BufferQueue.h revision eae59d2ea77ef57aab203fb185a880ce37ac38d6
1/* 2 * Copyright (C) 2012 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#ifndef ANDROID_GUI_BUFFERQUEUE_H 18#define ANDROID_GUI_BUFFERQUEUE_H 19 20#include <EGL/egl.h> 21 22#include <gui/IGraphicBufferAlloc.h> 23#include <gui/ISurfaceTexture.h> 24 25#include <ui/GraphicBuffer.h> 26 27#include <utils/String8.h> 28#include <utils/Vector.h> 29#include <utils/threads.h> 30 31namespace android { 32// ---------------------------------------------------------------------------- 33 34class BufferQueue : public BnSurfaceTexture { 35public: 36 enum { MIN_UNDEQUEUED_BUFFERS = 2 }; 37 enum { 38 MIN_ASYNC_BUFFER_SLOTS = MIN_UNDEQUEUED_BUFFERS + 1, 39 MIN_SYNC_BUFFER_SLOTS = MIN_UNDEQUEUED_BUFFERS 40 }; 41 enum { NUM_BUFFER_SLOTS = 32 }; 42 enum { NO_CONNECTED_API = 0 }; 43 enum { INVALID_BUFFER_SLOT = -1 }; 44 45 struct FrameAvailableListener : public virtual RefBase { 46 // onFrameAvailable() is called from queueBuffer() each time an 47 // additional frame becomes available for consumption. This means that 48 // frames that are queued while in asynchronous mode only trigger the 49 // callback if no previous frames are pending. Frames queued while in 50 // synchronous mode always trigger the callback. 51 // 52 // This is called without any lock held and can be called concurrently 53 // by multiple threads. 54 virtual void onFrameAvailable() = 0; 55 }; 56 57 // BufferQueue manages a pool of gralloc memory slots to be used 58 // by producers and consumers. 59 // allowSynchronousMode specifies whether or not synchronous mode can be 60 // enabled. 61 BufferQueue(bool allowSynchronousMode = true); 62 virtual ~BufferQueue(); 63 64 virtual int query(int what, int* value); 65 66 // setBufferCount updates the number of available buffer slots. After 67 // calling this all buffer slots are both unallocated and owned by the 68 // BufferQueue object (i.e. they are not owned by the client). 69 virtual status_t setBufferCount(int bufferCount); 70 71 virtual status_t requestBuffer(int slot, sp<GraphicBuffer>* buf); 72 73 // dequeueBuffer gets the next buffer slot index for the client to use. If a 74 // buffer slot is available then that slot index is written to the location 75 // pointed to by the buf argument and a status of OK is returned. If no 76 // slot is available then a status of -EBUSY is returned and buf is 77 // unmodified. 78 // The width and height parameters must be no greater than the minimum of 79 // GL_MAX_VIEWPORT_DIMS and GL_MAX_TEXTURE_SIZE (see: glGetIntegerv). 80 // An error due to invalid dimensions might not be reported until 81 // updateTexImage() is called. 82 virtual status_t dequeueBuffer(int *buf, uint32_t width, uint32_t height, 83 uint32_t format, uint32_t usage); 84 85 // queueBuffer returns a filled buffer to the BufferQueue. In addition, a 86 // timestamp must be provided for the buffer. The timestamp is in 87 // nanoseconds, and must be monotonically increasing. Its other semantics 88 // (zero point, etc) are client-dependent and should be documented by the 89 // client. 90 virtual status_t queueBuffer(int buf, int64_t timestamp, 91 uint32_t* outWidth, uint32_t* outHeight, uint32_t* outTransform); 92 virtual void cancelBuffer(int buf); 93 virtual status_t setCrop(const Rect& reg); 94 virtual status_t setTransform(uint32_t transform); 95 virtual status_t setScalingMode(int mode); 96 97 // setSynchronousMode set whether dequeueBuffer is synchronous or 98 // asynchronous. In synchronous mode, dequeueBuffer blocks until 99 // a buffer is available, the currently bound buffer can be dequeued and 100 // queued buffers will be retired in order. 101 // The default mode is asynchronous. 102 virtual status_t setSynchronousMode(bool enabled); 103 104 // connect attempts to connect a producer client API to the BufferQueue. 105 // This must be called before any other ISurfaceTexture methods are called 106 // except for getAllocator. 107 // 108 // This method will fail if the connect was previously called on the 109 // BufferQueue and no corresponding disconnect call was made. 110 virtual status_t connect(int api, 111 uint32_t* outWidth, uint32_t* outHeight, uint32_t* outTransform); 112 113 // disconnect attempts to disconnect a producer client API from the 114 // BufferQueue. Calling this method will cause any subsequent calls to other 115 // ISurfaceTexture methods to fail except for getAllocator and connect. 