test/launcher/unit_test_launcher.cc

// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/test/launcher/unit_test_launcher.h"

#include <map>
#include <memory>
#include <utility>

#include "base/base_switches.h"
#include "base/bind.h"
#include "base/callback_helpers.h"
#include "base/command_line.h"
#include "base/compiler_specific.h"
#include "base/debug/debugger.h"
#include "base/files/file_util.h"
#include "base/files/scoped_temp_dir.h"
#include "base/format_macros.h"
#include "base/location.h"
#include "base/macros.h"
#include "base/message_loop/message_loop.h"
#include "base/sequence_checker.h"
#include "base/single_thread_task_runner.h"
#include "base/stl_util.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_util.h"
#include "base/sys_info.h"
#include "base/test/gtest_xml_util.h"
#include "base/test/launcher/test_launcher.h"
#include "base/test/test_switches.h"
#include "base/test/test_timeouts.h"
#include "base/third_party/dynamic_annotations/dynamic_annotations.h"
#include "base/threading/thread_checker.h"
#include "base/threading/thread_task_runner_handle.h"
#include "build/build_config.h"
#include "testing/gtest/include/gtest/gtest.h"

#if defined(OS_POSIX)
#include "base/files/file_descriptor_watcher_posix.h"
#endif

namespace base {

namespace {

// This constant controls how many tests are run in a single batch by default.
const size_t kDefaultTestBatchLimit = 10;

const char kHelpFlag[] = "help";

// Flag to run all tests in a single process.
const char kSingleProcessTestsFlag[] = "single-process-tests";

void PrintUsage() {
  fprintf(stdout,
          "Runs tests using the gtest framework, each batch of tests being\n"
          "run in their own process. Supported command-line flags:\n"
          "\n"
          " Common flags:\n"
          "  --gtest_filter=...\n"
          "    Runs a subset of tests (see --gtest_help for more info).\n"
          "\n"
          "  --help\n"
          "    Shows this message.\n"
          "\n"
          "  --gtest_help\n"
          "    Shows the gtest help message.\n"
          "\n"
          "  --test-launcher-jobs=N\n"
          "    Sets the number of parallel test jobs to N.\n"
          "\n"
          "  --single-process-tests\n"
          "    Runs the tests and the launcher in the same process. Useful\n"
          "    for debugging a specific test in a debugger.\n"
          "\n"
          " Other flags:\n"
          "  --test-launcher-filter-file=PATH\n"
          "    Like --gtest_filter, but read the test filter from PATH.\n"
          "    One pattern per line; lines starting with '-' are exclusions.\n"
          "    See also //testing/buildbot/filters/README.md file.\n"
          "\n"
          "  --test-launcher-batch-limit=N\n"
          "    Sets the limit of test batch to run in a single process to N.\n"
          "\n"
          "  --test-launcher-debug-launcher\n"
          "    Disables autodetection of debuggers and similar tools,\n"
          "    making it possible to use them to debug launcher itself.\n"
          "\n"
          "  --test-launcher-retry-limit=N\n"
          "    Sets the limit of test retries on failures to N.\n"
          "\n"
          "  --test-launcher-summary-output=PATH\n"
          "    Saves a JSON machine-readable summary of the run.\n"
          "\n"
          "  --test-launcher-print-test-stdio=auto|always|never\n"
          "    Controls when full test output is printed.\n"
          "    auto means to print it when the test failed.\n"
          "\n"
          "  --test-launcher-test-part-results-limit=N\n"
          "    Sets the limit of failed EXPECT/ASSERT entries in the xml and\n"
          "    JSON outputs per test to N (default N=10). Negative value \n"
          "    will disable this limit.\n"
          "\n"
          "  --test-launcher-total-shards=N\n"
          "    Sets the total number of shards to N.\n"
          "\n"
          "  --test-launcher-shard-index=N\n"
          "    Sets the shard index to run to N (from 0 to TOTAL - 1).\n");
  fflush(stdout);
}

