1 #ifndef ANDROID_DVR_CONSUMER_BUFFER_H_ 2 #define ANDROID_DVR_CONSUMER_BUFFER_H_ 3 4 #include <private/dvr/buffer_hub_base.h> 5 6 namespace android { 7 namespace dvr { 8 9 // This is a connection to a producer buffer, which can be located in another 10 // application. When that buffer is Post()ed, this fd will be signaled and 11 // Acquire allows read access. The user is responsible for making sure that 12 // Acquire is called with the correct metadata structure. The only guarantee the 13 // API currently provides is that an Acquire() with metadata of the wrong size 14 // will fail. 15 class ConsumerBuffer : public pdx::ClientBase<ConsumerBuffer, BufferHubBase> { 16 public: 17 // This call assumes ownership of |fd|. 18 static std::unique_ptr<ConsumerBuffer> Import(LocalChannelHandle channel); 19 static std::unique_ptr<ConsumerBuffer> Import( 20 Status<LocalChannelHandle> status); 21 22 // Attempt to retrieve a post event from buffer hub. If successful, 23 // |ready_fence| will be set to a fence to wait on until the buffer is ready. 24 // This call will only succeed after the fd is signalled. This call may be 25 // performed as an alternative to the Acquire() with metadata. In such cases 26 // the metadata is not read. 27 // 28 // This returns zero or negative unix error code. 29 int Acquire(LocalHandle* ready_fence); 30 31 // Attempt to retrieve a post event from buffer hub. If successful, 32 // |ready_fence| is set to a fence signaling that the contents of the buffer 33 // are available. This call will only succeed if the buffer is in the posted 34 // state. 35 // Returns zero on success, or a negative errno code otherwise. 36 int Acquire(LocalHandle* ready_fence, void* meta, size_t user_metadata_size); 37 38 // Asynchronously acquires a bufer. 39 int AcquireAsync(DvrNativeBufferMetadata* out_meta, LocalHandle* out_fence); 40 41 // Releases the buffer from any buffer state. If the fence is valid the fence 42 // determines the buffer usage, otherwise the buffer is released immediately. 43 // This returns zero or a negative unix error code. 44 int Release(const LocalHandle& release_fence); 45 int ReleaseAsync(); 46 47 // Asynchronously releases a buffer. Similar to the synchronous version above, 48 // except that it does not wait for BufferHub to reply with success or error. 49 // The fence and metadata are passed to consumer via shared fd and shared 50 // memory. 51 int ReleaseAsync(const DvrNativeBufferMetadata* meta, 52 const LocalHandle& release_fence); 53 54 // May be called after or instead of Acquire to indicate that the consumer 55 // does not need to access the buffer this cycle. This returns zero or a 56 // negative unix error code. 57 int Discard(); 58 59 private: 60 friend BASE; 61 62 explicit ConsumerBuffer(LocalChannelHandle channel); 63 64 // Local state transition helpers. 65 int LocalAcquire(DvrNativeBufferMetadata* out_meta, LocalHandle* out_fence); 66 int LocalRelease(const DvrNativeBufferMetadata* meta, 67 const LocalHandle& release_fence); 68 }; 69 70 } // namespace dvr 71 } // namespace android 72 73 #endif // ANDROID_DVR_CONSUMER_BUFFER_H_ 74
