CanvasContext.cpp revision ac02eb9035a13a3d09c2def9ed63d04225eb2509
1/*
2 * Copyright (C) 2014 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#include "CanvasContext.h"
18
19#include "AnimationContext.h"
20#include "Caches.h"
21#include "DeferredLayerUpdater.h"
22#include "EglManager.h"
23#include "LayerRenderer.h"
24#include "OpenGLRenderer.h"
25#include "Properties.h"
26#include "RenderThread.h"
27#include "renderstate/RenderState.h"
28#include "renderstate/Stencil.h"
29#include "protos/hwui.pb.h"
30
31#include <cutils/properties.h>
32#include <google/protobuf/io/zero_copy_stream_impl.h>
33#include <private/hwui/DrawGlInfo.h>
34#include <strings.h>
35
36#include <algorithm>
37#include <fcntl.h>
38#include <sys/stat.h>
39
40#define TRIM_MEMORY_COMPLETE 80
41#define TRIM_MEMORY_UI_HIDDEN 20
42
43#define ENABLE_RENDERNODE_SERIALIZATION false
44
45#define LOG_FRAMETIME_MMA 0
46
47#if LOG_FRAMETIME_MMA
48static float sBenchMma = 0;
49static int sFrameCount = 0;
50static const float NANOS_PER_MILLIS_F = 1000000.0f;
51#endif
52
53namespace android {
54namespace uirenderer {
55namespace renderthread {
56
57CanvasContext::CanvasContext(RenderThread& thread, bool translucent,
58        RenderNode* rootRenderNode, IContextFactory* contextFactory)
59        : mRenderThread(thread)
60        , mEglManager(thread.eglManager())
61        , mOpaque(!translucent)
62        , mAnimationContext(contextFactory->createAnimationContext(mRenderThread.timeLord()))
63        , mJankTracker(thread.timeLord().frameIntervalNanos())
64        , mProfiler(mFrames)
65        , mContentDrawBounds(0, 0, 0, 0) {
66    mRenderNodes.emplace_back(rootRenderNode);
67    mRenderThread.renderState().registerCanvasContext(this);
68    mProfiler.setDensity(mRenderThread.mainDisplayInfo().density);
69}
70
71CanvasContext::~CanvasContext() {
72    destroy();
73    mRenderThread.renderState().unregisterCanvasContext(this);
74}
75
76void CanvasContext::destroy() {
77    stopDrawing();
78    setSurface(nullptr);
79    freePrefetechedLayers();
80    destroyHardwareResources();
81    mAnimationContext->destroy();
82    if (mCanvas) {
83        delete mCanvas;
84        mCanvas = nullptr;
85    }
86}
87
88void CanvasContext::setSurface(ANativeWindow* window) {
89    ATRACE_CALL();
90
91    mNativeWindow = window;
92
93    if (mEglSurface != EGL_NO_SURFACE) {
94        mEglManager.destroySurface(mEglSurface);
95        mEglSurface = EGL_NO_SURFACE;
96    }
97
98    if (window) {
99        mEglSurface = mEglManager.createSurface(window);
100    }
101
102    if (mEglSurface != EGL_NO_SURFACE) {
103        const bool preserveBuffer = (mSwapBehavior != kSwap_discardBuffer);
104        mBufferPreserved = mEglManager.setPreserveBuffer(mEglSurface, preserveBuffer);
105        mHaveNewSurface = true;
106        makeCurrent();
107    } else {
108        mRenderThread.removeFrameCallback(this);
109    }
110}
111
112void CanvasContext::requireSurface() {
113    LOG_ALWAYS_FATAL_IF(mEglSurface == EGL_NO_SURFACE,
114            "requireSurface() called but no surface set!");
115    makeCurrent();
116}
117
118void CanvasContext::setSwapBehavior(SwapBehavior swapBehavior) {
119    mSwapBehavior = swapBehavior;
120}
121
122bool CanvasContext::initialize(ANativeWindow* window) {
123    setSurface(window);
124    if (mCanvas) return false;
125    mCanvas = new OpenGLRenderer(mRenderThread.renderState());
126    mCanvas->initProperties();
127    return true;
128}
129
130void CanvasContext::updateSurface(ANativeWindow* window) {
131    setSurface(window);
132}
133
134bool CanvasContext::pauseSurface(ANativeWindow* window) {
135    return mRenderThread.removeFrameCallback(this);
136}
137
