base/process/process_unittest.cc

// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/process/process.h"

#include <memory>
#include <string>
#include <string_view>
#include <utility>

#include "base/at_exit.h"
#include "base/debug/invalid_access_win.h"
#include "base/process/kill.h"
#include "base/test/multiprocess_test.h"
#include "base/test/test_timeouts.h"
#include "base/threading/platform_thread.h"
#include "base/threading/platform_thread_internal_posix.h"
#include "base/threading/thread_local.h"
#include "build/build_config.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "testing/multiprocess_func_list.h"

#if BUILDFLAG(IS_CHROMEOS)
#include <sys/resource.h>
#include <unistd.h>

#include <vector>

#include "base/files/file_path.h"
#include "base/files/file_util.h"
#include "base/process/internal_linux.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_split.h"
#include "base/strings/string_util.h"
#include "base/strings/stringprintf.h"
#include "base/test/scoped_feature_list.h"
#include "base/test/task_environment.h"
#include "base/time/time.h"
#endif  // BUILDFLAG(IS_CHROMEOS)

#if BUILDFLAG(IS_WIN)
#include <windows.h>

#include "base/win/base_win_buildflags.h"
#endif

namespace {

#if BUILDFLAG(IS_WIN)
constexpr int kExpectedStillRunningExitCode = 0x102;
#else
constexpr int kExpectedStillRunningExitCode = 0;
#endif

constexpr int kDummyExitCode = 42;

#if BUILDFLAG(IS_APPLE)
// Fake port provider that returns the calling process's
// task port, ignoring its argument.
class FakePortProvider : public base::PortProvider {
  mach_port_t TaskForHandle(base::ProcessHandle process_handle) const override {
    return mach_task_self();
  }
};
#endif

#if BUILDFLAG(IS_CHROMEOS)
const char kForeground[] = "/chrome_renderers/foreground";
const char kCgroupRoot[] = "/sys/fs/cgroup/cpu";
const char kFullRendererCgroupRoot[] = "/sys/fs/cgroup/cpu/chrome_renderers";
const char kProcPath[] = "/proc/%d/cgroup";

std::string GetProcessCpuCgroup(const base::Process& process) {
  std::string proc;
  if (!base::ReadFileToString(
          base::FilePath(base::StringPrintf(kProcPath, process.Pid())),
          &proc)) {
    return std::string();
  }

  std::vector<std::string_view> lines = SplitStringPiece(
      proc, "\n", base::TRIM_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
  for (const auto& line : lines) {
    std::vector<std::string_view> fields = SplitStringPiece(
        line, ":", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
    if (fields.size() != 3U) {
      continue;
    }

    if (fields[1] == "cpu") {
      return static_cast<std::string>(fields[2]);
    }
  }

  return std::string();
}

bool AddProcessToCpuCgroup(const base::Process& process,
                           const std::string& cgroup) {
  base::FilePath path(cgroup);
  path = path.Append("cgroup.procs");
  return base::WriteFile(path, base::NumberToString(process.Pid()));
}
#endif  // BUILDFLAG(IS_CHROMEOS)

}  // namespace

namespace base {

class ProcessTest : public MultiProcessTest {
};

TEST_F(ProcessTest, Create) {
  Process process(SpawnChild("SimpleChildProcess"));
  ASSERT_TRUE(process.IsValid());
  ASSERT_FALSE(process.is_current());
  EXPECT_NE(process.Pid(), kNullProcessId);
  process.Close();
  ASSERT_FALSE(process.IsValid());
}

TEST_F(ProcessTest, CreateCurrent) {
  Process process = Process::Current();
  ASSERT_TRUE(process.IsValid());
  ASSERT_TRUE(process.is_current());
  EXPECT_NE(process.Pid(), kNullProcessId);
  process.Close();
  ASSERT_FALSE(process.IsValid());
}

TEST_F(ProcessTest, Move) {
  Process process1(SpawnChild("SimpleChildProcess"));
  EXPECT_TRUE(process1.IsValid());

  Process process2;
  EXPECT_FALSE(process2.IsValid());

  process2 = std::move(process1);
  EXPECT_TRUE(process2.IsValid());
  EXPECT_FALSE(process1.IsValid());
  EXPECT_FALSE(process2.is_current());

  Process process3 = Process::Current();
  process2 = std::move(process3);
  EXPECT_TRUE(process2.is_current());
  EXPECT_TRUE(process2.IsValid());
  EXPECT_FALSE(process3.IsValid());
}

TEST_F(ProcessTest, Duplicate) {
  Process process1(SpawnChild("SimpleChildProcess"));
  ASSERT_TRUE(process1.IsValid());

  Process process2 = process1.Duplicate();
  ASSERT_TRUE(process1.IsValid());
  ASSERT_TRUE(process2.IsValid());
  EXPECT_EQ(process1.Pid(), process2.Pid());
  EXPECT_FALSE(process1.is_current());
  EXPECT_FALSE(process2.is_current());

  process1.Close();
  ASSERT_TRUE(process2.IsValid());
}

TEST_F(ProcessTest, DuplicateCurrent) {
  Process process1 = Process::Current();
  ASSERT_TRUE(process1.IsValid());

