Avoid a potential race condition on mDisplays
The race could occur when transitioning in/out of VR flinger mode.
It is now avoided by ensuring that the primary |DisplayDevice| is always
created once |mStateLock| is released, and ensuring that all accesses
to the primary |DisplayDevice| are guarded by |mStateLock|.
Bug: 36194616
Test: Normal behavior is unchanged. Explicitly testing the race
condition required instrumenting code with sleep statements.
Change-Id: I1f8fcf23982c311d47267beca8127b6c29562ce5
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 26baaae..76a5d06 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -598,7 +598,7 @@
// make the GLContext current so that we can create textures when creating
// Layers (which may happens before we render something)
- getDefaultDisplayDevice()->makeCurrent(mEGLDisplay, mEGLContext);
+ getDefaultDisplayDeviceLocked()->makeCurrent(mEGLDisplay, mEGLContext);
mEventControlThread = new EventControlThread(this);
mEventControlThread->run("EventControl", PRIORITY_URGENT_DISPLAY);
@@ -714,8 +714,11 @@
info.density = density;
// TODO: this needs to go away (currently needed only by webkit)
- sp<const DisplayDevice> hw(getDefaultDisplayDevice());
- info.orientation = hw->getOrientation();
+ {
+ Mutex::Autolock _l(mStateLock);
+ sp<const DisplayDevice> hw(getDefaultDisplayDeviceLocked());
+ info.orientation = hw->getOrientation();
+ }
} else {
// TODO: where should this value come from?
static const int TV_DENSITY = 213;
@@ -772,10 +775,13 @@
ALOGE("%s : display is NULL", __func__);
return BAD_VALUE;
}
+
+ Mutex::Autolock _l(mStateLock);
sp<DisplayDevice> device(getDisplayDevice(display));
if (device != NULL) {
return device->getActiveConfig();
}
+
return BAD_VALUE;
}
@@ -863,6 +869,7 @@
}
android_color_mode_t SurfaceFlinger::getActiveColorMode(const sp<IBinder>& display) {
+ Mutex::Autolock _l(mStateLock);
sp<DisplayDevice> device(getDisplayDevice(display));
if (device != nullptr) {
return device->getActiveColorMode();
@@ -1124,55 +1131,60 @@
*compositorTiming = mCompositorTiming;
}
-void SurfaceFlinger::onHotplugReceived(int32_t disp, bool connected) {
+void SurfaceFlinger::createDefaultDisplayDevice() {
+ const int32_t type = DisplayDevice::DISPLAY_PRIMARY;
+ wp<IBinder> token = mBuiltinDisplays[type];
+
+ // All non-virtual displays are currently considered secure.
+ const bool isSecure = true;
+
+ sp<IGraphicBufferProducer> producer;
+ sp<IGraphicBufferConsumer> consumer;
+ BufferQueue::createBufferQueue(&producer, &consumer, new GraphicBufferAlloc());
+
+ sp<FramebufferSurface> fbs = new FramebufferSurface(*mHwc, type, consumer);
+
+ bool hasWideColorModes = false;
+ std::vector<android_color_mode_t> modes = getHwComposer().getColorModes(
+ type);
+ for (android_color_mode_t colorMode : modes) {
+ switch (colorMode) {
+ case HAL_COLOR_MODE_DISPLAY_P3:
+ case HAL_COLOR_MODE_ADOBE_RGB:
+ case HAL_COLOR_MODE_DCI_P3:
+ hasWideColorModes = true;
+ break;
+ default:
+ break;
+ }
+ }
+ sp<DisplayDevice> hw = new DisplayDevice(this, DisplayDevice::DISPLAY_PRIMARY, type, isSecure,
+ token, fbs, producer, mRenderEngine->getEGLConfig(),
+ hasWideColorModes && hasWideColorDisplay);
+ mDisplays.add(token, hw);
+ android_color_mode defaultColorMode = HAL_COLOR_MODE_NATIVE;
+ if (hasWideColorModes && hasWideColorDisplay) {
+ defaultColorMode = HAL_COLOR_MODE_SRGB;
+ }
+ setActiveColorModeInternal(hw, defaultColorMode);
+}
+
+void SurfaceFlinger::onHotplugReceived(HWComposer* composer, int32_t disp, bool connected) {
ALOGV("onHotplugReceived(%d, %s)", disp, connected ? "true" : "false");
+
+ if (composer->isUsingVrComposer()) {
+ // We handle initializing the primary display device for the VR
+ // window manager hwc explicitly at the time of transition.
