| #ifndef ANDROID_DVR_PRODUCER_BUFFER_H_ |
| #define ANDROID_DVR_PRODUCER_BUFFER_H_ |
| |
| #include <private/dvr/buffer_hub_base.h> |
| |
| namespace android { |
| namespace dvr { |
| |
| // This represents a writable buffer. Calling Post notifies all clients and |
| // makes the buffer read-only. Call Gain to acquire write access. A buffer |
| // may have many consumers. |
| // |
| // The user of ProducerBuffer is responsible with making sure that the Post() is |
| // done with the correct metadata type and size. The user is also responsible |
| // for making sure that remote ends (ConsumerBuffers) are also using the correct |
| // metadata when acquiring the buffer. The API guarantees that a Post() with a |
| // metadata of wrong size will fail. However, it currently does not do any |
| // type checking. |
| // The API also assumes that metadata is a serializable type (plain old data). |
| class ProducerBuffer : public pdx::ClientBase<ProducerBuffer, BufferHubBase> { |
| public: |
| // Imports a bufferhub producer channel, assuming ownership of its handle. |
| static std::unique_ptr<ProducerBuffer> Import(LocalChannelHandle channel); |
| static std::unique_ptr<ProducerBuffer> Import( |
| Status<LocalChannelHandle> status); |
| |
| // Asynchronously posts a buffer. The fence and metadata are passed to |
| // consumer via shared fd and shared memory. |
| int PostAsync(const DvrNativeBufferMetadata* meta, |
| const LocalHandle& ready_fence); |
| |
| // Post this buffer, passing |ready_fence| to the consumers. The bytes in |
| // |meta| are passed unaltered to the consumers. The producer must not modify |
| // the buffer until it is re-gained. |
| // This returns zero or a negative unix error code. |
| int Post(const LocalHandle& ready_fence, const void* meta, |
| size_t user_metadata_size); |
| |
| int Post(const LocalHandle& ready_fence) { |
| return Post(ready_fence, nullptr, 0); |
| } |
| |
| // Attempt to re-gain the buffer for writing. If |release_fence| is valid, it |
| // must be waited on before using the buffer. If it is not valid then the |
| // buffer is free for immediate use. This call will succeed if the buffer |
| // is in the released state, or in posted state and gain_posted_buffer is |
| // true. |
| // |
| // @param release_fence output fence. |
| // @param gain_posted_buffer whether to gain posted buffer or not. |
| // @return This returns zero or a negative unix error code. |
| int Gain(LocalHandle* release_fence, bool gain_posted_buffer = false); |
| |
| // Asynchronously marks a released buffer as gained. This method is similar to |
| // the synchronous version above, except that it does not wait for BufferHub |
| // to acknowledge success or failure. Because of the asynchronous nature of |
| // the underlying message, no error is returned if this method is called when |
| // the buffer is in an incorrect state. Returns zero if sending the message |
| // succeeded, or a negative errno code if local error check fails. |
| // TODO(b/112007999): gain_posted_buffer true is only used to prevent |
| // libdvrtracking from starving when there are non-responding clients. This |
| // gain_posted_buffer param can be removed once libdvrtracking start to use |
| // the new AHardwareBuffer API. |
| int GainAsync(DvrNativeBufferMetadata* out_meta, LocalHandle* out_fence, |
| bool gain_posted_buffer = false); |
| int GainAsync(); |
| |
| // Detaches a ProducerBuffer from an existing producer/consumer set. Can only |
| // be called when a producer buffer has exclusive access to the buffer (i.e. |
| // in the gain'ed state). On the successful return of the IPC call, a new |
| // LocalChannelHandle representing a detached buffer will be returned and all |
| // existing producer and consumer channels will be closed. Further IPCs |
| // towards those channels will return error. |
| Status<LocalChannelHandle> Detach(); |
| |
| private: |
| friend BASE; |
| |
| // Constructors are automatically exposed through ProducerBuffer::Create(...) |
| // static template methods inherited from ClientBase, which take the same |
| // arguments as the constructors. |
| |
| // Constructs a buffer with the given geometry and parameters. |
| ProducerBuffer(uint32_t width, uint32_t height, uint32_t format, |
| uint64_t usage, size_t metadata_size = 0); |
| |
| // Constructs a blob (flat) buffer with the given usage flags. |
| ProducerBuffer(uint64_t usage, size_t size); |
| |
| // Imports the given file handle to a producer channel, taking ownership. |
| explicit ProducerBuffer(LocalChannelHandle channel); |
| |
| // Local state transition helpers. |
| int LocalGain(DvrNativeBufferMetadata* out_meta, LocalHandle* out_fence, |
| bool gain_posted_buffer = false); |
| int LocalPost(const DvrNativeBufferMetadata* meta, |
| const LocalHandle& ready_fence); |
| }; |
| |
| } // namespace dvr |
| } // namespace android |
| |
| #endif // ANDROID_DVR_PRODUCER_BUFFER_H_ |