  Process process2 = process1.Duplicate();
  ASSERT_TRUE(process1.IsValid());
  ASSERT_TRUE(process2.IsValid());
  EXPECT_EQ(process1.Pid(), process2.Pid());
  EXPECT_TRUE(process1.is_current());
  EXPECT_TRUE(process2.is_current());

  process1.Close();
  ASSERT_TRUE(process2.IsValid());
}

MULTIPROCESS_TEST_MAIN(SleepyChildProcess) {
  PlatformThread::Sleep(TestTimeouts::action_max_timeout());
  return 0;
}

// TODO(https://crbug.com/726484): Enable these tests on Fuchsia when
// CreationTime() is implemented.
TEST_F(ProcessTest, CreationTimeCurrentProcess) {
  // The current process creation time should be less than or equal to the
  // current time.
  EXPECT_FALSE(Process::Current().CreationTime().is_null());
  EXPECT_LE(Process::Current().CreationTime(), Time::Now());
}

#if !BUILDFLAG(IS_ANDROID)  // Cannot read other processes' creation time on
                            // Android.
TEST_F(ProcessTest, CreationTimeOtherProcess) {
  // The creation time of a process should be between a time recorded before it
  // was spawned and a time recorded after it was spawned. However, since the
  // base::Time and process creation clocks don't match, tolerate some error.
  constexpr base::TimeDelta kTolerance =
#if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)
      // On Linux, process creation time is relative to boot time which has a
      // 1-second resolution. Tolerate 1 second for the imprecise boot time and
      // 100 ms for the imprecise clock.
      Milliseconds(1100);
#elif BUILDFLAG(IS_WIN)
      // On Windows, process creation time is based on the system clock while
      // Time::Now() is a combination of system clock and
      // QueryPerformanceCounter(). Tolerate 100 ms for the clock mismatch.
      Milliseconds(100);
#elif BUILDFLAG(IS_APPLE) || BUILDFLAG(IS_FUCHSIA)
      // On Mac and Fuchsia, process creation time should be very precise.
      Milliseconds(0);
#else
#error Unsupported platform
#endif
  const Time before_creation = Time::Now();
  Process process(SpawnChild("SleepyChildProcess"));
  const Time after_creation = Time::Now();
  const Time creation = process.CreationTime();
  EXPECT_LE(before_creation - kTolerance, creation);
  EXPECT_LE(creation, after_creation + kTolerance);
  EXPECT_TRUE(process.Terminate(kDummyExitCode, true));
}
#endif  // !BUILDFLAG(IS_ANDROID)

TEST_F(ProcessTest, Terminate) {
  Process process(SpawnChild("SleepyChildProcess"));
  ASSERT_TRUE(process.IsValid());

  int exit_code = kDummyExitCode;
  EXPECT_EQ(TERMINATION_STATUS_STILL_RUNNING,
            GetTerminationStatus(process.Handle(), &exit_code));
  EXPECT_EQ(kExpectedStillRunningExitCode, exit_code);

  exit_code = kDummyExitCode;
  int kExpectedExitCode = 250;
  process.Terminate(kExpectedExitCode, false);
  process.WaitForExitWithTimeout(TestTimeouts::action_max_timeout(),
                                 &exit_code);

  EXPECT_NE(TERMINATION_STATUS_STILL_RUNNING,
            GetTerminationStatus(process.Handle(), &exit_code));
#if BUILDFLAG(IS_WIN)
  // Only Windows propagates the |exit_code| set in Terminate().
  EXPECT_EQ(kExpectedExitCode, exit_code);
#endif
}

void AtExitHandler(void*) {
  // At-exit handler should not be called at
  // Process::TerminateCurrentProcessImmediately.
  DCHECK(false);
}

class ThreadLocalObject {
 public:
  ~ThreadLocalObject() {
    // Thread-local storage should not be destructed at
    // Process::TerminateCurrentProcessImmediately.
    DCHECK(false);
  }
};

MULTIPROCESS_TEST_MAIN(TerminateCurrentProcessImmediatelyWithCode0) {
  base::ThreadLocalOwnedPointer<ThreadLocalObject> object;
  object.Set(std::make_unique<ThreadLocalObject>());
  base::AtExitManager::RegisterCallback(&AtExitHandler, nullptr);
  Process::TerminateCurrentProcessImmediately(0);
}

TEST_F(ProcessTest, TerminateCurrentProcessImmediatelyWithZeroExitCode) {
  Process process(SpawnChild("TerminateCurrentProcessImmediatelyWithCode0"));
  ASSERT_TRUE(process.IsValid());
  int exit_code = 42;
  ASSERT_TRUE(process.WaitForExitWithTimeout(TestTimeouts::action_max_timeout(),
                                             &exit_code));
  EXPECT_EQ(0, exit_code);
}

