Event loop basics + libuv

libs/libuv/src/win/timer.c

@@ -0,0 +1,195 @@
+/* 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 <limits.h>
+
+#include "uv.h"
+#include "internal.h"
+#include "tree.h"
+#include "handle-inl.h"
+
+
+/* The number of milliseconds in one second. */
+#define UV__MILLISEC 1000
+
+
+void uv_update_time(uv_loop_t* loop) {
+  uint64_t new_time = uv__hrtime(UV__MILLISEC);
+  assert(new_time >= loop->time);
+  loop->time = new_time;
+}
+
+
+static int uv_timer_compare(uv_timer_t* a, uv_timer_t* b) {
+  if (a->due < b->due)
+    return -1;
+  if (a->due > b->due)
+    return 1;
+  /*
+   *  compare start_id when both has the same due. start_id is
+   *  allocated with loop->timer_counter in uv_timer_start().
+   */
+  if (a->start_id < b->start_id)
+    return -1;
+  if (a->start_id > b->start_id)
+    return 1;
+  return 0;
+}
+
+
+RB_GENERATE_STATIC(uv_timer_tree_s, uv_timer_s, tree_entry, uv_timer_compare);
+
+
+int uv_timer_init(uv_loop_t* loop, uv_timer_t* handle) {
+  uv__handle_init(loop, (uv_handle_t*) handle, UV_TIMER);
+  handle->timer_cb = NULL;
+  handle->repeat = 0;
+
+  return 0;
+}
+
+
+void uv_timer_endgame(uv_loop_t* loop, uv_timer_t* handle) {
+  if (handle->flags & UV__HANDLE_CLOSING) {
+    assert(!(handle->flags & UV_HANDLE_CLOSED));
+    uv__handle_close(handle);
+  }
+}
+
+
+static uint64_t get_clamped_due_time(uint64_t loop_time, uint64_t timeout) {
+  uint64_t clamped_timeout;
+
+  clamped_timeout = loop_time + timeout;
+  if (clamped_timeout < timeout)
+    clamped_timeout = (uint64_t) -1;
+
+  return clamped_timeout;
+}
+
+
+int uv_timer_start(uv_timer_t* handle, uv_timer_cb timer_cb, uint64_t timeout,
+    uint64_t repeat) {
+  uv_loop_t* loop = handle->loop;
+  uv_timer_t* old;
+
+  if (timer_cb == NULL)
+    return UV_EINVAL;
+
+  if (uv__is_active(handle))
+    uv_timer_stop(handle);
+
+  handle->timer_cb = timer_cb;
+  handle->due = get_clamped_due_time(loop->time, timeout);
+  handle->repeat = repeat;
+  uv__handle_start(handle);
+
+  /* start_id is the second index to be compared in uv__timer_cmp() */
+  handle->start_id = handle->loop->timer_counter++;
+
+  old = RB_INSERT(uv_timer_tree_s, &loop->timers, handle);
+  assert(old == NULL);
+
+  return 0;
+}
+
+
+int uv_timer_stop(uv_timer_t* handle) {
+  uv_loop_t* loop = handle->loop;
+
+  if (!uv__is_active(handle))
+    return 0;
+
+  RB_REMOVE(uv_timer_tree_s, &loop->timers, handle);
+  uv__handle_stop(handle);
+
+  return 0;
+}
+
+
+int uv_timer_again(uv_timer_t* handle) {
+  /* If timer_cb is NULL that means that the timer was never started. */
+  if (!handle->timer_cb) {
+    return UV_EINVAL;
+  }
+
+  if (handle->repeat) {
+    uv_timer_stop(handle);
+    uv_timer_start(handle, handle->timer_cb, handle->repeat, handle->repeat);
+  }
+
+  return 0;
+}
+
+
+void uv_timer_set_repeat(uv_timer_t* handle, uint64_t repeat) {
+  assert(handle->type == UV_TIMER);
+  handle->repeat = repeat;
+}
+
+
+uint64_t uv_timer_get_repeat(const uv_timer_t* handle) {
+  assert(handle->type == UV_TIMER);
+  return handle->repeat;
+}
+
+
+DWORD uv__next_timeout(const uv_loop_t* loop) {
+  uv_timer_t* timer;
+  int64_t delta;
+
+  /* Check if there are any running timers
+   * Need to cast away const first, since RB_MIN doesn't know what we are
+   * going to do with this return value, it can't be marked const
+   */
+  timer = RB_MIN(uv_timer_tree_s, &((uv_loop_t*)loop)->timers);
+  if (timer) {
+    delta = timer->due - loop->time;
+    if (delta >= UINT_MAX - 1) {
+      /* A timeout value of UINT_MAX means infinite, so that's no good. */
+      return UINT_MAX - 1;
+    } else if (delta < 0) {
+      /* Negative timeout values are not allowed */
+      return 0;
+    } else {
+      return (DWORD)delta;
+    }
+  } else {
+    /* No timers */
+    return INFINITE;
+  }
+}
+
+
+void uv_process_timers(uv_loop_t* loop) {
+  uv_timer_t* timer;
+
+  /* Call timer callbacks */
+  for (timer = RB_MIN(uv_timer_tree_s, &loop->timers);
+       timer != NULL && timer->due <= loop->time;
+       timer = RB_MIN(uv_timer_tree_s, &loop->timers)) {
+
+    uv_timer_stop(timer);
+    uv_timer_again(timer);
+    timer->timer_cb((uv_timer_t*) timer);
+  }
+}