CanvasContext.cpp revision ea7a7fb75acb7305eb774ca7bc7e96103bd49323
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        , mContentOverdrawProtectionBounds(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 (with - and clipped to - bounds mContentOverdrawProtectionBounds)
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 = mContentOverdrawProtectionBounds;
321    // If there is no content bounds we ignore the layering as stated above and start with 2.
322    int layer = mContentOverdrawProtectionBounds.isEmpty() ? 2 : 0;
323    // Draw all render nodes. Note that
324    for (const sp<RenderNode>& node : mRenderNodes) {
325        if (layer == 0) { // Backdrop.
326            // Draw the backdrop clipped to the inverse content bounds.
327            const RenderProperties& properties = node->properties();
328            Rect targetBounds(properties.getLeft(), properties.getTop(),
329                              properties.getRight(), properties.getBottom());
330            // Remember the intersection of the target bounds and the intersection bounds against
331            // which we have to crop the content.
332            backdropBounds.intersect(targetBounds);
333            // Check if we have to draw something on the left side ...
334            if (targetBounds.left < mContentOverdrawProtectionBounds.left) {
335                mCanvas->save(SkCanvas::kClip_SaveFlag);
336                if (mCanvas->clipRect(targetBounds.left, targetBounds.top,
337                                      mContentOverdrawProtectionBounds.left, targetBounds.bottom,
338                                      SkRegion::kIntersect_Op)) {
339                    mCanvas->drawRenderNode(node.get(), outBounds);
340                }
341                // Reduce the target area by the area we have just painted.
342                targetBounds.left = std::min(mContentOverdrawProtectionBounds.left,
343                                             targetBounds.right);
344                mCanvas->restore();
345            }
346            // ... or on the right side ...
347            if (targetBounds.right > mContentOverdrawProtectionBounds.right &&
348                !targetBounds.isEmpty()) {
349                mCanvas->save(SkCanvas::kClip_SaveFlag);
350                if (mCanvas->clipRect(mContentOverdrawProtectionBounds.right, targetBounds.top,
351                                      targetBounds.right, targetBounds.bottom,
352                                      SkRegion::kIntersect_Op)) {
353                    mCanvas->drawRenderNode(node.get(), outBounds);
354                }
355                // Reduce the target area by the area we have just painted.
356                targetBounds.right = std::max(targetBounds.left,
357                                              mContentOverdrawProtectionBounds.right);
358                mCanvas->restore();
359            }
360            // ... or at the top ...
361            if (targetBounds.top < mContentOverdrawProtectionBounds.top &&
362                !targetBounds.isEmpty()) {
363                mCanvas->save(SkCanvas::kClip_SaveFlag);
364                if (mCanvas->clipRect(targetBounds.left, targetBounds.top, targetBounds.right,
365                                      mContentOverdrawProtectionBounds.top,
366                                      SkRegion::kIntersect_Op)) {
367                    mCanvas->drawRenderNode(node.get(), outBounds);
368                }
369                // Reduce the target area by the area we have just painted.
370                targetBounds.top = std::min(mContentOverdrawProtectionBounds.top,
371                                            targetBounds.bottom);
372                mCanvas->restore();
373            }
374            // ... or at the bottom.
375            if (targetBounds.bottom > mContentOverdrawProtectionBounds.bottom &&
376                !targetBounds.isEmpty()) {
377                mCanvas->save(SkCanvas::kClip_SaveFlag);
378                if (mCanvas->clipRect(targetBounds.left,
379                                      mContentOverdrawProtectionBounds.bottom, targetBounds.right,
380                                      targetBounds.bottom, SkRegion::kIntersect_Op)) {
381                    mCanvas->drawRenderNode(node.get(), outBounds);
382                }
383                mCanvas->restore();
384            }
385        } else if (layer == 1) { // Content
386            // It gets cropped against the bounds of the backdrop to stay inside.
387            mCanvas->save(SkCanvas::kClip_SaveFlag);
388            if (mCanvas->clipRect(backdropBounds.left, backdropBounds.top,
389                                  backdropBounds.right, backdropBounds.bottom,
390                                  SkRegion::kIntersect_Op)) {
391                mCanvas->drawRenderNode(node.get(), outBounds);
392            }
393            mCanvas->restore();
394        } else { // draw the rest on top at will!