+ if (disp != DisplayDevice::DISPLAY_PRIMARY) {
+ ALOGE("External displays are not supported by the vr hardware composer.");
+ }
+ return;
+ }
+
if (disp == DisplayDevice::DISPLAY_PRIMARY) {
Mutex::Autolock lock(mStateLock);
-
- // All non-virtual displays are currently considered secure.
- bool isSecure = true;
-
- int32_t type = DisplayDevice::DISPLAY_PRIMARY;
-
- // When we're using the vr composer, the assumption is that we've
- // already created the IBinder object for the primary display.
- if (!mHwc->isUsingVrComposer()) {
- createBuiltinDisplayLocked(DisplayDevice::DISPLAY_PRIMARY);
- }
-
- wp<IBinder> token = mBuiltinDisplays[type];
-
- sp<IGraphicBufferProducer> producer;
- sp<IGraphicBufferConsumer> consumer;
- BufferQueue::createBufferQueue(&producer, &consumer,
- new GraphicBufferAlloc());
-
- sp<FramebufferSurface> fbs = new FramebufferSurface(*mHwc,
- DisplayDevice::DISPLAY_PRIMARY, consumer);
-
- bool hasWideColorModes = false;
- std::vector<android_color_mode_t> modes = getHwComposer().getColorModes(type);
- for (android_color_mode_t colorMode : modes) {
- switch (colorMode) {
- case HAL_COLOR_MODE_DISPLAY_P3:
- case HAL_COLOR_MODE_ADOBE_RGB:
- case HAL_COLOR_MODE_DCI_P3:
- hasWideColorModes = true;
- break;
- default:
- break;
- }
- }
- sp<DisplayDevice> hw =
- new DisplayDevice(this, DisplayDevice::DISPLAY_PRIMARY, disp, isSecure, token, fbs,
- producer, mRenderEngine->getEGLConfig(),
- hasWideColorModes && hasWideColorDisplay);
- mDisplays.add(token, hw);
- android_color_mode defaultColorMode = HAL_COLOR_MODE_NATIVE;
- if (hasWideColorModes && hasWideColorDisplay) {
- defaultColorMode = HAL_COLOR_MODE_SRGB;
- }
- setActiveColorModeInternal(hw, defaultColorMode);
+ createBuiltinDisplayLocked(DisplayDevice::DISPLAY_PRIMARY);
+ createDefaultDisplayDevice();
} else {
auto type = DisplayDevice::DISPLAY_EXTERNAL;
Mutex::Autolock _l(mStateLock);
@@ -1214,6 +1226,7 @@
}
}
+// Note: it is assumed the caller holds |mStateLock| when this is called
void SurfaceFlinger::resetHwc() {
disableHardwareVsync(true);
clearHwcLayers(mDrawingState.layersSortedByZ);
@@ -1234,36 +1247,46 @@
if (vrFlingerRequestsDisplay == mHwc->isUsingVrComposer()) {
return;
}
+
+ bool vrHwcNewlyInitialized = false;
+
if (vrFlingerRequestsDisplay && !mVrHwc) {
// Construct new HWComposer without holding any locks.
mVrHwc = new HWComposer(true);
+ vrHwcNewlyInitialized = true;
ALOGV("Vr HWC created");
}
- {
- Mutex::Autolock _l(mStateLock);
- if (vrFlingerRequestsDisplay) {
- resetHwc();
+ Mutex::Autolock _l(mStateLock);
- mHwc = mVrHwc;
- mVrFlinger->GrantDisplayOwnership();
- } else {
- mVrFlinger->SeizeDisplayOwnership();
+ if (vrFlingerRequestsDisplay) {
+ resetHwc();
- resetHwc();
+ mHwc = mVrHwc;
+ mVrFlinger->GrantDisplayOwnership();
- mHwc = mRealHwc;
- enableHardwareVsync();
+ if (vrHwcNewlyInitialized) {
+ mVrHwc->setEventHandler(
+ static_cast<HWComposer::EventHandler*>(this));
}
+ } else {
+ mVrFlinger->SeizeDisplayOwnership();
- mVisibleRegionsDirty = true;
- invalidateHwcGeometry();
- android_atomic_or(1, &mRepaintEverything);
- setTransactionFlags(eDisplayTransactionNeeded);
+ resetHwc();
+
+ mHwc = mRealHwc;
+ enableHardwareVsync();
}
- if (mVrHwc) {
- mVrHwc->setEventHandler(static_cast<HWComposer::EventHandler*>(this));
- }
+
+ mVisibleRegionsDirty = true;
+ invalidateHwcGeometry();
+
+ // Explicitly re-initialize the primary display. This is because some other
+ // parts of this class rely on the primary display always being available.
