src/ftrace_reader/ftrace_controller_unittest.cc - third_party/perfetto - Git at Google

 /*
  * Copyright (C) 2017 The Android Open Source Project
  *
  * 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 "perfetto/ftrace_reader/ftrace_controller.h"

 #include <fcntl.h>
 #include <sys/stat.h>
 #include <sys/types.h>

 #include "cpu_reader.h"
 #include "ftrace_procfs.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 #include "perfetto/ftrace_reader/ftrace_config.h"
 #include "proto_translation_table.h"

 #include "src/base/test/test_task_runner.h"

 #include "perfetto/trace/ftrace/ftrace_event_bundle.pbzero.h"

 using testing::_;
 using testing::AnyNumber;
 using testing::ByMove;
 using testing::Invoke;
 using testing::NiceMock;
 using testing::Return;

 using Table = perfetto::ProtoTranslationTable;
 using FtraceEventBundle = perfetto::protos::pbzero::FtraceEventBundle;

 namespace perfetto {

 namespace {

 const char kFooEnablePath[] = "/root/events/group/foo/enable";
 const char kBarEnablePath[] = "/root/events/group/bar/enable";

 class MockTaskRunner : public base::TaskRunner {
  public:
   MockTaskRunner() {
     ON_CALL(*this, PostTask(_))
         .WillByDefault(Invoke(this, &MockTaskRunner::OnPostTask));
     ON_CALL(*this, PostDelayedTask(_, _))
         .WillByDefault(Invoke(this, &MockTaskRunner::OnPostDelayedTask));
   }

   void OnPostTask(std::function<void()> task) {
     std::unique_lock<std::mutex> lock(lock_);
     EXPECT_FALSE(task_);
     task_ = std::move(task);
   }

   void OnPostDelayedTask(std::function<void()> task, int _delay) {
     std::unique_lock<std::mutex> lock(lock_);
     EXPECT_FALSE(task_);
     task_ = std::move(task);
   }

   void RunLastTask() { TakeTask()(); }

   std::function<void()> TakeTask() {
     std::unique_lock<std::mutex> lock(lock_);
     return std::move(task_);
   }

   MOCK_METHOD1(PostTask, void(std::function<void()>));
   MOCK_METHOD2(PostDelayedTask, void(std::function<void()>, int delay_ms));
   MOCK_METHOD2(AddFileDescriptorWatch, void(int fd, std::function<void()>));
   MOCK_METHOD1(RemoveFileDescriptorWatch, void(int fd));

  private:
   std::mutex lock_;
   std::function<void()> task_;
 };

 class MockDelegate : public perfetto::FtraceSink::Delegate {
  public:
   MOCK_METHOD1(GetBundleForCpu,
                protozero::ProtoZeroMessageHandle<FtraceEventBundle>(size_t));
   MOCK_METHOD2(OnBundleComplete_,
                void(size_t,
                     protozero::ProtoZeroMessageHandle<FtraceEventBundle>&));

   void OnBundleComplete(
       size_t cpu,
       protozero::ProtoZeroMessageHandle<FtraceEventBundle> bundle) {
     OnBundleComplete_(cpu, bundle);
   }
 };

 std::unique_ptr<Table> FakeTable() {
   std::vector<Field> common_fields;
   std::vector<Event> events;

   {
     Event event;
     event.name = "foo";
     event.group = "group";
     event.ftrace_event_id = 1;
     events.push_back(event);
   }

   {
     Event event;
     event.name = "bar";
     event.group = "group";
     event.ftrace_event_id = 10;
     events.push_back(event);
   }

   return std::unique_ptr<Table>(new Table(events, std::move(common_fields)));
 }

 class MockFtraceProcfs : public FtraceProcfs {
  public:
   MockFtraceProcfs(size_t cpu_count = 1) : FtraceProcfs("/root/") {
     ON_CALL(*this, NumberOfCpus()).WillByDefault(Return(cpu_count));
     EXPECT_CALL(*this, NumberOfCpus()).Times(AnyNumber());
   }

   base::ScopedFile OpenPipeForCpu(size_t cpu) override {
     return base::ScopedFile(open("/dev/null", O_RDONLY));
   }

   MOCK_METHOD2(WriteToFile,
                bool(const std::string& path, const std::string& str));
   MOCK_CONST_METHOD0(NumberOfCpus, size_t());
 };

 }  // namespace

 class TestFtraceController : public FtraceController {
  public:
   TestFtraceController(std::unique_ptr<MockFtraceProcfs> ftrace_procfs,
                        base::TaskRunner* runner,
                        std::unique_ptr<Table> table)
       : FtraceController(std::move(ftrace_procfs), runner, std::move(table)) {}