395            mCanvas->drawRenderNode(node.get(), outBounds);
396        }
397        layer++;
398    }
399
400    profiler().draw(mCanvas);
401
402    bool drew = mCanvas->finish();
403
404    // Even if we decided to cancel the frame, from the perspective of jank
405    // metrics the frame was swapped at this point
406    mCurrentFrameInfo->markSwapBuffers();
407
408    if (drew) {
409        if (CC_UNLIKELY(!mEglManager.swapBuffers(frame, screenDirty))) {
410            setSurface(nullptr);
411        }
412        mHaveNewSurface = false;
413    }
414
415    // TODO: Use a fence for real completion?
416    mCurrentFrameInfo->markFrameCompleted();
417
418#if LOG_FRAMETIME_MMA
419    float thisFrame = mCurrentFrameInfo->duration(
420            FrameInfoIndex::IssueDrawCommandsStart,
421            FrameInfoIndex::FrameCompleted) / NANOS_PER_MILLIS_F;
422    if (sFrameCount) {
423        sBenchMma = ((9 * sBenchMma) + thisFrame) / 10;
424    } else {
425        sBenchMma = thisFrame;
426    }
427    if (++sFrameCount == 10) {
428        sFrameCount = 1;
429        ALOGD("Average frame time: %.4f", sBenchMma);
430    }
431#endif
432
433    mJankTracker.addFrame(*mCurrentFrameInfo);
434    mRenderThread.jankTracker().addFrame(*mCurrentFrameInfo);
435}
436
437// Called by choreographer to do an RT-driven animation
438void CanvasContext::doFrame() {
439    if (CC_UNLIKELY(!mCanvas || mEglSurface == EGL_NO_SURFACE)) {
440        return;
441    }
442    prepareAndDraw(nullptr);
443}
444
445void CanvasContext::prepareAndDraw(RenderNode* node) {
446    ATRACE_CALL();
447
448    int64_t frameInfo[UI_THREAD_FRAME_INFO_SIZE];
449    UiFrameInfoBuilder(frameInfo)
450        .addFlag(FrameInfoFlags::RTAnimation)
451        .setVsync(mRenderThread.timeLord().computeFrameTimeNanos(),
452                mRenderThread.timeLord().latestVsync());
453
454    TreeInfo info(TreeInfo::MODE_RT_ONLY, mRenderThread.renderState());
455    prepareTree(info, frameInfo, systemTime(CLOCK_MONOTONIC), node);
456    if (info.out.canDrawThisFrame) {
457        draw();
458    }
459}
460
461void CanvasContext::invokeFunctor(RenderThread& thread, Functor* functor) {
462    ATRACE_CALL();
463    DrawGlInfo::Mode mode = DrawGlInfo::kModeProcessNoContext;
464    if (thread.eglManager().hasEglContext()) {
465        mode = DrawGlInfo::kModeProcess;
466    }
467
468    thread.renderState().invokeFunctor(functor, mode, nullptr);
469}
470
471void CanvasContext::markLayerInUse(RenderNode* node) {
472    if (mPrefetechedLayers.erase(node)) {
473        node->decStrong(nullptr);
474    }
475}
476
477static void destroyPrefetechedNode(RenderNode* node) {
478    ALOGW("Incorrectly called buildLayer on View: %s, destroying layer...", node->getName());
479    node->destroyHardwareResources();
480    node->decStrong(nullptr);
481}
482
483void CanvasContext::freePrefetechedLayers() {
484    if (mPrefetechedLayers.size()) {
485        std::for_each(mPrefetechedLayers.begin(), mPrefetechedLayers.end(), destroyPrefetechedNode);
486        mPrefetechedLayers.clear();
487    }
488}
489
490void CanvasContext::buildLayer(RenderNode* node) {
491    ATRACE_CALL();
492    if (!mEglManager.hasEglContext() || !mCanvas) {
493        return;
494    }
495    // buildLayer() will leave the tree in an unknown state, so we must stop drawing
496    stopDrawing();
497
498    TreeInfo info(TreeInfo::MODE_FULL, mRenderThread.renderState());
499    info.damageAccumulator = &mDamageAccumulator;
500    info.renderer = mCanvas;
501    info.runAnimations = false;
502    node->prepareTree(info);
503    SkRect ignore;
504    mDamageAccumulator.finish(&ignore);
505    // Tickle the GENERIC property on node to mark it as dirty for damaging
506    // purposes when the frame is actually drawn
507    node->setPropertyFieldsDirty(RenderNode::GENERIC);
508
509    mCanvas->markLayersAsBuildLayers();
510    mCanvas->flushLayerUpdates();
511
512    node->incStrong(nullptr);
513    mPrefetechedLayers.insert(node);
514}
