Roll forward to cl/338482889

Signed-off-by: Alexey Polyudov <apolyudov@google.com>
Change-Id: I9850950db8bd84f0904ea1a413151887f52098cf

cpp/platform/public/condition_variable_test.cc

@@ -0,0 +1,68 @@
+#include "platform/public/condition_variable.h"
+
+#include "platform/public/logging.h"
+#include "platform/public/mutex.h"
+#include "platform/public/single_thread_executor.h"
+#include "platform/public/system_clock.h"
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "absl/time/time.h"
+
+namespace location {
+namespace nearby {
+namespace {
+
+TEST(ConditionVariableTest, CanCreate) {
+  Mutex mutex;
+  ConditionVariable cond{&mutex};
+}
+
+TEST(ConditionVariableTest, CanWakeupWaiter) {
+  Mutex mutex;
+  ConditionVariable cond{&mutex};
+  bool done = false;
+  bool waiting = false;
+  NEARBY_LOG(INFO, "At start; done=%d", done);
+  {
+    SingleThreadExecutor executor;
+    executor.Execute([&cond, &mutex, &done, &waiting]() {
+      MutexLock lock(&mutex);
+      NEARBY_LOG(INFO, "Before cond.Wait(); done=%d", done);
+      waiting = true;
+      cond.Wait();
+      waiting = false;
+      done = true;
+      NEARBY_LOG(INFO, "After cond.Wait(); done=%d", done);
+    });
+    while (true) {
+      {
+        MutexLock lock(&mutex);
+        if (waiting) break;
+      }
+      SystemClock::Sleep(absl::Milliseconds(100));
+    }
+    {
+      MutexLock lock(&mutex);
+      cond.Notify();
+      EXPECT_FALSE(done);
+    }
+  }
+  NEARBY_LOG(INFO, "After executor shutdown: done=%d", done);
+  EXPECT_TRUE(done);
+}
+
+TEST(ConditionVariableTest, WaitTerminatesOnTimeoutWithoutNotify) {
+  Mutex mutex;
+  ConditionVariable cond{&mutex};
+  MutexLock lock(&mutex);
+
+  const absl::Duration kWaitTime = absl::Milliseconds(100);
+  absl::Time start = SystemClock::ElapsedRealtime();
+  cond.Wait(kWaitTime);
+  absl::Duration duration = SystemClock::ElapsedRealtime() - start;
+  EXPECT_GE(duration, kWaitTime);
+}
+
+}  // namespace
+}  // namespace nearby
+}  // namespace location