--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/libuv/src/win/signal.c	Wed Jan 14 19:39:52 2026 -0800
@@ -0,0 +1,282 @@
+/* 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 <signal.h>
+
+#include "uv.h"
+#include "internal.h"
+#include "handle-inl.h"
+#include "req-inl.h"
+
+
+RB_HEAD(uv_signal_tree_s, uv_signal_s);
+
+static struct uv_signal_tree_s uv__signal_tree = RB_INITIALIZER(uv__signal_tree);
+static CRITICAL_SECTION uv__signal_lock;
+
+static BOOL WINAPI uv__signal_control_handler(DWORD type);
+
+int uv__signal_start(uv_signal_t* handle,
+                     uv_signal_cb signal_cb,
+                     int signum,
+                     int oneshot);
+
+void uv__signals_init(void) {
+  InitializeCriticalSection(&uv__signal_lock);
+  if (!SetConsoleCtrlHandler(uv__signal_control_handler, TRUE))
+    abort();
+}
+
+
+void uv__signal_cleanup(void) {
+  /* TODO(bnoordhuis) Undo effects of uv_signal_init()? */
+}
+
+
+static int uv__signal_compare(uv_signal_t* w1, uv_signal_t* w2) {
+  /* Compare signums first so all watchers with the same signnum end up
+   * adjacent. */
+  if (w1->signum < w2->signum) return -1;
+  if (w1->signum > w2->signum) return 1;
+
+  /* Sort by loop pointer, so we can easily look up the first item after
+   * { .signum = x, .loop = NULL }. */
+  if ((uintptr_t) w1->loop < (uintptr_t) w2->loop) return -1;
+  if ((uintptr_t) w1->loop > (uintptr_t) w2->loop) return 1;
+
+  if ((uintptr_t) w1 < (uintptr_t) w2) return -1;
+  if ((uintptr_t) w1 > (uintptr_t) w2) return 1;
+
+  return 0;
+}
+
+
+RB_GENERATE_STATIC(uv_signal_tree_s, uv_signal_s, tree_entry, uv__signal_compare)
+
+
+/*
+ * Dispatches signal {signum} to all active uv_signal_t watchers in all loops.
+ * Returns 1 if the signal was dispatched to any watcher, or 0 if there were
+ * no active signal watchers observing this signal.
+ */
+int uv__signal_dispatch(int signum) {
+  uv_signal_t lookup;
+  uv_signal_t* handle;
+  int dispatched;
+
+  dispatched = 0;
+
+  EnterCriticalSection(&uv__signal_lock);
+
+  lookup.signum = signum;
+  lookup.loop = NULL;
+
+  for (handle = RB_NFIND(uv_signal_tree_s, &uv__signal_tree, &lookup);
+       handle != NULL && handle->signum == signum;
+       handle = RB_NEXT(uv_signal_tree_s, handle)) {
+    unsigned long previous = InterlockedExchange(
+            (volatile LONG*) &handle->pending_signum, signum);
+
+    if (handle->flags & UV_SIGNAL_ONE_SHOT_DISPATCHED)
+      continue;
+
+    if (!previous) {
+      POST_COMPLETION_FOR_REQ(handle->loop, &handle->signal_req);
+    }
+
+    dispatched = 1;
+    if (handle->flags & UV_SIGNAL_ONE_SHOT)
+      handle->flags |= UV_SIGNAL_ONE_SHOT_DISPATCHED;
+  }
+
+  LeaveCriticalSection(&uv__signal_lock);
+
+  return dispatched;
+}
+
+
+static BOOL WINAPI uv__signal_control_handler(DWORD type) {
+  switch (type) {
+    case CTRL_C_EVENT:
+      return uv__signal_dispatch(SIGINT);
+
+    case CTRL_BREAK_EVENT:
+      return uv__signal_dispatch(SIGBREAK);
+
+    case CTRL_CLOSE_EVENT:
+      if (uv__signal_dispatch(SIGHUP)) {
+        /* Windows will terminate the process after the control handler
+         * returns. After that it will just terminate our process. Therefore
+         * block the signal handler so the main loop has some time to pick up
+         * the signal and do something for a few seconds. */
+        Sleep(INFINITE);
+        return TRUE;
+      }
+      return FALSE;
+
+    case CTRL_LOGOFF_EVENT:
+    case CTRL_SHUTDOWN_EVENT:
+      /* These signals are only sent to services. Services have their own
+       * notification mechanism, so there's no point in handling these. */
+
+    default:
+      /* We don't handle these. */
+      return FALSE;
+  }
+}
+
+