+ createDefaultDisplayDevice();
+
+ android_atomic_or(1, &mRepaintEverything);
+ setTransactionFlags(eDisplayTransactionNeeded);
}
void SurfaceFlinger::onMessageReceived(int32_t what) {
@@ -1473,7 +1496,8 @@
layer->releasePendingBuffer(dequeueReadyTime);
}
- const sp<const DisplayDevice> hw(getDefaultDisplayDevice());
+ // |mStateLock| not needed as we are on the main thread
+ const sp<const DisplayDevice> hw(getDefaultDisplayDeviceLocked());
std::shared_ptr<FenceTime> glCompositionDoneFenceTime;
if (mHwc->hasClientComposition(HWC_DISPLAY_PRIMARY)) {
@@ -1821,7 +1845,8 @@
mLastSwapBufferTime = systemTime() - now;
mDebugInSwapBuffers = 0;
- uint32_t flipCount = getDefaultDisplayDevice()->getPageFlipCount();
+ // |mStateLock| not needed as we are on the main thread
+ uint32_t flipCount = getDefaultDisplayDeviceLocked()->getPageFlipCount();
if (flipCount % LOG_FRAME_STATS_PERIOD == 0) {
logFrameStats();
}
@@ -1906,7 +1931,7 @@
// Call makeCurrent() on the primary display so we can
// be sure that nothing associated with this display
// is current.
- const sp<const DisplayDevice> defaultDisplay(getDefaultDisplayDevice());
+ const sp<const DisplayDevice> defaultDisplay(getDefaultDisplayDeviceLocked());
defaultDisplay->makeCurrent(mEGLDisplay, mEGLContext);
sp<DisplayDevice> hw(getDisplayDevice(draw.keyAt(i)));
if (hw != NULL)
@@ -2096,7 +2121,7 @@
// could be null when this layer is using a layerStack
// that is not visible on any display. Also can occur at
// screen off/on times.
- disp = getDefaultDisplayDevice();
+ disp = getDefaultDisplayDeviceLocked();
}
layer->updateTransformHint(disp);
@@ -2452,7 +2477,9 @@
ALOGW("DisplayDevice::makeCurrent failed. Aborting surface composition for display %s",
displayDevice->getDisplayName().string());
eglMakeCurrent(mEGLDisplay, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
- if(!getDefaultDisplayDevice()->makeCurrent(mEGLDisplay, mEGLContext)) {
+
+ // |mStateLock| not needed as we are on the main thread
+ if(!getDefaultDisplayDeviceLocked()->makeCurrent(mEGLDisplay, mEGLContext)) {
ALOGE("DisplayDevice::makeCurrent on default display failed. Aborting.");
}
return false;
@@ -3539,7 +3566,7 @@
colorizer.reset(result);
HWComposer& hwc(getHwComposer());
- sp<const DisplayDevice> hw(getDefaultDisplayDevice());
+ sp<const DisplayDevice> hw(getDefaultDisplayDeviceLocked());
colorizer.bold(result);
result.appendFormat("EGL implementation : %s\n",
@@ -3769,7 +3796,7 @@
return NO_ERROR;
case 1013: {
Mutex::Autolock _l(mStateLock);
- sp<const DisplayDevice> hw(getDefaultDisplayDevice());
+ sp<const DisplayDevice> hw(getDefaultDisplayDeviceLocked());
reply->writeInt32(hw->getPageFlipCount());
return NO_ERROR;
}