SERVER-40085 Avoid using barriers in TimestampMonitorNotifiesListeners

1 files changed, 20 insertions, 10 deletions

diff --git a/src/mongo/db/storage/kv/kv_storage_engine_test.cpp b/src/mongo/db/storage/kv/kv_storage_engine_test.cpp
index 935bef73175..609df0dc661 100644
--- a/src/mongo/db/storage/kv/kv_storage_engine_test.cpp
+++ b/src/mongo/db/storage/kv/kv_storage_engine_test.cpp
@@ -573,34 +573,40 @@ TEST_F(TimestampKVEngineTest, TimestampListeners) {
 }
 
 TEST_F(TimestampKVEngineTest, TimestampMonitorNotifiesListeners) {
-    unittest::Barrier barrier(2);
+    stdx::mutex mutex;
+    stdx::condition_variable cv;
+
     bool changes[4] = {false, false, false, false};
 
     TimestampListener first(checkpoint, [&](Timestamp timestamp) {
+        stdx::lock_guard<stdx::mutex> lock(mutex);
         if (!changes[0]) {
             changes[0] = true;
-            barrier.countDownAndWait();
+            cv.notify_all();
         }
     });
 
     TimestampListener second(oldest, [&](Timestamp timestamp) {
+        stdx::lock_guard<stdx::mutex> lock(mutex);
         if (!changes[1]) {
             changes[1] = true;
-            barrier.countDownAndWait();
+            cv.notify_all();
         }
     });
 
     TimestampListener third(stable, [&](Timestamp timestamp) {
+        stdx::lock_guard<stdx::mutex> lock(mutex);
         if (!changes[2]) {
             changes[2] = true;
-            barrier.countDownAndWait();
+            cv.notify_all();
         }
     });
 
     TimestampListener fourth(stable, [&](Timestamp timestamp) {
+        stdx::lock_guard<stdx::mutex> lock(mutex);
         if (!changes[3]) {
             changes[3] = true;
-            barrier.countDownAndWait();
+            cv.notify_all();
         }
     });
 
@@ -610,11 +616,15 @@ TEST_F(TimestampKVEngineTest, TimestampMonitorNotifiesListeners) {
     _storageEngine->getTimestampMonitor()->addListener(&fourth);
 
     // Wait until all 4 listeners get notified at least once.
-    size_t listenersNotified = 0;
-    while (listenersNotified < 4) {
-        barrier.countDownAndWait();
-        listenersNotified++;
-    }
+    stdx::unique_lock<stdx::mutex> lk(mutex);
+    cv.wait(lk, [&] {
+        for (auto const& change : changes) {
+            if (!change) {
+                return false;
+            }
+        }
+        return true;
+    });
 
     _storageEngine->getTimestampMonitor()->removeListener(&first);
     _storageEngine->getTimestampMonitor()->removeListener(&second);