1 files changed, 188 insertions, 0 deletions
diff --git a/third_party/libwebrtc/api/task_queue/pending_task_safety_flag_unittest.cc b/third_party/libwebrtc/api/task_queue/pending_task_safety_flag_unittest.cc
new file mode 100644
index 0000000000..cedf0eb8df
--- /dev/null
+++ b/third_party/libwebrtc/api/task_queue/pending_task_safety_flag_unittest.cc
@@ -0,0 +1,188 @@
+/*
+ *  Copyright 2019 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "api/task_queue/pending_task_safety_flag.h"
+
+#include <memory>
+
+#include "rtc_base/event.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/task_queue_for_test.h"
+#include "test/gmock.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+
+TEST(PendingTaskSafetyFlagTest, Basic) {
+  rtc::scoped_refptr<PendingTaskSafetyFlag> safety_flag;
+  {
+    // Scope for the `owner` instance.
+    class Owner {
+     public:
+      Owner() = default;
+      ~Owner() { flag_->SetNotAlive(); }
+
+      rtc::scoped_refptr<PendingTaskSafetyFlag> flag_ =
+          PendingTaskSafetyFlag::Create();
+    } owner;
+    EXPECT_TRUE(owner.flag_->alive());
+    safety_flag = owner.flag_;
+    EXPECT_TRUE(safety_flag->alive());
+  }
+  // `owner` now out of scope.
+  EXPECT_FALSE(safety_flag->alive());
+}
+
+TEST(PendingTaskSafetyFlagTest, BasicScoped) {
+  rtc::scoped_refptr<PendingTaskSafetyFlag> safety_flag;
+  {
+    struct Owner {
+      ScopedTaskSafety safety;
+    } owner;
+    safety_flag = owner.safety.flag();
+    EXPECT_TRUE(safety_flag->alive());
+  }
+  // `owner` now out of scope.
+  EXPECT_FALSE(safety_flag->alive());
+}
+
+TEST(PendingTaskSafetyFlagTest, PendingTaskSuccess) {
+  TaskQueueForTest tq1("OwnerHere");
+  TaskQueueForTest tq2("OwnerNotHere");
+
+  class Owner {
+   public:
+    Owner() : tq_main_(TaskQueueBase::Current()) { RTC_DCHECK(tq_main_); }
+    ~Owner() {
+      RTC_DCHECK(tq_main_->IsCurrent());
+      flag_->SetNotAlive();
+    }
+
+    void DoStuff() {
+      RTC_DCHECK(!tq_main_->IsCurrent());
+      rtc::scoped_refptr<PendingTaskSafetyFlag> safe = flag_;
+      tq_main_->PostTask([safe = std::move(safe), this]() {
+        if (!safe->alive())
+          return;
+        stuff_done_ = true;
+      });
+    }
+
+    bool stuff_done() const { return stuff_done_; }
+
+   private:
+    TaskQueueBase* const tq_main_;
+    bool stuff_done_ = false;
+    rtc::scoped_refptr<PendingTaskSafetyFlag> flag_ =
+        PendingTaskSafetyFlag::Create();
+  };
+
+  std::unique_ptr<Owner> owner;
+  tq1.SendTask([&owner]() {
+    owner = std::make_unique<Owner>();
+    EXPECT_FALSE(owner->stuff_done());
+  });
+  ASSERT_TRUE(owner);
+  tq2.SendTask([&owner]() { owner->DoStuff(); });
+  tq1.SendTask([&owner]() {
+    EXPECT_TRUE(owner->stuff_done());
+    owner.reset();
+  });
+  ASSERT_FALSE(owner);
+}
+
+TEST(PendingTaskSafetyFlagTest, PendingTaskDropped) {
+  TaskQueueForTest tq1("OwnerHere");
+  TaskQueueForTest tq2("OwnerNotHere");
+
+  class Owner {
+   public:
+    explicit Owner(bool* stuff_done)
+        : tq_main_(TaskQueueBase::Current()), stuff_done_(stuff_done) {
+      RTC_DCHECK(tq_main_);
+      *stuff_done_ = false;
+    }
+    ~Owner() { RTC_DCHECK(tq_main_->IsCurrent()); }
+
+    void DoStuff() {
+      RTC_DCHECK(!tq_main_->IsCurrent());
+      tq_main_->PostTask(
+          SafeTask(safety_.flag(), [this]() { *stuff_done_ = true; }));
+    }
+
+   private:
+    TaskQueueBase* const tq_main_;
+    bool* const stuff_done_;
+    ScopedTaskSafety safety_;
+  };
+
+  std::unique_ptr<Owner> owner;
+  bool stuff_done = false;
+  tq1.SendTask([&owner, &stuff_done]() {
+    owner = std::make_unique<Owner>(&stuff_done);
+  });
+  ASSERT_TRUE(owner);
+  // Queue up a task on tq1 that will execute before the 'DoStuff' task
+  // can, and delete the `owner` before the 'stuff' task can execute.
+  rtc::Event blocker;
+  tq1.PostTask([&blocker, &owner]() {
+    blocker.Wait(rtc::Event::kForever);
+    owner.reset();
+  });
+
+  // Queue up a DoStuff...
+  tq2.SendTask([&owner]() { owner->DoStuff(); });
+
+  ASSERT_TRUE(owner);
+  blocker.Set();
+
+  // Run an empty task on tq1 to flush all the queued tasks.
+  tq1.WaitForPreviouslyPostedTasks();
+  ASSERT_FALSE(owner);
+  EXPECT_FALSE(stuff_done);
+}
+
+TEST(PendingTaskSafetyFlagTest, PendingTaskNotAliveInitialized) {
+  TaskQueueForTest tq("PendingTaskNotAliveInitialized");
+
+  // Create a new flag that initially not `alive`.
+  auto flag = PendingTaskSafetyFlag::CreateDetachedInactive();
+  tq.SendTask([&flag]() { EXPECT_FALSE(flag->alive()); });
+
+  bool task_1_ran = false;
+  bool task_2_ran = false;
+  tq.PostTask(SafeTask(flag, [&task_1_ran]() { task_1_ran = true; }));
+  tq.PostTask([&flag]() { flag->SetAlive(); });
+  tq.PostTask(SafeTask(flag, [&task_2_ran]() { task_2_ran = true; }));
+
+  tq.WaitForPreviouslyPostedTasks();
+  EXPECT_FALSE(task_1_ran);
+  EXPECT_TRUE(task_2_ran);
+}
+
+TEST(PendingTaskSafetyFlagTest, SafeTask) {
+  rtc::scoped_refptr<PendingTaskSafetyFlag> flag =
+      PendingTaskSafetyFlag::Create();
+
+  int count = 0;
+  // Create two identical tasks that increment the `count`.
+  auto task1 = SafeTask(flag, [&count] { ++count; });
+  auto task2 = SafeTask(flag, [&count] { ++count; });
+
+  EXPECT_EQ(count, 0);
+  std::move(task1)();
+  EXPECT_EQ(count, 1);
+  flag->SetNotAlive();
+  // Now task2 should actually not run.
+  std::move(task2)();
+  EXPECT_EQ(count, 1);
+}
+
+}  // namespace webrtc