class DefaultUnitTestPlatformDelegate : public UnitTestPlatformDelegate {
 public:
  DefaultUnitTestPlatformDelegate() = default;

 private:
  // UnitTestPlatformDelegate:
  bool GetTests(std::vector<TestIdentifier>* output) override {
    *output = GetCompiledInTests();
    return true;
  }

  bool CreateResultsFile(base::FilePath* path) override {
    if (!CreateNewTempDirectory(FilePath::StringType(), path))
      return false;
    *path = path->AppendASCII("test_results.xml");
    return true;
  }

  bool CreateTemporaryFile(base::FilePath* path) override {
    if (!temp_dir_.IsValid() && !temp_dir_.CreateUniqueTempDir())
      return false;
    return CreateTemporaryFileInDir(temp_dir_.GetPath(), path);
  }

  CommandLine GetCommandLineForChildGTestProcess(
      const std::vector<std::string>& test_names,
      const base::FilePath& output_file,
      const base::FilePath& flag_file) override {
    CommandLine new_cmd_line(*CommandLine::ForCurrentProcess());

    CHECK(base::PathExists(flag_file));

    std::string long_flags(
        std::string("--") + kGTestFilterFlag + "=" +
        JoinString(test_names, ":"));
    CHECK_EQ(static_cast<int>(long_flags.size()),
             WriteFile(flag_file, long_flags.data(),
                       static_cast<int>(long_flags.size())));

    new_cmd_line.AppendSwitchPath(switches::kTestLauncherOutput, output_file);
    new_cmd_line.AppendSwitchPath(kGTestFlagfileFlag, flag_file);
    new_cmd_line.AppendSwitch(kSingleProcessTestsFlag);

    return new_cmd_line;
  }

  std::string GetWrapperForChildGTestProcess() override {
    return std::string();
  }

  void RelaunchTests(TestLauncher* test_launcher,
                     const std::vector<std::string>& test_names,
                     int launch_flags) override {
    // Relaunch requested tests in parallel, but only use single
    // test per batch for more precise results (crashes, etc).
    for (const std::string& test_name : test_names) {
      std::vector<std::string> batch;
      batch.push_back(test_name);
      RunUnitTestsBatch(test_launcher, this, batch, launch_flags);
    }
  }

  ScopedTempDir temp_dir_;

  DISALLOW_COPY_AND_ASSIGN(DefaultUnitTestPlatformDelegate);
};

bool GetSwitchValueAsInt(const std::string& switch_name, int* result) {
  if (!CommandLine::ForCurrentProcess()->HasSwitch(switch_name))
    return true;

  std::string switch_value =
      CommandLine::ForCurrentProcess()->GetSwitchValueASCII(switch_name);
  if (!StringToInt(switch_value, result) || *result < 0) {
    LOG(ERROR) << "Invalid value for " << switch_name << ": " << switch_value;
    return false;
  }

  return true;
}

int LaunchUnitTestsInternal(RunTestSuiteCallback run_test_suite,
                            size_t parallel_jobs,
                            int default_batch_limit,
                            bool use_job_objects,
                            OnceClosure gtest_init) {
#if defined(OS_ANDROID)
  // We can't easily fork on Android, just run the test suite directly.
  return std::move(run_test_suite).Run();
#else
  bool force_single_process = false;
  if (CommandLine::ForCurrentProcess()->HasSwitch(
          switches::kTestLauncherDebugLauncher)) {
    fprintf(stdout, "Forcing test launcher debugging mode.\n");
    fflush(stdout);
  } else {
    if (base::debug::BeingDebugged()) {
      fprintf(stdout,
              "Debugger detected, switching to single process mode.\n"
              "Pass --test-launcher-debug-launcher to debug the launcher "
              "itself.\n");
      fflush(stdout);
      force_single_process = true;
    }
  }