138// TODO: don't pass viewport size, it's automatic via EGL
139void CanvasContext::setup(int width, int height, float lightRadius,
140        uint8_t ambientShadowAlpha, uint8_t spotShadowAlpha) {
141    if (!mCanvas) return;
142    mCanvas->initLight(lightRadius, ambientShadowAlpha, spotShadowAlpha);
143}
144
145void CanvasContext::setLightCenter(const Vector3& lightCenter) {
146    if (!mCanvas) return;
147    mCanvas->setLightCenter(lightCenter);
148}
149
150void CanvasContext::setOpaque(bool opaque) {
151    mOpaque = opaque;
152}
153
154void CanvasContext::makeCurrent() {
155    // TODO: Figure out why this workaround is needed, see b/13913604
156    // In the meantime this matches the behavior of GLRenderer, so it is not a regression
157    EGLint error = 0;
158    mHaveNewSurface |= mEglManager.makeCurrent(mEglSurface, &error);
159    if (error) {
160        setSurface(nullptr);
161    }
162}
163
164void CanvasContext::processLayerUpdate(DeferredLayerUpdater* layerUpdater) {
165    bool success = layerUpdater->apply();
166    LOG_ALWAYS_FATAL_IF(!success, "Failed to update layer!");
167    if (layerUpdater->backingLayer()->deferredUpdateScheduled) {
168        mCanvas->pushLayerUpdate(layerUpdater->backingLayer());
169    }
170}
171
172static bool wasSkipped(FrameInfo* info) {
173    return info && ((*info)[FrameInfoIndex::Flags] & FrameInfoFlags::SkippedFrame);
174}
175
176void CanvasContext::prepareTree(TreeInfo& info, int64_t* uiFrameInfo,
177        int64_t syncQueued, RenderNode* target) {
178    mRenderThread.removeFrameCallback(this);
179
180    // If the previous frame was dropped we don't need to hold onto it, so
181    // just keep using the previous frame's structure instead
182    if (!wasSkipped(mCurrentFrameInfo)) {
183        mCurrentFrameInfo = &mFrames.next();
184    }
185    mCurrentFrameInfo->importUiThreadInfo(uiFrameInfo);
186    mCurrentFrameInfo->set(FrameInfoIndex::SyncQueued) = syncQueued;
187    mCurrentFrameInfo->markSyncStart();
188
189    info.damageAccumulator = &mDamageAccumulator;
190    info.renderer = mCanvas;
191    info.canvasContext = this;
192
193    mAnimationContext->startFrame(info.mode);
194    for (const sp<RenderNode>& node : mRenderNodes) {
195        // Only the primary target node will be drawn full - all other nodes would get drawn in
196        // real time mode. In case of a window, the primary node is the window content and the other
197        // node(s) are non client / filler nodes.
198        info.mode = (node.get() == target ? TreeInfo::MODE_FULL : TreeInfo::MODE_RT_ONLY);
199        node->prepareTree(info);
200    }
201    mAnimationContext->runRemainingAnimations(info);
202
203    freePrefetechedLayers();
204
205    if (CC_UNLIKELY(!mNativeWindow.get())) {
206        mCurrentFrameInfo->addFlag(FrameInfoFlags::SkippedFrame);
207        info.out.canDrawThisFrame = false;
208        return;
209    }
210
211    int runningBehind = 0;
212    // TODO: This query is moderately expensive, investigate adding some sort
213    // of fast-path based off when we last called eglSwapBuffers() as well as
214    // last vsync time. Or something.
215    mNativeWindow->query(mNativeWindow.get(),
216            NATIVE_WINDOW_CONSUMER_RUNNING_BEHIND, &runningBehind);
217    info.out.canDrawThisFrame = !runningBehind;
218
219    if (!info.out.canDrawThisFrame) {
220        mCurrentFrameInfo->addFlag(FrameInfoFlags::SkippedFrame);
221    }
222
223    if (info.out.hasAnimations || !info.out.canDrawThisFrame) {
224        if (!info.out.requiresUiRedraw) {
225            // If animationsNeedsRedraw is set don't bother posting for an RT anim
226            // as we will just end up fighting the UI thread.