   MOCK_METHOD1(OnRawFtraceDataAvailable, void(size_t cpu));

   uint64_t NowMs() const override { return now_ms; }

   uint32_t drain_period_ms() { return GetDrainPeriodMs(); }

   std::function<void()> GetDataAvailableCallback(size_t cpu) {
     base::WeakPtr<FtraceController> weak_this = weak_factory_.GetWeakPtr();
     size_t generation = generation_;
     return [this, weak_this, generation, cpu] {
       OnDataAvailable(weak_this, generation, cpu, GetDrainPeriodMs());
     };
   }

   void WaitForData(size_t cpu) {
     while (true) {
       {
         std::unique_lock<std::mutex> lock(lock_);
         if (cpus_to_drain_[cpu])
           return;
       }
       usleep(5000);
     }
   }

   uint64_t now_ms = 0;

  private:
   TestFtraceController(const TestFtraceController&) = delete;
   TestFtraceController& operator=(const TestFtraceController&) = delete;
 };

 TEST(FtraceControllerTest, NonExistentEventsDontCrash) {
   NiceMock<MockTaskRunner> task_runner;
   auto ftrace_procfs =
       std::unique_ptr<MockFtraceProcfs>(new NiceMock<MockFtraceProcfs>());
   TestFtraceController controller(std::move(ftrace_procfs), &task_runner,
                                   FakeTable());

   MockDelegate delegate;
   FtraceConfig config = CreateFtraceConfig({"not_an_event"});

   std::unique_ptr<FtraceSink> sink = controller.CreateSink(config, &delegate);
 }

 TEST(FtraceControllerTest, RejectsBadEventNames) {
   NiceMock<MockTaskRunner> task_runner;
   auto ftrace_procfs =
       std::unique_ptr<MockFtraceProcfs>(new NiceMock<MockFtraceProcfs>());
   TestFtraceController controller(std::move(ftrace_procfs), &task_runner,
                                   FakeTable());

   MockDelegate delegate;
   FtraceConfig config = CreateFtraceConfig({"../try/to/escape"});
   EXPECT_FALSE(controller.CreateSink(config, &delegate));
 }

 TEST(FtraceControllerTest, OneSink) {
   MockTaskRunner task_runner;
   auto ftrace_procfs =
       std::unique_ptr<MockFtraceProcfs>(new MockFtraceProcfs());
   auto raw_ftrace_procfs = ftrace_procfs.get();
   TestFtraceController controller(std::move(ftrace_procfs), &task_runner,
                                   FakeTable());

   MockDelegate delegate;
   FtraceConfig config = CreateFtraceConfig({"foo"});

   EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/tracing_on", "1"));
   EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kFooEnablePath, "1"));
   EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/buffer_size_kb", _));
   std::unique_ptr<FtraceSink> sink = controller.CreateSink(config, &delegate);

   EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kFooEnablePath, "0"));
   EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/tracing_on", "0"));
   sink.reset();
 }

 TEST(FtraceControllerTest, MultipleSinks) {
   MockTaskRunner task_runner;
   auto ftrace_procfs =
       std::unique_ptr<MockFtraceProcfs>(new MockFtraceProcfs());
   auto raw_ftrace_procfs = ftrace_procfs.get();
   TestFtraceController controller(std::move(ftrace_procfs), &task_runner,
                                   FakeTable());

   MockDelegate delegate;

   FtraceConfig configA = CreateFtraceConfig({"foo"});
   FtraceConfig configB = CreateFtraceConfig({"foo", "bar"});

   EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/tracing_on", "1"));
   EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/buffer_size_kb", _));
   EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kFooEnablePath, "1"));
   std::unique_ptr<FtraceSink> sinkA = controller.CreateSink(configA, &delegate);

   EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kBarEnablePath, "1"));
   std::unique_ptr<FtraceSink> sinkB = controller.CreateSink(configB, &delegate);

   sinkA.reset();

   EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kFooEnablePath, "0"));
   EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kBarEnablePath, "0"));
   EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/tracing_on", "0"));
   sinkB.reset();
 }

 TEST(FtraceControllerTest, ControllerMayDieFirst) {
   MockTaskRunner task_runner;
   auto ftrace_procfs =
       std::unique_ptr<MockFtraceProcfs>(new MockFtraceProcfs());
   auto raw_ftrace_procfs = ftrace_procfs.get();
   std::unique_ptr<TestFtraceController> controller(new TestFtraceController(
       std::move(ftrace_procfs), &task_runner, FakeTable()));

   MockDelegate delegate;
   FtraceConfig config = CreateFtraceConfig({"foo"});

   EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/buffer_size_kb", _));
   EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/tracing_on", "1"));
   EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kFooEnablePath, "1"));
   std::unique_ptr<FtraceSink> sink = controller->CreateSink(config, &delegate);

   EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kFooEnablePath, "0"));
   EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/tracing_on", "0"));
   controller.reset();

   sink.reset();
 }

 TEST(FtraceControllerTest, TaskScheduling) {
   MockTaskRunner task_runner;
   auto ftrace_procfs =
       std::unique_ptr<MockFtraceProcfs>(new MockFtraceProcfs(2u));
   auto raw_ftrace_procfs = ftrace_procfs.get();
   TestFtraceController controller(std::move(ftrace_procfs), &task_runner,
                                   FakeTable());

   // For this test we don't care about calls to WriteToFile.
   EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(_, _)).Times(AnyNumber());

   MockDelegate delegate;
   FtraceConfig config = CreateFtraceConfig({"foo"});

   std::unique_ptr<FtraceSink> sink = controller.CreateSink(config, &delegate);

   // Only one call to drain should be scheduled for the next drain period.
   EXPECT_CALL(task_runner, PostDelayedTask(_, 100));

   // However both CPUs should be drained.
   EXPECT_CALL(controller, OnRawFtraceDataAvailable(_)).Times(2);

   // Finally, another task should be posted to unblock the workers.
   EXPECT_CALL(task_runner, PostTask(_));

   // Simulate two worker threads reporting available data.
   auto on_data_available0 = controller.GetDataAvailableCallback(0u);
   std::thread worker0([on_data_available0] { on_data_available0(); });

   auto on_data_available1 = controller.GetDataAvailableCallback(1u);
   std::thread worker1([on_data_available1] { on_data_available1(); });

   // Poll until both worker threads have reported available data.
   controller.WaitForData(0u);
   controller.WaitForData(1u);

   // Run the task to drain all CPUs.
   task_runner.RunLastTask();

   // Run the task to unblock all workers.
   task_runner.RunLastTask();

   worker0.join();
   worker1.join();

   sink.reset();
 }

 // TODO(b/73452932): Fix and reenable this test.
 TEST(FtraceControllerTest, DISABLED_DrainPeriodRespected) {
   MockTaskRunner task_runner;
   auto ftrace_procfs =
       std::unique_ptr<MockFtraceProcfs>(new MockFtraceProcfs());
   auto raw_ftrace_procfs = ftrace_procfs.get();
   TestFtraceController controller(std::move(ftrace_procfs), &task_runner,
                                   FakeTable());

   // For this test we don't care about calls to WriteToFile.
   EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(_, _)).Times(AnyNumber());

   MockDelegate delegate;
   FtraceConfig config = CreateFtraceConfig({"foo"});

   // Test several cycles of a worker producing data and make sure the drain
   // delay is consistent with the drain period.
   std::unique_ptr<FtraceSink> sink = controller.CreateSink(config, &delegate);

   const int kCycles = 50;
   EXPECT_CALL(task_runner, PostDelayedTask(_, controller.drain_period_ms()))
       .Times(kCycles);
   EXPECT_CALL(controller, OnRawFtraceDataAvailable(_)).Times(kCycles);
   EXPECT_CALL(task_runner, PostTask(_)).Times(kCycles);

   // Simulate a worker thread continually reporting pages of available data.
   auto on_data_available = controller.GetDataAvailableCallback(0u);
   std::thread worker([on_data_available] {
     for (int i = 0; i < kCycles; i++)
       on_data_available();
   });

   for (int i = 0; i < kCycles; i++) {
     controller.WaitForData(0u);
     // Run two tasks: one to drain each CPU and another to unblock the worker.
     task_runner.RunLastTask();
     task_runner.RunLastTask();
     controller.now_ms += controller.drain_period_ms();
   }

   worker.join();
   sink.reset();
 }

 TEST(FtraceControllerTest, BackToBackEnableDisable) {
   MockTaskRunner task_runner;
   auto ftrace_procfs =
       std::unique_ptr<MockFtraceProcfs>(new MockFtraceProcfs());
   auto raw_ftrace_procfs = ftrace_procfs.get();
   TestFtraceController controller(std::move(ftrace_procfs), &task_runner,
                                   FakeTable());

   // For this test we don't care about calls to WriteToFile.
   EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(_, _)).Times(AnyNumber());

   MockDelegate delegate;
   FtraceConfig config = CreateFtraceConfig({"foo"});

   EXPECT_CALL(task_runner, PostDelayedTask(_, 100)).Times(2);
   std::unique_ptr<FtraceSink> sink_a = controller.CreateSink(config, &delegate);

   auto on_data_available = controller.GetDataAvailableCallback(0u);
   std::thread worker([on_data_available] { on_data_available(); });
   controller.WaitForData(0u);

   // Disable the first sink and run the delayed task that it generated. It
   // should be a no-op.
   sink_a.reset();
   task_runner.RunLastTask();
   worker.join();