  if (CommandLine::ForCurrentProcess()->HasSwitch(kGTestHelpFlag) ||
      CommandLine::ForCurrentProcess()->HasSwitch(kGTestListTestsFlag) ||
      CommandLine::ForCurrentProcess()->HasSwitch(kSingleProcessTestsFlag) ||
      CommandLine::ForCurrentProcess()->HasSwitch(
          switches::kTestChildProcess) ||
      force_single_process) {
    return std::move(run_test_suite).Run();
  }
#endif

  if (CommandLine::ForCurrentProcess()->HasSwitch(kHelpFlag)) {
    PrintUsage();
    return 0;
  }

  TimeTicks start_time(TimeTicks::Now());

  std::move(gtest_init).Run();
  TestTimeouts::Initialize();

  int batch_limit = default_batch_limit;
  if (!GetSwitchValueAsInt(switches::kTestLauncherBatchLimit, &batch_limit))
    return 1;

  fprintf(stdout,
          "IMPORTANT DEBUGGING NOTE: batches of tests are run inside their\n"
          "own process. For debugging a test inside a debugger, use the\n"
          "--gtest_filter=<your_test_name> flag along with\n"
          "--single-process-tests.\n");
  fflush(stdout);

  MessageLoopForIO message_loop;
#if defined(OS_POSIX)
  FileDescriptorWatcher file_descriptor_watcher(&message_loop);
#endif

  DefaultUnitTestPlatformDelegate platform_delegate;
  UnitTestLauncherDelegate delegate(
      &platform_delegate, batch_limit, use_job_objects);
  TestLauncher launcher(&delegate, parallel_jobs);
  bool success = launcher.Run();

  fprintf(stdout, "Tests took %" PRId64 " seconds.\n",
          (TimeTicks::Now() - start_time).InSeconds());
  fflush(stdout);

  return (success ? 0 : 1);
}

void InitGoogleTestChar(int* argc, char** argv) {
  testing::InitGoogleTest(argc, argv);
}

#if defined(OS_WIN)
void InitGoogleTestWChar(int* argc, wchar_t** argv) {
  testing::InitGoogleTest(argc, argv);
}
#endif  // defined(OS_WIN)

// Interprets test results and reports to the test launcher. Returns true
// on success.
bool ProcessTestResults(
    TestLauncher* test_launcher,
    const std::vector<std::string>& test_names,
    const base::FilePath& output_file,
    const std::string& output,
    int exit_code,
    bool was_timeout,
    std::vector<std::string>* tests_to_relaunch) {
  std::vector<TestResult> test_results;
  bool crashed = false;
  bool have_test_results =
      ProcessGTestOutput(output_file, &test_results, &crashed);

  bool called_any_callback = false;

  if (have_test_results) {
    // TODO(phajdan.jr): Check for duplicates and mismatches between
    // the results we got from XML file and tests we intended to run.
    std::map<std::string, TestResult> results_map;
    for (size_t i = 0; i < test_results.size(); i++)
      results_map[test_results[i].full_name] = test_results[i];

    bool had_interrupted_test = false;

    // Results to be reported back to the test launcher.
    std::vector<TestResult> final_results;

    for (size_t i = 0; i < test_names.size(); i++) {
      if (ContainsKey(results_map, test_names[i])) {
        TestResult test_result = results_map[test_names[i]];
        if (test_result.status == TestResult::TEST_CRASH) {
          had_interrupted_test = true;

