// Copyright 2016 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/debug/activity_tracker.h"

#include <memory>

#include "base/bind.h"
#include "base/files/file.h"
#include "base/files/file_util.h"
#include "base/files/memory_mapped_file.h"
#include "base/files/scoped_temp_dir.h"
#include "base/memory/ptr_util.h"
#include "base/pending_task.h"
#include "base/rand_util.h"
#include "base/synchronization/condition_variable.h"
#include "base/synchronization/lock.h"
#include "base/synchronization/spin_wait.h"
#include "base/threading/platform_thread.h"
#include "base/threading/simple_thread.h"
#include "base/time/time.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace base {
namespace debug {

namespace {

class TestActivityTracker : public ThreadActivityTracker {
 public:
  TestActivityTracker(std::unique_ptr<char[]> memory, size_t mem_size)
      : ThreadActivityTracker(memset(memory.get(), 0, mem_size), mem_size),
        mem_segment_(std::move(memory)) {}

  ~TestActivityTracker() override {}

 private:
  std::unique_ptr<char[]> mem_segment_;
};

}  // namespace


class ActivityTrackerTest : public testing::Test {
 public:
  const int kMemorySize = 1 << 20;  // 1MiB
  const int kStackSize  = 1 << 10;  // 1KiB

  using ActivityId = ThreadActivityTracker::ActivityId;

  ActivityTrackerTest() {}

  ~ActivityTrackerTest() override {
    GlobalActivityTracker* global_tracker = GlobalActivityTracker::Get();
    if (global_tracker) {
      global_tracker->ReleaseTrackerForCurrentThreadForTesting();
      delete global_tracker;
    }
  }

  std::unique_ptr<ThreadActivityTracker> CreateActivityTracker() {
    std::unique_ptr<char[]> memory(new char[kStackSize]);
    return MakeUnique<TestActivityTracker>(std::move(memory), kStackSize);
  }

  size_t GetGlobalActiveTrackerCount() {
    GlobalActivityTracker* global_tracker = GlobalActivityTracker::Get();
    if (!global_tracker)
      return 0;
    return global_tracker->thread_tracker_count_.load(
        std::memory_order_relaxed);
  }

  size_t GetGlobalInactiveTrackerCount() {
    GlobalActivityTracker* global_tracker = GlobalActivityTracker::Get();
    if (!global_tracker)
      return 0;
    base::AutoLock autolock(global_tracker->thread_tracker_allocator_lock_);
    return global_tracker->thread_tracker_allocator_.cache_used();
  }

  size_t GetGlobalUserDataMemoryCacheUsed() {
    return GlobalActivityTracker::Get()->user_data_allocator_.cache_used();
  }

  static void DoNothing() {}
};

TEST_F(ActivityTrackerTest, UserDataTest) {
  char buffer[256];
  memset(buffer, 0, sizeof(buffer));
  ActivityUserData data(buffer, sizeof(buffer));
  ASSERT_EQ(sizeof(buffer) - 8, data.available_);

  data.SetInt("foo", 1);
  ASSERT_EQ(sizeof(buffer) - 8 - 24, data.available_);

  data.SetUint("b", 1U);  // Small names fit beside header in a word.
  ASSERT_EQ(sizeof(buffer) - 8 - 24 - 16, data.available_);

  data.Set("c", buffer, 10);
  ASSERT_EQ(sizeof(buffer) - 8 - 24 - 16 - 24, data.available_);

  data.SetString("dear john", "it's been fun");
  ASSERT_EQ(sizeof(buffer) - 8 - 24 - 16 - 24 - 32, data.available_);

  data.Set("c", buffer, 20);
  ASSERT_EQ(sizeof(buffer) - 8 - 24 - 16 - 24 - 32, data.available_);

  data.SetString("dear john", "but we're done together");
  ASSERT_EQ(sizeof(buffer) - 8 - 24 - 16 - 24 - 32, data.available_);

  data.SetString("dear john", "bye");
  ASSERT_EQ(sizeof(buffer) - 8 - 24 - 16 - 24 - 32, data.available_);

  data.SetChar("d", 'x');
  ASSERT_EQ(sizeof(buffer) - 8 - 24 - 16 - 24 - 32 - 8, data.available_);

  data.SetBool("ee", true);
  ASSERT_EQ(sizeof(buffer) - 8 - 24 - 16 - 24 - 32 - 8 - 16, data.available_);
}

TEST_F(ActivityTrackerTest, PushPopTest) {
  std::unique_ptr<ThreadActivityTracker> tracker = CreateActivityTracker();
  ThreadActivityTracker::Snapshot snapshot;