   // Register another sink and wait for it to generate data.
   std::unique_ptr<FtraceSink> sink_b = controller.CreateSink(config, &delegate);
   std::thread worker2([on_data_available] { on_data_available(); });
   controller.WaitForData(0u);

   // This drain should also be a no-op after the sink is unregistered.
   sink_b.reset();
   task_runner.RunLastTask();
   worker2.join();
 }

 TEST(FtraceControllerTest, BufferSize) {
   NiceMock<MockTaskRunner> task_runner;
   auto ftrace_procfs =
       std::unique_ptr<MockFtraceProcfs>(new MockFtraceProcfs());
   auto raw_ftrace_procfs = ftrace_procfs.get();
   TestFtraceController controller(std::move(ftrace_procfs), &task_runner,
                                   FakeTable());

   // For this test we don't care about most calls to WriteToFile.
   EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(_, _)).Times(AnyNumber());
   MockDelegate delegate;

   {
     // No buffer size -> good default.
     // 8192kb = 8mb
     EXPECT_CALL(*raw_ftrace_procfs,
                 WriteToFile("/root/buffer_size_kb", "4096"));
     FtraceConfig config = CreateFtraceConfig({"foo"});
     auto sink = controller.CreateSink(config, &delegate);
   }

   {
     // Way too big buffer size -> good default.
     EXPECT_CALL(*raw_ftrace_procfs,
                 WriteToFile("/root/buffer_size_kb", "4096"));
     FtraceConfig config = CreateFtraceConfig({"foo"});
     config.set_buffer_size_kb(10 * 1024 * 1024);
     auto sink = controller.CreateSink(config, &delegate);
   }

   {
     // The limit is 8mb, 9mb is too much.
     EXPECT_CALL(*raw_ftrace_procfs,
                 WriteToFile("/root/buffer_size_kb", "4096"));
     FtraceConfig config = CreateFtraceConfig({"foo"});
     ON_CALL(*raw_ftrace_procfs, NumberOfCpus()).WillByDefault(Return(2));
     config.set_buffer_size_kb(9 * 1024);
     auto sink = controller.CreateSink(config, &delegate);
   }

   {
     // Your size ends up with less than 1 page per cpu -> 1 page.
     EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/buffer_size_kb", "4"));
     FtraceConfig config = CreateFtraceConfig({"foo"});
     config.set_buffer_size_kb(1);
     auto sink = controller.CreateSink(config, &delegate);
   }

   {
     // You picked a good size -> your size rounded to nearest page.
     EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/buffer_size_kb", "40"));
     FtraceConfig config = CreateFtraceConfig({"foo"});
     config.set_buffer_size_kb(42);
     auto sink = controller.CreateSink(config, &delegate);
   }

   {
     // You picked a good size -> your size rounded to nearest page.
     EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/buffer_size_kb", "40"));
     FtraceConfig config = CreateFtraceConfig({"foo"});
     ON_CALL(*raw_ftrace_procfs, NumberOfCpus()).WillByDefault(Return(2));
     config.set_buffer_size_kb(42);
     auto sink = controller.CreateSink(config, &delegate);
   }
 }

 TEST(FtraceControllerTest, PeriodicDrainConfig) {
   MockTaskRunner task_runner;
   auto ftrace_procfs =
       std::unique_ptr<MockFtraceProcfs>(new MockFtraceProcfs());
   auto raw_ftrace_procfs = ftrace_procfs.get();
   TestFtraceController controller(std::move(ftrace_procfs), &task_runner,
                                   FakeTable());

   // For this test we don't care about calls to WriteToFile.
   EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(_, _)).Times(AnyNumber());
   MockDelegate delegate;

   {
     // No period -> good default.
     FtraceConfig config = CreateFtraceConfig({"foo"});
     auto sink = controller.CreateSink(config, &delegate);
     EXPECT_EQ(100u, controller.drain_period_ms());
   }

   {
     // Pick a tiny value -> good default.
     FtraceConfig config = CreateFtraceConfig({"foo"});
     config.set_drain_period_ms(0);
     auto sink = controller.CreateSink(config, &delegate);
     EXPECT_EQ(100u, controller.drain_period_ms());
   }

   {
     // Pick a huge value -> good default.
     FtraceConfig config = CreateFtraceConfig({"foo"});
     config.set_drain_period_ms(1000 * 60 * 60);
     auto sink = controller.CreateSink(config, &delegate);
     EXPECT_EQ(100u, controller.drain_period_ms());
   }

   {
     // Pick a resonable value -> get that value.
     FtraceConfig config = CreateFtraceConfig({"foo"});
     config.set_drain_period_ms(200);
     auto sink = controller.CreateSink(config, &delegate);
     EXPECT_EQ(200u, controller.drain_period_ms());
   }
 }

