Ensure that data is not overwritten in the audio input shared memory ring buffer that sits on the b…

content/browser/renderer_host/media/audio_input_sync_writer_unittest.cc

Index: content/browser/renderer_host/media/audio_input_sync_writer_unittest.cc
diff --git a/content/browser/renderer_host/media/audio_input_sync_writer_unittest.cc b/content/browser/renderer_host/media/audio_input_sync_writer_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..021f978e4f29072b366a0e135d92eda56b5f15bb
--- /dev/null
+++ b/content/browser/renderer_host/media/audio_input_sync_writer_unittest.cc
@@ -0,0 +1,233 @@
+// Copyright 2015 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/sync_socket.h"
+#include "base/time/time.h"
+#include "content/browser/renderer_host/media/audio_input_sync_writer.h"
+#include "content/public/test/test_browser_thread_bundle.h"
+#include "media/audio/audio_parameters.h"
+#include "media/base/audio_bus.h"
+#include "media/base/channel_layout.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+using ::testing::_;
+using base::TimeDelta;
+using media::AudioBus;
+using media::AudioParameters;
+
+namespace content {
+
+// Mocked out sockets used for Send/ReceiveWithTimeout. Counts the number of
+// outstanding reads, i.e. the diff between send and receive calls.
+class MockCancelableSyncSocket : public base::CancelableSyncSocket {
+ public:
+  MockCancelableSyncSocket(int buffer_size)
+      : in_failure_mode_(false),
+        writes_(0),
+        reads_(0),
+        receives_(0),
+        buffer_size_(buffer_size),
+        read_buffer_index_(0) {}
+
+  size_t Send(const void* buffer, size_t length) override {
+    EXPECT_EQ(length, sizeof(uint32_t));
+
+    ++writes_;
+    EXPECT_LE(NumberOfBuffersFilled(), buffer_size_);
+    return length;
+  }
+
+  size_t ReceiveWithTimeout(void* buffer, size_t length,
+                            TimeDelta timeout) override {
+    EXPECT_EQ(length, sizeof(uint32_t));
+
+    if (in_failure_mode_)
+      return 0;
+    if (receives_ == reads_)
+      return 0;
+
+    ++receives_;
+    EXPECT_LE(receives_, reads_);
+    ++read_buffer_index_;
+    *static_cast<uint32_t*>(buffer) = read_buffer_index_;
+    return length;
+  }
+
+  size_t Peek() override {
+    return (reads_ - receives_) * sizeof(uint32_t);
+  }
+
+  // Simluates reading |buffers| number of buffers from the ring buffer.
+  void Read(int buffers) {
+    reads_ += buffers;
+    EXPECT_LE(reads_, writes_);
+  }
+
+  // When |in_failure_mode_| == true, the socket fails to receive.
+  void SetFailureMode(bool in_failure_mode) {
+    in_failure_mode_ = in_failure_mode;
+  }
+
+  int NumberOfBuffersFilled() { return writes_ - reads_; }
+
+ private:
+  bool in_failure_mode_;
+  int writes_;
+  int reads_;
+  int receives_;
+  int buffer_size_;
+  uint32_t read_buffer_index_;
+
+  DISALLOW_COPY_AND_ASSIGN(MockCancelableSyncSocket);
+};
+
+class AudioInputSyncWriterUnderTest : public AudioInputSyncWriter {
+ public:
+  AudioInputSyncWriterUnderTest(void* shared_memory,
+                                size_t shared_memory_size,
+                                int shared_memory_segment_count,
+                                const media::AudioParameters& params,
+                                base::CancelableSyncSocket* socket)
+      : AudioInputSyncWriter(shared_memory, shared_memory_size,
+                             shared_memory_segment_count, params) {
+    socket_.reset(socket);
+  }
+
+  ~AudioInputSyncWriterUnderTest() override {}
+
+  MOCK_METHOD1(AddToNativeLog, void(const std::string& message));
+};
+
+class AudioInputSyncWriterTest : public testing::Test {
+ public:
+  AudioInputSyncWriterTest()
+      : socket_(nullptr) {
+    const media::ChannelLayout layout =
+        media::ChannelLayout::CHANNEL_LAYOUT_MONO;
+    const int channels = media::ChannelLayoutToChannelCount(layout);
+    const int sampling_frequency_hz = 16000;
+    const int frames = sampling_frequency_hz / 100;  // 10 ms
+    const int bits_per_sample = 16;
+
+    AudioParameters audio_params(
+          AudioParameters::AUDIO_FAKE, layout, channels,
+          sampling_frequency_hz, bits_per_sample, frames);
+
+    const uint32 segment_size =
+        sizeof(media::AudioInputBufferParameters) +
+        AudioBus::CalculateMemorySize(audio_params);
+    size_t data_size = kSegments * segment_size;
+    data_.reset(new uint8[data_size]);
+
+    socket_ = new MockCancelableSyncSocket(kSegments);
+    writer_.reset(new AudioInputSyncWriterUnderTest(
+        data_.get(), data_size, kSegments, audio_params, socket_));
+    audio_bus_ = AudioBus::Create(audio_params);
+  }
+
+  ~AudioInputSyncWriterTest() override {
+  }
+
+ protected:
+  const int kSegments = 10;
+
+  scoped_ptr<AudioInputSyncWriterUnderTest> writer_;
+  MockCancelableSyncSocket* socket_;
+  scoped_ptr<AudioBus> audio_bus_;
+  scoped_ptr<uint8[]> data_;
+
+ private:
+  TestBrowserThreadBundle thread_bundle_;
+
+  DISALLOW_COPY_AND_ASSIGN(AudioInputSyncWriterTest);
+};
+
+TEST_F(AudioInputSyncWriterTest, SingleWriteAndRead) {
+  // We always expect one log call at first write.