          if (was_timeout) {
            // Fix up the test status: we forcibly kill the child process
            // after the timeout, so from XML results it looks just like
            // a crash.
            test_result.status = TestResult::TEST_TIMEOUT;
          }
        } else if (test_result.status == TestResult::TEST_SUCCESS ||
                   test_result.status == TestResult::TEST_FAILURE) {
          // We run multiple tests in a batch with a timeout applied
          // to the entire batch. It is possible that with other tests
          // running quickly some tests take longer than the per-test timeout.
          // For consistent handling of tests independent of order and other
          // factors, mark them as timing out.
          if (test_result.elapsed_time >
              TestTimeouts::test_launcher_timeout()) {
            test_result.status = TestResult::TEST_TIMEOUT;
          }
        }
        test_result.output_snippet = GetTestOutputSnippet(test_result, output);
        final_results.push_back(test_result);
      } else if (had_interrupted_test) {
        tests_to_relaunch->push_back(test_names[i]);
      } else {
        // TODO(phajdan.jr): Explicitly pass the info that the test didn't
        // run for a mysterious reason.
        LOG(ERROR) << "no test result for " << test_names[i];
        TestResult test_result;
        test_result.full_name = test_names[i];
        test_result.status = TestResult::TEST_UNKNOWN;
        test_result.output_snippet = GetTestOutputSnippet(test_result, output);
        final_results.push_back(test_result);
      }
    }

    // TODO(phajdan.jr): Handle the case where processing XML output
    // indicates a crash but none of the test results is marked as crashing.

    if (final_results.empty())
      return false;

    bool has_non_success_test = false;
    for (size_t i = 0; i < final_results.size(); i++) {
      if (final_results[i].status != TestResult::TEST_SUCCESS) {
        has_non_success_test = true;
        break;
      }
    }

    if (!has_non_success_test && exit_code != 0) {
      // This is a bit surprising case: all tests are marked as successful,
      // but the exit code was not zero. This can happen e.g. under memory
      // tools that report leaks this way. Mark all tests as a failure on exit,
      // and for more precise info they'd need to be retried serially.
      for (size_t i = 0; i < final_results.size(); i++)
        final_results[i].status = TestResult::TEST_FAILURE_ON_EXIT;
    }

    for (size_t i = 0; i < final_results.size(); i++) {
      // Fix the output snippet after possible changes to the test result.
      final_results[i].output_snippet =
          GetTestOutputSnippet(final_results[i], output);
      test_launcher->OnTestFinished(final_results[i]);
      called_any_callback = true;
    }
  } else {
    fprintf(stdout,
            "Failed to get out-of-band test success data, "
            "dumping full stdio below:\n%s\n",
            output.c_str());
    fflush(stdout);

    // We do not have reliable details about test results (parsing test
    // stdout is known to be unreliable).
    if (test_names.size() == 1) {
      // There is only one test. Try to determine status by exit code.
      const std::string& test_name = test_names.front();
      TestResult test_result;
      test_result.full_name = test_name;

      if (was_timeout) {
        test_result.status = TestResult::TEST_TIMEOUT;
      } else if (exit_code != 0) {
        test_result.status = TestResult::TEST_FAILURE;
      } else {
        // It's strange case when test executed successfully,
        // but we failed to read machine-readable report for it.
        test_result.status = TestResult::TEST_UNKNOWN;
      }

      test_launcher->OnTestFinished(test_result);
      called_any_callback = true;
    } else {
      // There is more than one test. Retry them individually.
      for (const std::string& test_name : test_names)
        tests_to_relaunch->push_back(test_name);
    }
  }

  return called_any_callback;
}

class UnitTestProcessLifetimeObserver : public ProcessLifetimeObserver {
 public:
  ~UnitTestProcessLifetimeObserver() override {
    DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  }

  TestLauncher* test_launcher() { return test_launcher_; }
  UnitTestPlatformDelegate* platform_delegate() { return platform_delegate_; }
  const std::vector<std::string>& test_names() { return test_names_; }
  int launch_flags() { return launch_flags_; }
  const FilePath& output_file() { return output_file_; }
  const FilePath& flag_file() { return flag_file_; }

 protected:
  UnitTestProcessLifetimeObserver(TestLauncher* test_launcher,
                                  UnitTestPlatformDelegate* platform_delegate,
                                  const std::vector<std::string>& test_names,
                                  int launch_flags,
                                  const FilePath& output_file,
                                  const FilePath& flag_file)
      : ProcessLifetimeObserver(),
        test_launcher_(test_launcher),
        platform_delegate_(platform_delegate),
        test_names_(test_names),
        launch_flags_(launch_flags),
        output_file_(output_file),
        flag_file_(flag_file) {}