MULTIPROCESS_TEST_MAIN(TerminateCurrentProcessImmediatelyWithCode250) {
  Process::TerminateCurrentProcessImmediately(250);
}

TEST_F(ProcessTest, TerminateCurrentProcessImmediatelyWithNonZeroExitCode) {
  Process process(SpawnChild("TerminateCurrentProcessImmediatelyWithCode250"));
  ASSERT_TRUE(process.IsValid());
  int exit_code = 42;
  ASSERT_TRUE(process.WaitForExitWithTimeout(TestTimeouts::action_max_timeout(),
                                             &exit_code));
  EXPECT_EQ(250, exit_code);
}

MULTIPROCESS_TEST_MAIN(FastSleepyChildProcess) {
  PlatformThread::Sleep(TestTimeouts::tiny_timeout() * 10);
  return 0;
}

TEST_F(ProcessTest, WaitForExit) {
  Process process(SpawnChild("FastSleepyChildProcess"));
  ASSERT_TRUE(process.IsValid());

  int exit_code = kDummyExitCode;
  EXPECT_TRUE(process.WaitForExit(&exit_code));
  EXPECT_EQ(0, exit_code);
}

TEST_F(ProcessTest, WaitForExitWithTimeout) {
  Process process(SpawnChild("SleepyChildProcess"));
  ASSERT_TRUE(process.IsValid());

  int exit_code = kDummyExitCode;
  TimeDelta timeout = TestTimeouts::tiny_timeout();
  EXPECT_FALSE(process.WaitForExitWithTimeout(timeout, &exit_code));
  EXPECT_EQ(kDummyExitCode, exit_code);

  process.Terminate(kDummyExitCode, false);
}

#if BUILDFLAG(IS_WIN)
TEST_F(ProcessTest, WaitForExitOrEventWithProcessExit) {
  Process process(SpawnChild("FastSleepyChildProcess"));
  ASSERT_TRUE(process.IsValid());

  base::win::ScopedHandle stop_watching_handle(
      CreateEvent(nullptr, TRUE, FALSE, nullptr));

  int exit_code = kDummyExitCode;
  EXPECT_EQ(process.WaitForExitOrEvent(stop_watching_handle, &exit_code),
            base::Process::WaitExitStatus::PROCESS_EXITED);
  EXPECT_EQ(0, exit_code);
}

TEST_F(ProcessTest, WaitForExitOrEventWithEventSet) {
  Process process(SpawnChild("SleepyChildProcess"));
  ASSERT_TRUE(process.IsValid());

  base::win::ScopedHandle stop_watching_handle(
      CreateEvent(nullptr, TRUE, TRUE, nullptr));

  int exit_code = kDummyExitCode;
  EXPECT_EQ(process.WaitForExitOrEvent(stop_watching_handle, &exit_code),
            base::Process::WaitExitStatus::STOP_EVENT_SIGNALED);
  EXPECT_EQ(kDummyExitCode, exit_code);

  process.Terminate(kDummyExitCode, false);
}
#endif  // BUILDFLAG(IS_WIN)

// Ensure that the priority of a process is restored correctly after
// backgrounding and restoring.
// Note: a platform may not be willing or able to lower the priority of
// a process. The calls to SetProcessPriority should be noops then.
TEST_F(ProcessTest, SetProcessPriority) {
  if (!Process::CanSetPriority()) {
    return;
  }
  Process process(SpawnChild("SimpleChildProcess"));
  int old_os_priority = process.GetOSPriority();
#if BUILDFLAG(IS_APPLE)
  // On the Mac, backgrounding a process requires a port to that process.
  // In the browser it's available through the MachBroker class, which is not
  // part of base. Additionally, there is an indefinite amount of time between
  // spawning a process and receiving its port. Because this test just checks
  // the ability to background/foreground a process, we can use the current
  // process's port instead.
  FakePortProvider provider;
  EXPECT_TRUE(process.SetPriority(&provider, Process::Priority::kBestEffort));
  EXPECT_EQ(process.GetPriority(&provider), Process::Priority::kBestEffort);
  EXPECT_TRUE(process.SetPriority(&provider, Process::Priority::kUserBlocking));
  EXPECT_EQ(process.GetPriority(&provider), Process::Priority::kUserBlocking);

#else
  EXPECT_TRUE(process.SetPriority(base::Process::Priority::kBestEffort));
  EXPECT_EQ(process.GetPriority(), Process::Priority::kBestEffort);
  EXPECT_TRUE(process.SetPriority(base::Process::Priority::kUserBlocking));
  EXPECT_EQ(process.GetPriority(), Process::Priority::kUserBlocking);
#endif
  int new_os_priority = process.GetOSPriority();
  EXPECT_EQ(old_os_priority, new_os_priority);
}

