From 3e0b846bdb3afb3730d8fd37f28445438e0eef9e Mon Sep 17 00:00:00 2001
From: Trevor Norris <trev.norris@gmail.com>
Date: Tue, 28 Mar 2023 14:47:15 -0600
Subject: [PATCH] bench: add bench to check uv_loop_alive (#4065 1/2)

---
 test/benchmark-list.h       |  2 ++
 test/benchmark-loop-count.c | 42 +++++++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/test/benchmark-list.h b/test/benchmark-list.h
index 1ab8f258..901e5ffa 100644
--- a/test/benchmark-list.h
+++ b/test/benchmark-list.h
@@ -22,6 +22,7 @@
 BENCHMARK_DECLARE (sizes)
 BENCHMARK_DECLARE (loop_count)
 BENCHMARK_DECLARE (loop_count_timed)
+BENCHMARK_DECLARE (loop_alive)
 BENCHMARK_DECLARE (ping_pongs)
 BENCHMARK_DECLARE (ping_udp1)
 BENCHMARK_DECLARE (ping_udp10)
@@ -89,6 +90,7 @@ TASK_LIST_START
   BENCHMARK_ENTRY  (sizes)
   BENCHMARK_ENTRY  (loop_count)
   BENCHMARK_ENTRY  (loop_count_timed)
+  BENCHMARK_ENTRY  (loop_alive)
 
   BENCHMARK_ENTRY  (ping_pongs)
   BENCHMARK_HELPER (ping_pongs, tcp4_echo_server)
diff --git a/test/benchmark-loop-count.c b/test/benchmark-loop-count.c
index 4aa39867..72f25b56 100644
--- a/test/benchmark-loop-count.c
+++ b/test/benchmark-loop-count.c
@@ -26,6 +26,7 @@
 #include <stdlib.h>
 
 #define NUM_TICKS (2 * 1000 * 1000)
+#define NUM_TICKS2 (2 * 1000 * 1000 * 100)
 
 static unsigned long ticks;
 static uv_idle_t idle_handle;
@@ -37,6 +38,19 @@ static void idle_cb(uv_idle_t* handle) {
     uv_idle_stop(handle);
 }
 
+static void idle_alive_cb(uv_idle_t* handle) {
+  int ticks = 0;
+
+  while (++ticks < NUM_TICKS2) {
+    int r = uv_loop_alive(handle->loop);
+    if (r == 0)
+      abort();
+  }
+
+  *(int*)handle->data = ticks;
+  uv_idle_stop(handle);
+}
+
 
 static void idle2_cb(uv_idle_t* handle) {
   ticks++;
@@ -90,3 +104,31 @@ BENCHMARK_IMPL(loop_count_timed) {
   MAKE_VALGRIND_HAPPY(loop);
   return 0;
 }
+
+/* Measure the performance of running uv_loop_alive(). Adding this so we can get
+ * some sort of metric for the impact of switching active_reqs.count to use
+ * atomics. No other code sits in a hot path. */
+BENCHMARK_IMPL(loop_alive) {
+  uv_loop_t* loop = uv_default_loop();
+  int ticks = 0;
+  uint64_t ns;
+
+  uv_idle_init(loop, &idle_handle);
+  idle_handle.data = &ticks;
+  uv_idle_start(&idle_handle, idle_alive_cb);
+
+  ns = uv_hrtime();
+  uv_run(loop, UV_RUN_DEFAULT);
+  ns = uv_hrtime() - ns;
+
+  ASSERT_EQ(ticks, NUM_TICKS2);
+
+  fprintf(stderr, "loop_alive: %d ticks in %.2fs (%.0f/s)\n",
+          NUM_TICKS2,
+          ns / 1e9,
+          NUM_TICKS2 / (ns / 1e9));
+  fflush(stderr);
+
+  MAKE_VALGRIND_HAPPY(loop);
+  return 0;
+}