 }  // namespace perfetto
	/*
	* Copyright (C) 2017 The Android Open Source Project
	*
	* 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 "perfetto/ftrace_reader/ftrace_controller.h"

	#include <fcntl.h>
	#include <sys/stat.h>
	#include <sys/types.h>

	#include "cpu_reader.h"
	#include "ftrace_procfs.h"
	#include "gmock/gmock.h"
	#include "gtest/gtest.h"
	#include "perfetto/ftrace_reader/ftrace_config.h"
	#include "proto_translation_table.h"

	#include "src/base/test/test_task_runner.h"

	#include "perfetto/trace/ftrace/ftrace_event_bundle.pbzero.h"

	using testing::_;
	using testing::AnyNumber;
	using testing::ByMove;
	using testing::Invoke;
	using testing::NiceMock;
	using testing::Return;

	using Table = perfetto::ProtoTranslationTable;
	using FtraceEventBundle = perfetto::protos::pbzero::FtraceEventBundle;

	namespace perfetto {

	namespace {

	const char kFooEnablePath[] = "/root/events/group/foo/enable";
	const char kBarEnablePath[] = "/root/events/group/bar/enable";

	class MockTaskRunner : public base::TaskRunner {
	public:
	MockTaskRunner() {
	ON_CALL(*this, PostTask(_))
	.WillByDefault(Invoke(this, &MockTaskRunner::OnPostTask));
	ON_CALL(*this, PostDelayedTask(_, _))
	.WillByDefault(Invoke(this, &MockTaskRunner::OnPostDelayedTask));
	}

	void OnPostTask(std::function<void()> task) {
	std::unique_lock<std::mutex> lock(lock_);
	EXPECT_FALSE(task_);
	task_ = std::move(task);
	}

	void OnPostDelayedTask(std::function<void()> task, int _delay) {
	std::unique_lock<std::mutex> lock(lock_);
	EXPECT_FALSE(task_);
	task_ = std::move(task);
	}

	void RunLastTask() { TakeTask()(); }

	std::function<void()> TakeTask() {
	std::unique_lock<std::mutex> lock(lock_);
	return std::move(task_);
	}

	MOCK_METHOD1(PostTask, void(std::function<void()>));
	MOCK_METHOD2(PostDelayedTask, void(std::function<void()>, int delay_ms));
	MOCK_METHOD2(AddFileDescriptorWatch, void(int fd, std::function<void()>));
	MOCK_METHOD1(RemoveFileDescriptorWatch, void(int fd));

	private:
	std::mutex lock_;
	std::function<void()> task_;
	};

	class MockDelegate : public perfetto::FtraceSink::Delegate {
	public:
	MOCK_METHOD1(GetBundleForCpu,
	protozero::ProtoZeroMessageHandle<FtraceEventBundle>(size_t));
	MOCK_METHOD2(OnBundleComplete_,
	void(size_t,
	protozero::ProtoZeroMessageHandle<FtraceEventBundle>&));

	void OnBundleComplete(
	size_t cpu,
	protozero::ProtoZeroMessageHandle<FtraceEventBundle> bundle) {
	OnBundleComplete_(cpu, bundle);
	}
	};

	std::unique_ptr<Table> FakeTable() {
	std::vector<Field> common_fields;
	std::vector<Event> events;

	{
	Event event;
	event.name = "foo";
	event.group = "group";
	event.ftrace_event_id = 1;
	events.push_back(event);
	}

	{
	Event event;
	event.name = "bar";
	event.group = "group";
	event.ftrace_event_id = 10;
	events.push_back(event);
	}

	return std::unique_ptr<Table>(new Table(events, std::move(common_fields)));
	}

	class MockFtraceProcfs : public FtraceProcfs {
	public:
	MockFtraceProcfs(size_t cpu_count = 1) : FtraceProcfs("/root/") {
	ON_CALL(*this, NumberOfCpus()).WillByDefault(Return(cpu_count));
	EXPECT_CALL(*this, NumberOfCpus()).Times(AnyNumber());
	}

	base::ScopedFile OpenPipeForCpu(size_t cpu) override {
	return base::ScopedFile(open("/dev/null", O_RDONLY));
	}

	MOCK_METHOD2(WriteToFile,
	bool(const std::string& path, const std::string& str));
	MOCK_CONST_METHOD0(NumberOfCpus, size_t());
	};

	} // namespace

	class TestFtraceController : public FtraceController {
	public:
	TestFtraceController(std::unique_ptr<MockFtraceProcfs> ftrace_procfs,
	base::TaskRunner* runner,
	std::unique_ptr<Table> table)
	: FtraceController(std::move(ftrace_procfs), runner, std::move(table)) {}

