--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/libuv/test/test-condvar.c	Wed Jan 14 19:39:52 2026 -0800
@@ -0,0 +1,248 @@
+/* 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 "task.h"
+
+#include <string.h>
+#include <errno.h>
+
+struct worker_config;
+
+typedef void (*signal_func)(struct worker_config* c, int* flag);
+typedef int (*wait_func)(struct worker_config* c, const int* flag);
+
+typedef struct worker_config {
+  uv_sem_t sem_waiting; /* post before waiting. */
+  uv_sem_t sem_signaled; /* post after signaling. */
+  uv_mutex_t mutex;
+  uv_cond_t cond;
+  int use_broadcast;
+  int posted_1;
+  int posted_2;
+  signal_func signal_cond;
+  wait_func wait_cond;
+} worker_config;
+
+void worker_config_init(worker_config* wc,
+                        int use_broadcast,
+                        signal_func signal_f,
+                        wait_func wait_f) {
+  /* Wipe. */
+  memset(wc, 0, sizeof(*wc));
+
+  /* Copy vars. */
+  wc->signal_cond = signal_f;
+  wc->wait_cond = wait_f;
+  wc->use_broadcast = use_broadcast;
+
+  /* Init. */
+  ASSERT_OK(uv_sem_init(&wc->sem_waiting, 0));
+  ASSERT_OK(uv_sem_init(&wc->sem_signaled, 0));
+  ASSERT_OK(uv_cond_init(&wc->cond));
+  ASSERT_OK(uv_mutex_init(&wc->mutex));
+}
+
+void worker_config_destroy(worker_config* wc) {
+  uv_mutex_destroy(&wc->mutex);
+  uv_cond_destroy(&wc->cond);
+  uv_sem_destroy(&wc->sem_signaled);
+  uv_sem_destroy(&wc->sem_waiting);
+}
+
+/* arg is a worker_config.
+ * Call signal_cond then wait_cond.
+ * Partner should call wait then signal. */
+static void worker(void* arg) {
+  worker_config* c = arg;
+  c->signal_cond(c, &c->posted_1);
+  c->wait_cond(c, &c->posted_2);
+}
+
+/* 1. Signal a waiting waiter.
+ * 2. Tell waiter we finished. */
+static void condvar_signal(worker_config* c, int* flag) {
+  /* Wait until waiter holds mutex and is preparing to wait. */
+  uv_sem_wait(&c->sem_waiting);
+
+  /* Make sure waiter has begun waiting. */
+  uv_mutex_lock(&c->mutex);
+
+  /* Help waiter differentiate between spurious and legitimate wakeup. */
+  ASSERT_OK(*flag);
+  *flag = 1;
+
+  if (c->use_broadcast)
+    uv_cond_broadcast(&c->cond);
+  else
+    uv_cond_signal(&c->cond);
+
+  uv_mutex_unlock(&c->mutex);
+
+  /* Done signaling. */
+  uv_sem_post(&c->sem_signaled);
+}
+
+/* 1. Wait on a signal.
+ * 2. Ensure that the signaler finished. */
+static int condvar_wait(worker_config* c, const int* flag) {
+  uv_mutex_lock(&c->mutex);
+
+  /* Tell signal'er that I am waiting. */
+  uv_sem_post(&c->sem_waiting);
+
+  /* Wait until I get a non-spurious signal. */
+  do {
+    uv_cond_wait(&c->cond, &c->mutex);
+  } while (*flag == 0);
+  ASSERT_EQ(1, *flag);
+
+  uv_mutex_unlock(&c->mutex);
+
+  /* Wait for my signal'er to finish. */
+  uv_sem_wait(&c->sem_signaled);
+
+  return 0;
+}
+
+/* uv_cond_wait: One thread signals, the other waits. */
+TEST_IMPL(condvar_1) {
+  worker_config wc;
+  uv_thread_t thread;
+
+  /* Helper signal-then-wait. */
+  worker_config_init(&wc, 0, condvar_signal, condvar_wait);
+  ASSERT_OK(uv_thread_create(&thread, worker, &wc));
+
+  /* We wait-then-signal. */
+  ASSERT_OK(wc.wait_cond(&wc, &wc.posted_1));
+  wc.signal_cond(&wc, &wc.posted_2);
+
+  ASSERT_OK(uv_thread_join(&thread));
+  worker_config_destroy(&wc);
+
+  return 0;
+}
+
+/* uv_cond_wait: One thread broadcasts, the other waits. */
+TEST_IMPL(condvar_2) {
+  worker_config wc;
+  uv_thread_t thread;
+
+  /* Helper to signal-then-wait. */
+  worker_config_init(&wc, 1, condvar_signal, condvar_wait);
+  ASSERT_OK(uv_thread_create(&thread, worker, &wc));
+
+  /* We wait-then-signal. */
+  ASSERT_OK(wc.wait_cond(&wc, &wc.posted_1));
+  wc.signal_cond(&wc, &wc.posted_2);
+
+  ASSERT_OK(uv_thread_join(&thread));
+  worker_config_destroy(&wc);
+
+  return 0;
+}
+
+/* 1. Wait on a signal (hopefully not timeout, else we'll hang).