116 // Successfully calling connect after this will allow the other methods to 117 // succeed again. 118 // 119 // This method will fail if the the BufferQueue is not currently 120 // connected to the specified client API. 121 virtual status_t disconnect(int api); 122 123 // dump our state in a String 124 virtual void dump(String8& result) const; 125 virtual void dump(String8& result, const char* prefix, char* buffer, size_t SIZE) const; 126 127 // public facing structure for BufferSlot 128 struct BufferItem { 129 130 BufferItem() 131 : 132 mTransform(0), 133 mScalingMode(NATIVE_WINDOW_SCALING_MODE_FREEZE), 134 mTimestamp(0), 135 mFrameNumber(0), 136 mBuf(INVALID_BUFFER_SLOT) { 137 mCrop.makeInvalid(); 138 } 139 // mGraphicBuffer points to the buffer allocated for this slot or is NULL 140 // if no buffer has been allocated. 141 sp<GraphicBuffer> mGraphicBuffer; 142 143 // mCrop is the current crop rectangle for this buffer slot. This gets 144 // set to mNextCrop each time queueBuffer gets called for this buffer. 145 Rect mCrop; 146 147 // mTransform is the current transform flags for this buffer slot. This 148 // gets set to mNextTransform each time queueBuffer gets called for this 149 // slot. 150 uint32_t mTransform; 151 152 // mScalingMode is the current scaling mode for this buffer slot. This 153 // gets set to mNextScalingMode each time queueBuffer gets called for 154 // this slot. 155 uint32_t mScalingMode; 156 157 // mTimestamp is the current timestamp for this buffer slot. This gets 158 // to set by queueBuffer each time this slot is queued. 159 int64_t mTimestamp; 160 161 // mFrameNumber is the number of the queued frame for this slot. 162 uint64_t mFrameNumber; 163 164 // buf is the slot index of this buffer 165 int mBuf; 166 167 }; 168 169 // The following public functions is the consumer facing interface 170 171 // acquire consumes a buffer by transferring its ownership to a consumer. 172 // buffer contains the GraphicBuffer and its corresponding information. 173 // buffer.mGraphicsBuffer will be NULL when the buffer has been already 174 // acquired by the consumer. 175 176 status_t acquire(BufferItem *buffer); 177 178 // releaseBuffer releases a buffer slot from the consumer back to the 179 // BufferQueue pending a fence sync. 180 status_t releaseBuffer(int buf, EGLDisplay display, EGLSyncKHR fence); 181 182 // consumerDisconnect disconnects a consumer from the BufferQueue. All 183 // buffers will be freed. 184 status_t consumerDisconnect(); 185 186 // setDefaultBufferSize is used to set the size of buffers returned by 187 // requestBuffers when a with and height of zero is requested. 188 status_t setDefaultBufferSize(uint32_t w, uint32_t h); 189 190 // setBufferCountServer set the buffer count. If the client has requested 191 // a buffer count using setBufferCount, the server-buffer count will 192 // take effect once the client sets the count back to zero. 193 status_t setBufferCountServer(int bufferCount); 194 195 // isSynchronousMode returns whether the SurfaceTexture is currently in 196 // synchronous mode. 197 bool isSynchronousMode() const; 198 199 // setConsumerName sets the name used in logging 200 void setConsumerName(const String8& name); 201 202 // setFrameAvailableListener sets the listener object that will be notified 203 // when a new frame becomes available. 204 void setFrameAvailableListener(const sp<FrameAvailableListener>& listener); 205 206 207private: 208 // freeBufferLocked frees the resources (both GraphicBuffer and EGLImage) 209 // for the given slot. 210 void freeBufferLocked(int index); 211 212 // freeAllBuffersLocked frees the resources (both GraphicBuffer and 213 // EGLImage) for all slots. 214 void freeAllBuffersLocked(); 215 216 // freeAllBuffersExceptHeadLocked frees the resources (both GraphicBuffer 217 // and EGLImage) for all slots except the head of mQueue 218 void freeAllBuffersExceptHeadLocked(); 219 220 // drainQueueLocked drains the buffer queue if we're in synchronous mode 221 // returns immediately otherwise. It returns NO_INIT if the BufferQueue 222 // became abandoned or disconnected during this call. 223 status_t drainQueueLocked(); 224 225 // drainQueueAndFreeBuffersLocked drains the buffer queue if we're in 226 // synchronous mode and free all buffers. In asynchronous mode, all buffers 227 // are freed except the current buffer. 