From b203ed3c071361826f3b24d940e6bfa1c3d19f81 Mon Sep 17 00:00:00 2001
From: Alexander Polcyn <apolcyn@google.com>
Date: Fri, 30 Nov 2018 01:59:15 -0800
Subject: Cancel still-active c-ares queries after 10 seconds to avoid chance
 of deadlock

---
 test/cpp/naming/cancel_ares_query_test.cc | 59 ++++++++++++++++++++++++++++---
 1 file changed, 54 insertions(+), 5 deletions(-)

(limited to 'test/cpp/naming')

diff --git a/test/cpp/naming/cancel_ares_query_test.cc b/test/cpp/naming/cancel_ares_query_test.cc
index dec7c171dc..4c7a7c3735 100644
--- a/test/cpp/naming/cancel_ares_query_test.cc
+++ b/test/cpp/naming/cancel_ares_query_test.cc
@@ -260,8 +260,15 @@ TEST(CancelDuringAresQuery, TestFdsAreDeletedFromPollsetSet) {
   grpc_pollset_set_destroy(fake_other_pollset_set);
 }
 
-TEST(CancelDuringAresQuery,
-     TestHitDeadlineAndDestroyChannelDuringAresResolutionIsGraceful) {
+// Settings for TestCancelDuringActiveQuery test
+typedef enum {
+  NONE,
+  SHORT,
+  ZERO,
+} cancellation_test_query_timeout_setting;
+
+void TestCancelDuringActiveQuery(
+    cancellation_test_query_timeout_setting query_timeout_setting) {
   // Start up fake non responsive DNS server
   int fake_dns_port = grpc_pick_unused_port_or_die();
   FakeNonResponsiveDNSServer fake_dns_server(fake_dns_port);
@@ -271,9 +278,33 @@ TEST(CancelDuringAresQuery,
       &client_target,
       "dns://[::1]:%d/dont-care-since-wont-be-resolved.test.com:1234",
       fake_dns_port));
+  gpr_log(GPR_DEBUG, "TestCancelActiveDNSQuery. query timeout setting: %d",
+          query_timeout_setting);
+  grpc_channel_args* client_args = nullptr;
+  grpc_status_code expected_status_code = GRPC_STATUS_OK;
+  if (query_timeout_setting == NONE) {
+    expected_status_code = GRPC_STATUS_DEADLINE_EXCEEDED;
+    client_args = nullptr;
+  } else if (query_timeout_setting == SHORT) {
+    expected_status_code = GRPC_STATUS_UNAVAILABLE;
+    grpc_arg arg;
+    arg.type = GRPC_ARG_INTEGER;
+    arg.key = const_cast<char*>(GRPC_ARG_DNS_ARES_QUERY_TIMEOUT_MS);
+    arg.value.integer =
+        1;  // Set this shorter than the call deadline so that it goes off.
+    client_args = grpc_channel_args_copy_and_add(nullptr, &arg, 1);
+  } else if (query_timeout_setting == ZERO) {
+    expected_status_code = GRPC_STATUS_DEADLINE_EXCEEDED;
+    grpc_arg arg;
+    arg.type = GRPC_ARG_INTEGER;
+    arg.key = const_cast<char*>(GRPC_ARG_DNS_ARES_QUERY_TIMEOUT_MS);
+    arg.value.integer = 0;  // Set this to zero to disable query timeouts.
+    client_args = grpc_channel_args_copy_and_add(nullptr, &arg, 1);
+  } else {
+    abort();
+  }
   grpc_channel* client =
-      grpc_insecure_channel_create(client_target,
-                                   /* client_args */ nullptr, nullptr);
+      grpc_insecure_channel_create(client_target, client_args, nullptr);
   gpr_free(client_target);
   grpc_completion_queue* cq = grpc_completion_queue_create_for_next(nullptr);
   cq_verifier* cqv = cq_verifier_create(cq);
@@ -325,8 +356,9 @@ TEST(CancelDuringAresQuery,
   EXPECT_EQ(GRPC_CALL_OK, error);
   CQ_EXPECT_COMPLETION(cqv, Tag(1), 1);
   cq_verify(cqv);
-  EXPECT_EQ(status, GRPC_STATUS_DEADLINE_EXCEEDED);
+  EXPECT_EQ(status, expected_status_code);
   // Teardown
+  grpc_channel_args_destroy(client_args);
   grpc_slice_unref(details);
   gpr_free((void*)error_string);
   grpc_metadata_array_destroy(&initial_metadata_recv);
@@ -338,6 +370,23 @@ TEST(CancelDuringAresQuery,
   EndTest(client, cq);
 }
 
+TEST(CancelDuringAresQuery,
+     TestHitDeadlineAndDestroyChannelDuringAresResolutionIsGraceful) {
+  TestCancelDuringActiveQuery(NONE /* don't set query timeouts */);
+}
+
+TEST(
+    CancelDuringAresQuery,
+    TestHitDeadlineAndDestroyChannelDuringAresResolutionWithQueryTimeoutIsGraceful) {
+  TestCancelDuringActiveQuery(SHORT /* set short query timeout */);
+}
+
+TEST(
+    CancelDuringAresQuery,
+    TestHitDeadlineAndDestroyChannelDuringAresResolutionWithZeroQueryTimeoutIsGraceful) {
+  TestCancelDuringActiveQuery(ZERO /* disable query timeouts */);
+}
+
 }  // namespace
 
 int main(int argc, char** argv) {
-- 
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