初始化

LFtid1056/lib/libuv-v1.51.0/src/unix/poll.c

@@ -0,0 +1,159 @@
+/* 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 "uv.h"
+#include "internal.h"
+
+#include <unistd.h>
+#include <assert.h>
+
+
+static void uv__poll_io(uv_loop_t* loop, uv__io_t* w, unsigned int events) {
+  uv_poll_t* handle;
+  int pevents;
+
+  handle = container_of(w, uv_poll_t, io_watcher);
+
+  /*
+   * As documented in the kernel source fs/kernfs/file.c #780
+   * poll will return POLLERR|POLLPRI in case of sysfs
+   * polling. This does not happen in case of out-of-band
+   * TCP messages.
+   *
+   * The above is the case on (at least) FreeBSD and Linux.
+   *
+   * So to properly determine a POLLPRI or a POLLERR we need
+   * to check for both.
+   */
+  if ((events & POLLERR) && !(events & UV__POLLPRI)) {
+    uv__io_stop(loop, w, POLLIN | POLLOUT | UV__POLLRDHUP | UV__POLLPRI);
+    uv__handle_stop(handle);
+    handle->poll_cb(handle, UV_EBADF, 0);
+    return;
+  }
+
+  pevents = 0;
+  if (events & POLLIN)
+    pevents |= UV_READABLE;
+  if (events & UV__POLLPRI)
+    pevents |= UV_PRIORITIZED;
+  if (events & POLLOUT)
+    pevents |= UV_WRITABLE;
+  if (events & UV__POLLRDHUP)
+    pevents |= UV_DISCONNECT;
+
+  handle->poll_cb(handle, 0, pevents);
+}
+
+
+int uv_poll_init(uv_loop_t* loop, uv_poll_t* handle, int fd) {
+  int err;
+
+  if (uv__fd_exists(loop, fd))
+    return UV_EEXIST;
+
+  err = uv__io_check_fd(loop, fd);
+  if (err)
+    return err;
+
+  /* If ioctl(FIONBIO) reports ENOTTY, try fcntl(F_GETFL) + fcntl(F_SETFL).
+   * Workaround for e.g. kqueue fds not supporting ioctls.
+   */
+  err = uv__nonblock(fd, 1);
+#if UV__NONBLOCK_IS_IOCTL
+  if (err == UV_ENOTTY)
+    err = uv__nonblock_fcntl(fd, 1);
+#endif
+
+  if (err)
+    return err;
+
+  uv__handle_init(loop, (uv_handle_t*) handle, UV_POLL);
+  uv__io_init(&handle->io_watcher, uv__poll_io, fd);
+  handle->poll_cb = NULL;
+  return 0;
+}
+
+
+int uv_poll_init_socket(uv_loop_t* loop, uv_poll_t* handle,
+    uv_os_sock_t socket) {
+  return uv_poll_init(loop, handle, socket);
+}
+
+
+static void uv__poll_stop(uv_poll_t* handle) {
+  uv__io_stop(handle->loop,
+              &handle->io_watcher,
+              POLLIN | POLLOUT | UV__POLLRDHUP | UV__POLLPRI);
+  uv__handle_stop(handle);
+  uv__platform_invalidate_fd(handle->loop, handle->io_watcher.fd);
+}
+
+
+int uv_poll_stop(uv_poll_t* handle) {
+  assert(!uv__is_closing(handle));
+  uv__poll_stop(handle);
+  return 0;
+}
+
+
+int uv_poll_start(uv_poll_t* handle, int pevents, uv_poll_cb poll_cb) {
+  uv__io_t** watchers;
+  uv__io_t* w;
+  int events;
+
+  assert((pevents & ~(UV_READABLE | UV_WRITABLE | UV_DISCONNECT |
+                      UV_PRIORITIZED)) == 0);
+  assert(!uv__is_closing(handle));
+
+  watchers = handle->loop->watchers;
+  w = &handle->io_watcher;
+
+  if (uv__fd_exists(handle->loop, w->fd))
+    if (watchers[w->fd] != w)
+      return UV_EEXIST;
+
+  uv__poll_stop(handle);
+
+  if (pevents == 0)
+    return 0;
+
+  events = 0;
+  if (pevents & UV_READABLE)
+    events |= POLLIN;
+  if (pevents & UV_PRIORITIZED)
+    events |= UV__POLLPRI;
+  if (pevents & UV_WRITABLE)
+    events |= POLLOUT;
+  if (pevents & UV_DISCONNECT)
+    events |= UV__POLLRDHUP;
+
+  uv__io_start(handle->loop, &handle->io_watcher, events);
+  uv__handle_start(handle);
+  handle->poll_cb = poll_cb;
+
+  return 0;
+}
+
+
+void uv__poll_close(uv_poll_t* handle) {
+  uv__poll_stop(handle);
+}