#if BUILDFLAG(IS_CHROMEOS)
bool IsThreadRT(PlatformThreadId thread_id) {
  // Check if the thread is running in real-time mode
  int sched = sched_getscheduler(
      PlatformThread::CurrentId() == thread_id ? 0 : thread_id);
  if (sched == -1) {
    // The thread may disappear for any reason so ignore ESRCH.
    DPLOG_IF(ERROR, errno != ESRCH)
        << "Failed to call sched_getscheduler on thread_id=" << thread_id;
    return false;
  }
  return sched == SCHED_RR || sched == SCHED_FIFO;
}

// Verify that all the threads in a process are RT or not.
void AssertThreadsRT(int process_id, bool is_rt) {
  internal::ForEachProcessTask(
      process_id, [is_rt](PlatformThreadId tid, const FilePath& /* path */) {
        EXPECT_EQ(IsThreadRT(tid), is_rt);
      });
}

void AssertThreadsType(int process_id, ThreadType type) {
  internal::ForEachProcessTask(process_id, [process_id, type](
                                               PlatformThreadId tid,
                                               const FilePath& path) {
    EXPECT_EQ(PlatformThread::GetThreadTypeFromThreadId(process_id, tid), type);
  });
}

void AssertThreadsBgState(int process_id, bool is_bg) {
  internal::ForEachProcessTask(
      process_id, [is_bg](PlatformThreadId tid, const FilePath& path) {
        EXPECT_EQ(PlatformThreadLinux::IsThreadBackgroundedForTest(tid), is_bg);
      });
}

namespace {

class FunctionTestThread : public PlatformThread::Delegate {
 public:
  FunctionTestThread() = default;

  FunctionTestThread(const FunctionTestThread&) = delete;
  FunctionTestThread& operator=(const FunctionTestThread&) = delete;

  void ThreadMain() override {
    PlatformThread::SetCurrentThreadType(ThreadType::kCompositing);
    while (true) {
      PlatformThread::Sleep(Milliseconds(100));
    }
  }
};

class RTAudioFunctionTestThread : public PlatformThread::Delegate {
 public:
  RTAudioFunctionTestThread() = default;

  RTAudioFunctionTestThread(const RTAudioFunctionTestThread&) = delete;
  RTAudioFunctionTestThread& operator=(const RTAudioFunctionTestThread&) =
      delete;

  void ThreadMain() override {
    PlatformThread::SetCurrentThreadType(ThreadType::kRealtimeAudio);
    while (true) {
      PlatformThread::Sleep(Milliseconds(100));
    }
  }
};

class RTDisplayFunctionTestThread : public PlatformThread::Delegate {
 public:
  RTDisplayFunctionTestThread() = default;

  RTDisplayFunctionTestThread(const RTDisplayFunctionTestThread&) = delete;
  RTDisplayFunctionTestThread& operator=(const RTDisplayFunctionTestThread&) =
      delete;

  void ThreadMain() override {
    PlatformThread::SetCurrentThreadType(ThreadType::kCompositing);
    while (true) {
      PlatformThread::Sleep(Milliseconds(100));
    }
  }
};

int create_threads_after_bg;
bool bg_threads_created;
bool prebg_threads_created;
bool audio_rt_threads_created;
bool display_rt_threads_created;

void sig_create_threads_after_bg(int signum) {
  if (signum == SIGUSR1) {
    create_threads_after_bg = true;
  }
}

void sig_prebg_threads_created_handler(int signum) {
  if (signum == SIGUSR1) {
    prebg_threads_created = true;
  }
}

void sig_bg_threads_created_handler(int signum) {
  if (signum == SIGUSR2) {
    bg_threads_created = true;
  }
}

void sig_audio_rt_threads_created_handler(int signum) {
  if (signum == SIGUSR1) {
    audio_rt_threads_created = true;
  }
}

void sig_display_rt_threads_created_handler(int signum) {
  if (signum == SIGUSR1) {
    display_rt_threads_created = true;
  }
}

}  // namespace

MULTIPROCESS_TEST_MAIN(ProcessThreadBackgroundingMain) {
  PlatformThreadHandle handle1, handle2, handle3;
  FunctionTestThread thread1, thread2, thread3;
  base::test::ScopedFeatureList scoped_feature_list(kSetThreadBgForBgProcess);
  PlatformThreadChromeOS::InitializeFeatures();
  PlatformThread::SetCurrentThreadType(ThreadType::kCompositing);

  // Register signal handler to be notified to create threads after backgrounding.
  signal(SIGUSR1, sig_create_threads_after_bg);

  if (!PlatformThread::Create(0, &thread1, &handle1)) {
    ADD_FAILURE() << "ProcessThreadBackgroundingMain: Failed to create thread1";
    return 1;
  }

  if (!PlatformThread::Create(0, &thread2, &handle2)) {
    ADD_FAILURE() << "ProcessThreadBackgroundingMain: Failed to create thread2";
    return 1;
  }

  // Signal that the pre-backgrounding threads were created.
  kill(getppid(), SIGUSR1);