	MOCK_METHOD1(OnRawFtraceDataAvailable, void(size_t cpu));

	uint64_t NowMs() const override { return now_ms; }

	uint32_t drain_period_ms() { return GetDrainPeriodMs(); }

	std::function<void()> GetDataAvailableCallback(size_t cpu) {
	base::WeakPtr<FtraceController> weak_this = weak_factory_.GetWeakPtr();
	size_t generation = generation_;
	return [this, weak_this, generation, cpu] {
	OnDataAvailable(weak_this, generation, cpu, GetDrainPeriodMs());
	};
	}

	void WaitForData(size_t cpu) {
	while (true) {
	{
	std::unique_lock<std::mutex> lock(lock_);
	if (cpus_to_drain_[cpu])
	return;
	}
	usleep(5000);
	}
	}

	uint64_t now_ms = 0;

	private:
	TestFtraceController(const TestFtraceController&) = delete;
	TestFtraceController& operator=(const TestFtraceController&) = delete;
	};

	TEST(FtraceControllerTest, NonExistentEventsDontCrash) {
	NiceMock<MockTaskRunner> task_runner;
	auto ftrace_procfs =
	std::unique_ptr<MockFtraceProcfs>(new NiceMock<MockFtraceProcfs>());
	TestFtraceController controller(std::move(ftrace_procfs), &task_runner,
	FakeTable());

	MockDelegate delegate;
	FtraceConfig config = CreateFtraceConfig({"not_an_event"});

	std::unique_ptr<FtraceSink> sink = controller.CreateSink(config, &delegate);
	}

	TEST(FtraceControllerTest, RejectsBadEventNames) {
	NiceMock<MockTaskRunner> task_runner;
	auto ftrace_procfs =
	std::unique_ptr<MockFtraceProcfs>(new NiceMock<MockFtraceProcfs>());
	TestFtraceController controller(std::move(ftrace_procfs), &task_runner,
	FakeTable());

	MockDelegate delegate;
	FtraceConfig config = CreateFtraceConfig({"../try/to/escape"});
	EXPECT_FALSE(controller.CreateSink(config, &delegate));
	}

	TEST(FtraceControllerTest, OneSink) {
	MockTaskRunner task_runner;
	auto ftrace_procfs =
	std::unique_ptr<MockFtraceProcfs>(new MockFtraceProcfs());
	auto raw_ftrace_procfs = ftrace_procfs.get();
	TestFtraceController controller(std::move(ftrace_procfs), &task_runner,
	FakeTable());

	MockDelegate delegate;
	FtraceConfig config = CreateFtraceConfig({"foo"});

	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/tracing_on", "1"));
	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kFooEnablePath, "1"));
	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/buffer_size_kb", _));
	std::unique_ptr<FtraceSink> sink = controller.CreateSink(config, &delegate);

	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kFooEnablePath, "0"));
	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/tracing_on", "0"));
	sink.reset();
	}

	TEST(FtraceControllerTest, MultipleSinks) {
	MockTaskRunner task_runner;
	auto ftrace_procfs =
	std::unique_ptr<MockFtraceProcfs>(new MockFtraceProcfs());
	auto raw_ftrace_procfs = ftrace_procfs.get();
	TestFtraceController controller(std::move(ftrace_procfs), &task_runner,
	FakeTable());

	MockDelegate delegate;

	FtraceConfig configA = CreateFtraceConfig({"foo"});
	FtraceConfig configB = CreateFtraceConfig({"foo", "bar"});

	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/tracing_on", "1"));
	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/buffer_size_kb", _));
	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kFooEnablePath, "1"));
	std::unique_ptr<FtraceSink> sinkA = controller.CreateSink(configA, &delegate);

	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kBarEnablePath, "1"));
	std::unique_ptr<FtraceSink> sinkB = controller.CreateSink(configB, &delegate);

	sinkA.reset();

	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kFooEnablePath, "0"));
	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kBarEnablePath, "0"));
	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/tracing_on", "0"));
	sinkB.reset();
	}

	TEST(FtraceControllerTest, ControllerMayDieFirst) {
	MockTaskRunner task_runner;
	auto ftrace_procfs =
	std::unique_ptr<MockFtraceProcfs>(new MockFtraceProcfs());
	auto raw_ftrace_procfs = ftrace_procfs.get();
	std::unique_ptr<TestFtraceController> controller(new TestFtraceController(
	std::move(ftrace_procfs), &task_runner, FakeTable()));

	MockDelegate delegate;
	FtraceConfig config = CreateFtraceConfig({"foo"});

	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/buffer_size_kb", _));
	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/tracing_on", "1"));
	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kFooEnablePath, "1"));
	std::unique_ptr<FtraceSink> sink = controller->CreateSink(config, &delegate);

