Roll forward to cl/338482889

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

cpp/platform/public/single_thread_executor_test.cc

@@ -0,0 +1,71 @@
+#include "platform/public/single_thread_executor.h"
+
+#include <atomic>
+#include <functional>
+
+#include "platform/base/exception.h"
+#include "gtest/gtest.h"
+#include "absl/synchronization/mutex.h"
+#include "absl/time/clock.h"
+
+namespace location {
+namespace nearby {
+
+TEST(SingleThreadExecutorTest, ConsructorDestructorWorks) {
+  SingleThreadExecutor executor;
+}
+
+TEST(SingleThreadExecutorTest, CanExecute) {
+  absl::CondVar cond;
+  std::atomic_bool done = false;
+  SingleThreadExecutor executor;
+  executor.Execute([&done, &cond]() {
+    done = true;
+    cond.SignalAll();
+  });
+  absl::Mutex mutex;
+  {
+    absl::MutexLock lock(&mutex);
+    if (!done) {
+      cond.WaitWithTimeout(&mutex, absl::Seconds(1));
+    }
+  }
+  EXPECT_TRUE(done);
+}
+
+TEST(SingleThreadExecutorTest, JobsExecuteInOrder) {
+  std::vector<int> results;
+  SingleThreadExecutor executor;
+
+  for (int i = 0; i < 10; ++i) {
+    executor.Execute([i, &results]() { results.push_back(i); });
+  }
+
+  absl::CondVar cond;
+  std::atomic_bool done = false;
+  executor.Execute([&done, &cond]() {
+    done = true;
+    cond.SignalAll();
+  });
+  absl::Mutex mutex;
+  {
+    absl::MutexLock lock(&mutex);
+    if (!done) {
+      cond.WaitWithTimeout(&mutex, absl::Seconds(1));
+    }
+  }
+  EXPECT_TRUE(done);
+  EXPECT_EQ(results, (std::vector<int>{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}));
+}
+
+TEST(SingleThreadExecutorTest, CanSubmit) {
+  SingleThreadExecutor executor;
+  Future<bool> future;
+  bool submitted =
+      executor.Submit<bool>([]() { return ExceptionOr<bool>{true}; }, &future);
+  EXPECT_TRUE(submitted);
+  EXPECT_TRUE(future.Get().result());
+}
+
+}  // namespace nearby
+}  // namespace location