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 // --------------------------------------------------------------------------- 26 namespace android { 27 // --------------------------------------------------------------------------- 28 29 class HWComposer; 30 class 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 */ 71 class VirtualDisplaySurface : public DisplaySurface, 72 public BnGraphicBufferProducer, 73 private ConsumerBase { 74 public: 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 dump(String8& result) const; 90 virtual void resizeBuffers(const uint32_t w, const uint32_t h); 91 92 private: 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 setBufferCount(int bufferCount); 102 virtual status_t dequeueBuffer(int* pslot, sp<Fence>* fence, bool async, 103 uint32_t w, uint32_t h, uint32_t format, uint32_t usage); 104 virtual status_t detachBuffer(int slot); 105 virtual status_t detachNextBuffer(sp<GraphicBuffer>* outBuffer, 106 sp<Fence>* outFence); 107 virtual status_t attachBuffer(int* slot, const sp<GraphicBuffer>& buffer); 108 virtual status_t queueBuffer(int pslot, 109 const QueueBufferInput& input, QueueBufferOutput* output); 110 virtual void cancelBuffer(int pslot, const sp<Fence>& fence); 111 virtual int query(int what, int* value); 112 virtual status_t connect(const sp<IProducerListener>& listener, 113 int api, bool producerControlledByApp, QueueBufferOutput* output); 114 virtual status_t disconnect(int api); 115 virtual status_t setSidebandStream(const sp<NativeHandle>& stream); 116 virtual void allocateBuffers(bool async, uint32_t width, uint32_t height, 117 uint32_t format, uint32_t usage); 118 119 // 120 // Utility methods 121 // 122 static Source fbSourceForCompositionType(CompositionType type); 123 status_t dequeueBuffer(Source source, uint32_t format, uint32_t usage, 124 int* sslot, sp<Fence>* fence); 125 void updateQueueBufferOutput(const QueueBufferOutput& qbo); 126 void resetPerFrameState(); 127 status_t refreshOutputBuffer(); 128 129 // Both the sink and scratch buffer pools have their own set of slots 130 // ("source slots", or "sslot"). We have to merge these into the single 131 // set of slots used by the GLES producer ("producer slots" or "pslot") and 132 // internally in the VirtualDisplaySurface. To minimize the number of times 133 // a producer slot switches which source it comes from, we map source slot 134 // numbers to producer slot numbers differently for each source. 135 static int mapSource2ProducerSlot(Source source, int sslot); 136 static int mapProducer2SourceSlot(Source source, int pslot); 137 138 // 139 // Immutable after construction 140 // 141 HWComposer& mHwc; 142 const int32_t mDisplayId; 143 const String8 mDisplayName; 144 sp<IGraphicBufferProducer> mSource[2]; // indexed by SOURCE_* 145 uint32_t mDefaultOutputFormat; 146 147 // 148 // Inter-frame state 149 // 150 151 // To avoid buffer reallocations, we track the buffer usage and format 152 // we used on the previous frame and use it again on the new frame. If 153 // the composition type changes or the GLES driver starts requesting 154 // different usage/format, we'll get a new buffer. 155 uint32_t mOutputFormat; 156 uint32_t mOutputUsage; 157 158 // Since we present a single producer interface to the GLES driver, but 159 // are internally muxing between the sink and scratch producers, we have 160 // to keep track of which source last returned each producer slot from 161 // dequeueBuffer. Each bit in mProducerSlotSource corresponds to a producer 162 // slot. Both mProducerSlotSource and mProducerBuffers are indexed by a 163 // "producer slot"; see the mapSlot*() functions. 164 uint64_t mProducerSlotSource; 165 sp<GraphicBuffer> mProducerBuffers[BufferQueue::NUM_BUFFER_SLOTS]; 166 167 // The QueueBufferOutput with the latest info from the sink, and with the 168 // transform hint cleared. Since we defer queueBuffer from the GLES driver 169 // to the sink, we have to return the previous version. 170 QueueBufferOutput mQueueBufferOutput; 171 172 // Details of the current sink buffer. These become valid when a buffer is 173 // dequeued from the sink, and are used when queueing the buffer. 174 uint32_t mSinkBufferWidth, mSinkBufferHeight; 175 176 // 177 // Intra-frame state 178 // 179 180 // Composition type and GLES buffer source for the current frame. 181 // Valid after prepareFrame(), cleared in onFrameCommitted. 182 CompositionType mCompositionType; 183 184 // mFbFence is the fence HWC should wait for before reading the framebuffer 185 // target buffer. 186 sp<Fence> mFbFence; 187 188 // mOutputFence is the fence HWC should wait for before writing to the 189 // output buffer. 190 sp<Fence> mOutputFence; 191 192 // Producer slot numbers for the buffers to use for HWC framebuffer target 193 // and output. 194 int mFbProducerSlot; 195 int mOutputProducerSlot; 196 197 // Debug only -- track the sequence of events in each frame so we can make 198 // sure they happen in the order we expect. This class implicitly models 199 // a state machine; this enum/variable makes it explicit. 200 // 201 // +-----------+-------------------+-------------+ 202 // | State | Event || Next State | 203 // +-----------+-------------------+-------------+ 204 // | IDLE | beginFrame || BEGUN | 205 // | BEGUN | prepareFrame || PREPARED | 206 // | PREPARED | dequeueBuffer [1] || GLES | 207 // | PREPARED | advanceFrame [2] || HWC | 208 // | GLES | queueBuffer || GLES_DONE | 209 // | GLES_DONE | advanceFrame || HWC | 210 // | HWC | onFrameCommitted || IDLE | 211 // +-----------+-------------------++------------+ 212 // [1] COMPOSITION_GLES and COMPOSITION_MIXED frames. 213 // [2] COMPOSITION_HWC frames. 214 // 215 enum DbgState { 216 // no buffer dequeued, don't know anything about the next frame 217 DBG_STATE_IDLE, 218 // output buffer dequeued, framebuffer source not yet known 219 DBG_STATE_BEGUN, 220 // output buffer dequeued, framebuffer source known but not provided 221 // to GLES yet. 222 DBG_STATE_PREPARED, 223 // GLES driver has a buffer dequeued 224 DBG_STATE_GLES, 225 // GLES driver has queued the buffer, we haven't sent it to HWC yet 226 DBG_STATE_GLES_DONE, 227 // HWC has the buffer for this frame 228 DBG_STATE_HWC, 229 }; 230 DbgState mDbgState; 231 CompositionType mDbgLastCompositionType; 232 233 const char* dbgStateStr() const; 234 static const char* dbgSourceStr(Source s); 235 236 bool mMustRecompose; 237 }; 238 239 // --------------------------------------------------------------------------- 240 } // namespace android 241 // --------------------------------------------------------------------------- 242 243 #endif // ANDROID_SF_VIRTUAL_DISPLAY_SURFACE_H 244 245
