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@@ -0,0 +1,324 @@
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+/* Copyright libuv project contributors. All rights reserved.
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+ *
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+ * Permission is hereby granted, free of charge, to any person obtaining a copy
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+ * of this software and associated documentation files (the "Software"), to
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+ * deal in the Software without restriction, including without limitation the
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+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
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+ * sell copies of the Software, and to permit persons to whom the Software is
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+ * furnished to do so, subject to the following conditions:
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+ *
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+ * The above copyright notice and this permission notice shall be included in
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+ * all copies or substantial portions of the Software.
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+ *
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+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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+ * IN THE SOFTWARE.
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+ */
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+
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+#include "uv.h"
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+#include "internal.h"
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+
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+/* POSIX defines poll() as a portable way to wait on file descriptors.
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+ * Here we maintain a dynamically sized array of file descriptors and
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+ * events to pass as the first argument to poll().
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+ */
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+
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+#include <assert.h>
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+#include <stddef.h>
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+#include <stdint.h>
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+#include <errno.h>
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+#include <unistd.h>
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+
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+int uv__platform_loop_init(uv_loop_t* loop) {
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+ loop->poll_fds = NULL;
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+ loop->poll_fds_used = 0;
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+ loop->poll_fds_size = 0;
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+ loop->poll_fds_iterating = 0;
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+ return 0;
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+}
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+
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+void uv__platform_loop_delete(uv_loop_t* loop) {
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+ uv__free(loop->poll_fds);
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+ loop->poll_fds = NULL;
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+}
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+
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+int uv__io_fork(uv_loop_t* loop) {
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+ uv__platform_loop_delete(loop);
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+ return uv__platform_loop_init(loop);
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+}
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+
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+/* Allocate or dynamically resize our poll fds array. */
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+static void uv__pollfds_maybe_resize(uv_loop_t* loop) {
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+ size_t i;
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+ size_t n;
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+ struct pollfd* p;
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+
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+ if (loop->poll_fds_used < loop->poll_fds_size)
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+ return;
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+
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+ n = loop->poll_fds_size ? loop->poll_fds_size * 2 : 64;
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+ p = uv__realloc(loop->poll_fds, n * sizeof(*loop->poll_fds));
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+ if (p == NULL)
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+ abort();
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+
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+ loop->poll_fds = p;
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+ for (i = loop->poll_fds_size; i < n; i++) {
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+ loop->poll_fds[i].fd = -1;
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+ loop->poll_fds[i].events = 0;
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+ loop->poll_fds[i].revents = 0;
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+ }
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+ loop->poll_fds_size = n;
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+}
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+
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+/* Primitive swap operation on poll fds array elements. */
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+static void uv__pollfds_swap(uv_loop_t* loop, size_t l, size_t r) {
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+ struct pollfd pfd;
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+ pfd = loop->poll_fds[l];
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+ loop->poll_fds[l] = loop->poll_fds[r];
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+ loop->poll_fds[r] = pfd;
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+}
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+
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+/* Add a watcher's fd to our poll fds array with its pending events. */
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+static void uv__pollfds_add(uv_loop_t* loop, uv__io_t* w) {
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+ size_t i;
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+ struct pollfd* pe;
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+
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+ /* If the fd is already in the set just update its events. */
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+ assert(!loop->poll_fds_iterating);
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+ for (i = 0; i < loop->poll_fds_used; ++i) {
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+ if (loop->poll_fds[i].fd == w->fd) {
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+ loop->poll_fds[i].events = w->pevents;
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+ return;
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+ }
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+ }
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+
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+ /* Otherwise, allocate a new slot in the set for the fd. */
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+ uv__pollfds_maybe_resize(loop);
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+ pe = &loop->poll_fds[loop->poll_fds_used++];
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+ pe->fd = w->fd;
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+ pe->events = w->pevents;
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+}
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+
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+/* Remove a watcher's fd from our poll fds array. */
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+static void uv__pollfds_del(uv_loop_t* loop, int fd) {
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+ size_t i;
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+ assert(!loop->poll_fds_iterating);
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+ for (i = 0; i < loop->poll_fds_used; ++i) {
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+ if (loop->poll_fds[i].fd == fd) {
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+ /* swap to last position and remove */
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+ --loop->poll_fds_used;
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+ uv__pollfds_swap(loop, i, loop->poll_fds_used);
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+ loop->poll_fds[loop->poll_fds_used].fd = -1;
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+ loop->poll_fds[loop->poll_fds_used].events = 0;
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+ loop->poll_fds[loop->poll_fds_used].revents = 0;
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+ return;
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+ }
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+ }
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+}
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+
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+
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+void uv__io_poll(uv_loop_t* loop, int timeout) {
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+ sigset_t* pset;
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+ sigset_t set;
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+ uint64_t time_base;
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+ uint64_t time_diff;
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+ QUEUE* q;
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+ uv__io_t* w;
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+ size_t i;
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+ unsigned int nevents;
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+ int nfds;
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+ int have_signals;
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+ struct pollfd* pe;
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+ int fd;
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+
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+ if (loop->nfds == 0) {
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+ assert(QUEUE_EMPTY(&loop->watcher_queue));
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+ return;
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+ }
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+
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+ /* Take queued watchers and add their fds to our poll fds array. */
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+ while (!QUEUE_EMPTY(&loop->watcher_queue)) {
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+ q = QUEUE_HEAD(&loop->watcher_queue);
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+ QUEUE_REMOVE(q);
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+ QUEUE_INIT(q);
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+
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+ w = QUEUE_DATA(q, uv__io_t, watcher_queue);
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+ assert(w->pevents != 0);
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+ assert(w->fd >= 0);
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+ assert(w->fd < (int) loop->nwatchers);
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+
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+ uv__pollfds_add(loop, w);
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+
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+ w->events = w->pevents;
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+ }
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+
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+ /* Prepare a set of signals to block around poll(), if any. */
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+ pset = NULL;
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+ if (loop->flags & UV_LOOP_BLOCK_SIGPROF) {
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+ pset = &set;
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+ sigemptyset(pset);
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+ sigaddset(pset, SIGPROF);
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+ }
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+
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+ assert(timeout >= -1);
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+ time_base = loop->time;
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+
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+ /* Loop calls to poll() and processing of results. If we get some
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+ * results from poll() but they turn out not to be interesting to
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+ * our caller then we need to loop around and poll() again.
