From c8046ad6bc847dd825b5969e176989954ca7793b Mon Sep 17 00:00:00 2001
From: Esun Kim <veblush@google.com>
Date: Wed, 30 Sep 2020 11:57:00 -0700
Subject: [PATCH] Skip eventmanager_libuv_test under TSAN

---
 test/core/iomgr/poller/BUILD                      | 5 +++++
 test/core/iomgr/poller/eventmanager_libuv_test.cc | 4 ++++
 2 files changed, 9 insertions(+)

diff --git a/test/core/iomgr/poller/BUILD b/test/core/iomgr/poller/BUILD
index 28d36195cc8..e5998f3546c 100644
--- a/test/core/iomgr/poller/BUILD
+++ b/test/core/iomgr/poller/BUILD
@@ -28,6 +28,11 @@ grpc_cc_test(
         "gtest",
     ],
     language = "C++",
+    tags = [
+        # TSAN has a false-positive for ShutdownRefAsync
+        # https://github.com/grpc/grpc/issues/24242
+        "notsan",
+    ],
     uses_polling = False,
     deps = [
         "//:eventmanager_libuv",
diff --git a/test/core/iomgr/poller/eventmanager_libuv_test.cc b/test/core/iomgr/poller/eventmanager_libuv_test.cc
index 724a7a2f235..8443e9f4c02 100644
--- a/test/core/iomgr/poller/eventmanager_libuv_test.cc
+++ b/test/core/iomgr/poller/eventmanager_libuv_test.cc
@@ -58,6 +58,10 @@ TEST(LibuvEventManager, ShutdownRefAsync) {
     for (int j = 0; j < i; j++) {
       em->ShutdownRef();
     }
+    // TSAN doesn't like this approach although this would work. TSAN considers
+    // it dangerous to have a destructor being called while its member function
+    // is called but LibuvEventManager handles this by making LibuvEventManager
+    // wait until all pending operations finish.
     grpc_core::Thread deleter(
         "deleter", [](void* em) { delete static_cast<LibuvEventManager*>(em); },
         em);