_metrics_mutex_init;

  /* To prevent uninitialized memory access, loop->time must be initialized

   * to zero before calling uv_update_time for the first time.

   */

  loop->time = 0;

  uv_update_time(loop);

  QUEUE_INIT(&loop->wq);

  QUEUE_INIT(&loop->handle_queue);

  loop->active_reqs.count = 0;

  loop->active_handles = 0;

  loop->pending_reqs_tail = NULL;

  loop->endgame_handles = NULL;

  loop->timer_heap = timer_heap = uv__malloc(sizeof(*timer_heap));

  if (timer_heap == NULL) {

    err = UV_ENOMEM;

    goto fail_timers_alloc;

  }

  heap_init(timer_heap);

  loop->check_handles = NULL;

  loop->prepare_handles = NULL;

  loop->idle_handles = NULL;

  loop->next_prepare_handle = NULL;

  loop->next_check_handle = NULL;

  loop->next_idle_handle = NULL;

  memset(&loop->poll_peer_sockets, 0, sizeof loop->poll_peer_sockets);

  loop->active_tcp_streams = 0;

  loop->active_udp_streams = 0;

  loop->timer_counter = 0;

  loop->stop_flag = 0;

  err = uv_mutex_init(&loop->wq_mutex);

  if (err)

    goto fail_mutex_init;

  err = uv_async_init(loop, &loop->wq_async, uv__work_done);

  if (err)

    goto fail_async_init;

  uv__handle_unref(&loop->wq_async);

  loop->wq_async.flags |= UV_HANDLE_INTERNAL;

  err = uv__loops_add(loop);

  if (err)

    goto fail_async_init;

  return 0;

fail_async_init:

  uv_mutex_destroy(&loop->wq_mutex);

fail_mutex_init:

  uv__free(timer_heap);

  loop->timer_heap = NULL;

fail_timers_alloc:

  uv_mutex_destroy(&lfields->loop_metrics.lock);

fail_metrics_mutex_init:

  uv__free(lfields);

  loop->internal_fields = NULL;

  CloseHandle(loop->iocp);

  loop->iocp = INVALID_HANDLE_VALUE;

  return err;

}

void uv_update_time(uv_loop_t* loop) {

  uint64_t new_time = uv__hrtime(1000);

  assert(new_time >= loop->time);

  loop->time = new_time;

}

void uv__once_init(void) {

  uv_once(&uv_init_guard_, uv_init);

}

void uv__loop_close(uv_loop_t* loop) {

  uv__loop_internal_fields_t* lfields;

  size_t i;

  uv__loops_remove(loop);

  /* Close the async handle without needing an extra loop iteration.

   * We might have a pending message, but we're just going to destroy the IOCP

   * soon, so we can just discard it now without the usual risk of a getting

   * another notification from GetQueuedCompletionStatusEx after calling the

   * close_cb (which we also skip defining). We'll assert later that queue was

   * actually empty and all reqs handled. */

  loop->wq_async.async_sent = 0;

  loop->wq_async.close_cb = NULL;

  uv__handle_closing(&loop->wq_async);

  uv__handle_close(&loop->wq_async);

  for (i = 0; i < ARRAY_SIZE(loop->poll_peer_sockets); i++) {

    SOCKET sock = loop->poll_peer_sockets[i];

    if (sock != 0 && sock != INVALID_SOCKET)

      closesocket(sock);

  }

  uv_mutex_lock(&loop->wq_mutex);

  assert(QUEUE_EMPTY(&loop->wq) && "thread pool work queue not empty!");

  assert(!uv__has_active_reqs(loop));

  uv_mutex_unlock(&loop->wq_mutex);

  uv_mutex_destroy(&loop->wq_mutex);

  uv__free(loop->timer_heap);

  loop->timer_heap = NULL;

  lfields = uv__get_internal_fields(loop);

  uv_mutex_destroy(&lfields->loop_metrics.lock);

  uv__free(lfields);

  loop->internal_fields = NULL;

  CloseHandle(loop->iocp);

}

int uv__loop_configure(uv_loop_t* loop, uv_loop_option option, va_list ap) {

  uv__loop_internal_fields_t* lfields;

  lfields = uv__get_internal_fields(loop);

  if (option == UV_METRICS_IDLE_TIME) {

    lfields->flags |= UV_METRICS_IDLE_TIME;

    return 0;

  }

  return UV_ENOSYS;

}

int uv_backend_fd(const uv_loop_t* loop) {

  return -1;

}

int uv_loop_fork(uv_loop_t* loop) {

  return UV_ENOSYS;

}

int uv_backend_timeout(const uv_loop_t* loop) {

  if (loop->stop_flag != 0)

    return 0;

  if (!uv__has_active_handles(loop) && !uv__has_active_reqs(loop))

    return 0;

  if (loop->pending_reqs_tail)

    return 0;

  if (loop->endgame_handles)

    return 0;

  if (loop->idle_handles)

    return 0;

  return uv__next_timeout(loop);

