SurfaceFlingerConsumer.cpp revision 399184a4cd728ea1421fb0bc1722274a29e38f4a 
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#define ATRACE_TAG ATRACE_TAG_GRAPHICS
18//#define LOG_NDEBUG 0
19
20#include "SurfaceFlingerConsumer.h"
21
22#include <private/gui/SyncFeatures.h>
23
24#include <utils/Errors.h>
25#include <utils/NativeHandle.h>
26#include <utils/Trace.h>
27
28namespace android {
29
30// ---------------------------------------------------------------------------
31
32status_t SurfaceFlingerConsumer::updateTexImage(BufferRejecter* rejecter)
33{
34    ATRACE_CALL();
35    ALOGV("updateTexImage");
36    Mutex::Autolock lock(mMutex);
37
38    if (mAbandoned) {
39        ALOGE("updateTexImage: GLConsumer is abandoned!");
40        return NO_INIT;
41    }
42
43    // Make sure the EGL state is the same as in previous calls.
44    status_t err = checkAndUpdateEglStateLocked();
45    if (err != NO_ERROR) {
46        return err;
47    }
48
49    BufferQueue::BufferItem item;
50
51    // Acquire the next buffer.
52    // In asynchronous mode the list is guaranteed to be one buffer
53    // deep, while in synchronous mode we use the oldest buffer.
54    err = acquireBufferLocked(&item, computeExpectedPresent());
55    if (err != NO_ERROR) {
56        if (err == BufferQueue::NO_BUFFER_AVAILABLE) {
57            err = NO_ERROR;
58        } else if (err == BufferQueue::PRESENT_LATER) {
59            // return the error, without logging
60        } else {
61            ALOGE("updateTexImage: acquire failed: %s (%d)",
62                strerror(-err), err);
63        }
64        return err;
65    }
66
67
68    // We call the rejecter here, in case the caller has a reason to
69    // not accept this buffer.  This is used by SurfaceFlinger to
70    // reject buffers which have the wrong size
71    int buf = item.mBuf;
72    if (rejecter && rejecter->reject(mSlots[buf].mGraphicBuffer, item)) {
73        releaseBufferLocked(buf, mSlots[buf].mGraphicBuffer, EGL_NO_SYNC_KHR);
74        return NO_ERROR;
75    }
76
77    // Release the previous buffer.
78    err = updateAndReleaseLocked(item);
79    if (err != NO_ERROR) {
80        return err;
81    }
82
83    if (!SyncFeatures::getInstance().useNativeFenceSync()) {
84        // Bind the new buffer to the GL texture.
85        //
86        // Older devices require the "implicit" synchronization provided
87        // by glEGLImageTargetTexture2DOES, which this method calls.  Newer
88        // devices will either call this in Layer::onDraw, or (if it's not
89        // a GL-composited layer) not at all.
90        err = bindTextureImageLocked();
91    }
92
93    return err;
94}
95
96status_t SurfaceFlingerConsumer::bindTextureImage()
97{
98    Mutex::Autolock lock(mMutex);
99
100    return bindTextureImageLocked();
101}
102
103status_t SurfaceFlingerConsumer::acquireBufferLocked(
104        BufferQueue::BufferItem *item, nsecs_t presentWhen) {
105    status_t result = GLConsumer::acquireBufferLocked(item, presentWhen);
106    if (result == NO_ERROR) {
107        mTransformToDisplayInverse = item->mTransformToDisplayInverse;
108    }
109    return result;
110}
111
112bool SurfaceFlingerConsumer::getTransformToDisplayInverse() const {
113    return mTransformToDisplayInverse;
114}
115
116sp<NativeHandle> SurfaceFlingerConsumer::getSidebandStream() const {
117    return mConsumer->getSidebandStream();
118}
119
120// We need to determine the time when a buffer acquired now will be
121// displayed.  This can be calculated:
122//   time when previous buffer's actual-present fence was signaled
123//    + current display refresh rate * HWC latency
124//    + a little extra padding
125//
126// Buffer producers are expected to set their desired presentation time
127// based on choreographer time stamps, which (coming from vsync events)
128// will be slightly later then the actual-present timing.  If we get a
129// desired-present time that is unintentionally a hair after the next
130// vsync, we'll hold the frame when we really want to display it.  We
131// want to use an expected-presentation time that is slightly late to
132// avoid this sort of edge case.
133nsecs_t SurfaceFlingerConsumer::computeExpectedPresent()
134{
135    // Don't yet have an easy way to get actual buffer flip time for
136    // the specific display, so use the current time.  This is typically
137    // 1.3ms past the vsync event time.
138    const nsecs_t prevVsync = systemTime(CLOCK_MONOTONIC);
139
140    // Given a SurfaceFlinger reference, and information about what display
141    // we're destined for, we could query the HWC for the refresh rate.  This
142    // could change over time, e.g. we could switch to 24fps for a movie.
143    // For now, assume 60fps.
144    //const nsecs_t vsyncPeriod =
145    //        getHwComposer().getRefreshPeriod(HWC_DISPLAY_PRIMARY);
146    const nsecs_t vsyncPeriod = 16700000;
147
148    // The HWC doesn't currently have a way to report additional latency.
149    // Assume that whatever we submit now will appear on the next flip,
150    // i.e. 1 frame of latency w.r.t. the previous flip.
151    const uint32_t hwcLatency = 1;
152
153    // A little extra padding to compensate for slack between actual vsync
154    // time and vsync event receipt.  Currently not needed since we're
155    // using "now" instead of a vsync time.
156    const nsecs_t extraPadding = 0;
157
158    // Total it up.
159    return prevVsync + hwcLatency * vsyncPeriod + extraPadding;
160}
161
162void SurfaceFlingerConsumer::setContentsChangedListener(
163        const wp<ContentsChangedListener>& listener) {
164    setFrameAvailableListener(listener);
165    Mutex::Autolock lock(mMutex);
166    mContentsChangedListener = listener;
167}
168
169void SurfaceFlingerConsumer::onSidebandStreamChanged() {
170    sp<ContentsChangedListener> listener;
171    {   // scope for the lock
172        Mutex::Autolock lock(mMutex);
173        ALOG_ASSERT(mFrameAvailableListener.unsafe_get() == mContentsChangedListener.unsafe_get());
174        listener = mContentsChangedListener.promote();
175    }
176
177    if (listener != NULL) {
178        listener->onSidebandStreamChanged();
179    }
180}
181
182// ---------------------------------------------------------------------------
183}; // namespace android
184
185