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-rw-r--r--deps/uv/src/unix/posix-poll.c324
1 files changed, 324 insertions, 0 deletions
diff --git a/deps/uv/src/unix/posix-poll.c b/deps/uv/src/unix/posix-poll.c
new file mode 100644
index 0000000000..3fba96e1bf
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+++ b/deps/uv/src/unix/posix-poll.c
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+/* Copyright libuv project 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"
+
+/* POSIX defines poll() as a portable way to wait on file descriptors.
+ * Here we maintain a dynamically sized array of file descriptors and
+ * events to pass as the first argument to poll().
+ */
+
+#include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <errno.h>
+#include <unistd.h>
+
+int uv__platform_loop_init(uv_loop_t* loop) {
+ loop->poll_fds = NULL;
+ loop->poll_fds_used = 0;
+ loop->poll_fds_size = 0;
+ loop->poll_fds_iterating = 0;
+ return 0;
+}
+
+void uv__platform_loop_delete(uv_loop_t* loop) {
+ uv__free(loop->poll_fds);
+ loop->poll_fds = NULL;
+}
+
+int uv__io_fork(uv_loop_t* loop) {
+ uv__platform_loop_delete(loop);
+ return uv__platform_loop_init(loop);
+}
+
+/* Allocate or dynamically resize our poll fds array. */
+static void uv__pollfds_maybe_resize(uv_loop_t* loop) {
+ size_t i;
+ size_t n;
+ struct pollfd* p;
+
+ if (loop->poll_fds_used < loop->poll_fds_size)
+ return;
+
+ n = loop->poll_fds_size ? loop->poll_fds_size * 2 : 64;
+ p = uv__realloc(loop->poll_fds, n * sizeof(*loop->poll_fds));
+ if (p == NULL)
+ abort();
+
+ loop->poll_fds = p;
+ for (i = loop->poll_fds_size; i < n; i++) {
+ loop->poll_fds[i].fd = -1;
+ loop->poll_fds[i].events = 0;
+ loop->poll_fds[i].revents = 0;
+ }
+ loop->poll_fds_size = n;
+}
+
+/* Primitive swap operation on poll fds array elements. */
+static void uv__pollfds_swap(uv_loop_t* loop, size_t l, size_t r) {
+ struct pollfd pfd;
+ pfd = loop->poll_fds[l];
+ loop->poll_fds[l] = loop->poll_fds[r];
+ loop->poll_fds[r] = pfd;
+}
+
+/* Add a watcher's fd to our poll fds array with its pending events. */
+static void uv__pollfds_add(uv_loop_t* loop, uv__io_t* w) {
+ size_t i;
+ struct pollfd* pe;
+
+ /* If the fd is already in the set just update its events. */
+ assert(!loop->poll_fds_iterating);
+ for (i = 0; i < loop->poll_fds_used; ++i) {
+ if (loop->poll_fds[i].fd == w->fd) {
+ loop->poll_fds[i].events = w->pevents;
+ return;
+ }
+ }
+
+ /* Otherwise, allocate a new slot in the set for the fd. */
+ uv__pollfds_maybe_resize(loop);
+ pe = &loop->poll_fds[loop->poll_fds_used++];
+ pe->fd = w->fd;
+ pe->events = w->pevents;
+}
+
+/* Remove a watcher's fd from our poll fds array. */
+static void uv__pollfds_del(uv_loop_t* loop, int fd) {
+ size_t i;
+ assert(!loop->poll_fds_iterating);
+ for (i = 0; i < loop->poll_fds_used; ++i) {
+ if (loop->poll_fds[i].fd == fd) {
+ /* swap to last position and remove */
+ --loop->poll_fds_used;
+ uv__pollfds_swap(loop, i, loop->poll_fds_used);
+ loop->poll_fds[loop->poll_fds_used].fd = -1;
+ loop->poll_fds[loop->poll_fds_used].events = 0;
+ loop->poll_fds[loop->poll_fds_used].revents = 0;
+ return;
+ }
+ }
+}
+
+
+void uv__io_poll(uv_loop_t* loop, int timeout) {
+ sigset_t* pset;
+ sigset_t set;
+ uint64_t time_base;
+ uint64_t time_diff;
+ QUEUE* q;
+ uv__io_t* w;
+ size_t i;
+ unsigned int nevents;
+ int nfds;
+ int have_signals;
+ struct pollfd* pe;
+ int fd;
+
+ if (loop->nfds == 0) {
+ assert(QUEUE_EMPTY(&loop->watcher_queue));
+ return;
+ }
+
+ /* Take queued watchers and add their fds to our poll fds array. */
+ while (!QUEUE_EMPTY(&loop->watcher_queue)) {
+ q = QUEUE_HEAD(&loop->watcher_queue);
+ QUEUE_REMOVE(q);
+ QUEUE_INIT(q);
+
+ w = QUEUE_DATA(q, uv__io_t, watcher_queue);
+ assert(w->pevents != 0);
+ assert(w->fd >= 0);
+ assert(w->fd < (int) loop->nwatchers);
+
+ uv__pollfds_add(loop, w);
+
+ w->events = w->pevents;
+ }
+
+ /* Prepare a set of signals to block around poll(), if any. */
+ pset = NULL;
+ if (loop->flags & UV_LOOP_BLOCK_SIGPROF) {
+ pset = &set;
+ sigemptyset(pset);
+ sigaddset(pset, SIGPROF);
+ }
+
+ assert(timeout >= -1);
+ time_base = loop->time;
+
+ /* Loop calls to poll() and processing of results. If we get some
+ * results from poll() but they turn out not to be interesting to
+ * our caller then we need to loop around and poll() again.