  SEQUENCE_CHECKER(sequence_checker_);

 private:
  TestLauncher* const test_launcher_;
  UnitTestPlatformDelegate* const platform_delegate_;
  const std::vector<std::string> test_names_;
  const int launch_flags_;
  const FilePath output_file_;
  const FilePath flag_file_;

  DISALLOW_COPY_AND_ASSIGN(UnitTestProcessLifetimeObserver);
};

class ParallelUnitTestProcessLifetimeObserver
    : public UnitTestProcessLifetimeObserver {
 public:
  ParallelUnitTestProcessLifetimeObserver(
      TestLauncher* test_launcher,
      UnitTestPlatformDelegate* platform_delegate,
      const std::vector<std::string>& test_names,
      int launch_flags,
      const FilePath& output_file,
      const FilePath& flag_file)
      : UnitTestProcessLifetimeObserver(test_launcher,
                                        platform_delegate,
                                        test_names,
                                        launch_flags,
                                        output_file,
                                        flag_file) {}
  ~ParallelUnitTestProcessLifetimeObserver() override = default;

 private:
  // ProcessLifetimeObserver:
  void OnCompleted(int exit_code,
                   TimeDelta elapsed_time,
                   bool was_timeout,
                   const std::string& output) override;

  DISALLOW_COPY_AND_ASSIGN(ParallelUnitTestProcessLifetimeObserver);
};

void ParallelUnitTestProcessLifetimeObserver::OnCompleted(
    int exit_code,
    TimeDelta elapsed_time,
    bool was_timeout,
    const std::string& output) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  std::vector<std::string> tests_to_relaunch;
  ProcessTestResults(test_launcher(), test_names(), output_file(), output,
                     exit_code, was_timeout, &tests_to_relaunch);

  if (!tests_to_relaunch.empty()) {
    platform_delegate()->RelaunchTests(test_launcher(), tests_to_relaunch,
                                       launch_flags());
  }

  // The temporary file's directory is also temporary.
  DeleteFile(output_file().DirName(), true);
  if (!flag_file().empty())
    DeleteFile(flag_file(), false);
}

class SerialUnitTestProcessLifetimeObserver
    : public UnitTestProcessLifetimeObserver {
 public:
  SerialUnitTestProcessLifetimeObserver(
      TestLauncher* test_launcher,
      UnitTestPlatformDelegate* platform_delegate,
      const std::vector<std::string>& test_names,
      int launch_flags,
      const FilePath& output_file,
      const FilePath& flag_file,
      std::vector<std::string>&& next_test_names)
      : UnitTestProcessLifetimeObserver(test_launcher,
                                        platform_delegate,
                                        test_names,
                                        launch_flags,
                                        output_file,
                                        flag_file),
        next_test_names_(std::move(next_test_names)) {}
  ~SerialUnitTestProcessLifetimeObserver() override = default;

 private:
  // ProcessLifetimeObserver:
  void OnCompleted(int exit_code,
                   TimeDelta elapsed_time,
                   bool was_timeout,
                   const std::string& output) override;

  std::vector<std::string> next_test_names_;

  DISALLOW_COPY_AND_ASSIGN(SerialUnitTestProcessLifetimeObserver);
};

void SerialUnitTestProcessLifetimeObserver::OnCompleted(
    int exit_code,
    TimeDelta elapsed_time,
    bool was_timeout,
    const std::string& output) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  std::vector<std::string> tests_to_relaunch;
  bool called_any_callbacks =
      ProcessTestResults(test_launcher(), test_names(), output_file(), output,
                         exit_code, was_timeout, &tests_to_relaunch);

