VirtualDisplaySurface.h revision 7dde599bf1a0dbef7390d91c2689d506371cdbd7
1/* 2 * Copyright 2013 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_SF_VIRTUAL_DISPLAY_SURFACE_H 18#define ANDROID_SF_VIRTUAL_DISPLAY_SURFACE_H 19 20#include <gui/ConsumerBase.h> 21#include <gui/IGraphicBufferProducer.h> 22 23#include "DisplaySurface.h" 24 25// --------------------------------------------------------------------------- 26namespace android { 27// --------------------------------------------------------------------------- 28 29class HWComposer; 30class IProducerListener; 31 32/* This DisplaySurface implementation supports virtual displays, where GLES 33 * and/or HWC compose into a buffer that is then passed to an arbitrary 34 * consumer (the sink) running in another process. 35 * 36 * The simplest case is when the virtual display will never use the h/w 37 * composer -- either the h/w composer doesn't support writing to buffers, or 38 * there are more virtual displays than it supports simultaneously. In this 39 * case, the GLES driver works directly with the output buffer queue, and 40 * calls to the VirtualDisplay from SurfaceFlinger and DisplayHardware do 41 * nothing. 42 * 43 * If h/w composer might be used, then each frame will fall into one of three 44 * configurations: GLES-only, HWC-only, and MIXED composition. In all of these, 45 * we must provide a FB target buffer and output buffer for the HWC set() call. 46 * 47 * In GLES-only composition, the GLES driver is given a buffer from the sink to 48 * render into. When the GLES driver queues the buffer to the 49 * VirtualDisplaySurface, the VirtualDisplaySurface holds onto it instead of 50 * immediately queueing it to the sink. The buffer is used as both the FB 51 * target and output buffer for HWC, though on these frames the HWC doesn't 52 * do any work for this display and doesn't write to the output buffer. After 53 * composition is complete, the buffer is queued to the sink. 54 * 55 * In HWC-only composition, the VirtualDisplaySurface dequeues a buffer from 56 * the sink and passes it to HWC as both the FB target buffer and output 57 * buffer. The HWC doesn't need to read from the FB target buffer, but does 58 * write to the output buffer. After composition is complete, the buffer is 59 * queued to the sink. 60 * 61 * On MIXED frames, things become more complicated, since some h/w composer 62 * implementations can't read from and write to the same buffer. This class has 63 * an internal BufferQueue that it uses as a scratch buffer pool. The GLES 64 * driver is given a scratch buffer to render into. When it finishes rendering, 65 * the buffer is queued and then immediately acquired by the 66 * VirtualDisplaySurface. The scratch buffer is then used as the FB target 67 * buffer for HWC, and a separate buffer is dequeued from the sink and used as 68 * the HWC output buffer. When HWC composition is complete, the scratch buffer 69 * is released and the output buffer is queued to the sink. 70 */ 71class VirtualDisplaySurface : public DisplaySurface, 72 public BnGraphicBufferProducer, 73 private ConsumerBase { 74public: 75 VirtualDisplaySurface(HWComposer& hwc, int32_t dispId, 76 const sp<IGraphicBufferProducer>& sink, 77 const sp<IGraphicBufferProducer>& bqProducer, 78 const sp<IGraphicBufferConsumer>& bqConsumer, 79 const String8& name); 80 81 // 82 // DisplaySurface interface 83 // 84 virtual status_t beginFrame(bool mustRecompose); 85 virtual status_t prepareFrame(CompositionType compositionType); 86 virtual status_t compositionComplete(); 87 virtual status_t advanceFrame(); 88 virtual void onFrameCommitted(); 89 virtual void dumpAsString(String8& result) const; 90 virtual void resizeBuffers(const uint32_t w, const uint32_t h); 91 92private: 93 enum Source {SOURCE_SINK = 0, SOURCE_SCRATCH = 1}; 94 95 virtual ~VirtualDisplaySurface(); 96 97 // 98 // IGraphicBufferProducer interface, used by the GLES driver. 99 // 100 virtual status_t requestBuffer(int pslot, sp<GraphicBuffer>* outBuf); 101 virtual status_t setMaxDequeuedBufferCount(int maxDequeuedBuffers); 102 virtual status_t setAsyncMode(bool async); 103 virtual status_t dequeueBuffer(int* pslot, sp<Fence>* fence, uint32_t w, 104 uint32_t h, PixelFormat format, uint32_t usage); 105 virtual status_t detachBuffer(int slot); 106 virtual status_t detachNextBuffer(sp<GraphicBuffer>* outBuffer, 107 sp<Fence>* outFence); 108 virtual status_t attachBuffer(int* slot, const sp<GraphicBuffer>& buffer); 109 virtual status_t queueBuffer(int pslot, 110 const QueueBufferInput& input, QueueBufferOutput* output); 111 virtual status_t cancelBuffer(int pslot, const sp<Fence>& fence); 112 virtual int query(int what, int* value); 113 virtual status_t connect(const sp<IProducerListener>& listener, 114 int api, bool producerControlledByApp, QueueBufferOutput* output); 115 virtual status_t disconnect(int api); 116 virtual status_t setSidebandStream(const sp<NativeHandle>& stream); 117 virtual void allocateBuffers(uint32_t width, uint32_t height, 118 PixelFormat format, uint32_t usage); 119 virtual status_t allowAllocation(bool allow); 120 virtual status_t setGenerationNumber(uint32_t