+ */
+ for (;;) {
+ if (pset != NULL)
+ if (pthread_sigmask(SIG_BLOCK, pset, NULL))
+ abort();
+ nfds = poll(loop->poll_fds, (nfds_t)loop->poll_fds_used, timeout);
+ if (pset != NULL)
+ if (pthread_sigmask(SIG_UNBLOCK, pset, NULL))
+ abort();
+
+ /* Update loop->time unconditionally. It's tempting to skip the update when
+ * timeout == 0 (i.e. non-blocking poll) but there is no guarantee that the
+ * operating system didn't reschedule our process while in the syscall.
+ */
+ SAVE_ERRNO(uv__update_time(loop));
+
+ if (nfds == 0) {
+ assert(timeout != -1);
+ return;
+ }
+
+ if (nfds == -1) {
+ if (errno != EINTR)
+ abort();
+
+ if (timeout == -1)
+ continue;
+
+ if (timeout == 0)
+ return;
+
+ /* Interrupted by a signal. Update timeout and poll again. */
+ goto update_timeout;
+ }
+
+ /* Tell uv__platform_invalidate_fd not to manipulate our array
+ * while we are iterating over it.
+ */
+ loop->poll_fds_iterating = 1;
+
+ /* Initialize a count of events that we care about. */
+ nevents = 0;
+ have_signals = 0;
+
+ /* Loop over the entire poll fds array looking for returned events. */
+ for (i = 0; i < loop->poll_fds_used; i++) {
+ pe = loop->poll_fds + i;
+ fd = pe->fd;
+
+ /* Skip invalidated events, see uv__platform_invalidate_fd. */
+ if (fd == -1)
+ continue;
+
+ assert(fd >= 0);
+ assert((unsigned) fd < loop->nwatchers);
+
+ w = loop->watchers[fd];
+
+ if (w == NULL) {
+ /* File descriptor that we've stopped watching, ignore. */
+ uv__platform_invalidate_fd(loop, fd);
+ continue;
+ }
+
+ /* Filter out events that user has not requested us to watch
+ * (e.g. POLLNVAL).
+ */
+ pe->revents &= w->pevents | POLLERR | POLLHUP;
+
+ if (pe->revents != 0) {
+ /* Run signal watchers last. */
+ if (w == &loop->signal_io_watcher) {
+ have_signals = 1;
+ } else {
+ w->cb(loop, w, pe->revents);
+ }
+
+ nevents++;
+ }
+ }
+
+ if (have_signals != 0)
+ loop->signal_io_watcher.cb(loop, &loop->signal_io_watcher, POLLIN);
+
+ loop->poll_fds_iterating = 0;
+
+ /* Purge invalidated fds from our poll fds array. */
+ uv__pollfds_del(loop, -1);
+
+ if (have_signals != 0)
+ return; /* Event loop should cycle now so don't poll again. */
+
+ if (nevents != 0)
+ return;
+
+ if (timeout == 0)
+ return;
+
+ if (timeout == -1)
+ continue;
+
+update_timeout:
+ assert(timeout > 0);
+
+ time_diff = loop->time - time_base;
+ if (time_diff >= (uint64_t) timeout)
+ return;
+
+ timeout -= time_diff;
+ }
+}
+
+/* Remove the given fd from our poll fds array because no one
+ * is interested in its events anymore.
+ */
+void uv__platform_invalidate_fd(uv_loop_t* loop, int fd) {
+ size_t i;
+
+ if (loop->poll_fds_iterating) {
+ /* uv__io_poll is currently iterating. Just invalidate fd. */
+ for (i = 0; i < loop->poll_fds_used; i++)
+ if (loop->poll_fds[i].fd == fd) {
+ loop->poll_fds[i].fd = -1;
+ loop->poll_fds[i].events = 0;
+ loop->poll_fds[i].revents = 0;
+ }
+ } else {
+ /* uv__io_poll is not iterating. Delete fd from the set. */
+ uv__pollfds_del(loop, fd);
+ }
+}
+
+/* Check whether the given fd is supported by poll(). */
+int uv__io_check_fd(uv_loop_t* loop, int fd) {
+ struct pollfd p[1];
+ int rv;
+
+ p[0].fd = fd;
+ p[0].events = POLLIN;
+
+ do
+ rv = poll(p, 1, 0);
+ while (rv == -1 && (errno == EINTR || errno == EAGAIN));
+
+ if (rv == -1)
+ return -errno;
+
+ if (p[0].revents & POLLNVAL)
+ return -EINVAL;
+
+ return 0;
+}