Chrome power profiler service

content/browser/power_profiler/power_profiler_service_unittest.cc

+// Copyright 2014 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/message_loop/message_loop.h"
+#include "base/run_loop.h"
+#include "content/browser/browser_thread_impl.h"
+#include "content/browser/power_profiler/power_profiler_service.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace content {
+
+namespace {
+
+const int kNumEvents = 3;
+const int kNumObservers = 3;
+
+// Provide a set number of power events.
+class TestPowerDataProvider : public PowerDataProvider {
+ public:
+  TestPowerDataProvider(int count) : num_events_to_send_(count) {}
+  virtual ~TestPowerDataProvider() {}
+
+  virtual PowerEventVector GetData() OVERRIDE {
+    PowerEventVector events;
+    if (num_events_to_send_ == 0)
+      return events;
+
+    PowerEvent event;
+    event.type = PowerEvent::SOC_PACKAGE;
+    event.time = base::TimeTicks::Now();
+    event.value = 1.0;
+    events.push_back(event);
+
+    num_events_to_send_--;
+    return events;
+  }
+
+ private:
+  int num_events_to_send_;
+  DISALLOW_COPY_AND_ASSIGN(TestPowerDataProvider);
+};
+
+class TestPowerProfilerObserver : public PowerProfilerObserver {
+ public:
+  TestPowerProfilerObserver() : valid_event_count_(0) {}
+  virtual ~TestPowerProfilerObserver() {}
+
+  virtual void OnPowerEvent(const PowerEventVector& events) OVERRIDE {
+    if (IsValidEvent(events[0])) {
+      ++valid_event_count_;
+      if (valid_event_count_ == kNumEvents)
+        ++all_receive_counter;
+      if (all_receive_counter == kNumObservers)
+        base::MessageLoop::current()->Quit();
+    }
+  }
+
+  int valid_event_count() const { return valid_event_count_; }
+
+  static int all_receive_counter;

[jeremy, 2014/02/18 10:28:57]

Much better!

The only issue is the use of a class static here, this would be a problem for
example if we added additional tests to this file or if tests are ever run in
parallel.

I would prefer that this counter be a local variable in the test whose address
you pass to the observers.

you could then change the code in OnPowerEvent to:

(*total_num_events_received)++;
if (*total_num_events_received >= kNumEvents * kNumObservers) {
  // All expected events received, exiting.
  base::MessageLoop::current()->Quit();
}
  

[Pan, 2014/02/18 12:58:39]

thanks, done

+
+ private:
+  bool IsValidEvent(const PowerEvent& event) {
+    return event.type == PowerEvent::SOC_PACKAGE &&
+           !event.time.is_null() &&
+           event.value > 0;
+  }
+
+  int valid_event_count_;
+  DISALLOW_COPY_AND_ASSIGN(TestPowerProfilerObserver);
+};
+
+int TestPowerProfilerObserver::all_receive_counter = 0;
+
+} // namespace
+
+class PowerProfilerServiceTest : public testing::Test {
+ public:
+  void ServiceStartTest() {
+    service_ = new PowerProfilerService(
+        make_scoped_ptr<PowerDataProvider>(
+            new TestPowerDataProvider(kNumEvents)),
+        message_loop_.message_loop_proxy(),
+        base::TimeDelta::FromMilliseconds(5));

[qsr, 2014/02/18 10:01:22]

If you do not check anything related to time, make that even smaller to have the
test as quick as possible. FromMicroseconds(1) for example.

[Pan, 2014/02/18 12:58:39]

thanks, done.

+    EXPECT_TRUE(service_->IsAvailable());
+  }
+
+  void AddObserverTest() {
+    for (int index = 0; index < kNumObservers; ++index)
+      service_->AddObserver(&observers_[index]);
+
+    // No PowerEvents received.
+    for (int index = 0; index < kNumObservers; ++index)
+      EXPECT_EQ(observers_[0].valid_event_count(), 0);
+  }
+
+  void RemoveObserverTest() {
+    for (int index = 0; index < kNumObservers; ++index)
+      service_->RemoveObserver(&observers_[index]);
+
+    // Everyone received |kNumEvents| events.
+    for (int index = 0; index < kNumObservers; ++index)
+      EXPECT_EQ(observers_[index].valid_event_count(), kNumEvents);
+  }
+
+ protected:
+  PowerProfilerServiceTest() : ui_thread_(BrowserThread::UI, &message_loop_) {}
+  virtual ~PowerProfilerServiceTest() {}
+
+ private:
+  PowerProfilerService* service_;
+  TestPowerProfilerObserver observers_[kNumObservers];
+
+  // UI thread.
+  base::MessageLoopForUI message_loop_;
+  BrowserThreadImpl ui_thread_;
+
+  DISALLOW_COPY_AND_ASSIGN(PowerProfilerServiceTest);
+};
+
+// Test whether PowerProfilerService dispatches power events to observers
+// properly.
+TEST_F(PowerProfilerServiceTest, AvailableService) {
+  ServiceStartTest();
+  AddObserverTest();
+  base::MessageLoop::current()->Run();
+  RemoveObserverTest();
+}
+
+}  // namespace content