From 24d1d0802d2c6ff6d0b2e556c0c2b1a5ebf33493 Mon Sep 17 00:00:00 2001
From: Trevor Norris <trev.norris@gmail.com>
Date: Wed, 14 Jun 2023 10:25:55 -0600
Subject: [PATCH] src: don't run timers if loop is stopped/unref'd (#4048)

The initial run of timers shouldn't happen if uv_stop() has been run
before uv_run() was called, and for backwards compatibility they also
shouldn't run if they have been unref'd before calling uv_run().
---
 src/unix/core.c       |  5 ++---
 src/win/core.c        |  5 ++---
 test/test-list.h      |  4 ++++
 test/test-loop-stop.c | 11 +++++++++++
 test/test-timer.c     | 12 ++++++++++++
 5 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/src/unix/core.c b/src/unix/core.c
index 4db2b0af..0756364f 100644
--- a/src/unix/core.c
+++ b/src/unix/core.c
@@ -424,9 +424,8 @@ int uv_run(uv_loop_t* loop, uv_run_mode mode) {
    * while loop for UV_RUN_DEFAULT. Otherwise timers only need to be executed
    * once, which should be done after polling in order to maintain proper
    * execution order of the conceptual event loop. */
-  if (mode == UV_RUN_DEFAULT) {
-    if (r)
-      uv__update_time(loop);
+  if (mode == UV_RUN_DEFAULT && r != 0 && loop->stop_flag == 0) {
+    uv__update_time(loop);
     uv__run_timers(loop);
   }
 
diff --git a/src/win/core.c b/src/win/core.c
index 2ae8aa7d..e9885a0f 100644
--- a/src/win/core.c
+++ b/src/win/core.c
@@ -629,9 +629,8 @@ int uv_run(uv_loop_t *loop, uv_run_mode mode) {
    * while loop for UV_RUN_DEFAULT. Otherwise timers only need to be executed
    * once, which should be done after polling in order to maintain proper
    * execution order of the conceptual event loop. */
-  if (mode == UV_RUN_DEFAULT) {
-    if (r)
-      uv_update_time(loop);
+  if (mode == UV_RUN_DEFAULT && r != 0 && loop->stop_flag == 0) {
+    uv_update_time(loop);
     uv__run_timers(loop);
   }
 
diff --git a/test/test-list.h b/test/test-list.h
index b2c88170..0d385f21 100644
--- a/test/test-list.h
+++ b/test/test-list.h
@@ -29,6 +29,7 @@ TEST_DECLARE   (loop_alive)
 TEST_DECLARE   (loop_close)
 TEST_DECLARE   (loop_instant_close)
 TEST_DECLARE   (loop_stop)
+TEST_DECLARE   (loop_stop_before_run)
 TEST_DECLARE   (loop_update_time)
 TEST_DECLARE   (loop_backend_timeout)
 TEST_DECLARE   (loop_configure)
@@ -233,6 +234,7 @@ TEST_DECLARE   (timer_null_callback)
 TEST_DECLARE   (timer_early_check)
 TEST_DECLARE   (timer_no_double_call_once)
 TEST_DECLARE   (timer_no_double_call_nowait)
+TEST_DECLARE   (timer_no_run_on_unref)
 TEST_DECLARE   (idle_starvation)
 TEST_DECLARE   (idle_check)
 TEST_DECLARE   (loop_handles)
@@ -573,6 +575,7 @@ TASK_LIST_START
   TEST_ENTRY  (loop_close)
   TEST_ENTRY  (loop_instant_close)
   TEST_ENTRY  (loop_stop)
+  TEST_ENTRY  (loop_stop_before_run)
   TEST_ENTRY  (loop_update_time)
   TEST_ENTRY  (loop_backend_timeout)
   TEST_ENTRY  (loop_configure)
@@ -846,6 +849,7 @@ TASK_LIST_START
   TEST_ENTRY  (timer_early_check)
   TEST_ENTRY  (timer_no_double_call_once)
   TEST_ENTRY  (timer_no_double_call_nowait)
+  TEST_ENTRY  (timer_no_run_on_unref)
 
   TEST_ENTRY  (idle_starvation)
   TEST_ENTRY  (idle_check)
diff --git a/test/test-loop-stop.c b/test/test-loop-stop.c
index 02aa12f1..981d20d1 100644
--- a/test/test-loop-stop.c
+++ b/test/test-loop-stop.c
@@ -70,3 +70,14 @@ TEST_IMPL(loop_stop) {
   MAKE_VALGRIND_HAPPY(uv_default_loop());
   return 0;
 }
+
+
+TEST_IMPL(loop_stop_before_run) {
+  ASSERT_OK(uv_timer_init(uv_default_loop(), &timer_handle));
+  ASSERT_OK(uv_timer_start(&timer_handle, (uv_timer_cb) abort, 0, 0));
+  uv_stop(uv_default_loop());
+  ASSERT_NE(uv_run(uv_default_loop(), UV_RUN_DEFAULT), 0);
+
+  MAKE_VALGRIND_HAPPY(uv_default_loop());
+  return 0;
+}
diff --git a/test/test-timer.c b/test/test-timer.c
index eb54bb25..2488f14c 100644
--- a/test/test-timer.c
+++ b/test/test-timer.c
@@ -407,3 +407,15 @@ TEST_IMPL(timer_no_double_call_nowait) {
   MAKE_VALGRIND_HAPPY(uv_default_loop());
   return 0;
 }
+
+TEST_IMPL(timer_no_run_on_unref) {
+  uv_timer_t timer_handle;
+
+  ASSERT_OK(uv_timer_init(uv_default_loop(), &timer_handle));
+  ASSERT_OK(uv_timer_start(&timer_handle, (uv_timer_cb) abort, 0, 0));
+  uv_unref((uv_handle_t*) &timer_handle);
+  ASSERT_EQ(uv_run(uv_default_loop(), UV_RUN_DEFAULT), 0);
+
+  MAKE_VALGRIND_HAPPY(uv_default_loop());
+  return 0;
+}