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+ */
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+ for (;;) {
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+ if (pset != NULL)
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+ if (pthread_sigmask(SIG_BLOCK, pset, NULL))
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+ abort();
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+ nfds = poll(loop->poll_fds, (nfds_t)loop->poll_fds_used, timeout);
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+ if (pset != NULL)
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+ if (pthread_sigmask(SIG_UNBLOCK, pset, NULL))
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+ abort();
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+
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+ /* Update loop->time unconditionally. It's tempting to skip the update when
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+ * timeout == 0 (i.e. non-blocking poll) but there is no guarantee that the
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+ * operating system didn't reschedule our process while in the syscall.
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+ */
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+ SAVE_ERRNO(uv__update_time(loop));
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+
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+ if (nfds == 0) {
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+ assert(timeout != -1);
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+ return;
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+ }
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+
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+ if (nfds == -1) {
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+ if (errno != EINTR)
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+ abort();
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+
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+ if (timeout == -1)
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+ continue;
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+
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+ if (timeout == 0)
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+ return;
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+
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+ /* Interrupted by a signal. Update timeout and poll again. */
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+ goto update_timeout;
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+ }
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+
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+ /* Tell uv__platform_invalidate_fd not to manipulate our array
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+ * while we are iterating over it.
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+ */
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+ loop->poll_fds_iterating = 1;
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+
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+ /* Initialize a count of events that we care about. */
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+ nevents = 0;
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+ have_signals = 0;
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+
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+ /* Loop over the entire poll fds array looking for returned events. */
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+ for (i = 0; i < loop->poll_fds_used; i++) {
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+ pe = loop->poll_fds + i;
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+ fd = pe->fd;
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+
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+ /* Skip invalidated events, see uv__platform_invalidate_fd. */
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+ if (fd == -1)
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+ continue;
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+
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+ assert(fd >= 0);
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+ assert((unsigned) fd < loop->nwatchers);
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+
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+ w = loop->watchers[fd];
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+
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+ if (w == NULL) {
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+ /* File descriptor that we've stopped watching, ignore. */
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+ uv__platform_invalidate_fd(loop, fd);
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+ continue;
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+ }
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+
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+ /* Filter out events that user has not requested us to watch
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+ * (e.g. POLLNVAL).
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+ */
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+ pe->revents &= w->pevents | POLLERR | POLLHUP;
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+
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+ if (pe->revents != 0) {
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+ /* Run signal watchers last. */
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+ if (w == &loop->signal_io_watcher) {
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+ have_signals = 1;
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+ } else {
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+ w->cb(loop, w, pe->revents);
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+ }
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+
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+ nevents++;
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+ }
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+ }
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+
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+ if (have_signals != 0)
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+ loop->signal_io_watcher.cb(loop, &loop->signal_io_watcher, POLLIN);
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+
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+ loop->poll_fds_iterating = 0;
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+
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+ /* Purge invalidated fds from our poll fds array. */
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+ uv__pollfds_del(loop, -1);
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+
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+ if (have_signals != 0)
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+ return; /* Event loop should cycle now so don't poll again. */
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+
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+ if (nevents != 0)
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+ return;
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+
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+ if (timeout == 0)
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+ return;
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+
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+ if (timeout == -1)
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+ continue;
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+
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+update_timeout:
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+ assert(timeout > 0);
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+
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+ time_diff = loop->time - time_base;
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+ if (time_diff >= (uint64_t) timeout)
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+ return;
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+
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+ timeout -= time_diff;
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+ }
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+}
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+
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+/* Remove the given fd from our poll fds array because no one
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+ * is interested in its events anymore.
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+ */
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+void uv__platform_invalidate_fd(uv_loop_t* loop, int fd) {
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+ size_t i;
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+
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+ if (loop->poll_fds_iterating) {
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+ /* uv__io_poll is currently iterating. Just invalidate fd. */
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+ for (i = 0; i < loop->poll_fds_used; i++)
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+ if (loop->poll_fds[i].fd == fd) {
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+ loop->poll_fds[i].fd = -1;
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+ loop->poll_fds[i].events = 0;
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+ loop->poll_fds[i].revents = 0;
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+ }
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+ } else {
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+ /* uv__io_poll is not iterating. Delete fd from the set. */
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+ uv__pollfds_del(loop, fd);
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+ }
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+}
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+
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+/* Check whether the given fd is supported by poll(). */
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+int uv__io_check_fd(uv_loop_t* loop, int fd) {
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+ struct pollfd p[1];
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+ int rv;
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+
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+ p[0].fd = fd;
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+ p[0].events = POLLIN;
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+
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+ do
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+ rv = poll(p, 1, 0);
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+ while (rv == -1 && (errno == EINTR || errno == EAGAIN));
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+
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+ if (rv == -1)
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+ return -errno;
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+
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+ if (p[0].revents & POLLNVAL)
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+ return -EINVAL;
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+
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+ return 0;
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+}
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