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 "DisplaySurface.h"
21#include "HWComposerBufferCache.h"
22
23#include <gui/ConsumerBase.h>
24#include <gui/IGraphicBufferProducer.h>
25
26// ---------------------------------------------------------------------------
27namespace android {
28// ---------------------------------------------------------------------------
29
30class HWComposer;
31class IProducerListener;
32
33/* This DisplaySurface implementation supports virtual displays, where GLES
34 * and/or HWC compose into a buffer that is then passed to an arbitrary
35 * consumer (the sink) running in another process.
36 *
37 * The simplest case is when the virtual display will never use the h/w
38 * composer -- either the h/w composer doesn't support writing to buffers, or
39 * there are more virtual displays than it supports simultaneously. In this
40 * case, the GLES driver works directly with the output buffer queue, and
41 * calls to the VirtualDisplay from SurfaceFlinger and DisplayHardware do
42 * nothing.
43 *
44 * If h/w composer might be used, then each frame will fall into one of three
45 * configurations: GLES-only, HWC-only, and MIXED composition. In all of these,
46 * we must provide a FB target buffer and output buffer for the HWC set() call.
47 *
48 * In GLES-only composition, the GLES driver is given a buffer from the sink to
49 * render into. When the GLES driver queues the buffer to the
50 * VirtualDisplaySurface, the VirtualDisplaySurface holds onto it instead of
51 * immediately queueing it to the sink. The buffer is used as both the FB
52 * target and output buffer for HWC, though on these frames the HWC doesn't
53 * do any work for this display and doesn't write to the output buffer. After
54 * composition is complete, the buffer is queued to the sink.
55 *
56 * In HWC-only composition, the VirtualDisplaySurface dequeues a buffer from
57 * the sink and passes it to HWC as both the FB target buffer and output
58 * buffer. The HWC doesn't need to read from the FB target buffer, but does
59 * write to the output buffer. After composition is complete, the buffer is
60 * queued to the sink.
61 *
62 * On MIXED frames, things become more complicated, since some h/w composer
63 * implementations can't read from and write to the same buffer. This class has
64 * an internal BufferQueue that it uses as a scratch buffer pool. The GLES
65 * driver is given a scratch buffer to render into. When it finishes rendering,
66 * the buffer is queued and then immediately acquired by the
67 * VirtualDisplaySurface. The scratch buffer is then used as the FB target
68 * buffer for HWC, and a separate buffer is dequeued from the sink and used as
69 * the HWC output buffer. When HWC composition is complete, the scratch buffer
70 * is released and the output buffer is queued to the sink.
71 */
72class VirtualDisplaySurface : public DisplaySurface,
73                              public BnGraphicBufferProducer,
74                              private ConsumerBase {
75public:
76    VirtualDisplaySurface(HWComposer& hwc, int32_t dispId,
77            const sp<IGraphicBufferProducer>& sink,
78            const sp<IGraphicBufferProducer>& bqProducer,
79            const sp<IGraphicBufferConsumer>& bqConsumer,
80            const String8& name);
81
82    //
83    // DisplaySurface interface
84    //
85    virtual status_t beginFrame(bool mustRecompose);
86    virtual status_t prepareFrame(CompositionType compositionType);
87#ifndef USE_HWC2
88    virtual status_t compositionComplete();
89#endif
90    virtual status_t advanceFrame();
91    virtual void onFrameCommitted();
92    virtual void dumpAsString(String8& result) const;
93    virtual void resizeBuffers(const uint32_t w, const uint32_t h);
94    virtual const sp<Fence>& getClientTargetAcquireFence() const override;
95
96private:
97    enum Source {SOURCE_SINK = 0, SOURCE_SCRATCH = 1};
98
99    virtual ~VirtualDisplaySurface();
100
101    //
102    // IGraphicBufferProducer interface, used by the GLES driver.
103    //
104    virtual status_t requestBuffer(int pslot, sp<GraphicBuffer>* outBuf);
105    virtual status_t setMaxDequeuedBufferCount(int maxDequeuedBuffers);
106    virtual status_t setAsyncMode(bool async);
107    virtual status_t dequeueBuffer(int* pslot, sp<Fence>* fence, uint32_t w,
108            uint32_t h, PixelFormat format, uint32_t usage,
109            FrameEventHistoryDelta *outTimestamps);
110    virtual status_t detachBuffer(int slot);
111    virtual status_t detachNextBuffer(sp<GraphicBuffer>* outBuffer,
112            sp<Fence>* outFence);
113    virtual status_t attachBuffer(int* slot, const sp<GraphicBuffer>& buffer);
114    virtual status_t queueBuffer(int pslot,
115            const QueueBufferInput& input, QueueBufferOutput* output);
116    virtual status_t cancelBuffer(int pslot, const sp<Fence>& fence);
117    virtual int query(int what, int* value);
118    virtual status_t connect(const sp<IProducerListener>& listener,
119            int api, bool producerControlledByApp, QueueBufferOutput* output);
120    virtual status_t disconnect(int api, DisconnectMode mode);
121    virtual status_t setSidebandStream(const sp<NativeHandle>& stream);
122    virtual void allocateBuffers(uint32_t width, uint32_t height,
123            PixelFormat format, uint32_t usage);
124    virtual status_t allowAllocation(bool allow);
125    virtual status_t setGenerationNumber(uint32_t generationNumber);
126    virtual String8 getConsumerName() const override;
127    virtual status_t setSharedBufferMode(bool sharedBufferMode) override;
128    virtual status_t setAutoRefresh(bool autoRefresh) override;
129    virtual status_t setDequeueTimeout(nsecs_t timeout) override;
130    virtual status_t getLastQueuedBuffer(sp<GraphicBuffer>* outBuffer,
131            sp<Fence>* outFence, float outTransformMatrix[16]) override;
132    virtual status_t getUniqueId(uint64_t* outId) const override;
133
134    //
135    // Utility methods
136    //
137    static Source fbSourceForCompositionType(CompositionType type);
138    status_t dequeueBuffer(Source source, PixelFormat format, uint32_t usage,
139            int* sslot, sp<Fence>* fence);
140    void updateQueueBufferOutput(QueueBufferOutput&& qbo);
141    void resetPerFrameState();
142    status_t refreshOutputBuffer();
143
144    // Both the sink and scratch buffer pools have their own set of slots
145    // ("source slots", or "sslot"). We have to merge these into the single
146    // set of slots used by the GLES producer ("producer slots" or "pslot") and
147    // internally in the VirtualDisplaySurface. To minimize the number of times
148    // a producer slot switches which source it comes from, we map source slot
149    // numbers to producer slot numbers differently for each source.