  // Wait for the signal to background.
  while (create_threads_after_bg == 0) {
    PlatformThread::Sleep(Milliseconds(100));
  }

  // Test creation of thread while process is backgrounded.
  if (!PlatformThread::Create(0, &thread3, &handle3)) {
    ADD_FAILURE() << "ProcessThreadBackgroundingMain: Failed to create thread3";
    return 1;
  }

  // Signal that the thread after backgrounding was created.
  kill(getppid(), SIGUSR2);

  while (true) {
    PlatformThread::Sleep(Milliseconds(100));
  }
}

// ProcessThreadBackgrounding: A test to create a process and verify
// that the threads in the process are backgrounded correctly.
TEST_F(ProcessTest, ProcessThreadBackgrounding) {
  if (!PlatformThread::CanChangeThreadType(ThreadType::kDefault,
                                           ThreadType::kCompositing)) {
    return;
  }

  base::test::ScopedFeatureList scoped_feature_list(kSetThreadBgForBgProcess);
  PlatformThreadChromeOS::InitializeFeatures();

  // Register signal handlers to be notified of events in child process.
  signal(SIGUSR1, sig_prebg_threads_created_handler);
  signal(SIGUSR2, sig_bg_threads_created_handler);

  Process process(SpawnChild("ProcessThreadBackgroundingMain"));
  EXPECT_TRUE(process.IsValid());

  // Wait for the signal that the initial pre-backgrounding
  // threads were created.
  while (!prebg_threads_created) {
    PlatformThread::Sleep(Milliseconds(100));
  }

  // Verify that the threads are initially in the foreground.
  AssertThreadsType(process.Pid(), ThreadType::kCompositing);
  AssertThreadsBgState(process.Pid(), false);

  EXPECT_TRUE(process.SetPriority(Process::Priority::kBestEffort));

  // Send a signal to create a thread while the process is backgrounded.
  kill(process.Pid(), SIGUSR1);

  // Wait for the signal that backgrounding completed
  while (!bg_threads_created) {
    PlatformThread::Sleep(Milliseconds(100));
  }

  // Verify that the threads are backgrounded.
  AssertThreadsType(process.Pid(), ThreadType::kCompositing);
  AssertThreadsBgState(process.Pid(), true);

  EXPECT_TRUE(process.SetPriority(Process::Priority::kUserBlocking));
  EXPECT_TRUE(process.GetPriority() == base::Process::Priority::kUserBlocking);

  // Verify that the threads are foregrounded.
  AssertThreadsType(process.Pid(), ThreadType::kCompositing);
  AssertThreadsBgState(process.Pid(), false);
}

MULTIPROCESS_TEST_MAIN(ProcessRTAudioBgMain) {
  PlatformThreadHandle handle1;
  RTAudioFunctionTestThread thread1;
  base::test::ScopedFeatureList scoped_feature_list(kSetThreadBgForBgProcess);
  PlatformThreadChromeOS::InitializeFeatures();
  PlatformThread::SetCurrentThreadType(ThreadType::kRealtimeAudio);

  if (!PlatformThread::Create(0, &thread1, &handle1)) {
    ADD_FAILURE() << "ProcessRTAudioBgMain: Failed to create thread1";
    return 1;
  }

  // Signal that the RT thread was created.
  kill(getppid(), SIGUSR1);

  while (true) {
    PlatformThread::Sleep(Milliseconds(100));
  }
}

// Test the property of kRealTimeAudio threads in a backgrounded process.
TEST_F(ProcessTest, ProcessRTAudioBg) {
  if (!PlatformThread::CanChangeThreadType(ThreadType::kDefault,
                                           ThreadType::kCompositing)) {
    return;
  }

  base::test::ScopedFeatureList scoped_feature_list(kSetThreadBgForBgProcess);
  PlatformThreadChromeOS::InitializeFeatures();

  // Register signal handler to check if RT thread was created by child process.
  signal(SIGUSR1, sig_audio_rt_threads_created_handler);

  Process process(SpawnChild("ProcessRTAudioBgMain"));
  EXPECT_TRUE(process.IsValid());

  // Wait for signal that threads were spawned
  while (!audio_rt_threads_created) {
    PlatformThread::Sleep(Milliseconds(100));
  }

  AssertThreadsRT(process.Pid(), true);
  AssertThreadsType(process.Pid(), ThreadType::kRealtimeAudio);
  AssertThreadsBgState(process.Pid(), false);

  EXPECT_TRUE(process.SetPriority(Process::Priority::kBestEffort));
  EXPECT_TRUE(process.GetPriority() == base::Process::Priority::kBestEffort);

  // Verify that nothing changed when process is kBestEffort
  AssertThreadsRT(process.Pid(), true);
  AssertThreadsType(process.Pid(), ThreadType::kRealtimeAudio);
  AssertThreadsBgState(process.Pid(), false);

  EXPECT_TRUE(process.SetPriority(Process::Priority::kUserBlocking));
  EXPECT_TRUE(process.GetPriority() == base::Process::Priority::kUserBlocking);