227            mRenderThread.postFrameCallback(this);
228        }
229    }
230}
231
232void CanvasContext::stopDrawing() {
233    mRenderThread.removeFrameCallback(this);
234}
235
236void CanvasContext::notifyFramePending() {
237    ATRACE_CALL();
238    mRenderThread.pushBackFrameCallback(this);
239}
240
241void CanvasContext::draw() {
242    LOG_ALWAYS_FATAL_IF(!mCanvas || mEglSurface == EGL_NO_SURFACE,
243            "drawRenderNode called on a context with no canvas or surface!");
244
245    SkRect dirty;
246    mDamageAccumulator.finish(&dirty);
247
248    // TODO: Re-enable after figuring out cause of b/22592975
249//    if (dirty.isEmpty() && Properties::skipEmptyFrames) {
250//        mCurrentFrameInfo->addFlag(FrameInfoFlags::SkippedFrame);
251//        return;
252//    }
253
254    mCurrentFrameInfo->markIssueDrawCommandsStart();
255
256    Frame frame = mEglManager.beginFrame(mEglSurface);
257    if (frame.width() != mCanvas->getViewportWidth()
258            || frame.height() != mCanvas->getViewportHeight()) {
259        // can't rely on prior content of window if viewport size changes
260        dirty.setEmpty();
261    } else if (mHaveNewSurface || frame.bufferAge() == 0) {
262        // New surface needs a full draw
263        dirty.setEmpty();
264    } else {
265        if (!dirty.isEmpty() && !dirty.intersect(0, 0, frame.width(), frame.height())) {
266            ALOGW("Dirty " RECT_STRING " doesn't intersect with 0 0 %d %d ?",
267                    SK_RECT_ARGS(dirty), frame.width(), frame.height());
268            dirty.setEmpty();
269        }
270        profiler().unionDirty(&dirty);
271    }
272
273    if (dirty.isEmpty()) {
274        dirty.set(0, 0, frame.width(), frame.height());
275    }
276
277    // At this point dirty is the area of the screen to update. However,
278    // the area of the frame we need to repaint is potentially different, so
279    // stash the screen area for later
280    SkRect screenDirty(dirty);
281
282    // If the buffer age is 0 we do a full-screen repaint (handled above)
283    // If the buffer age is 1 the buffer contents are the same as they were
284    // last frame so there's nothing to union() against
285    // Therefore we only care about the > 1 case.
286    if (frame.bufferAge() > 1) {
287        if (frame.bufferAge() > (int) mDamageHistory.size()) {
288            // We don't have enough history to handle this old of a buffer
289            // Just do a full-draw
290            dirty.set(0, 0, frame.width(), frame.height());
291        } else {
292            // At this point we haven't yet added the latest frame
293            // to the damage history (happens below)
294            // So we need to damage
295            for (int i = mDamageHistory.size() - 1;
296                    i > ((int) mDamageHistory.size()) - frame.bufferAge(); i--) {
297                dirty.join(mDamageHistory[i]);
298            }
299        }
300    }
301
302    // Add the screen damage to the ring buffer.
303    mDamageHistory.next() = screenDirty;
304
305    mEglManager.damageFrame(frame, dirty);
306    mCanvas->prepareDirty(frame.width(), frame.height(),
307            dirty.fLeft, dirty.fTop, dirty.fRight, dirty.fBottom, mOpaque);
308
309    Rect outBounds;
310    // It there are multiple render nodes, they are as follows:
311    // #0 - backdrop
312    // #1 - content (positioned at (0,0) and clipped to - its bounds mContentDrawBounds)
313    // #2 - frame
314    // Usually the backdrop cannot be seen since it will be entirely covered by the content. While
315    // resizing however it might become partially visible. The following render loop will crop the
316    // backdrop against the content and draw the remaining part of it. It will then crop the content
317    // against the backdrop (since that indicates a shrinking of the window) and then the frame
318    // around everything.
319    // The bounds of the backdrop against which the content should be clipped.
320    Rect backdropBounds = mContentDrawBounds;
321    // Usually the contents bounds should be mContentDrawBounds - however - we will
322    // move it towards the fixed edge to give it a more stable appearance (for the moment).
323    Rect contentBounds;
324    // If there is no content bounds we ignore the layering as stated above and start with 2.
325    int layer = (mContentDrawBounds.isEmpty() || mRenderNodes.size() <= 2) ? 2 : 0;
326    // Draw all render nodes. Note that
327    for (const sp<RenderNode>& node : mRenderNodes) {
328        if (layer == 0) { // Backdrop.
329            // Draw the backdrop clipped to the inverse content bounds, but assume that the content
330            // was moved to the upper left corner.