+ * 2. Ensure that the signaler finished. */
+static int condvar_timedwait(worker_config* c, const int* flag) {
+  int r;
+
+  r = 0;
+
+  uv_mutex_lock(&c->mutex);
+
+  /* Tell signal'er that I am waiting. */
+  uv_sem_post(&c->sem_waiting);
+
+  /* Wait until I get a non-spurious signal. */
+  do {
+    r = uv_cond_timedwait(&c->cond, &c->mutex, (uint64_t)(1 * 1e9)); /* 1 s */
+    ASSERT_OK(r); /* Should not time out. */
+  } while (*flag == 0);
+  ASSERT_EQ(1, *flag);
+
+  uv_mutex_unlock(&c->mutex);
+
+  /* Wait for my signal'er to finish. */
+  uv_sem_wait(&c->sem_signaled);
+  return r;
+}
+
+/* uv_cond_timedwait: One thread signals, the other timedwaits. */
+TEST_IMPL(condvar_3) {
+  worker_config wc;
+  uv_thread_t thread;
+
+  /* Helper to signal-then-wait. */
+  worker_config_init(&wc, 0, condvar_signal, condvar_timedwait);
+  ASSERT_OK(uv_thread_create(&thread, worker, &wc));
+
+  /* We wait-then-signal. */
+  wc.wait_cond(&wc, &wc.posted_1);
+  wc.signal_cond(&wc, &wc.posted_2);
+
+  ASSERT_OK(uv_thread_join(&thread));
+  worker_config_destroy(&wc);
+
+  return 0;
+}
+
+/* uv_cond_timedwait: One thread broadcasts, the other waits. */
+TEST_IMPL(condvar_4) {
+  worker_config wc;
+  uv_thread_t thread;
+
+  /* Helper to signal-then-wait. */
+  worker_config_init(&wc, 1, condvar_signal, condvar_timedwait);
+  ASSERT_OK(uv_thread_create(&thread, worker, &wc));
+
+  /* We wait-then-signal. */
+  wc.wait_cond(&wc, &wc.posted_1);
+  wc.signal_cond(&wc, &wc.posted_2);
+
+  ASSERT_OK(uv_thread_join(&thread));
+  worker_config_destroy(&wc);
+
+  return 0;
+}
+
+/* uv_cond_timedwait: One thread waits, no signal. Timeout should be delivered. */
+TEST_IMPL(condvar_5) {
+  worker_config wc;
+  uint64_t timeout;
+
+  timeout = 100 * 1000 * 1000; /* 100 ms in ns */
+
+  /* Mostly irrelevant. We need cond and mutex initialized. */
+  worker_config_init(&wc, 0, NULL, NULL);
+
+  uv_mutex_lock(&wc.mutex);
+
+  /* We wait. No signaler, so this will only return if timeout is delivered. */
+  ASSERT_EQ(UV_ETIMEDOUT, uv_cond_timedwait(&wc.cond, &wc.mutex, timeout));
+
+  uv_mutex_unlock(&wc.mutex);
+
+  worker_config_destroy(&wc);
+
+  return 0;
+}