515
516bool CanvasContext::copyLayerInto(DeferredLayerUpdater* layer, SkBitmap* bitmap) {
517    layer->apply();
518    return LayerRenderer::copyLayer(mRenderThread.renderState(), layer->backingLayer(), bitmap);
519}
520
521void CanvasContext::destroyHardwareResources() {
522    stopDrawing();
523    if (mEglManager.hasEglContext()) {
524        freePrefetechedLayers();
525        for (const sp<RenderNode>& node : mRenderNodes) {
526            node->destroyHardwareResources();
527        }
528        Caches& caches = Caches::getInstance();
529        // Make sure to release all the textures we were owning as there won't
530        // be another draw
531        caches.textureCache.resetMarkInUse(this);
532        caches.flush(Caches::FlushMode::Layers);
533    }
534}
535
536void CanvasContext::trimMemory(RenderThread& thread, int level) {
537    // No context means nothing to free
538    if (!thread.eglManager().hasEglContext()) return;
539
540    ATRACE_CALL();
541    if (level >= TRIM_MEMORY_COMPLETE) {
542        Caches::getInstance().flush(Caches::FlushMode::Full);
543        thread.eglManager().destroy();
544    } else if (level >= TRIM_MEMORY_UI_HIDDEN) {
545        Caches::getInstance().flush(Caches::FlushMode::Moderate);
546    }
547}
548
549void CanvasContext::runWithGlContext(RenderTask* task) {
550    LOG_ALWAYS_FATAL_IF(!mEglManager.hasEglContext(),
551            "GL context not initialized!");
552    task->run();
553}
554
555Layer* CanvasContext::createTextureLayer() {
556    requireSurface();
557    return LayerRenderer::createTextureLayer(mRenderThread.renderState());
558}
559
560void CanvasContext::setTextureAtlas(RenderThread& thread,
561        const sp<GraphicBuffer>& buffer, int64_t* map, size_t mapSize) {
562    thread.eglManager().setTextureAtlas(buffer, map, mapSize);
563}
564
565void CanvasContext::dumpFrames(int fd) {
566    FILE* file = fdopen(fd, "a");
567    fprintf(file, "\n\n---PROFILEDATA---\n");
568    for (size_t i = 0; i < static_cast<size_t>(FrameInfoIndex::NumIndexes); i++) {
569        fprintf(file, "%s", FrameInfoNames[i].c_str());
570        fprintf(file, ",");
571    }
572    for (size_t i = 0; i < mFrames.size(); i++) {
573        FrameInfo& frame = mFrames[i];
574        if (frame[FrameInfoIndex::SyncStart] == 0) {
575            continue;
576        }
577        fprintf(file, "\n");
578        for (int i = 0; i < static_cast<int>(FrameInfoIndex::NumIndexes); i++) {
579            fprintf(file, "%" PRId64 ",", frame[i]);
580        }
581    }
582    fprintf(file, "\n---PROFILEDATA---\n\n");
583    fflush(file);
584}
585
586void CanvasContext::resetFrameStats() {
587    mFrames.clear();
588    mRenderThread.jankTracker().reset();
589}
590
591void CanvasContext::serializeDisplayListTree() {
592#if ENABLE_RENDERNODE_SERIALIZATION
593    using namespace google::protobuf::io;
594    char package[128];
595    // Check whether tracing is enabled for this process.
596    FILE * file = fopen("/proc/self/cmdline", "r");
597    if (file) {
598        if (!fgets(package, 128, file)) {
599            ALOGE("Error reading cmdline: %s (%d)", strerror(errno), errno);
600            fclose(file);
601            return;
602        }
603        fclose(file);
604    } else {
605        ALOGE("Error opening /proc/self/cmdline: %s (%d)", strerror(errno),
606                errno);
607        return;
608    }
609    char path[1024];
610    snprintf(path, 1024, "/data/data/%s/cache/rendertree_dump", package);
611    int fd = open(path, O_CREAT | O_WRONLY, S_IRWXU | S_IRGRP | S_IROTH);
612    if (fd == -1) {
613        ALOGD("Failed to open '%s'", path);
614        return;
615    }
616    proto::RenderNode tree;
617    // TODO: Streaming writes?
618    mRootRenderNode->copyTo(&tree);
619    std::string data = tree.SerializeAsString();
620    write(fd, data.c_str(), data.length());
621    close(fd);
622#endif
623}
624
625} /* namespace renderthread */
626} /* namespace uirenderer */
627} /* namespace android */
628