1 // Copyright (c) 2012 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 #ifndef MEDIA_AUDIO_SHARED_MEMORY_UTIL_H_ 6 #define MEDIA_AUDIO_SHARED_MEMORY_UTIL_H_ 7 8 #include "base/basictypes.h" 9 #include "base/memory/shared_memory.h" 10 #include "media/base/media_export.h" 11 12 namespace media { 13 14 // Value sent by the controller to the renderer in low-latency mode 15 // indicating that the stream is paused. 16 enum { kPauseMark = -1 }; 17 18 // Functions that handle data buffer passed between processes in the shared 19 // memory. Called on both IPC sides. These are necessary because the shared 20 // memory has a layout: the last word in the block is the data size in bytes. 21 22 MEDIA_EXPORT uint32 TotalSharedMemorySizeInBytes(uint32 packet_size); 23 MEDIA_EXPORT uint32 PacketSizeInBytes(uint32 shared_memory_created_size); 24 MEDIA_EXPORT uint32 GetActualDataSizeInBytes(base::SharedMemory* shared_memory, 25 uint32 packet_size); 26 MEDIA_EXPORT void SetActualDataSizeInBytes(base::SharedMemory* shared_memory, 27 uint32 packet_size, 28 uint32 actual_data_size); 29 MEDIA_EXPORT void SetActualDataSizeInBytes(void* shared_memory_ptr, 30 uint32 packet_size, 31 uint32 actual_data_size); 32 MEDIA_EXPORT void SetUnknownDataSize(base::SharedMemory* shared_memory, 33 uint32 packet_size); 34 MEDIA_EXPORT bool IsUnknownDataSize(base::SharedMemory* shared_memory, 35 uint32 packet_size); 36 37 } // namespace media 38 39 #endif // MEDIA_AUDIO_SHARED_MEMORY_UTIL_H_ 40
