base/trace_event/trace_event_system_stats_monitor_unittest.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/trace_event/trace_event_system_stats_monitor.h"
   6
   7 #include <sstream>
   8 #include <string>
   9
  10 #include "base/trace_event/trace_event_impl.h"
  11 #include "testing/gtest/include/gtest/gtest.h"
  12
  13 namespace base {
  14 namespace trace_event {
  15
  16 #if !defined(OS_IOS)
  17 // Tests for the system stats monitor.
  18 // Exists as a class so it can be a friend of TraceEventSystemStatsMonitor.
  19 class TraceSystemStatsMonitorTest : public testing::Test {
  20  public:
  21   TraceSystemStatsMonitorTest() {}
  22   ~TraceSystemStatsMonitorTest() override {}
  23
  24  private:
  25   DISALLOW_COPY_AND_ASSIGN(TraceSystemStatsMonitorTest);
  26 };
  27
  28 //////////////////////////////////////////////////////////////////////////////
  29
  30 TEST_F(TraceSystemStatsMonitorTest, TraceEventSystemStatsMonitor) {
  31   MessageLoop message_loop;
  32
  33   // Start with no observers of the TraceLog.
  34   EXPECT_EQ(0u, TraceLog::GetInstance()->GetObserverCountForTest());
  35
  36   // Creating a system stats monitor adds it to the TraceLog observer list.
  37   scoped_ptr<TraceEventSystemStatsMonitor> system_stats_monitor(
  38       new TraceEventSystemStatsMonitor(message_loop.task_runner()));
  39   EXPECT_EQ(1u, TraceLog::GetInstance()->GetObserverCountForTest());
  40   EXPECT_TRUE(
  41       TraceLog::GetInstance()->HasEnabledStateObserver(
  42           system_stats_monitor.get()));
  43
  44   // By default the observer isn't dumping memory profiles.
  45   EXPECT_FALSE(system_stats_monitor->IsTimerRunningForTest());
  46
  47   // Simulate enabling tracing.
  48   system_stats_monitor->StartProfiling();
  49   message_loop.RunUntilIdle();
  50   EXPECT_TRUE(system_stats_monitor->IsTimerRunningForTest());
  51
  52   // Simulate disabling tracing.
  53   system_stats_monitor->StopProfiling();
  54   message_loop.RunUntilIdle();
  55   EXPECT_FALSE(system_stats_monitor->IsTimerRunningForTest());
  56
  57   // Deleting the observer removes it from the TraceLog observer list.
  58   system_stats_monitor.reset();
  59   EXPECT_EQ(0u, TraceLog::GetInstance()->GetObserverCountForTest());
  60 }
  61 #endif  // !defined(OS_IOS)
  62
  63 }  // namespace trace_event
  64 }  // namespace base