228 status_t drainQueueAndFreeBuffersLocked(); 229 230 status_t setBufferCountServerLocked(int bufferCount); 231 232 struct BufferSlot { 233 234 BufferSlot() 235 : mEglDisplay(EGL_NO_DISPLAY), 236 mBufferState(BufferSlot::FREE), 237 mRequestBufferCalled(false), 238 mTransform(0), 239 mScalingMode(NATIVE_WINDOW_SCALING_MODE_FREEZE), 240 mTimestamp(0), 241 mFrameNumber(0), 242 mFence(EGL_NO_SYNC_KHR), 243 mAcquireCalled(false) { 244 mCrop.makeInvalid(); 245 } 246 247 // mGraphicBuffer points to the buffer allocated for this slot or is NULL 248 // if no buffer has been allocated. 249 sp<GraphicBuffer> mGraphicBuffer; 250 251 // mEglDisplay is the EGLDisplay used to create mEglImage. 252 EGLDisplay mEglDisplay; 253 254 // BufferState represents the different states in which a buffer slot 255 // can be. 256 enum BufferState { 257 // FREE indicates that the buffer is not currently being used and 258 // will not be used in the future until it gets dequeued and 259 // subsequently queued by the client. 260 // aka "owned by BufferQueue, ready to be dequeued" 261 FREE = 0, 262 263 // DEQUEUED indicates that the buffer has been dequeued by the 264 // client, but has not yet been queued or canceled. The buffer is 265 // considered 'owned' by the client, and the server should not use 266 // it for anything. 267 // 268 // Note that when in synchronous-mode (mSynchronousMode == true), 269 // the buffer that's currently attached to the texture may be 270 // dequeued by the client. That means that the current buffer can 271 // be in either the DEQUEUED or QUEUED state. In asynchronous mode, 272 // however, the current buffer is always in the QUEUED state. 273 // aka "owned by producer, ready to be queued" 274 DEQUEUED = 1, 275 276 // QUEUED indicates that the buffer has been queued by the client, 277 // and has not since been made available for the client to dequeue. 278 // Attaching the buffer to the texture does NOT transition the 279 // buffer away from the QUEUED state. However, in Synchronous mode 280 // the current buffer may be dequeued by the client under some 281 // circumstances. See the note about the current buffer in the 282 // documentation for DEQUEUED. 283 // aka "owned by BufferQueue, ready to be acquired" 284 QUEUED = 2, 285 286 // aka "owned by consumer, ready to be released" 287 ACQUIRED = 3 288 }; 289 290 // mBufferState is the current state of this buffer slot. 291 BufferState mBufferState; 292 293 // mRequestBufferCalled is used for validating that the client did 294 // call requestBuffer() when told to do so. Technically this is not 295 // needed but useful for debugging and catching client bugs. 296 bool mRequestBufferCalled; 297 298 // mCrop is the current crop rectangle for this buffer slot. This gets 299 // set to mNextCrop each time queueBuffer gets called for this buffer. 300 Rect mCrop; 301 302 // mTransform is the current transform flags for this buffer slot. This 303 // gets set to mNextTransform each time queueBuffer gets called for this 304 // slot. 305 uint32_t mTransform; 306 307 // mScalingMode is the current scaling mode for this buffer slot. This 308 // gets set to mNextScalingMode each time queueBuffer gets called for 309 // this slot. 310 uint32_t mScalingMode; 311 312 // mTimestamp is the current timestamp for this buffer slot. This gets 313 // to set by queueBuffer each time this slot is queued. 314 int64_t mTimestamp; 315 316 // mFrameNumber is the number of the queued frame for this slot. 317 uint64_t mFrameNumber; 318 319 // mFence is the EGL sync object that must signal before the buffer 320 // associated with this buffer slot may be dequeued. It is initialized 321 // to EGL_NO_SYNC_KHR when the buffer is created and (optionally, based 322 // on a compile-time option) set to a new sync object in updateTexImage. 