	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kFooEnablePath, "0"));
	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/tracing_on", "0"));
	controller.reset();

	sink.reset();
	}

	TEST(FtraceControllerTest, TaskScheduling) {
	MockTaskRunner task_runner;
	auto ftrace_procfs =
	std::unique_ptr<MockFtraceProcfs>(new MockFtraceProcfs(2u));
	auto raw_ftrace_procfs = ftrace_procfs.get();
	TestFtraceController controller(std::move(ftrace_procfs), &task_runner,
	FakeTable());

	// For this test we don't care about calls to WriteToFile.
	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(_, _)).Times(AnyNumber());

	MockDelegate delegate;
	FtraceConfig config = CreateFtraceConfig({"foo"});

	std::unique_ptr<FtraceSink> sink = controller.CreateSink(config, &delegate);

	// Only one call to drain should be scheduled for the next drain period.
	EXPECT_CALL(task_runner, PostDelayedTask(_, 100));

	// However both CPUs should be drained.
	EXPECT_CALL(controller, OnRawFtraceDataAvailable(_)).Times(2);

	// Finally, another task should be posted to unblock the workers.
	EXPECT_CALL(task_runner, PostTask(_));

	// Simulate two worker threads reporting available data.
	auto on_data_available0 = controller.GetDataAvailableCallback(0u);
	std::thread worker0([on_data_available0] { on_data_available0(); });

	auto on_data_available1 = controller.GetDataAvailableCallback(1u);
	std::thread worker1([on_data_available1] { on_data_available1(); });

	// Poll until both worker threads have reported available data.
	controller.WaitForData(0u);
	controller.WaitForData(1u);

	// Run the task to drain all CPUs.
	task_runner.RunLastTask();

	// Run the task to unblock all workers.
	task_runner.RunLastTask();

	worker0.join();
	worker1.join();

	sink.reset();
	}

	// TODO(b/73452932): Fix and reenable this test.
	TEST(FtraceControllerTest, DISABLED_DrainPeriodRespected) {
	MockTaskRunner task_runner;
	auto ftrace_procfs =
	std::unique_ptr<MockFtraceProcfs>(new MockFtraceProcfs());
	auto raw_ftrace_procfs = ftrace_procfs.get();
	TestFtraceController controller(std::move(ftrace_procfs), &task_runner,
	FakeTable());

	// For this test we don't care about calls to WriteToFile.
	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(_, _)).Times(AnyNumber());

	MockDelegate delegate;
	FtraceConfig config = CreateFtraceConfig({"foo"});

	// Test several cycles of a worker producing data and make sure the drain
	// delay is consistent with the drain period.
	std::unique_ptr<FtraceSink> sink = controller.CreateSink(config, &delegate);

	const int kCycles = 50;
	EXPECT_CALL(task_runner, PostDelayedTask(_, controller.drain_period_ms()))
	.Times(kCycles);
	EXPECT_CALL(controller, OnRawFtraceDataAvailable(_)).Times(kCycles);
	EXPECT_CALL(task_runner, PostTask(_)).Times(kCycles);

	// Simulate a worker thread continually reporting pages of available data.
	auto on_data_available = controller.GetDataAvailableCallback(0u);
	std::thread worker([on_data_available] {
	for (int i = 0; i < kCycles; i++)
	on_data_available();
	});

	for (int i = 0; i < kCycles; i++) {
	controller.WaitForData(0u);
	// Run two tasks: one to drain each CPU and another to unblock the worker.
	task_runner.RunLastTask();
	task_runner.RunLastTask();
	controller.now_ms += controller.drain_period_ms();
	}

	worker.join();
	sink.reset();
	}

	TEST(FtraceControllerTest, BackToBackEnableDisable) {
	MockTaskRunner task_runner;
	auto ftrace_procfs =
	std::unique_ptr<MockFtraceProcfs>(new MockFtraceProcfs());
	auto raw_ftrace_procfs = ftrace_procfs.get();
	TestFtraceController controller(std::move(ftrace_procfs), &task_runner,
	FakeTable());

	// For this test we don't care about calls to WriteToFile.
	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(_, _)).Times(AnyNumber());

	MockDelegate delegate;
	FtraceConfig config = CreateFtraceConfig({"foo"});

	EXPECT_CALL(task_runner, PostDelayedTask(_, 100)).Times(2);
	std::unique_ptr<FtraceSink> sink_a = controller.CreateSink(config, &delegate);

	auto on_data_available = controller.GetDataAvailableCallback(0u);
	std::thread worker([on_data_available] { on_data_available(); });
	controller.WaitForData(0u);

	// Disable the first sink and run the delayed task that it generated. It
	// should be a no-op.
	sink_a.reset();
	task_runner.RunLastTask();
	worker.join();

