Move MockFFmpeg instance setting into the constructor/destructor.

media/base/mock_ffmpeg.cc

-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// 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 "media/base/mock_ffmpeg.h"
 
 #include "base/logging.h"
 #include "media/ffmpeg/ffmpeg_common.h"
 
 using ::testing::_;
 using ::testing::AtMost;
 using ::testing::DoAll;
 using ::testing::Return;
 using ::testing::SaveArg;
 
 namespace media {
 
 MockFFmpeg* MockFFmpeg::instance_ = NULL;
 URLProtocol* MockFFmpeg::protocol_ = NULL;
 
 MockFFmpeg::MockFFmpeg()
     : outstanding_packets_(0) {
+  CHECK(instance_ == NULL) << "Only a single MockFFmpeg instance can exist";
+  instance_ = this;
+
   // If we haven't assigned our static copy of URLProtocol, set up expectations
   // to catch the URLProtocol registered when the singleton instance of
   // FFmpegGlue is created.
   //
   // TODO(scherkus): this feels gross and I need to think of a way to better
   // inject/mock singletons.
   if (!protocol_) {
     EXPECT_CALL(*this, AVLogSetLevel(AV_LOG_QUIET))
         .Times(AtMost(1))
         .WillOnce(Return());
     EXPECT_CALL(*this, AVCodecInit())
         .Times(AtMost(1))
         .WillOnce(Return());
     EXPECT_CALL(*this, AVRegisterProtocol2(_,_))
         .Times(AtMost(1))
         .WillOnce(DoAll(SaveArg<0>(&protocol_), Return(0)));
     EXPECT_CALL(*this, AVRegisterAll())
         .Times(AtMost(1))
         .WillOnce(Return());
   }
-  // av_lockmgr_register() is also called from ~FFmpegLock(), so we expect
-  // it to be called at the end.
-  EXPECT_CALL(*this, AVRegisterLockManager(_))
-    .Times(AtMost(2))
-    .WillRepeatedly(Return(0));
 }
 
 MockFFmpeg::~MockFFmpeg() {
   CHECK(!outstanding_packets_)
       << "MockFFmpeg destroyed with outstanding packets";
+  CHECK(instance_);
+  instance_ = NULL;
 }
 
 void MockFFmpeg::inc_outstanding_packets() {
   ++outstanding_packets_;
 }
 
 void MockFFmpeg::dec_outstanding_packets() {
   CHECK(outstanding_packets_ > 0);
   --outstanding_packets_;
 }
 
 // static
-void MockFFmpeg::set(MockFFmpeg* instance) {
-  instance_ = instance;
-}
-
-// static
 MockFFmpeg* MockFFmpeg::get() {
   return instance_;
 }
 
 // static
 URLProtocol* MockFFmpeg::protocol() {
   return protocol_;
 }
 
 // static
 void MockFFmpeg::DestructPacket(AVPacket* packet) {
   delete [] packet->data;
   packet->data = NULL;
   packet->size = 0;
 }
 
 // FFmpeg stubs that delegate to the FFmpegMock instance.
 extern "C" {
 void avcodec_init() {
-  media::MockFFmpeg::get()->AVCodecInit();
+  MockFFmpeg::get()->AVCodecInit();
 }
 
 int av_register_protocol2(URLProtocol* protocol, int size) {
-  return media::MockFFmpeg::get()->AVRegisterProtocol2(protocol, size);
+  return MockFFmpeg::get()->AVRegisterProtocol2(protocol, size);
 }
 
 void av_register_all() {
-  media::MockFFmpeg::get()->AVRegisterAll();
+  MockFFmpeg::get()->AVRegisterAll();
 }
 
 int av_lockmgr_register(int (*cb)(void**, enum AVLockOp)) {
-  media::MockFFmpeg* mock = media::MockFFmpeg::get();
   // Here |mock| may be NULL when this function is called from ~FFmpegGlue().
-  if (mock != NULL) {
-    return mock->AVRegisterLockManager(cb);
-  } else {
-    return 0;
+  if (MockFFmpeg::get()) {
+    return MockFFmpeg::get()->AVRegisterLockManager(cb);
   }
+  return 0;
 }
 
 AVCodec* avcodec_find_decoder(enum CodecID id) {
-  return media::MockFFmpeg::get()->AVCodecFindDecoder(id);
+  return MockFFmpeg::get()->AVCodecFindDecoder(id);
 }
 
 int avcodec_open(AVCodecContext* avctx, AVCodec* codec) {
-  return media::MockFFmpeg::get()->AVCodecOpen(avctx, codec);
+  return MockFFmpeg::get()->AVCodecOpen(avctx, codec);
 }
 
 int avcodec_close(AVCodecContext* avctx) {
-  return media::MockFFmpeg::get()->AVCodecClose(avctx);
+  return MockFFmpeg::get()->AVCodecClose(avctx);
 }
 
 int avcodec_thread_init(AVCodecContext* avctx, int threads) {
-  return media::MockFFmpeg::get()->AVCodecThreadInit(avctx, threads);
+  return MockFFmpeg::get()->AVCodecThreadInit(avctx, threads);
 }
 
 void avcodec_flush_buffers(AVCodecContext* avctx) {
-  return media::MockFFmpeg::get()->AVCodecFlushBuffers(avctx);
+  return MockFFmpeg::get()->AVCodecFlushBuffers(avctx);
 }
 
