From 4dfa808e75fbf0fd94a9787c596bedaabb684215 Mon Sep 17 00:00:00 2001
From: Prashant Jaikumar <pjaikumar@google.com>
Date: Fri, 23 Aug 2019 17:12:41 -0700
Subject: [PATCH] Add test for timer expiry racing with cancelation

---
 test/cpp/common/timer_test.cc | 71 +++++++++++++++++++++++++++++------
 1 file changed, 60 insertions(+), 11 deletions(-)

diff --git a/test/cpp/common/timer_test.cc b/test/cpp/common/timer_test.cc
index 9b23be2885a..1abed1660e8 100644
--- a/test/cpp/common/timer_test.cc
+++ b/test/cpp/common/timer_test.cc
@@ -77,7 +77,7 @@ TEST_F(TimerTest, OneTimerExpires) {
   grpc_core::ExecCtx exec_ctx;
   grpc_timer timer;
   int timer_fired = 0;
-  grpc_timer_init(&timer, 500,
+  grpc_timer_init(&timer, grpc_core::ExecCtx::Get()->Now() + 500,
                   GRPC_CLOSURE_CREATE(
                       [](void* arg, grpc_error*) {
                         int* timer_fired = static_cast<int*>(arg);
@@ -102,7 +102,7 @@ TEST_F(TimerTest, MultipleTimersExpire) {
   grpc_timer timers[kNumTimers];
   int timer_fired = 0;
   for (int i = 0; i < kNumTimers; ++i) {
-    grpc_timer_init(&timers[i], 500 + i,
+    grpc_timer_init(&timers[i], grpc_core::ExecCtx::Get()->Now() + 500 + i,
                     GRPC_CLOSURE_CREATE(
                         [](void* arg, grpc_error*) {
                           int* timer_fired = static_cast<int*>(arg);
@@ -129,7 +129,7 @@ TEST_F(TimerTest, CancelSomeTimers) {
   grpc_timer timers[kNumTimers];
   int timer_fired = 0;
   for (int i = 0; i < kNumTimers; ++i) {
-    grpc_timer_init(&timers[i], 500 + i,
+    grpc_timer_init(&timers[i], grpc_core::ExecCtx::Get()->Now() + 500 + i,
                     GRPC_CLOSURE_CREATE(
                         [](void* arg, grpc_error* error) {
                           if (error == GRPC_ERROR_CANCELLED) {
@@ -157,17 +157,66 @@ TEST_F(TimerTest, CancelSomeTimers) {
 
 // Enable the following test after
 // https://github.com/grpc/grpc/issues/20049 has been fixed.
-#if 0
-TEST_F(TimerTest, TimerNotCanceled) {
+TEST_F(TimerTest, DISABLED_TimerNotCanceled) {
   grpc_core::ExecCtx exec_ctx;
   grpc_timer timer;
-  grpc_timer_init(&timer, 10000,
-                  GRPC_CLOSURE_CREATE(
-                      [](void*, grpc_error*) {
-                      },
-                      nullptr, grpc_schedule_on_exec_ctx));
+  grpc_timer_init(&timer, grpc_core::ExecCtx::Get()->Now() + 10000,
+                  GRPC_CLOSURE_CREATE([](void*, grpc_error*) {}, nullptr,
+                                      grpc_schedule_on_exec_ctx));
+}
+
+// Enable the following test after
+// https://github.com/grpc/grpc/issues/20064 has been fixed.
+TEST_F(TimerTest, DISABLED_CancelRace) {
+  MAYBE_SKIP_TEST;
+  grpc_core::ExecCtx exec_ctx;
+  const int kNumTimers = 10;
+  grpc_timer timers[kNumTimers];
+  for (int i = 0; i < kNumTimers; ++i) {
+    grpc_timer* arg = (i != 0) ? &timers[i - 1] : nullptr;
+    grpc_timer_init(&timers[i], grpc_core::ExecCtx::Get()->Now() + 100,
+                    GRPC_CLOSURE_CREATE(
+                        [](void* arg, grpc_error* error) {
+                          grpc_timer* timer = static_cast<grpc_timer*>(arg);
+                          if (timer) {
+                            grpc_timer_cancel(timer);
+                          }
+                        },
+                        arg, grpc_schedule_on_exec_ctx));
+  }
+  gpr_sleep_until(grpc_timeout_milliseconds_to_deadline(100));
+}
+
+// Enable the following test after
+// https://github.com/grpc/grpc/issues/20066 has been fixed.
+TEST_F(TimerTest, DISABLED_CancelNextTimer) {
+  MAYBE_SKIP_TEST;
+  grpc_core::ExecCtx exec_ctx;
+  const int kNumTimers = 10;
+  grpc_timer timers[kNumTimers];
+
+  for (int i = 0; i < kNumTimers; ++i) {
+    grpc_timer_init_unset(&timers[i]);
+  }
+
+  for (int i = 0; i < kNumTimers; ++i) {
+    grpc_timer* arg = nullptr;
+    if (i < kNumTimers - 1) {
+      arg = &timers[i + 1];
+    }
+    grpc_timer_init(&timers[i], grpc_core::ExecCtx::Get()->Now() + 100,
+                    GRPC_CLOSURE_CREATE(
+                        [](void* arg, grpc_error* error) {
+                          grpc_timer* timer = static_cast<grpc_timer*>(arg);
+                          if (timer) {
+                            grpc_timer_cancel(timer);
+                          }
+                        },
+                        arg, grpc_schedule_on_exec_ctx));
+  }
+  grpc_timer_cancel(&timers[0]);
+  gpr_sleep_until(grpc_timeout_milliseconds_to_deadline(100));
 }
-#endif
 
 int main(int argc, char** argv) {
   grpc::testing::TestEnvironment env(argc, argv);