}

static void uv__poll_wine(uv_loop_t* loop, DWORD timeout) {

  DWORD bytes;

  ULONG_PTR key;

  OVERLAPPED* overlapped;

  uv_req_t* req;

  int repeat;

  uint64_t timeout_time;

  uint64_t user_timeout;

  int reset_timeout;

  timeout_time = loop->time + timeout;

  if (uv__get_internal_fields(loop)->flags & UV_METRICS_IDLE_TIME) {

    reset_timeout = 1;

    user_timeout = timeout;

    timeout = 0;

  } else {

    reset_timeout = 0;

  }

  for (repeat = 0; ; repeat++) {

    /* Only need to set the provider_entry_time if timeout != 0. The function

     * will return early if the loop isn't configured with UV_METRICS_IDLE_TIME.

     */

    if (timeout != 0)

      uv__metrics_set_provider_entry_time(loop);

    GetQueuedCompletionStatus(loop->iocp,

                              &bytes,

                              &key,

                              &overlapped,

                              timeout);

    if (reset_timeout != 0) {

      timeout = user_timeout;

      reset_timeout = 0;

    }

    /* Placed here because on success the loop will break whether there is an

     * empty package or not, or if GetQueuedCompletionStatus returned early then

     * the timeout will be updated and the loop will run again. In either case

     * the idle time will need to be updated.

     */

    uv__metrics_update_idle_time(loop);

    if (overlapped) {

      /* Package was dequeued */

      req = uv_overlapped_to_req(overlapped);

      uv_insert_pending_req(loop, req);

      /* Some time might have passed waiting for I/O,

       * so update the loop time here.

       */

      uv_update_time(loop);

    } else if (GetLastError() != WAIT_TIMEOUT) {

      /* Serious error */

      uv_fatal_error(GetLastError(), "GetQueuedCompletionStatus");

    } else if (timeout > 0) {

      /* GetQueuedCompletionStatus can occasionally return a little early.

       * Make sure that the desired timeout target time is reached.

       */

      uv_update_time(loop);

      if (timeout_time > loop->time) {

        timeout = (DWORD)(timeout_time - loop->time);

        /* The first call to GetQueuedCompletionStatus should return very

         * close to the target time and the second should reach it, but

         * this is not stated in the documentation. To make sure a busy

         * loop cannot happen, the timeout is increased exponentially

         * starting on the third round.

         */

        timeout += repeat ? (1 << (repeat - 1)) : 0;

        continue;

      }

    }

    break;

  }

}

static void uv__poll(uv_loop_t* loop, DWORD timeout) {

  BOOL success;

  uv_req_t* req;

  OVERLAPPED_ENTRY overlappeds[128];

  ULONG count;

  ULONG i;

  int repeat;

  uint64_t timeout_time;

  uint64_t user_timeout;

  int reset_timeout;

  timeout_time = loop->time + timeout;

  if (uv__get_internal_fields(loop)->flags & UV_METRICS_IDLE_TIME) {

    reset_timeout = 1;

    user_timeout = timeout;

    timeout = 0;

  } else {

    reset_timeout = 0;

  }

  for (repeat = 0; ; repeat++) {

    /* Only need to set the provider_entry_time if timeout != 0. The function

     * will return early if the loop isn't configured with UV_METRICS_IDLE_TIME.

     */

    if (timeout != 0)

      uv__metrics_set_provider_entry_time(loop);

    success = pGetQueuedCompletionStatusEx(loop->iocp,

                                           overlappeds,

                                           ARRAY_SIZE(overlappeds),

                                           &count,

                                           timeout,

                                           FALSE);

    if (reset_timeout != 0) {

      timeout = user_timeout;

      reset_timeout = 0;

    }

    /* Placed here because on success the loop will break whether there is an

     * empty package or not, or if GetQueuedCompletionStatus returned early then

     * the timeout will be updated and the loop will run again. In either case

     * the idle time will need to be updated.

     */

    uv__metrics_update_idle_time(loop);

    if (success) {

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

        /* Package was dequeued, but see if it is not a empty package

         * meant only to wake us up.

         */

        if (overlappeds[i].lpOverlapped) {

          req = uv_overlapped_to_req(overlappeds[i].lpOverlapped);

          uv_insert_pending_req(loop, req);

        }

      }

      /* Some time might have passed waiting for I/O,

       * so update the loop time here.

       */

      uv_update_time(loop);

    } else if (GetLastError() != WAIT_TIMEOUT) {

      /* Serious error */

      uv_fatal_error(GetLastError(), "GetQueuedCompletionStatusEx");

    } else if (timeout > 0) {

      /* GetQueuedCompletionStatus can occasionally return a little early.

       * Make sure that the desired timeout target time is reached.

       */

      uv_update_time(loop);

      if (timeout_time > loop->time) {

        timeout = (DWORD)(timeout_time - loop->time);

        /* The first call to GetQueuedCompletionStatus should return very

         * close to the target time and the second should reach it, but

         * this is not stated in the documentation. To make sure a busy

         * loop cannot happen, the timeout is increased exponentially

         * starting on the third round.