 AVFrame* avcodec_alloc_frame() {
-  return media::MockFFmpeg::get()->AVCodecAllocFrame();
+  return MockFFmpeg::get()->AVCodecAllocFrame();
 }
 
 int avcodec_decode_video2(AVCodecContext* avctx, AVFrame* picture,
                           int* got_picture_ptr, AVPacket* avpkt) {
-  return media::MockFFmpeg::get()->
+  return MockFFmpeg::get()->
       AVCodecDecodeVideo2(avctx, picture, got_picture_ptr, avpkt);
 }
 
 AVBitStreamFilterContext* av_bitstream_filter_init(const char* name) {
-  return media::MockFFmpeg::get()->AVBitstreamFilterInit(name);
+  return MockFFmpeg::get()->AVBitstreamFilterInit(name);
 }
 
 int av_bitstream_filter_filter(AVBitStreamFilterContext* bsfc,
                                AVCodecContext* avctx,
                                const char* args,
                                uint8_t** poutbuf,
                                int* poutbuf_size,
                                const uint8_t* buf,
                                int buf_size,
                                int keyframe) {
-  return media::MockFFmpeg::get()->
+  return MockFFmpeg::get()->
       AVBitstreamFilterFilter(bsfc, avctx, args, poutbuf, poutbuf_size, buf,
                               buf_size, keyframe);
 }
 
 void av_bitstream_filter_close(AVBitStreamFilterContext* bsf) {
-  return media::MockFFmpeg::get()->AVBitstreamFilterClose(bsf);
+  return MockFFmpeg::get()->AVBitstreamFilterClose(bsf);
 }
 
 int av_open_input_file(AVFormatContext** format, const char* filename,
                        AVInputFormat* input_format, int buffer_size,
                        AVFormatParameters* parameters) {
-  return media::MockFFmpeg::get()->AVOpenInputFile(format, filename,
+  return MockFFmpeg::get()->AVOpenInputFile(format, filename,
                                                    input_format, buffer_size,
                                                    parameters);
 }
 
 void av_close_input_file(AVFormatContext* format) {
-  media::MockFFmpeg::get()->AVCloseInputFile(format);
+  MockFFmpeg::get()->AVCloseInputFile(format);
 }
 
 int av_find_stream_info(AVFormatContext* format) {
-  return media::MockFFmpeg::get()->AVFindStreamInfo(format);
+  return MockFFmpeg::get()->AVFindStreamInfo(format);
 }
 
 int64 av_rescale_q(int64 a, AVRational bq, AVRational cq) {
   // Because this is a math function there's little point in mocking it, so we
   // implement a cheap version that's capable of overflowing.
   int64 num = bq.num * cq.den;
   int64 den = cq.num * bq.den;
   return a * num / den;
 }
 
 int av_read_frame(AVFormatContext* format, AVPacket* packet) {
-  return media::MockFFmpeg::get()->AVReadFrame(format, packet);
+  return MockFFmpeg::get()->AVReadFrame(format, packet);
 }
 
 int av_seek_frame(AVFormatContext *format, int stream_index, int64_t timestamp,
                   int flags) {
-  return media::MockFFmpeg::get()->AVSeekFrame(format, stream_index, timestamp,
+  return MockFFmpeg::get()->AVSeekFrame(format, stream_index, timestamp,
                                                flags);
 }
 
 void av_init_packet(AVPacket* pkt) {
-  return media::MockFFmpeg::get()->AVInitPacket(pkt);
+  return MockFFmpeg::get()->AVInitPacket(pkt);
 }
 
 int av_new_packet(AVPacket* packet, int size) {
-  return media::MockFFmpeg::get()->AVNewPacket(packet, size);
+  return MockFFmpeg::get()->AVNewPacket(packet, size);
 }
 
 void av_free_packet(AVPacket* packet) {
-  media::MockFFmpeg::get()->AVFreePacket(packet);
+  MockFFmpeg::get()->AVFreePacket(packet);
 }
 
 void av_free(void* ptr) {
   // Freeing NULL pointers are valid, but they aren't interesting from a mock
   // perspective.
   if (ptr) {
-    media::MockFFmpeg::get()->AVFree(ptr);
+    MockFFmpeg::get()->AVFree(ptr);
   }
 }
 
 int av_dup_packet(AVPacket* packet) {
-  return media::MockFFmpeg::get()->AVDupPacket(packet);
+  return MockFFmpeg::get()->AVDupPacket(packet);
 }
 
 void av_log_set_level(int level) {
-  media::MockFFmpeg::get()->AVLogSetLevel(level);
+  MockFFmpeg::get()->AVLogSetLevel(level);
 }
 
 void av_destruct_packet(AVPacket *pkt) {
-  media::MockFFmpeg::get()->AVDestructPacket(pkt);
+  MockFFmpeg::get()->AVDestructPacket(pkt);
 }
 
 }  // extern "C"
 
 }  // namespace media