  // Verify that nothing changed when process is kUserBlocking
  AssertThreadsRT(process.Pid(), true);
  AssertThreadsType(process.Pid(), ThreadType::kRealtimeAudio);
  AssertThreadsBgState(process.Pid(), false);
}

MULTIPROCESS_TEST_MAIN(ProcessRTDisplayBgMain) {
  PlatformThreadHandle handle1;
  RTDisplayFunctionTestThread thread1;
  base::test::ScopedFeatureList scoped_feature_list;
  scoped_feature_list.InitWithFeatures(
      {kSetThreadBgForBgProcess, kSetRtForDisplayThreads}, {});
  PlatformThreadChromeOS::InitializeFeatures();

  PlatformThread::SetCurrentThreadType(ThreadType::kCompositing);

  if (!PlatformThread::Create(0, &thread1, &handle1)) {
    ADD_FAILURE() << "ProcessRTDisplayBgMain: Failed to create thread1";
    return 1;
  }

  // Signal that the RT thread was created.
  kill(getppid(), SIGUSR1);

  while (true) {
    PlatformThread::Sleep(Milliseconds(100));
  }
}

// Test the property of kCompositing threads in a backgrounded process.
TEST_F(ProcessTest, ProcessRTDisplayBg) {
  if (!PlatformThread::CanChangeThreadType(ThreadType::kDefault,
                                           ThreadType::kCompositing)) {
    return;
  }

  base::test::ScopedFeatureList scoped_feature_list;
  scoped_feature_list.InitWithFeatures(
      {kSetThreadBgForBgProcess, kSetRtForDisplayThreads}, {});
  PlatformThreadChromeOS::InitializeFeatures();

  // Register signal handler to check if RT thread was created by child process.
  signal(SIGUSR1, sig_display_rt_threads_created_handler);

  Process process(SpawnChild("ProcessRTDisplayBgMain"));
  EXPECT_TRUE(process.IsValid());

  // Wait for signal that threads were spawned
  while (!display_rt_threads_created) {
    PlatformThread::Sleep(Milliseconds(100));
  }

  AssertThreadsRT(process.Pid(), true);
  AssertThreadsType(process.Pid(), ThreadType::kCompositing);
  AssertThreadsBgState(process.Pid(), false);

  EXPECT_TRUE(process.SetPriority(Process::Priority::kBestEffort));
  EXPECT_TRUE(process.GetPriority() == base::Process::Priority::kBestEffort);

  // Verify that the threads transitioned away from RT when process is
  // kBestEffort
  AssertThreadsRT(process.Pid(), false);
  AssertThreadsType(process.Pid(), ThreadType::kCompositing);
  AssertThreadsBgState(process.Pid(), true);

  EXPECT_TRUE(process.SetPriority(Process::Priority::kUserBlocking));
  EXPECT_TRUE(process.GetPriority() == base::Process::Priority::kUserBlocking);

  // Verify that it is back to RT when process is kUserBlocking
  AssertThreadsRT(process.Pid(), true);
  AssertThreadsType(process.Pid(), ThreadType::kCompositing);
  AssertThreadsBgState(process.Pid(), false);
}

#endif  // BUILDFLAG(IS_CHROMEOS)

// Consumers can use WaitForExitWithTimeout(base::TimeDelta(), nullptr) to check
// whether the process is still running. This may not be safe because of the
// potential reusing of the process id. So we won't export Process::IsRunning()
// on all platforms. But for the controllable scenario in the test cases, the
// behavior should be guaranteed.
TEST_F(ProcessTest, CurrentProcessIsRunning) {
  EXPECT_FALSE(Process::Current().WaitForExitWithTimeout(
      base::TimeDelta(), nullptr));
}

#if BUILDFLAG(IS_APPLE)
// On Mac OSX, we can detect whether a non-child process is running.
TEST_F(ProcessTest, PredefinedProcessIsRunning) {
  // Process 1 is the /sbin/launchd, it should be always running.
  EXPECT_FALSE(Process::Open(1).WaitForExitWithTimeout(
      base::TimeDelta(), nullptr));
}
#endif

// Test is disabled on Windows AMR64 because
// TerminateWithHeapCorruption() isn't expected to work there.
// See: https://crbug.com/1054423
#if BUILDFLAG(IS_WIN)
#if defined(ARCH_CPU_ARM64)
#define MAYBE_HeapCorruption DISABLED_HeapCorruption
#else
#define MAYBE_HeapCorruption HeapCorruption
#endif
TEST_F(ProcessTest, MAYBE_HeapCorruption) {
  EXPECT_EXIT(base::debug::win::TerminateWithHeapCorruption(),
              ::testing::ExitedWithCode(STATUS_HEAP_CORRUPTION), "");
}

