Merge pull request #8866 from ctiller/fixit5

Fix filter_latency tests

test/core/end2end/tests/filter_latency.c

@@ -226,18 +226,6 @@ static void test_request(grpc_end2end_test_config config) {
   grpc_call_destroy(s);
   grpc_call_destroy(c);
 
-  const gpr_timespec end_time = gpr_now(GPR_CLOCK_MONOTONIC);
-  const gpr_timespec max_latency = gpr_time_sub(end_time, start_time);
-
-  gpr_mu_lock(&g_mu);
-  GPR_ASSERT(gpr_time_cmp(max_latency, g_client_latency) >= 0);
-  GPR_ASSERT(gpr_time_cmp(gpr_time_0(GPR_TIMESPAN), g_client_latency) < 0);
-  GPR_ASSERT(gpr_time_cmp(max_latency, g_server_latency) >= 0);
-  GPR_ASSERT(gpr_time_cmp(gpr_time_0(GPR_TIMESPAN), g_server_latency) < 0);
-  // Server latency should always be smaller than client latency.
-  GPR_ASSERT(gpr_time_cmp(g_server_latency, g_client_latency) < 0);
-  gpr_mu_unlock(&g_mu);
-
   cq_verifier_destroy(cqv);
 
   grpc_byte_buffer_destroy(request_payload);
@@ -245,6 +233,24 @@ static void test_request(grpc_end2end_test_config config) {
 
   end_test(&f);
   config.tear_down_data(&f);
+
+  const gpr_timespec end_time = gpr_now(GPR_CLOCK_MONOTONIC);
+  const gpr_timespec max_latency = gpr_time_sub(end_time, start_time);
+
+  // Perform checks after test tear-down
+  // Guards against the case that there's outstanding channel-related work on a
+  // call prior to verification
+  gpr_mu_lock(&g_mu);
+  GPR_ASSERT(gpr_time_cmp(max_latency, g_client_latency) >= 0);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_0(GPR_TIMESPAN), g_client_latency) <= 0);
+  GPR_ASSERT(gpr_time_cmp(max_latency, g_server_latency) >= 0);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_0(GPR_TIMESPAN), g_server_latency) <= 0);
+  // Server latency should always be smaller than client latency, however since
+  // we only calculate latency at destruction time, and that might mean that we
+  // need to wait for outstanding channel-related work, this isn't verifiable
+  // right now (the server MAY hold on to the call for longer than the client).
+  // GPR_ASSERT(gpr_time_cmp(g_server_latency, g_client_latency) < 0);
+  gpr_mu_unlock(&g_mu);
 }
 
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