         */

        timeout += repeat ? (1 << (repeat - 1)) : 0;

        continue;

      }

    }

    break;

  }

}

static int uv__loop_alive(const uv_loop_t* loop) {

  return uv__has_active_handles(loop) ||

         uv__has_active_reqs(loop) ||

         loop->endgame_handles != NULL;

}

int uv_loop_alive(const uv_loop_t* loop) {

    return uv__loop_alive(loop);

}

int uv_run(uv_loop_t *loop, uv_run_mode mode) {

  DWORD timeout;

  int r;

  int ran_pending;

  r = uv__loop_alive(loop);

  if (!r)

    uv_update_time(loop);

  while (r != 0 && loop->stop_flag == 0) {

    uv_update_time(loop);

    uv__run_timers(loop);

    ran_pending = uv_process_reqs(loop);

    uv_idle_invoke(loop);

    uv_prepare_invoke(loop);

    timeout = 0;

    if ((mode == UV_RUN_ONCE && !ran_pending) || mode == UV_RUN_DEFAULT)

      timeout = uv_backend_timeout(loop);

    if (pGetQueuedCompletionStatusEx)

      uv__poll(loop, timeout);

    else

      uv__poll_wine(loop, timeout);

    /* Run one final update on the provider_idle_time in case uv__poll*

     * returned because the timeout expired, but no events were received. This

     * call will be ignored if the provider_entry_time was either never set (if

     * the timeout == 0) or was already updated b/c an event was received.

     */

    uv__metrics_update_idle_time(loop);

    uv_check_invoke(loop);

    uv_process_endgames(loop);

    if (mode == UV_RUN_ONCE) {

      /* UV_RUN_ONCE implies forward progress: at least one callback must have

       * been invoked when it returns. uv__io_poll() can return without doing

       * I/O (meaning: no callbacks) when its timeout expires - which means we

       * have pending timers that satisfy the forward progress constraint.

       *

       * UV_RUN_NOWAIT makes no guarantees about progress so it's omitted from

       * the check.

       */

      uv__run_timers(loop);

    }

    r = uv__loop_alive(loop);

    if (mode == UV_RUN_ONCE || mode == UV_RUN_NOWAIT)

      break;

  }

  /* The if statement lets the compiler compile it to a conditional store.

   * Avoids dirtying a cache line.

   */

  if (loop->stop_flag != 0)

    loop->stop_flag = 0;

  return r;

}

int uv_fileno(const uv_handle_t* handle, uv_os_fd_t* fd) {

  uv_os_fd_t fd_out;

  switch (handle->type) {

  case UV_TCP:

    fd_out = (uv_os_fd_t)((uv_tcp_t*) handle)->socket;

    break;

  case UV_NAMED_PIPE:

    fd_out = ((uv_pipe_t*) handle)->handle;

    break;

  case UV_TTY:

    fd_out = ((uv_tty_t*) handle)->handle;

    break;

  case UV_UDP:

    fd_out = (uv_os_fd_t)((uv_udp_t*) handle)->socket;

    break;

  case UV_POLL:

    fd_out = (uv_os_fd_t)((uv_poll_t*) handle)->socket;

    break;

  default:

    return UV_EINVAL;

  }

  if (uv_is_closing(handle) || fd_out == INVALID_HANDLE_VALUE)

    return UV_EBADF;

  *fd = fd_out;

  return 0;

}

int uv__socket_sockopt(uv_handle_t* handle, int optname, int* value) {

  int r;

  int len;

  SOCKET socket;

  if (handle == NULL || value == NULL)

    return UV_EINVAL;

  if (handle->type == UV_TCP)

    socket = ((uv_tcp_t*) handle)->socket;

  else if (handle->type == UV_UDP)

    socket = ((uv_udp_t*) handle)->socket;

  else

    return UV_ENOTSUP;

  len = sizeof(*value);

  if (*value == 0)

    r = getsockopt(socket, SOL_SOCKET, optname, (char*) value, &len;;

  else

    r = setsockopt(socket, SOL_SOCKET, optname, (const char*) value, len);

  if (r == SOCKET_ERROR)

    return uv_translate_sys_error(WSAGetLastError());

  return 0;

}

int uv_cpumask_size(void) {

  return (int)(sizeof(DWORD_PTR) * 8);

}

int uv__getsockpeername(const uv_handle_t* handle,

                        uv__peersockfunc func,

                        struct sockaddr* name,

                        int* namelen,

                        int delayed_error) {

  int result;

  uv_os_fd_t fd;

  result = uv_fileno(handle, &fd;;

  if (result != 0)

    return result;

  if (delayed_error)

    return uv_translate_sys_error(delayed_error);

  result = func((SOCKET) fd, name, namelen);

  if (result != 0)

    return uv_translate_sys_error(WSAGetLastError());

  return 0;

}