#if BUILDFLAG(WIN_ENABLE_CFG_GUARDS)
#define MAYBE_ControlFlowViolation ControlFlowViolation
#else
#define MAYBE_ControlFlowViolation DISABLED_ControlFlowViolation
#endif
TEST_F(ProcessTest, MAYBE_ControlFlowViolation) {
  // CFG causes ntdll!RtlFailFast2 to be called resulting in uncatchable
  // 0xC0000409 (STATUS_STACK_BUFFER_OVERRUN) exception.
  EXPECT_EXIT(base::debug::win::TerminateWithControlFlowViolation(),
              ::testing::ExitedWithCode(STATUS_STACK_BUFFER_OVERRUN), "");
}

#endif  // BUILDFLAG(IS_WIN)

TEST_F(ProcessTest, ChildProcessIsRunning) {
  Process process(SpawnChild("SleepyChildProcess"));
  EXPECT_FALSE(process.WaitForExitWithTimeout(
      base::TimeDelta(), nullptr));
  process.Terminate(0, true);
  EXPECT_TRUE(process.WaitForExitWithTimeout(
      base::TimeDelta(), nullptr));
}

#if BUILDFLAG(IS_CHROMEOS)

// Tests that the function GetProcessPriorityCGroup() can parse the contents
// of the /proc/<pid>/cgroup file successfully.
TEST_F(ProcessTest, TestGetProcessPriorityCGroup) {
  const char kNotBackgroundedCGroup[] = "5:cpuacct,cpu,cpuset:/daemons\n";
  const char kBackgroundedCGroup[] =
      "2:freezer:/chrome_renderers/to_be_frozen\n"
      "1:cpu:/chrome_renderers/background\n";

  EXPECT_EQ(GetProcessPriorityCGroup(kNotBackgroundedCGroup),
            Process::Priority::kUserBlocking);
  EXPECT_EQ(GetProcessPriorityCGroup(kBackgroundedCGroup),
            Process::Priority::kBestEffort);
}

TEST_F(ProcessTest, InitializePriorityEmptyProcess) {
  // TODO(b/172213843): base::Process is used by base::TestSuite::Initialize
  // before we can use ScopedFeatureList here. Update the test to allow the
  // use of ScopedFeatureList before base::TestSuite::Initialize runs.
  if (!Process::OneGroupPerRendererEnabledForTesting())
    return;

  Process process;
  process.InitializePriority();
  const std::string unique_token = process.unique_token();
  ASSERT_TRUE(unique_token.empty());
}

TEST_F(ProcessTest, SetProcessBackgroundedOneCgroupPerRender) {
  if (!Process::OneGroupPerRendererEnabledForTesting())
    return;

  base::test::TaskEnvironment task_env;

  Process process(SpawnChild("SimpleChildProcess"));
  process.InitializePriority();
  const std::string unique_token = process.unique_token();
  ASSERT_FALSE(unique_token.empty());

  EXPECT_TRUE(process.SetPriority(Process::Priority::kUserBlocking));
  EXPECT_EQ(process.GetPriority(), Process::Priority::kUserBlocking);
  std::string cgroup = GetProcessCpuCgroup(process);
  EXPECT_FALSE(cgroup.empty());
  EXPECT_NE(cgroup.find(unique_token), std::string::npos);

  EXPECT_TRUE(process.SetPriority(Process::Priority::kBestEffort));
  EXPECT_EQ(process.GetPriority(), Process::Priority::kBestEffort);

  EXPECT_TRUE(process.Terminate(0, false));
  // Terminate should post a task, wait for it to run
  task_env.RunUntilIdle();

  cgroup = std::string(kCgroupRoot) + cgroup;
  EXPECT_FALSE(base::DirectoryExists(FilePath(cgroup)));
}

TEST_F(ProcessTest, CleanUpBusyProcess) {
  if (!Process::OneGroupPerRendererEnabledForTesting())
    return;

  base::test::TaskEnvironment task_env;

  Process process(SpawnChild("SimpleChildProcess"));
  process.InitializePriority();
  const std::string unique_token = process.unique_token();
  ASSERT_FALSE(unique_token.empty());

  EXPECT_TRUE(process.SetPriority(Process::Priority::kUserBlocking));
  EXPECT_EQ(process.GetPriority(), Process::Priority::kUserBlocking);
  std::string cgroup = GetProcessCpuCgroup(process);
  EXPECT_FALSE(cgroup.empty());
  EXPECT_NE(cgroup.find(unique_token), std::string::npos);

  // Add another process to the cgroup to ensure it stays busy.
  cgroup = std::string(kCgroupRoot) + cgroup;
  Process process2(SpawnChild("SimpleChildProcess"));
  EXPECT_TRUE(AddProcessToCpuCgroup(process2, cgroup));

  // Terminate the first process that should tirgger a cleanup of the cgroup
  EXPECT_TRUE(process.Terminate(0, false));
  // Wait until the background task runs once. This should fail and requeue
  // another task to retry.
  task_env.RunUntilIdle();
  EXPECT_TRUE(base::DirectoryExists(FilePath(cgroup)));