  // There is only one test, there cannot be other tests to relaunch
  // due to a crash.
  DCHECK(tests_to_relaunch.empty());

  // There is only one test, we should have called back with its result.
  DCHECK(called_any_callbacks);

  // The temporary file's directory is also temporary.
  DeleteFile(output_file().DirName(), true);

  if (!flag_file().empty())
    DeleteFile(flag_file(), false);

  ThreadTaskRunnerHandle::Get()->PostTask(
      FROM_HERE,
      BindOnce(&RunUnitTestsSerially, test_launcher(), platform_delegate(),
               std::move(next_test_names_), launch_flags()));
}

}  // namespace

int LaunchUnitTests(int argc,
                    char** argv,
                    RunTestSuiteCallback run_test_suite) {
  CommandLine::Init(argc, argv);
  size_t parallel_jobs = NumParallelJobs();
  if (parallel_jobs == 0U) {
    return 1;
  }
  return LaunchUnitTestsInternal(std::move(run_test_suite), parallel_jobs,
                                 kDefaultTestBatchLimit, true,
                                 BindOnce(&InitGoogleTestChar, &argc, argv));
}

int LaunchUnitTestsSerially(int argc,
                            char** argv,
                            RunTestSuiteCallback run_test_suite) {
  CommandLine::Init(argc, argv);
  return LaunchUnitTestsInternal(std::move(run_test_suite), 1U,
                                 kDefaultTestBatchLimit, true,
                                 BindOnce(&InitGoogleTestChar, &argc, argv));
}

int LaunchUnitTestsWithOptions(int argc,
                               char** argv,
                               size_t parallel_jobs,
                               int default_batch_limit,
                               bool use_job_objects,
                               RunTestSuiteCallback run_test_suite) {
  CommandLine::Init(argc, argv);
  return LaunchUnitTestsInternal(std::move(run_test_suite), parallel_jobs,
                                 default_batch_limit, use_job_objects,
                                 BindOnce(&InitGoogleTestChar, &argc, argv));
}

#if defined(OS_WIN)
int LaunchUnitTests(int argc,
                    wchar_t** argv,
                    bool use_job_objects,
                    RunTestSuiteCallback run_test_suite) {
  // Windows CommandLine::Init ignores argv anyway.
  CommandLine::Init(argc, NULL);
  size_t parallel_jobs = NumParallelJobs();
  if (parallel_jobs == 0U) {
    return 1;
  }
  return LaunchUnitTestsInternal(std::move(run_test_suite), parallel_jobs,
                                 kDefaultTestBatchLimit, use_job_objects,
                                 BindOnce(&InitGoogleTestWChar, &argc, argv));
}
#endif  // defined(OS_WIN)

void RunUnitTestsSerially(
    TestLauncher* test_launcher,
    UnitTestPlatformDelegate* platform_delegate,
    const std::vector<std::string>& test_names,
    int launch_flags) {
  if (test_names.empty())
    return;

  // Create a dedicated temporary directory to store the xml result data
  // per run to ensure clean state and make it possible to launch multiple
  // processes in parallel.
  FilePath output_file;
  CHECK(platform_delegate->CreateResultsFile(&output_file));
  FilePath flag_file;
  platform_delegate->CreateTemporaryFile(&flag_file);

  auto observer = std::make_unique<SerialUnitTestProcessLifetimeObserver>(
      test_launcher, platform_delegate,
      std::vector<std::string>(1, test_names.back()), launch_flags, output_file,
      flag_file,
      std::vector<std::string>(test_names.begin(), test_names.end() - 1));

  CommandLine cmd_line(platform_delegate->GetCommandLineForChildGTestProcess(
      observer->test_names(), output_file, flag_file));