+  EXPECT_CALL(*writer_.get(), AddToNativeLog(_));
+
+  writer_->Write(audio_bus_.get(), 0, false, 0);
+  EXPECT_EQ(1, socket_->NumberOfBuffersFilled());
+  EXPECT_EQ(0u, socket_->Peek());
+
+  socket_->Read(1);
+  EXPECT_EQ(0, socket_->NumberOfBuffersFilled());
+  EXPECT_EQ(sizeof(uint32_t), socket_->Peek());
+}
+
+TEST_F(AudioInputSyncWriterTest, MultipleWritesAndReads) {
+  EXPECT_CALL(*writer_.get(), AddToNativeLog(_));
+
+  for (int i = 1; i <= 2 * kSegments; ++i) {
+    writer_->Write(audio_bus_.get(), 0, false, 0);
+    EXPECT_EQ(1, socket_->NumberOfBuffersFilled());
+    EXPECT_EQ(0u, socket_->Peek());
+
+    socket_->Read(1);
+    EXPECT_EQ(0, socket_->NumberOfBuffersFilled());
+    EXPECT_EQ(sizeof(uint32_t), socket_->Peek());
+  }
+}
+
+TEST_F(AudioInputSyncWriterTest, MultipleWritesNoReads) {
+  EXPECT_CALL(*writer_.get(), AddToNativeLog(_)).Times(1 + kSegments);
+
+  for (int i = 1; i <= kSegments; ++i) {
+    writer_->Write(audio_bus_.get(), 0, false, 0);
+    EXPECT_EQ(i, socket_->NumberOfBuffersFilled());
+    EXPECT_EQ(0u, socket_->Peek());
+  }
+
+  // Now the ring buffer is full, do more writes. We should get an extra error
+  // log call for each write. See top EXPECT_CALL.
+  for (int i = 1; i <= kSegments; ++i) {
+    writer_->Write(audio_bus_.get(), 0, false, 0);
+    EXPECT_EQ(kSegments, socket_->NumberOfBuffersFilled());
+    EXPECT_EQ(0u, socket_->Peek());
+  }
+}
+
+TEST_F(AudioInputSyncWriterTest, FillAndEmptyRingBuffer) {
+  EXPECT_CALL(*writer_.get(), AddToNativeLog(_)).Times(2);
+
+  // Fill ring buffer.
+  for (int i = 1; i <= kSegments; ++i) {
+    writer_->Write(audio_bus_.get(), 0, false, 0);
+  }
+  EXPECT_EQ(kSegments, socket_->NumberOfBuffersFilled());
+  EXPECT_EQ(0u, socket_->Peek());
+
+  // Empty half of the ring buffer.
+  int buffers_to_read = kSegments / 2;
+  socket_->Read(buffers_to_read);
+  EXPECT_EQ(kSegments - buffers_to_read, socket_->NumberOfBuffersFilled());
+  EXPECT_EQ(buffers_to_read * sizeof(uint32_t), socket_->Peek());
+
+  // Fill up again. The first write should do receive until that queue is
+  // empty.
+  for (int i = kSegments - buffers_to_read + 1; i <= kSegments; ++i) {
+    writer_->Write(audio_bus_.get(), 0, false, 0);
+    EXPECT_EQ(i, socket_->NumberOfBuffersFilled());
+    EXPECT_EQ(0u, socket_->Peek());
+  }
+
+  // Another write, should render and extra error log call.
+  writer_->Write(audio_bus_.get(), 0, false, 0);
+  EXPECT_EQ(kSegments, socket_->NumberOfBuffersFilled());
+  EXPECT_EQ(0u, socket_->Peek());
+
+  // Empty the ring buffer.
+  socket_->Read(kSegments);
+  EXPECT_EQ(0, socket_->NumberOfBuffersFilled());
+  EXPECT_EQ(kSegments * sizeof(uint32_t), socket_->Peek());
+
+  // Another write, should do receive until that queue is empty.
+  writer_->Write(audio_bus_.get(), 0, false, 0);
+  EXPECT_EQ(1, socket_->NumberOfBuffersFilled());
+  EXPECT_EQ(0u, socket_->Peek());
+}
+
+}  // namespace content