  // Move the second process to free the cgroup
  std::string foreground_path =
      std::string(kCgroupRoot) + std::string(kForeground);
  EXPECT_TRUE(AddProcessToCpuCgroup(process2, foreground_path));

  // Wait for the retry.
  PlatformThread::Sleep(base::Milliseconds(1100));
  task_env.RunUntilIdle();
  // The cgroup should be deleted now.
  EXPECT_FALSE(base::DirectoryExists(FilePath(cgroup)));

  process2.Terminate(0, false);
}

TEST_F(ProcessTest, SetProcessBackgroundedEmptyToken) {
  if (!Process::OneGroupPerRendererEnabledForTesting())
    return;

  Process process(SpawnChild("SimpleChildProcess"));
  const std::string unique_token = process.unique_token();
  ASSERT_TRUE(unique_token.empty());

  // Moving to the foreground should use the default foreground path.
  EXPECT_TRUE(process.SetPriority(Process::Priority::kUserBlocking));
  EXPECT_EQ(process.GetPriority(), Process::Priority::kUserBlocking);
  std::string cgroup = GetProcessCpuCgroup(process);
  EXPECT_FALSE(cgroup.empty());
  EXPECT_EQ(cgroup, kForeground);
}

TEST_F(ProcessTest, CleansUpStaleGroups) {
  if (!Process::OneGroupPerRendererEnabledForTesting())
    return;

  base::test::TaskEnvironment task_env;

  // Create a process that will not be cleaned up
  Process process(SpawnChild("SimpleChildProcess"));
  process.InitializePriority();
  const std::string unique_token = process.unique_token();
  ASSERT_FALSE(unique_token.empty());

  EXPECT_TRUE(process.SetPriority(Process::Priority::kBestEffort));
  EXPECT_EQ(process.GetPriority(), Process::Priority::kBestEffort);

  // Create a stale cgroup
  std::string root = kFullRendererCgroupRoot;
  std::string cgroup = root + "/" + unique_token;
  std::vector<std::string> tokens = base::SplitString(
      cgroup, "-", base::KEEP_WHITESPACE, base::SPLIT_WANT_ALL);
  tokens[1] = "fake";
  std::string fake_cgroup = base::JoinString(tokens, "-");
  EXPECT_TRUE(base::CreateDirectory(FilePath(fake_cgroup)));

  // Clean up stale groups
  Process::CleanUpStaleProcessStates();

  // validate the fake group is deleted
  EXPECT_FALSE(base::DirectoryExists(FilePath(fake_cgroup)));

  // validate the active process cgroup is not deleted
  EXPECT_TRUE(base::DirectoryExists(FilePath(cgroup)));

  // validate foreground and background are not deleted
  EXPECT_TRUE(base::DirectoryExists(FilePath(root + "/foreground")));
  EXPECT_TRUE(base::DirectoryExists(FilePath(root + "/background")));

  // clean up the process
  EXPECT_TRUE(process.Terminate(0, false));
  // Terminate should post a task, wait for it to run
  task_env.RunUntilIdle();
  EXPECT_FALSE(base::DirectoryExists(FilePath(cgroup)));
}

TEST_F(ProcessTest, OneCgroupDoesNotCleanUpGroupsWithWrongPrefix) {
  if (!Process::OneGroupPerRendererEnabledForTesting())
    return;

  base::test::TaskEnvironment task_env;

  // Create a process that will not be cleaned up
  Process process(SpawnChild("SimpleChildProcess"));
  process.InitializePriority();
  const std::string unique_token = process.unique_token();
  ASSERT_FALSE(unique_token.empty());

  EXPECT_TRUE(process.SetPriority(Process::Priority::kUserBlocking));
  EXPECT_EQ(process.GetPriority(), Process::Priority::kUserBlocking);
  std::string cgroup = GetProcessCpuCgroup(process);
  EXPECT_FALSE(cgroup.empty());
  EXPECT_NE(cgroup.find(unique_token), std::string::npos);

  // Create a stale cgroup
  FilePath cgroup_path = FilePath(std::string(kCgroupRoot) + cgroup);
  FilePath fake_cgroup = FilePath(kFullRendererCgroupRoot).AppendASCII("fake");
  EXPECT_TRUE(base::CreateDirectory(fake_cgroup));

  // Clean up stale groups
  Process::CleanUpStaleProcessStates();

  // validate the fake group is deleted
  EXPECT_TRUE(base::DirectoryExists(fake_cgroup));
  EXPECT_TRUE(base::DirectoryExists(cgroup_path));

  // clean up the process
  EXPECT_TRUE(process.SetPriority(Process::Priority::kBestEffort));
  EXPECT_EQ(process.GetPriority(), Process::Priority::kBestEffort);
  EXPECT_TRUE(process.Terminate(0, false));
  task_env.RunUntilIdle();
  EXPECT_FALSE(base::DirectoryExists(cgroup_path));
  base::DeleteFile(fake_cgroup);
}
#endif  // BUILDFLAG(IS_CHROMEOS)

}  // namespace base