+int uv_signal_init(uv_loop_t* loop, uv_signal_t* handle) {
+  uv__handle_init(loop, (uv_handle_t*) handle, UV_SIGNAL);
+  handle->pending_signum = 0;
+  handle->signum = 0;
+  handle->signal_cb = NULL;
+
+  UV_REQ_INIT(&handle->signal_req, UV_SIGNAL_REQ);
+  handle->signal_req.data = handle;
+
+  return 0;
+}
+
+
+int uv_signal_stop(uv_signal_t* handle) {
+  uv_signal_t* removed_handle;
+
+  /* If the watcher wasn't started, this is a no-op. */
+  if (handle->signum == 0)
+    return 0;
+
+  EnterCriticalSection(&uv__signal_lock);
+
+  removed_handle = RB_REMOVE(uv_signal_tree_s, &uv__signal_tree, handle);
+  assert(removed_handle == handle);
+
+  LeaveCriticalSection(&uv__signal_lock);
+
+  handle->signum = 0;
+  uv__handle_stop(handle);
+
+  return 0;
+}
+
+
+int uv_signal_start(uv_signal_t* handle, uv_signal_cb signal_cb, int signum) {
+  return uv__signal_start(handle, signal_cb, signum, 0);
+}
+
+
+int uv_signal_start_oneshot(uv_signal_t* handle,
+                            uv_signal_cb signal_cb,
+                            int signum) {
+  return uv__signal_start(handle, signal_cb, signum, 1);
+}
+
+
+int uv__signal_start(uv_signal_t* handle,
+                            uv_signal_cb signal_cb,
+                            int signum,
+                            int oneshot) {
+  /* Test for invalid signal values. */
+  if (signum <= 0 || signum >= NSIG)
+    return UV_EINVAL;
+
+  /* Short circuit: if the signal watcher is already watching {signum} don't go
+   * through the process of deregistering and registering the handler.
+   * Additionally, this avoids pending signals getting lost in the (small) time
+   * frame that handle->signum == 0. */
+  if (signum == handle->signum) {
+    handle->signal_cb = signal_cb;
+    return 0;
+  }
+
+  /* If the signal handler was already active, stop it first. */
+  if (handle->signum != 0) {
+    int r = uv_signal_stop(handle);
+    /* uv_signal_stop is infallible. */
+    assert(r == 0);
+  }
+
+  EnterCriticalSection(&uv__signal_lock);
+
+  handle->signum = signum;
+  if (oneshot)
+    handle->flags |= UV_SIGNAL_ONE_SHOT;
+
+  RB_INSERT(uv_signal_tree_s, &uv__signal_tree, handle);
+
+  LeaveCriticalSection(&uv__signal_lock);
+
+  handle->signal_cb = signal_cb;
+  uv__handle_start(handle);
+
+  return 0;
+}
+
+
+void uv__process_signal_req(uv_loop_t* loop, uv_signal_t* handle,
+    uv_req_t* req) {
+  long dispatched_signum;
+
+  assert(handle->type == UV_SIGNAL);
+  assert(req->type == UV_SIGNAL_REQ);
+
+  dispatched_signum = InterlockedExchange(
+          (volatile LONG*) &handle->pending_signum, 0);
+  assert(dispatched_signum != 0);
+
+  /* Check if the pending signal equals the signum that we are watching for.
+   * These can get out of sync when the handler is stopped and restarted while
+   * the signal_req is pending. */
+  if (dispatched_signum == handle->signum)
+    handle->signal_cb(handle, dispatched_signum);
+
+  if (handle->flags & UV_SIGNAL_ONE_SHOT)
+    uv_signal_stop(handle);
+
+  if (handle->flags & UV_HANDLE_CLOSING) {
+    /* When it is closing, it must be stopped at this point. */
+    assert(handle->signum == 0);
+    uv__want_endgame(loop, (uv_handle_t*) handle);
+  }
+}
+
+
+void uv__signal_close(uv_loop_t* loop, uv_signal_t* handle) {
+  uv_signal_stop(handle);
+  uv__handle_closing(handle);
+
+  if (handle->pending_signum == 0) {
+    uv__want_endgame(loop, (uv_handle_t*) handle);
+  }
+}
+
+
+void uv__signal_endgame(uv_loop_t* loop, uv_signal_t* handle) {
+  assert(handle->flags & UV_HANDLE_CLOSING);
+  assert(!(handle->flags & UV_HANDLE_CLOSED));
+
+  assert(handle->signum == 0);
+  assert(handle->pending_signum == 0);
+
+  handle->flags |= UV_HANDLE_CLOSED;
+
+  uv__handle_close(handle);
+}