	// Register another sink and wait for it to generate data.
	std::unique_ptr<FtraceSink> sink_b = controller.CreateSink(config, &delegate);
	std::thread worker2([on_data_available] { on_data_available(); });
	controller.WaitForData(0u);

	// This drain should also be a no-op after the sink is unregistered.
	sink_b.reset();
	task_runner.RunLastTask();
	worker2.join();
	}

	TEST(FtraceControllerTest, BufferSize) {
	NiceMock<MockTaskRunner> task_runner;
	auto ftrace_procfs =
	std::unique_ptr<MockFtraceProcfs>(new MockFtraceProcfs());
	auto raw_ftrace_procfs = ftrace_procfs.get();
	TestFtraceController controller(std::move(ftrace_procfs), &task_runner,
	FakeTable());

	// For this test we don't care about most calls to WriteToFile.
	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(_, _)).Times(AnyNumber());
	MockDelegate delegate;

	{
	// No buffer size -> good default.
	// 8192kb = 8mb
	EXPECT_CALL(*raw_ftrace_procfs,
	WriteToFile("/root/buffer_size_kb", "4096"));
	FtraceConfig config = CreateFtraceConfig({"foo"});
	auto sink = controller.CreateSink(config, &delegate);
	}

	{
	// Way too big buffer size -> good default.
	EXPECT_CALL(*raw_ftrace_procfs,
	WriteToFile("/root/buffer_size_kb", "4096"));
	FtraceConfig config = CreateFtraceConfig({"foo"});
	config.set_buffer_size_kb(10 * 1024 * 1024);
	auto sink = controller.CreateSink(config, &delegate);
	}

	{
	// The limit is 8mb, 9mb is too much.
	EXPECT_CALL(*raw_ftrace_procfs,
	WriteToFile("/root/buffer_size_kb", "4096"));
	FtraceConfig config = CreateFtraceConfig({"foo"});
	ON_CALL(*raw_ftrace_procfs, NumberOfCpus()).WillByDefault(Return(2));
	config.set_buffer_size_kb(9 * 1024);
	auto sink = controller.CreateSink(config, &delegate);
	}

	{
	// Your size ends up with less than 1 page per cpu -> 1 page.
	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/buffer_size_kb", "4"));
	FtraceConfig config = CreateFtraceConfig({"foo"});
	config.set_buffer_size_kb(1);
	auto sink = controller.CreateSink(config, &delegate);
	}

	{
	// You picked a good size -> your size rounded to nearest page.
	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/buffer_size_kb", "40"));
	FtraceConfig config = CreateFtraceConfig({"foo"});
	config.set_buffer_size_kb(42);
	auto sink = controller.CreateSink(config, &delegate);
	}

	{
	// You picked a good size -> your size rounded to nearest page.
	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/buffer_size_kb", "40"));
	FtraceConfig config = CreateFtraceConfig({"foo"});
	ON_CALL(*raw_ftrace_procfs, NumberOfCpus()).WillByDefault(Return(2));
	config.set_buffer_size_kb(42);
	auto sink = controller.CreateSink(config, &delegate);
	}
	}

	TEST(FtraceControllerTest, PeriodicDrainConfig) {
	MockTaskRunner task_runner;
	auto ftrace_procfs =
	std::unique_ptr<MockFtraceProcfs>(new MockFtraceProcfs());
	auto raw_ftrace_procfs = ftrace_procfs.get();
	TestFtraceController controller(std::move(ftrace_procfs), &task_runner,
	FakeTable());

	// For this test we don't care about calls to WriteToFile.
	EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(_, _)).Times(AnyNumber());
	MockDelegate delegate;

	{
	// No period -> good default.
	FtraceConfig config = CreateFtraceConfig({"foo"});
	auto sink = controller.CreateSink(config, &delegate);
	EXPECT_EQ(100u, controller.drain_period_ms());
	}

	{
	// Pick a tiny value -> good default.
	FtraceConfig config = CreateFtraceConfig({"foo"});
	config.set_drain_period_ms(0);
	auto sink = controller.CreateSink(config, &delegate);
	EXPECT_EQ(100u, controller.drain_period_ms());
	}

	{
	// Pick a huge value -> good default.
	FtraceConfig config = CreateFtraceConfig({"foo"});
	config.set_drain_period_ms(1000 * 60 * 60);
	auto sink = controller.CreateSink(config, &delegate);
	EXPECT_EQ(100u, controller.drain_period_ms());
	}

	{
	// Pick a resonable value -> get that value.
	FtraceConfig config = CreateFtraceConfig({"foo"});
	config.set_drain_period_ms(200);
	auto sink = controller.CreateSink(config, &delegate);
	EXPECT_EQ(200u, controller.drain_period_ms());
	}
	}

	} // namespace perfetto