--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/libuv/src/unix/posix-poll.c	Wed Jan 14 19:39:52 2026 -0800
@@ -0,0 +1,385 @@
+/* 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__reallocf(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;) {
+    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;
+      /* This method is called with an fd of -1 to purge the invalidated fds,
+       * so we may possibly have multiples to remove.
+       */
+      if (-1 != fd)
+        return;
+    } else {
+      /* We must only increment the loop counter when the fds do not match.
+       * Otherwise, when we are purging an invalidated fd, the value just
+       * swapped here from the previous end of the array will be skipped.
+       */
+       ++i;
+    }
+  }
+}
+
+
+void uv__io_poll(uv_loop_t* loop, int timeout) {
+  uv__loop_internal_fields_t* lfields;
+  sigset_t* pset;
+  sigset_t set;
+  uint64_t time_base;
+  uint64_t time_diff;
+  struct uv__queue* q;
+  uv__io_t* w;
+  size_t i;
+  unsigned int nevents;
+  int nfds;
+  int have_signals;
+  struct pollfd* pe;
+  int fd;
+  int user_timeout;
+  int reset_timeout;
+
+  if (loop->nfds == 0) {
+    assert(uv__queue_empty(&loop->watcher_queue));
+    return;
+  }
+
+  lfields = uv__get_internal_fields(loop);
+
+  /* Take queued watchers and add their fds to our poll fds array.  */
+  while (!uv__queue_empty(&loop->watcher_queue)) {
+    q = uv__queue_head(&loop->watcher_queue);
+    uv__queue_remove(q);
+    uv__queue_init(q);
+
+    w = uv__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;
+
+  if (lfields->flags & UV_METRICS_IDLE_TIME) {
+    reset_timeout = 1;
+    user_timeout = timeout;
+    timeout = 0;
+  } else {
+    reset_timeout = 0;
+  }
+
+  /* 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 (;;) {
+    /* 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);
+
+    /* Store the current timeout in a location that's globally accessible so
+     * other locations like uv__work_done() can determine whether the queue
+     * of events in the callback were waiting when poll was called.
+     */
+    lfields->current_timeout = timeout;
+
+    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) {
+      if (reset_timeout != 0) {
+        timeout = user_timeout;
+        reset_timeout = 0;
+        if (timeout == -1)
+          continue;
+        if (timeout > 0)
+          goto update_timeout;
+      }
+
+      assert(timeout != -1);
+      return;
+    }
+
+    if (nfds == -1) {
+      if (errno != EINTR)
+        abort();
+
+      if (reset_timeout != 0) {
+        timeout = user_timeout;
+        reset_timeout = 0;
+      }
+
+      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 {
+          uv__metrics_update_idle_time(loop);
+          w->cb(loop, w, pe->revents);
+        }
+
+        nevents++;
+      }
+    }
+
+    uv__metrics_inc_events(loop, nevents);
+    if (reset_timeout != 0) {
+      timeout = user_timeout;
+      reset_timeout = 0;
+      uv__metrics_inc_events_waiting(loop, nevents);
+    }
+
+    if (have_signals != 0) {
+      uv__metrics_update_idle_time(loop);
+      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;
+
+  assert(fd >= 0);
+
+  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 UV__ERR(errno);
+
+  if (p[0].revents & POLLNVAL)
+    return UV_EINVAL;
+
+  return 0;
+}