  ASSERT_TRUE(tracker->CreateSnapshot(&snapshot));
  ASSERT_EQ(0U, snapshot.activity_stack_depth);
  ASSERT_EQ(0U, snapshot.activity_stack.size());

  char origin1;
  ActivityId id1 = tracker->PushActivity(&origin1, Activity::ACT_TASK,
                                         ActivityData::ForTask(11));
  ASSERT_TRUE(tracker->CreateSnapshot(&snapshot));
  ASSERT_EQ(1U, snapshot.activity_stack_depth);
  ASSERT_EQ(1U, snapshot.activity_stack.size());
  EXPECT_NE(0, snapshot.activity_stack[0].time_internal);
  EXPECT_EQ(Activity::ACT_TASK, snapshot.activity_stack[0].activity_type);
  EXPECT_EQ(reinterpret_cast<uintptr_t>(&origin1),
            snapshot.activity_stack[0].origin_address);
  EXPECT_EQ(11U, snapshot.activity_stack[0].data.task.sequence_id);

  char origin2;
  char lock2;
  ActivityId id2 = tracker->PushActivity(&origin2, Activity::ACT_LOCK,
                                         ActivityData::ForLock(&lock2));
  ASSERT_TRUE(tracker->CreateSnapshot(&snapshot));
  ASSERT_EQ(2U, snapshot.activity_stack_depth);
  ASSERT_EQ(2U, snapshot.activity_stack.size());
  EXPECT_LE(snapshot.activity_stack[0].time_internal,
            snapshot.activity_stack[1].time_internal);
  EXPECT_EQ(Activity::ACT_LOCK, snapshot.activity_stack[1].activity_type);
  EXPECT_EQ(reinterpret_cast<uintptr_t>(&origin2),
            snapshot.activity_stack[1].origin_address);
  EXPECT_EQ(reinterpret_cast<uintptr_t>(&lock2),
            snapshot.activity_stack[1].data.lock.lock_address);

  tracker->PopActivity(id2);
  ASSERT_TRUE(tracker->CreateSnapshot(&snapshot));
  ASSERT_EQ(1U, snapshot.activity_stack_depth);
  ASSERT_EQ(1U, snapshot.activity_stack.size());
  EXPECT_EQ(Activity::ACT_TASK, snapshot.activity_stack[0].activity_type);
  EXPECT_EQ(reinterpret_cast<uintptr_t>(&origin1),
            snapshot.activity_stack[0].origin_address);
  EXPECT_EQ(11U, snapshot.activity_stack[0].data.task.sequence_id);

  tracker->PopActivity(id1);
  ASSERT_TRUE(tracker->CreateSnapshot(&snapshot));
  ASSERT_EQ(0U, snapshot.activity_stack_depth);
  ASSERT_EQ(0U, snapshot.activity_stack.size());
}

TEST_F(ActivityTrackerTest, ScopedTaskTest) {
  GlobalActivityTracker::CreateWithLocalMemory(kMemorySize, 0, "", 3);

  ThreadActivityTracker* tracker =
      GlobalActivityTracker::Get()->GetOrCreateTrackerForCurrentThread();
  ThreadActivityTracker::Snapshot snapshot;
  ASSERT_EQ(0U, GetGlobalUserDataMemoryCacheUsed());

  ASSERT_TRUE(tracker->CreateSnapshot(&snapshot));
  ASSERT_EQ(0U, snapshot.activity_stack_depth);
  ASSERT_EQ(0U, snapshot.activity_stack.size());

  {
    PendingTask task1(FROM_HERE, base::Bind(&DoNothing));
    ScopedTaskRunActivity activity1(task1);
    ActivityUserData& user_data1 = activity1.user_data();
    (void)user_data1;  // Tell compiler it's been used.

    ASSERT_TRUE(tracker->CreateSnapshot(&snapshot));
    ASSERT_EQ(1U, snapshot.activity_stack_depth);
    ASSERT_EQ(1U, snapshot.activity_stack.size());
    EXPECT_EQ(Activity::ACT_TASK, snapshot.activity_stack[0].activity_type);

    {
      PendingTask task2(FROM_HERE, base::Bind(&DoNothing));
      ScopedTaskRunActivity activity2(task2);
      ActivityUserData& user_data2 = activity2.user_data();
      (void)user_data2;  // Tell compiler it's been used.

