Track thread activities in order to diagnose hangs.

base/debug/activity_tracker_unittest.cc

Index: base/debug/activity_tracker_unittest.cc
diff --git a/base/debug/activity_tracker_unittest.cc b/base/debug/activity_tracker_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..75d5d3cdeca53f3eb47e91a43931c374c948e9f0
--- /dev/null
+++ b/base/debug/activity_tracker_unittest.cc
@@ -0,0 +1,252 @@
+// 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/synchronization/condition_variable.h"
+#include "base/synchronization/lock.h"
+#include "base/synchronization/spin_wait.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 << 10;  // 1KiB
+  const int kStackSize  = 256;
+
+  using StackEntry = ThreadActivityTracker::StackEntry;
+  using StackEntryData = ThreadActivityTracker::StackEntryData;
+
+  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 WrapUnique(new 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;
+    return global_tracker->available_memories_count_.load(
+        std::memory_order_relaxed);
+  }
+
+  static void DoNothing() {}
+};
+
+TEST_F(ActivityTrackerTest, PushPopTest) {
+  std::unique_ptr<ThreadActivityTracker> tracker = CreateActivityTracker();
+  std::vector<ThreadActivityTracker::StackEntry> stack;
+  ThreadActivityAnalyzer analyzer(tracker.get());
+
+  ASSERT_EQ(0U, analyzer.SnapshotStack(&stack));
+  ASSERT_EQ(0U, stack.size());
+
+  char source1;
+  tracker->PushActivity(&source1, ThreadActivityTracker::ACT_TASK,
+                        StackEntryData::ForTask(11));
+  ASSERT_EQ(1U, analyzer.SnapshotStack(&stack));
+  ASSERT_EQ(1U, stack.size());
+  EXPECT_NE(0, stack[0].time_ticks);
+  EXPECT_EQ(ThreadActivityTracker::ACT_TASK, stack[0].activity_type);
+  EXPECT_EQ(reinterpret_cast<uintptr_t>(&source1), stack[0].source_address);
+  EXPECT_EQ(11U, stack[0].data.task.sequence_id);
+
+  char source2;
+  char lock2;
+  tracker->PushActivity(&source2, ThreadActivityTracker::ACT_LOCK,
+                        StackEntryData::ForLock(&lock2));
+  ASSERT_EQ(2U, analyzer.SnapshotStack(&stack));
+  ASSERT_EQ(2U, stack.size());
+  EXPECT_LE(stack[0].time_ticks, stack[1].time_ticks);
+  EXPECT_EQ(ThreadActivityTracker::ACT_LOCK, stack[1].activity_type);
+  EXPECT_EQ(reinterpret_cast<uintptr_t>(&source2), stack[1].source_address);
+  EXPECT_EQ(reinterpret_cast<uintptr_t>(&lock2),
+            stack[1].data.lock.lock_address);
+
+  tracker->PopActivity(&source2);
+  ASSERT_EQ(1U, analyzer.SnapshotStack(&stack));
+  ASSERT_EQ(1U, stack.size());
+  EXPECT_EQ(ThreadActivityTracker::ACT_TASK, stack[0].activity_type);
+  EXPECT_EQ(reinterpret_cast<uintptr_t>(&source1), stack[0].source_address);
+  EXPECT_EQ(11U, stack[0].data.task.sequence_id);
+
+  tracker->PopActivity(&source1);
+  ASSERT_EQ(0U, analyzer.SnapshotStack(&stack));
+  ASSERT_EQ(0U, stack.size());
+}
+
+TEST_F(ActivityTrackerTest, ScopedTaskTest) {
+  GlobalActivityTracker::CreateWithLocalMemory(kMemorySize, 0, "", 3);
+
+  ThreadActivityTracker* tracker =
+      GlobalActivityTracker::Get()->GetOrCreateTrackerForCurrentThread();
+  std::vector<ThreadActivityTracker::StackEntry> stack;
+  ThreadActivityAnalyzer analyzer(tracker);
+
+  ASSERT_EQ(0U, analyzer.SnapshotStack(&stack));
+  ASSERT_EQ(0U, stack.size());
+
+  {
+    PendingTask task1(FROM_HERE, base::Bind(&DoNothing));
+    ScopedTaskActivity activity1(task1);
+
+    ASSERT_EQ(1U, analyzer.SnapshotStack(&stack));
+    ASSERT_EQ(1U, stack.size());
+    EXPECT_EQ(ThreadActivityTracker::ACT_TASK, stack[0].activity_type);
+
+    {
+      PendingTask task2(FROM_HERE, base::Bind(&DoNothing));
+      ScopedTaskActivity activity2(task2);
+
+      ASSERT_EQ(2U, analyzer.SnapshotStack(&stack));
+      ASSERT_EQ(2U, stack.size());
+      EXPECT_EQ(ThreadActivityTracker::ACT_TASK, stack[1].activity_type);
+    }
+
+    ASSERT_EQ(1U, analyzer.SnapshotStack(&stack));
+    ASSERT_EQ(1U, stack.size());
+    EXPECT_EQ(ThreadActivityTracker::ACT_TASK, stack[0].activity_type);
+  }
+
+  ASSERT_EQ(0U, analyzer.SnapshotStack(&stack));
+  ASSERT_EQ(0U, stack.size());
+}
+
+class SimpleActivityThread : public SimpleThread {
+ public:
+  SimpleActivityThread(const std::string& name,
+                       const void* source,
+                       ThreadActivityTracker::ActivityType activity,
+                       const ThreadActivityTracker::StackEntryData& data)
+      : SimpleThread(name, Options()),
+        source_(source),
+        activity_(activity),
+        data_(data),
+        exit_condition_(&lock_) {}
+
+  ~SimpleActivityThread() override {}
+
+  void Run() override {
+    GlobalActivityTracker::Get()
+        ->GetOrCreateTrackerForCurrentThread()
+        ->PushActivity(source_, activity_, data_);
+
+    {
+      AutoLock auto_lock(lock_);
+      ready_ = true;
+      while (!exit_)
+        exit_condition_.Wait();
+    }
+
+    GlobalActivityTracker::Get()
+        ->GetOrCreateTrackerForCurrentThread()
+        ->PopActivity(source_);
+  }
+
+  void Exit() {
+    AutoLock auto_lock(lock_);
+    exit_ = true;
+    exit_condition_.Signal();
+  }
+
+  void WaitReady() {
+    SPIN_FOR_1_SECOND_OR_UNTIL_TRUE(ready_);
+  }
+
+ private:
+  const void* source_;
+  ThreadActivityTracker::ActivityType activity_;
+  ThreadActivityTracker::StackEntryData 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, ThreadActivityTracker::ACT_TASK,
+                          StackEntryData::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, ThreadActivityTracker::ACT_TASK,
+                          StackEntryData::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