150    static int mapSource2ProducerSlot(Source source, int sslot);
151    static int mapProducer2SourceSlot(Source source, int pslot);
152
153    //
154    // Immutable after construction
155    //
156    HWComposer& mHwc;
157    const int32_t mDisplayId;
158    const String8 mDisplayName;
159    sp<IGraphicBufferProducer> mSource[2]; // indexed by SOURCE_*
160    uint32_t mDefaultOutputFormat;
161
162    //
163    // Inter-frame state
164    //
165
166    // To avoid buffer reallocations, we track the buffer usage and format
167    // we used on the previous frame and use it again on the new frame. If
168    // the composition type changes or the GLES driver starts requesting
169    // different usage/format, we'll get a new buffer.
170    uint32_t mOutputFormat;
171    uint32_t mOutputUsage;
172
173    // Since we present a single producer interface to the GLES driver, but
174    // are internally muxing between the sink and scratch producers, we have
175    // to keep track of which source last returned each producer slot from
176    // dequeueBuffer. Each bit in mProducerSlotSource corresponds to a producer
177    // slot. Both mProducerSlotSource and mProducerBuffers are indexed by a
178    // "producer slot"; see the mapSlot*() functions.
179    uint64_t mProducerSlotSource;
180    sp<GraphicBuffer> mProducerBuffers[BufferQueueDefs::NUM_BUFFER_SLOTS];
181
182    // The QueueBufferOutput with the latest info from the sink, and with the
183    // transform hint cleared. Since we defer queueBuffer from the GLES driver
184    // to the sink, we have to return the previous version.
185    // Moves instead of copies are performed to avoid duplicate
186    // FrameEventHistoryDeltas.
187    QueueBufferOutput mQueueBufferOutput;
188
189    // Details of the current sink buffer. These become valid when a buffer is
190    // dequeued from the sink, and are used when queueing the buffer.
191    uint32_t mSinkBufferWidth, mSinkBufferHeight;
192
193    //
194    // Intra-frame state
195    //
196
197    // Composition type and GLES buffer source for the current frame.
198    // Valid after prepareFrame(), cleared in onFrameCommitted.
199    CompositionType mCompositionType;
200
201    // mFbFence is the fence HWC should wait for before reading the framebuffer
202    // target buffer.
203    sp<Fence> mFbFence;
204
205    // mOutputFence is the fence HWC should wait for before writing to the
206    // output buffer.
207    sp<Fence> mOutputFence;
208
209    // Producer slot numbers for the buffers to use for HWC framebuffer target
210    // and output.
211    int mFbProducerSlot;
212    int mOutputProducerSlot;
213
214    // Debug only -- track the sequence of events in each frame so we can make
215    // sure they happen in the order we expect. This class implicitly models
216    // a state machine; this enum/variable makes it explicit.
217    //
218    // +-----------+-------------------+-------------+
219    // | State     | Event             || Next State |
220    // +-----------+-------------------+-------------+
221    // | IDLE      | beginFrame        || BEGUN      |
222    // | BEGUN     | prepareFrame      || PREPARED   |
223    // | PREPARED  | dequeueBuffer [1] || GLES       |
224    // | PREPARED  | advanceFrame [2]  || HWC        |
225    // | GLES      | queueBuffer       || GLES_DONE  |
226    // | GLES_DONE | advanceFrame      || HWC        |
227    // | HWC       | onFrameCommitted  || IDLE       |
228    // +-----------+-------------------++------------+
229    // [1] COMPOSITION_GLES and COMPOSITION_MIXED frames.
230    // [2] COMPOSITION_HWC frames.
231    //
232    enum DbgState {
233        // no buffer dequeued, don't know anything about the next frame
234        DBG_STATE_IDLE,
235        // output buffer dequeued, framebuffer source not yet known
236        DBG_STATE_BEGUN,
237        // output buffer dequeued, framebuffer source known but not provided
238        // to GLES yet.
239        DBG_STATE_PREPARED,
240        // GLES driver has a buffer dequeued
241        DBG_STATE_GLES,
242        // GLES driver has queued the buffer, we haven't sent it to HWC yet
243        DBG_STATE_GLES_DONE,
244        // HWC has the buffer for this frame
245        DBG_STATE_HWC,
246    };
247    DbgState mDbgState;
248    CompositionType mDbgLastCompositionType;
249
250    const char* dbgStateStr() const;
251    static const char* dbgSourceStr(Source s);
252
253    bool mMustRecompose;
254
255#ifdef USE_HWC2
256    HWComposerBufferCache mHwcBufferCache;
257#endif
258
259
260    bool mForceHwcCopy;
261};
262
263// ---------------------------------------------------------------------------
264} // namespace android
265// ---------------------------------------------------------------------------
266
267#endif // ANDROID_SF_VIRTUAL_DISPLAY_SURFACE_H
268