      ASSERT_TRUE(tracker->CreateSnapshot(&snapshot));
      ASSERT_EQ(2U, snapshot.activity_stack_depth);
      ASSERT_EQ(2U, snapshot.activity_stack.size());
      EXPECT_EQ(Activity::ACT_TASK, snapshot.activity_stack[1].activity_type);
    }

    ASSERT_TRUE(tracker->CreateSnapshot(&snapshot));
    ASSERT_EQ(1U, snapshot.activity_stack_depth);
    ASSERT_EQ(1U, snapshot.activity_stack.size());
    EXPECT_EQ(Activity::ACT_TASK, snapshot.activity_stack[0].activity_type);
  }

  ASSERT_TRUE(tracker->CreateSnapshot(&snapshot));
  ASSERT_EQ(0U, snapshot.activity_stack_depth);
  ASSERT_EQ(0U, snapshot.activity_stack.size());
  ASSERT_EQ(2U, GetGlobalUserDataMemoryCacheUsed());
}

TEST_F(ActivityTrackerTest, CreateWithFileTest) {
  const char temp_name[] = "CreateWithFileTest";
  ScopedTempDir temp_dir;
  ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
  FilePath temp_file = temp_dir.GetPath().AppendASCII(temp_name);
  const size_t temp_size = 64 << 10;  // 64 KiB

  // Create a global tracker on a new file.
  ASSERT_FALSE(PathExists(temp_file));
  GlobalActivityTracker::CreateWithFile(temp_file, temp_size, 0, "foo", 3);
  GlobalActivityTracker* global = GlobalActivityTracker::Get();
  EXPECT_EQ(std::string("foo"), global->allocator()->Name());
  global->ReleaseTrackerForCurrentThreadForTesting();
  delete global;

  // Create a global tracker over an existing file, replacing it. If the
  // replacement doesn't work, the name will remain as it was first created.
  ASSERT_TRUE(PathExists(temp_file));
  GlobalActivityTracker::CreateWithFile(temp_file, temp_size, 0, "bar", 3);
  global = GlobalActivityTracker::Get();
  EXPECT_EQ(std::string("bar"), global->allocator()->Name());
  global->ReleaseTrackerForCurrentThreadForTesting();
  delete global;
}


// GlobalActivityTracker tests below.

class SimpleActivityThread : public SimpleThread {
 public:
  SimpleActivityThread(const std::string& name,
                       const void* origin,
                       Activity::Type activity,
                       const ActivityData& data)
      : SimpleThread(name, Options()),
        origin_(origin),
        activity_(activity),
        data_(data),
        exit_condition_(&lock_) {}

  ~SimpleActivityThread() override {}

  void Run() override {
    ThreadActivityTracker::ActivityId id =
        GlobalActivityTracker::Get()
            ->GetOrCreateTrackerForCurrentThread()
            ->PushActivity(origin_, activity_, data_);

    {
      AutoLock auto_lock(lock_);
      ready_ = true;
      while (!exit_)
        exit_condition_.Wait();
    }

    GlobalActivityTracker::Get()->GetTrackerForCurrentThread()->PopActivity(id);
  }

  void Exit() {
    AutoLock auto_lock(lock_);
    exit_ = true;
    exit_condition_.Signal();
  }

  void WaitReady() {
    SPIN_FOR_1_SECOND_OR_UNTIL_TRUE(ready_);
  }

 private:
  const void* origin_;
  Activity::Type activity_;
  ActivityData data_;

  bool ready_ = false;
  bool exit_ = false;
  Lock lock_;
  ConditionVariable exit_condition_;

  DISALLOW_COPY_AND_ASSIGN(SimpleActivityThread);
};

TEST_F(ActivityTrackerTest, ThreadDeathTest) {
  GlobalActivityTracker::CreateWithLocalMemory(kMemorySize, 0, "", 3);
  GlobalActivityTracker::Get()->GetOrCreateTrackerForCurrentThread();
  const size_t starting_active = GetGlobalActiveTrackerCount();
  const size_t starting_inactive = GetGlobalInactiveTrackerCount();

  SimpleActivityThread t1("t1", nullptr, Activity::ACT_TASK,
                          ActivityData::ForTask(11));
  t1.Start();
  t1.WaitReady();
  EXPECT_EQ(starting_active + 1, GetGlobalActiveTrackerCount());
  EXPECT_EQ(starting_inactive, GetGlobalInactiveTrackerCount());

  t1.Exit();
  t1.Join();
  EXPECT_EQ(starting_active, GetGlobalActiveTrackerCount());
  EXPECT_EQ(starting_inactive + 1, GetGlobalInactiveTrackerCount());

  // Start another thread and ensure it re-uses the existing memory.

  SimpleActivityThread t2("t2", nullptr, Activity::ACT_TASK,
                          ActivityData::ForTask(22));
  t2.Start();
  t2.WaitReady();
  EXPECT_EQ(starting_active + 1, GetGlobalActiveTrackerCount());
  EXPECT_EQ(starting_inactive, GetGlobalInactiveTrackerCount());

  t2.Exit();
  t2.Join();
  EXPECT_EQ(starting_active, GetGlobalActiveTrackerCount());
  EXPECT_EQ(starting_inactive + 1, GetGlobalInactiveTrackerCount());
}

}  // namespace debug
}  // namespace base