generationNumber); 121 virtual String8 getConsumerName() const override; 122 virtual uint64_t getNextFrameNumber() const override; 123 124 // 125 // Utility methods 126 // 127 static Source fbSourceForCompositionType(CompositionType type); 128 status_t dequeueBuffer(Source source, PixelFormat format, uint32_t usage, 129 int* sslot, sp<Fence>* fence); 130 void updateQueueBufferOutput(const QueueBufferOutput& qbo); 131 void resetPerFrameState(); 132 status_t refreshOutputBuffer(); 133 134 // Both the sink and scratch buffer pools have their own set of slots 135 // ("source slots", or "sslot"). We have to merge these into the single 136 // set of slots used by the GLES producer ("producer slots" or "pslot") and 137 // internally in the VirtualDisplaySurface. To minimize the number of times 138 // a producer slot switches which source it comes from, we map source slot 139 // numbers to producer slot numbers differently for each source. 140 static int mapSource2ProducerSlot(Source source, int sslot); 141 static int mapProducer2SourceSlot(Source source, int pslot); 142 143 // 144 // Immutable after construction 145 // 146 HWComposer& mHwc; 147 const int32_t mDisplayId; 148 const String8 mDisplayName; 149 sp<IGraphicBufferProducer> mSource[2]; // indexed by SOURCE_* 150 uint32_t mDefaultOutputFormat; 151 152 // 153 // Inter-frame state 154 // 155 156 // To avoid buffer reallocations, we track the buffer usage and format 157 // we used on the previous frame and use it again on the new frame. If 158 // the composition type changes or the GLES driver starts requesting 159 // different usage/format, we'll get a new buffer. 160 uint32_t mOutputFormat; 161 uint32_t mOutputUsage; 162 163 // Since we present a single producer interface to the GLES driver, but 164 // are internally muxing between the sink and scratch producers, we have 165 // to keep track of which source last returned each producer slot from 166 // dequeueBuffer. Each bit in mProducerSlotSource corresponds to a producer 167 // slot. Both mProducerSlotSource and mProducerBuffers are indexed by a 168 // "producer slot"; see the mapSlot*() functions. 169 uint64_t mProducerSlotSource; 170 sp<GraphicBuffer> mProducerBuffers[BufferQueue::NUM_BUFFER_SLOTS]; 171 172 // The QueueBufferOutput with the latest info from the sink, and with the 173 // transform hint cleared. Since we defer queueBuffer from the GLES driver 174 // to the sink, we have to return the previous version. 175 QueueBufferOutput mQueueBufferOutput; 176 177 // Details of the current sink buffer. These become valid when a buffer is 178 // dequeued from the sink, and are used when queueing the buffer. 179 uint32_t mSinkBufferWidth, mSinkBufferHeight; 180 181 // 182 // Intra-frame state 183 // 184 185 // Composition type and GLES buffer source for the current frame. 186 // Valid after prepareFrame(), cleared in onFrameCommitted. 187 CompositionType mCompositionType; 188 189 // mFbFence is the fence HWC should wait for before reading the framebuffer 190 // target buffer. 191 sp<Fence> mFbFence; 192 193 // mOutputFence is the fence HWC should wait for before writing to the 194 // output buffer. 195 sp<Fence> mOutputFence; 196 197 // Producer slot numbers for the buffers to use for HWC framebuffer target 198 // and output. 199 int mFbProducerSlot; 200 int mOutputProducerSlot; 201 202 // Debug only -- track the sequence of events in each frame so we can make 203 // sure they happen in the order we expect. This class implicitly models 204 // a state machine; this enum/variable makes it explicit. 205 // 206 // +-----------+-------------------+-------------+ 207 // | State | Event || Next State | 208 // +-----------+-------------------+-------------+ 209 // | IDLE | beginFrame || BEGUN | 210 // | BEGUN | prepareFrame || PREPARED | 211 // | PREPARED | dequeueBuffer [1] || GLES | 212 // | PREPARED | advanceFrame [2] || HWC | 213 // | GLES | queueBuffer || GLES_DONE | 214 // | GLES_DONE | advanceFrame || HWC | 215 // | HWC | onFrameCommitted || IDLE | 216 // +-----------+-------------------++------------+ 217 // [1] COMPOSITION_GLES and COMPOSITION_MIXED frames. 218 // [2] COMPOSITION_HWC frames. 219 // 220 enum DbgState { 221 // no buffer dequeued, don't know anything about the next frame 222 DBG_STATE_IDLE, 223 // output buffer dequeued, framebuffer source not yet known 224 DBG_STATE_BEGUN, 225 // output buffer dequeued, framebuffer source known but not provided 226 // to GLES yet. 227 DBG_STATE_PREPARED, 228 // GLES driver has a buffer dequeued 229 DBG_STATE_GLES, 230 // GLES driver has queued the buffer, we haven't sent it to HWC yet 231 DBG_STATE_GLES_DONE, 232 // HWC has the buffer for this frame 233 DBG_STATE_HWC, 234 }; 235 DbgState mDbgState; 236 CompositionType mDbgLastCompositionType; 237 238 const char* dbgStateStr() const; 239 static const char* dbgSourceStr(Source s); 240 241 bool mMustRecompose; 242}; 243 244// --------------------------------------------------------------------------- 245} // namespace android 246// --------------------------------------------------------------------------- 247 248#endif // ANDROID_SF_VIRTUAL_DISPLAY_SURFACE_H 249 250