  TestLauncher::LaunchOptions launch_options;
  launch_options.flags = launch_flags;
  test_launcher->LaunchChildGTestProcess(
      cmd_line, platform_delegate->GetWrapperForChildGTestProcess(),
      TestTimeouts::test_launcher_timeout(), launch_options,
      std::move(observer));
}

void RunUnitTestsBatch(
    TestLauncher* test_launcher,
    UnitTestPlatformDelegate* platform_delegate,
    const std::vector<std::string>& test_names,
    int launch_flags) {
  if (test_names.empty())
    return;

  // Create a dedicated temporary directory to store the xml result data
  // per run to ensure clean state and make it possible to launch multiple
  // processes in parallel.
  FilePath output_file;
  CHECK(platform_delegate->CreateResultsFile(&output_file));
  FilePath flag_file;
  platform_delegate->CreateTemporaryFile(&flag_file);

  auto observer = std::make_unique<ParallelUnitTestProcessLifetimeObserver>(
      test_launcher, platform_delegate, test_names, launch_flags, output_file,
      flag_file);

  CommandLine cmd_line(platform_delegate->GetCommandLineForChildGTestProcess(
      test_names, output_file, flag_file));

  // Adjust the timeout depending on how many tests we're running
  // (note that e.g. the last batch of tests will be smaller).
  // TODO(phajdan.jr): Consider an adaptive timeout, which can change
  // depending on how many tests ran and how many remain.
  // Note: do NOT parse child's stdout to do that, it's known to be
  // unreliable (e.g. buffering issues can mix up the output).
  TimeDelta timeout = test_names.size() * TestTimeouts::test_launcher_timeout();

  TestLauncher::LaunchOptions options;
  options.flags = launch_flags;
  test_launcher->LaunchChildGTestProcess(
      cmd_line, platform_delegate->GetWrapperForChildGTestProcess(), timeout,
      options, std::move(observer));
}

UnitTestLauncherDelegate::UnitTestLauncherDelegate(
    UnitTestPlatformDelegate* platform_delegate,
    size_t batch_limit,
    bool use_job_objects)
    : platform_delegate_(platform_delegate),
      batch_limit_(batch_limit),
      use_job_objects_(use_job_objects) {
}

UnitTestLauncherDelegate::~UnitTestLauncherDelegate() {
  DCHECK(thread_checker_.CalledOnValidThread());
}

bool UnitTestLauncherDelegate::GetTests(std::vector<TestIdentifier>* output) {
  DCHECK(thread_checker_.CalledOnValidThread());
  return platform_delegate_->GetTests(output);
}

bool UnitTestLauncherDelegate::ShouldRunTest(const std::string& test_case_name,
                                             const std::string& test_name) {
  DCHECK(thread_checker_.CalledOnValidThread());

  // There is no additional logic to disable specific tests.
  return true;
}

size_t UnitTestLauncherDelegate::RunTests(
    TestLauncher* test_launcher,
    const std::vector<std::string>& test_names) {
  DCHECK(thread_checker_.CalledOnValidThread());

  int launch_flags = use_job_objects_ ? TestLauncher::USE_JOB_OBJECTS : 0;

  std::vector<std::string> batch;
  for (size_t i = 0; i < test_names.size(); i++) {
    batch.push_back(test_names[i]);

    // Use 0 to indicate unlimited batch size.
    if (batch.size() >= batch_limit_ && batch_limit_ != 0) {
      RunUnitTestsBatch(test_launcher, platform_delegate_, batch, launch_flags);
      batch.clear();
    }
  }

  RunUnitTestsBatch(test_launcher, platform_delegate_, batch, launch_flags);

  return test_names.size();
}

size_t UnitTestLauncherDelegate::RetryTests(
    TestLauncher* test_launcher,
    const std::vector<std::string>& test_names) {
  ThreadTaskRunnerHandle::Get()->PostTask(
      FROM_HERE,
      BindOnce(&RunUnitTestsSerially, test_launcher, platform_delegate_,
               test_names,
               use_job_objects_ ? TestLauncher::USE_JOB_OBJECTS : 0));
  return test_names.size();
}

}  // namespace base