C++ migration: add AsyncQueue, the C++ version of FSTDispatchQueue (#1176)

AsyncQueue is a queue that executes given operations asynchronously,
enforcing that only a single operation is executing at any given time,
and that in-progress operations don't spawn more operations. The actual
execution is delegated to a platform-specific executor. Executor is an
interface for a FIFO queue that executes given operations serially. Two
implementations of Executor, one using libdispatch and the other using
C++11 standard library, are provided.

AsyncQueue is not used anywhere in the code base at this point.

1 files changed, 46 insertions, 0 deletions

diff --git a/Firestore/core/test/firebase/firestore/util/executor_test.h b/Firestore/core/test/firebase/firestore/util/executor_test.h
new file mode 100644
index 0000000..8b78d50
--- /dev/null
+++ b/Firestore/core/test/firebase/firestore/util/executor_test.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright 2018 Google
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef FIRESTORE_CORE_TEST_FIREBASE_FIRESTORE_UTIL_EXECUTOR_TEST_H_
+#define FIRESTORE_CORE_TEST_FIREBASE_FIRESTORE_UTIL_EXECUTOR_TEST_H_
+
+#include <memory>
+
+#include "gtest/gtest.h"
+
+#include "Firestore/core/src/firebase/firestore/util/executor.h"
+#include "Firestore/core/test/firebase/firestore/util/async_tests_util.h"
+
+namespace firebase {
+namespace firestore {
+namespace util {
+
+using FactoryFunc = std::unique_ptr<internal::Executor> (*)();
+
+class ExecutorTest : public TestWithTimeoutMixin,
+                     public ::testing::TestWithParam<FactoryFunc> {
+ public:
+  // `GetParam()` must return a factory function.
+  ExecutorTest() : executor{GetParam()()} {
+  }
+
+  std::unique_ptr<internal::Executor> executor;
+};
+}  // namespace util
+}  // namespace firestore
+}  // namespace firebase
+
+#endif  // FIRESTORE_CORE_TEST_FIREBASE_FIRESTORE_UTIL_EXECUTOR_TEST_H_