From 38824e721ebaa3f50e443e1ea4b47d34030e4703 Mon Sep 17 00:00:00 2001
From: Konstantin Varlamov <var-const@users.noreply.github.com>
Date: Mon, 7 May 2018 12:22:57 -0400
Subject: 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.
---
 .../firestore/util/async_queue_test_libdispatch.cc | 86 ++++++++++++++++++++++
 1 file changed, 86 insertions(+)
 create mode 100644 Firestore/core/test/firebase/firestore/util/async_queue_test_libdispatch.cc

(limited to 'Firestore/core/test/firebase/firestore/util/async_queue_test_libdispatch.cc')

diff --git a/Firestore/core/test/firebase/firestore/util/async_queue_test_libdispatch.cc b/Firestore/core/test/firebase/firestore/util/async_queue_test_libdispatch.cc
new file mode 100644
index 0000000..b4b9c63
--- /dev/null
+++ b/Firestore/core/test/firebase/firestore/util/async_queue_test_libdispatch.cc
@@ -0,0 +1,86 @@
+/*
+ * 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.
+ */
+
+#include "Firestore/core/test/firebase/firestore/util/async_queue_test.h"
+
+#include "Firestore/core/src/firebase/firestore/util/executor_libdispatch.h"
+
+#include "absl/memory/memory.h"
+#include "gtest/gtest.h"
+
+namespace firebase {
+namespace firestore {
+namespace util {
+
+namespace {
+
+dispatch_queue_t CreateDispatchQueue() {
+  return dispatch_queue_create("AsyncQueueTests", DISPATCH_QUEUE_SERIAL);
+}
+
+std::unique_ptr<internal::Executor> CreateExecutorFromQueue(
+    const dispatch_queue_t queue) {
+  return absl::make_unique<internal::ExecutorLibdispatch>(queue);
+}
+
+std::unique_ptr<internal::Executor> CreateExecutorLibdispatch() {
+  return CreateExecutorFromQueue(CreateDispatchQueue());
+}
+
+}  // namespace
+
+INSTANTIATE_TEST_CASE_P(AsyncQueueLibdispatch,
+                        AsyncQueueTest,
+                        ::testing::Values(CreateExecutorLibdispatch));
+
+class AsyncQueueTestLibdispatchOnly : public TestWithTimeoutMixin,
+                                      public ::testing::Test {
+ public:
+  AsyncQueueTestLibdispatchOnly()
+      : underlying_queue{CreateDispatchQueue()},
+        queue{CreateExecutorFromQueue(underlying_queue)} {
+  }
+
+  dispatch_queue_t underlying_queue;
+  AsyncQueue queue;
+};
+
+// Additional tests to see how libdispatch-based version of `AsyncQueue`
+// interacts with raw usage of libdispatch.
+
+TEST_F(AsyncQueueTestLibdispatchOnly, SameQueueIsAllowedForUnownedActions) {
+  internal::DispatchAsync(underlying_queue, [this] {
+    queue.Enqueue([this] { signal_finished(); });
+  });
+  EXPECT_TRUE(WaitForTestToFinish());
+}
+
+TEST_F(AsyncQueueTestLibdispatchOnly,
+       VerifyIsCurrentQueueRequiresOperationInProgress) {
+  internal::DispatchSync(underlying_queue, [this] {
+    EXPECT_ANY_THROW(queue.VerifyIsCurrentQueue());
+  });
+}
+
+TEST_F(AsyncQueueTestLibdispatchOnly,
+       VerifyIsCurrentQueueRequiresBeingCalledAsync) {
+  ASSERT_NE(underlying_queue, dispatch_get_main_queue());
+  EXPECT_ANY_THROW(queue.VerifyIsCurrentQueue());
+}
+
+}  // namespace util
+}  // namespace firestore
+}  // namespace firebase
-- 
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