331            const RenderProperties& properties = node->properties();
332            Rect targetBounds(properties.getLeft(), properties.getTop(),
333                              properties.getRight(), properties.getBottom());
334            // Move the content bounds towards the fixed corner of the backdrop.
335            const int x = targetBounds.left;
336            const int y = targetBounds.top;
337            contentBounds.set(x, y, x + mContentDrawBounds.getWidth(),
338                                    y + mContentDrawBounds.getHeight());
339            // Remember the intersection of the target bounds and the intersection bounds against
340            // which we have to crop the content.
341            backdropBounds.set(x, y, x + backdropBounds.getWidth(), y + backdropBounds.getHeight());
342            backdropBounds.doIntersect(targetBounds);
343            // Check if we have to draw something on the left side ...
344            if (targetBounds.left < contentBounds.left) {
345                mCanvas->save(SkCanvas::kClip_SaveFlag);
346                if (mCanvas->clipRect(targetBounds.left, targetBounds.top,
347                                      contentBounds.left, targetBounds.bottom,
348                                      SkRegion::kIntersect_Op)) {
349                    mCanvas->drawRenderNode(node.get(), outBounds);
350                }
351                // Reduce the target area by the area we have just painted.
352                targetBounds.left = std::min(contentBounds.left, targetBounds.right);
353                mCanvas->restore();
354            }
355            // ... or on the right side ...
356            if (targetBounds.right > contentBounds.right &&
357                !targetBounds.isEmpty()) {
358                mCanvas->save(SkCanvas::kClip_SaveFlag);
359                if (mCanvas->clipRect(contentBounds.right, targetBounds.top,
360                                      targetBounds.right, targetBounds.bottom,
361                                      SkRegion::kIntersect_Op)) {
362                    mCanvas->drawRenderNode(node.get(), outBounds);
363                }
364                // Reduce the target area by the area we have just painted.
365                targetBounds.right = std::max(targetBounds.left, contentBounds.right);
366                mCanvas->restore();
367            }
368            // ... or at the top ...
369            if (targetBounds.top < contentBounds.top &&
370                !targetBounds.isEmpty()) {
371                mCanvas->save(SkCanvas::kClip_SaveFlag);
372                if (mCanvas->clipRect(targetBounds.left, targetBounds.top, targetBounds.right,
373                                      contentBounds.top,
374                                      SkRegion::kIntersect_Op)) {
375                    mCanvas->drawRenderNode(node.get(), outBounds);
376                }
377                // Reduce the target area by the area we have just painted.
378                targetBounds.top = std::min(contentBounds.top, targetBounds.bottom);
379                mCanvas->restore();
380            }
381            // ... or at the bottom.
382            if (targetBounds.bottom > contentBounds.bottom &&
383                !targetBounds.isEmpty()) {
384                mCanvas->save(SkCanvas::kClip_SaveFlag);
385                if (mCanvas->clipRect(targetBounds.left, contentBounds.bottom, targetBounds.right,
386                                      targetBounds.bottom, SkRegion::kIntersect_Op)) {
387                    mCanvas->drawRenderNode(node.get(), outBounds);
388                }
389                mCanvas->restore();
390            }
391        } else if (layer == 1) { // Content
392            // It gets cropped against the bounds of the backdrop to stay inside.
393            mCanvas->save(SkCanvas::kClip_SaveFlag | SkCanvas::kMatrix_SaveFlag);
394
395            // We shift and clip the content to match its final location in the window.
396            const float left = mContentDrawBounds.left;
397            const float top = mContentDrawBounds.top;
398            const float dx = backdropBounds.left - left;
399            const float dy = backdropBounds.top - top;
400            const float width = backdropBounds.getWidth();
401            const float height = backdropBounds.getHeight();
402            mCanvas->translate(dx, dy);
403            if (mCanvas->clipRect(left, top, left + width, top + height, SkRegion::kIntersect_Op)) {
404                mCanvas->drawRenderNode(node.get(), outBounds);
405            }
406            mCanvas->restore();
407        } else { // draw the rest on top at will!
408            mCanvas->drawRenderNode(node.get(), outBounds);
409        }
410        layer++;
411    }
412
413    profiler().draw(mCanvas);
414
415    bool drew = mCanvas->finish();
416
417    // Even if we decided to cancel the frame, from the perspective of jank
418    // metrics the frame was swapped at this point
419    mCurrentFrameInfo->markSwapBuffers();
420
421    if (drew) {
422        if (CC_UNLIKELY(!mEglManager.swapBuffers(frame, screenDirty))) {
423            setSurface(nullptr);
424        }
425        mHaveNewSurface = false;
426    }
427
428    // TODO: Use a fence for real completion?