323 EGLSyncKHR mFence; 324 325 // Indicates whether this buffer has been seen by a consumer yet 326 bool mAcquireCalled; 327 }; 328 329 // mSlots is the array of buffer slots that must be mirrored on the client 330 // side. This allows buffer ownership to be transferred between the client 331 // and server without sending a GraphicBuffer over binder. The entire array 332 // is initialized to NULL at construction time, and buffers are allocated 333 // for a slot when requestBuffer is called with that slot's index. 334 BufferSlot mSlots[NUM_BUFFER_SLOTS]; 335 336 // mDefaultWidth holds the default width of allocated buffers. It is used 337 // in requestBuffers() if a width and height of zero is specified. 338 uint32_t mDefaultWidth; 339 340 // mDefaultHeight holds the default height of allocated buffers. It is used 341 // in requestBuffers() if a width and height of zero is specified. 342 uint32_t mDefaultHeight; 343 344 // mPixelFormat holds the pixel format of allocated buffers. It is used 345 // in requestBuffers() if a format of zero is specified. 346 uint32_t mPixelFormat; 347 348 // mBufferCount is the number of buffer slots that the client and server 349 // must maintain. It defaults to MIN_ASYNC_BUFFER_SLOTS and can be changed 350 // by calling setBufferCount or setBufferCountServer 351 int mBufferCount; 352 353 // mClientBufferCount is the number of buffer slots requested by the client. 354 // The default is zero, which means the client doesn't care how many buffers 355 // there is. 356 int mClientBufferCount; 357 358 // mServerBufferCount buffer count requested by the server-side 359 int mServerBufferCount; 360 361 // mNextCrop is the crop rectangle that will be used for the next buffer 362 // that gets queued. It is set by calling setCrop. 363 Rect mNextCrop; 364 365 // mNextTransform is the transform identifier that will be used for the next 366 // buffer that gets queued. It is set by calling setTransform. 367 uint32_t mNextTransform; 368 369 // mNextScalingMode is the scaling mode that will be used for the next 370 // buffers that get queued. It is set by calling setScalingMode. 371 int mNextScalingMode; 372 373 // mGraphicBufferAlloc is the connection to SurfaceFlinger that is used to 374 // allocate new GraphicBuffer objects. 375 sp<IGraphicBufferAlloc> mGraphicBufferAlloc; 376 377 // mFrameAvailableListener is the listener object that will be called when a 378 // new frame becomes available. If it is not NULL it will be called from 379 // queueBuffer. 380 sp<FrameAvailableListener> mFrameAvailableListener; 381 382 // mSynchronousMode whether we're in synchronous mode or not 383 bool mSynchronousMode; 384 385 // mAllowSynchronousMode whether we allow synchronous mode or not 386 const bool mAllowSynchronousMode; 387 388 // mConnectedApi indicates the API that is currently connected to this 389 // BufferQueue. It defaults to NO_CONNECTED_API (= 0), and gets updated 390 // by the connect and disconnect methods. 391 int mConnectedApi; 392 393 // mDequeueCondition condition used for dequeueBuffer in synchronous mode 394 mutable Condition mDequeueCondition; 395 396 // mQueue is a FIFO of queued buffers used in synchronous mode 397 typedef Vector<int> Fifo; 398 Fifo mQueue; 399 400 // mAbandoned indicates that the BufferQueue will no longer be used to 401 // consume images buffers pushed to it using the ISurfaceTexture interface. 402 // It is initialized to false, and set to true in the abandon method. A 403 // BufferQueue that has been abandoned will return the NO_INIT error from 404 // all ISurfaceTexture methods capable of returning an error. 405 bool mAbandoned; 406 407 // mName is a string used to identify the BufferQueue in log messages. 408 // It is set by the setName method. 409 String8 mConsumerName; 410 411 // mMutex is the mutex used to prevent concurrent access to the member 412 // variables of BufferQueue objects. It must be locked whenever the 413 // member variables are accessed. 414 mutable Mutex mMutex; 415 416 // mFrameCounter is the free running counter, incremented for every buffer queued 417 // with the surface Texture. 418 uint64_t mFrameCounter; 419 420 bool mBufferHasBeenQueued; 421}; 422 423// ---------------------------------------------------------------------------- 424}; // namespace android 425 426#endif // ANDROID_GUI_BUFFERQUEUE_H 427