Add gamepad hardware data fetcher, and higher level thread container

content/browser/gamepad/gamepad_provider_unittest.cc

Index: content/browser/gamepad/gamepad_provider_unittest.cc
diff --git a/content/browser/gamepad/gamepad_provider_unittest.cc b/content/browser/gamepad/gamepad_provider_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e4bd01915e90c48ad8b5ce1891f28f5dc9dda124
--- /dev/null
+++ b/content/browser/gamepad/gamepad_provider_unittest.cc
@@ -0,0 +1,117 @@
+// Copyright (c) 2011 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/memory/scoped_ptr.h"
+#include "base/process_util.h"
+#include "base/synchronization/waitable_event.h"
+#include "base/system_monitor/system_monitor.h"
+#include "content/browser/gamepad/gamepad_provider.h"
+#include "content/common/gamepad_messages.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+class MockDataFetcher : public gamepad::DataFetcher {
+ public:
+  MockDataFetcher() : read_data_(false, false) {
+    memset(&test_data, 0, sizeof(test_data));
+  }
+  virtual void GetGamepadData(WebKit::WebGamepads* pads,
+                              bool devices_changed_hint) OVERRIDE {
+    *pads = test_data;
+    read_data_.Signal();
+  }
+
+  void SetData(WebKit::WebGamepads& data) {
+    test_data = data;
+  }
+
+  void WaitForDataRead() { return read_data_.Wait(); }
+
+  WebKit::WebGamepads test_data;
+  base::WaitableEvent read_data_;
+};
+
+// Main test fixture
+class GamepadProviderTest : public testing::Test {
+ public:
+  gamepad::Provider* CreateProvider() {
+#if defined(OS_MACOSX)
+    base::SystemMonitor::AllocateSystemIOPorts();
+#endif
+    system_monitor_.reset(new base::SystemMonitor);
+    mock_data_fetcher_ = new MockDataFetcher;
+    provider_ = new gamepad::Provider(mock_data_fetcher_);
+    return provider_.get();
+  }
+
+ protected:
+  GamepadProviderTest() {
+  }
+
+  MessageLoop main_message_loop_;
+  scoped_ptr<base::SystemMonitor> system_monitor_;
+  MockDataFetcher* mock_data_fetcher_;
+  scoped_refptr<gamepad::Provider> provider_;
+};
+
+TEST_F(GamepadProviderTest, BasicStartStop) {
+  gamepad::Provider* provider = CreateProvider();
+  provider->Start();
+  provider->Stop();
+  // Just ensure that there's no asserts on startup, shutdown, or destroy.
+}
+
+TEST_F(GamepadProviderTest, PollingAccess) {
+  using namespace gamepad;
+
+  Provider* provider = CreateProvider();
+  provider->Start();
+
+  WebKit::WebGamepads test_data;
+  test_data.length = 1;
+  test_data.items[0].connected = true;
+  test_data.items[0].timestamp = 0;
+  test_data.items[0].buttonsLength = 1;
+  test_data.items[0].axesLength = 2;
+  test_data.items[0].buttons[0] = 1.f;
+  test_data.items[0].axes[0] = -1.f;
+  test_data.items[0].axes[1] = .5f;
+  mock_data_fetcher_->SetData(test_data);
+
+  main_message_loop_.RunAllPending();
+
+  mock_data_fetcher_->WaitForDataRead();
+
+  // Renderer-side, pull data out of poll buffer.
+  base::SharedMemoryHandle handle =
+      provider->GetRendererSharedMemoryHandle(base::GetCurrentProcessHandle());
+  base::SharedMemory* shared_memory = new base::SharedMemory(handle, true);
+  EXPECT_TRUE(shared_memory->Map(sizeof(GamepadHardwareBuffer)));
+  void* mem = shared_memory->memory();
+
+  GamepadHardwareBuffer* hwbuf = static_cast<GamepadHardwareBuffer*>(mem);
+  // See gamepad_hardware_buffer.h for details on the read discipline.
+  base::subtle::Atomic32 start, end;
+  WebKit::WebGamepads output;
+  int contention_count;
+  for (contention_count = 0; contention_count < 10; ++contention_count) {

[Paweł Hajdan Jr., 2011/11/21 12:09:37]

Please add a comment here, summarizing main points from the discussion in this
review (no more than 2-3 lines).

I don't know underlying code to comment further on this. It may be flaky, but
it's better than hanging.

+    end = base::subtle::Acquire_Load(&hwbuf->end_marker);
+    memcpy(&output, &hwbuf->buffer, sizeof(output));
+    start = base::subtle::Acquire_Load(&hwbuf->start_marker);
+    if (start == end) break;

[Paweł Hajdan Jr., 2011/11/21 12:09:37]

nit: Don't cram two statements in one line.

+    base::PlatformThread::YieldCurrentThread();
+  }
+  EXPECT_GT(10, contention_count);
+  EXPECT_EQ(1u, output.length);
+  EXPECT_EQ(1u, output.items[0].buttonsLength);
+  EXPECT_EQ(1.f, output.items[0].buttons[0]);
+  EXPECT_EQ(2u, output.items[0].axesLength);
+  EXPECT_EQ(-1.f, output.items[0].axes[0]);
+  EXPECT_EQ(0.5f, output.items[0].axes[1]);
+
+  provider->Stop();
+}
+
+}  // namespace