429    mCurrentFrameInfo->markFrameCompleted();
430
431#if LOG_FRAMETIME_MMA
432    float thisFrame = mCurrentFrameInfo->duration(
433            FrameInfoIndex::IssueDrawCommandsStart,
434            FrameInfoIndex::FrameCompleted) / NANOS_PER_MILLIS_F;
435    if (sFrameCount) {
436        sBenchMma = ((9 * sBenchMma) + thisFrame) / 10;
437    } else {
438        sBenchMma = thisFrame;
439    }
440    if (++sFrameCount == 10) {
441        sFrameCount = 1;
442        ALOGD("Average frame time: %.4f", sBenchMma);
443    }
444#endif
445
446    mJankTracker.addFrame(*mCurrentFrameInfo);
447    mRenderThread.jankTracker().addFrame(*mCurrentFrameInfo);
448}
449
450// Called by choreographer to do an RT-driven animation
451void CanvasContext::doFrame() {
452    if (CC_UNLIKELY(!mCanvas || mEglSurface == EGL_NO_SURFACE)) {
453        return;
454    }
455    prepareAndDraw(nullptr);
456}
457
458void CanvasContext::prepareAndDraw(RenderNode* node) {
459    ATRACE_CALL();
460
461    int64_t frameInfo[UI_THREAD_FRAME_INFO_SIZE];
462    UiFrameInfoBuilder(frameInfo)
463        .addFlag(FrameInfoFlags::RTAnimation)
464        .setVsync(mRenderThread.timeLord().computeFrameTimeNanos(),
465                mRenderThread.timeLord().latestVsync());
466
467    TreeInfo info(TreeInfo::MODE_RT_ONLY, mRenderThread.renderState());
468    prepareTree(info, frameInfo, systemTime(CLOCK_MONOTONIC), node);
469    if (info.out.canDrawThisFrame) {
470        draw();
471    }
472}
473
474void CanvasContext::invokeFunctor(RenderThread& thread, Functor* functor) {
475    ATRACE_CALL();
476    DrawGlInfo::Mode mode = DrawGlInfo::kModeProcessNoContext;
477    if (thread.eglManager().hasEglContext()) {
478        mode = DrawGlInfo::kModeProcess;
479    }
480
481    thread.renderState().invokeFunctor(functor, mode, nullptr);
482}
483
484void CanvasContext::markLayerInUse(RenderNode* node) {
485    if (mPrefetechedLayers.erase(node)) {
486        node->decStrong(nullptr);
487    }
488}
489
490static void destroyPrefetechedNode(RenderNode* node) {
491    ALOGW("Incorrectly called buildLayer on View: %s, destroying layer...", node->getName());
492    node->destroyHardwareResources();
493    node->decStrong(nullptr);
494}
495
496void CanvasContext::freePrefetechedLayers() {
497    if (mPrefetechedLayers.size()) {
498        std::for_each(mPrefetechedLayers.begin(), mPrefetechedLayers.end(), destroyPrefetechedNode);
499        mPrefetechedLayers.clear();
500    }
501}
502
503void CanvasContext::buildLayer(RenderNode* node) {
504    ATRACE_CALL();
505    if (!mEglManager.hasEglContext() || !mCanvas) {
506        return;
507    }
508    // buildLayer() will leave the tree in an unknown state, so we must stop drawing
509    stopDrawing();
510
511    TreeInfo info(TreeInfo::MODE_FULL, mRenderThread.renderState());
512    info.damageAccumulator = &mDamageAccumulator;
513    info.renderer = mCanvas;
514    info.runAnimations = false;
515    node->prepareTree(info);
516    SkRect ignore;
517    mDamageAccumulator.finish(&ignore);
518    // Tickle the GENERIC property on node to mark it as dirty for damaging
519    // purposes when the frame is actually drawn
520    node->setPropertyFieldsDirty(RenderNode::GENERIC);
521
522    mCanvas->markLayersAsBuildLayers();
523    mCanvas->flushLayerUpdates();
524
525    node->incStrong(nullptr);
526    mPrefetechedLayers.insert(node);
527}
528
529bool CanvasContext::copyLayerInto(DeferredLayerUpdater* layer, SkBitmap* bitmap) {
530    layer->apply();
531    return LayerRenderer::copyLayer(mRenderThread.renderState(), layer->backingLayer(), bitmap);
532}
533
534void CanvasContext::destroyHardwareResources() {
535    stopDrawing();
536    if (mEglManager.hasEglContext()) {
537        freePrefetechedLayers();
538        for (const sp<RenderNode>& node : mRenderNodes) {
539            node->destroyHardwareResources();
540        }
541        Caches& caches = Caches::getInstance();
542        // Make sure to release all the textures we were owning as there won't
543        // be another draw
544        caches.textureCache.resetMarkInUse(this);
545        caches.flush(Caches::FlushMode::Layers);
546    }
547}
548
549void CanvasContext::trimMemory(RenderThread& thread, int level) {
550    // No context means nothing to free
551    if (!thread.eglManager().hasEglContext()) return;
552
553    ATRACE_CALL();
554    if (level >= TRIM_MEMORY_COMPLETE) {
555        Caches::getInstance().flush(Caches::FlushMode::Full);
556        thread.eglManager().destroy();
557    } else if (level >= TRIM_MEMORY_UI_HIDDEN) {
558        Caches::getInstance().flush(Caches::FlushMode::Moderate);
559    }
560}
561
562void CanvasContext::runWithGlContext(RenderTask* task) {
563    LOG_ALWAYS_FATAL_IF(!mEglManager.hasEglContext(),
564            "GL context not initialized!");
565    task->run();
566}
567
568Layer* CanvasContext::createTextureLayer() {
569    requireSurface();
570    return LayerRenderer::createTextureLayer(mRenderThread.renderState());
571}
572
573void CanvasContext::setTextureAtlas(RenderThread& thread,
574        const sp<GraphicBuffer>& buffer, int64_t* map, size_t mapSize) {
575    thread.eglManager().setTextureAtlas(buffer, map, mapSize);
576}
577
578void CanvasContext::dumpFrames(int fd) {
579    FILE* file = fdopen(fd, "a");
580    fprintf(file, "\n\n---PROFILEDATA---\n");
581    for (size_t i = 0; i < static_cast<size_t>(FrameInfoIndex::NumIndexes); i++) {
582        fprintf(file, "%s", FrameInfoNames[i].c_str());
583        fprintf(file, ",");
584    }
585    for (size_t i = 0; i < mFrames.size(); i++) {
586        FrameInfo& frame = mFrames[i];
587        if (frame[FrameInfoIndex::SyncStart] == 0) {
588            continue;
589        }
590        fprintf(file, "\n");
591        for (int i = 0; i < static_cast<int>(FrameInfoIndex::NumIndexes); i++) {
592            fprintf(file, "%" PRId64 ",", frame[i]);
593        }
594    }
595    fprintf(file, "\n---PROFILEDATA---\n\n");
596    fflush(file);
597}
598
599void CanvasContext::resetFrameStats() {
600    mFrames.clear();
601    mRenderThread.jankTracker().reset();
602}
603
604void CanvasContext::serializeDisplayListTree() {
605#if ENABLE_RENDERNODE_SERIALIZATION
606    using namespace google::protobuf::io;
607    char package[128];
608    // Check whether tracing is enabled for this process.
609    FILE * file = fopen("/proc/self/cmdline", "r");
610    if (file) {
611        if (!fgets(package, 128, file)) {
612            ALOGE("Error reading cmdline: %s (%d)", strerror(errno), errno);
613            fclose(file);
614            return;
615        }
616        fclose(file);
617    } else {
618        ALOGE("Error opening /proc/self/cmdline: %s (%d)", strerror(errno),
619                errno);
620        return;
621    }
622    char path[1024];
623    snprintf(path, 1024, "/data/data/%s/cache/rendertree_dump", package);
624    int fd = open(path, O_CREAT | O_WRONLY, S_IRWXU | S_IRGRP | S_IROTH);
625    if (fd == -1) {
626        ALOGD("Failed to open '%s'", path);
627        return;
628    }
629    proto::RenderNode tree;
630    // TODO: Streaming writes?
631    mRootRenderNode->copyTo(&tree);
632    std::string data = tree.SerializeAsString();
633    write(fd, data.c_str(), data.length());
634    close(fd);
635#endif
636}
637
638} /* namespace renderthread */
639} /* namespace uirenderer */
640} /* namespace android */
641