/* * Copyright (C) 2007 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include #include #include #include #include #include #include #include #include #include #include #include "clz.h" #include "GLExtensions.h" #include "Layer.h" #include "SurfaceFlinger.h" #include "DisplayHardware/DisplayHardware.h" #define DEBUG_RESIZE 0 namespace android { template inline T min(T a, T b) { return a& client) : LayerBaseClient(flinger, display, client), mGLExtensions(GLExtensions::getInstance()), mNeedsBlending(true), mNeedsDithering(false), mSecure(false), mTextureManager(), mBufferManager(mTextureManager), mWidth(0), mHeight(0), mNeedsScaling(false), mFixedSize(false), mBypassState(false) { } Layer::~Layer() { // FIXME: must be called from the main UI thread EGLDisplay dpy(mFlinger->graphicPlane(0).getEGLDisplay()); mBufferManager.destroy(dpy); // we can use getUserClientUnsafe here because we know we're // single-threaded at that point. sp ourClient(mUserClientRef.getUserClientUnsafe()); if (ourClient != 0) { ourClient->detachLayer(this); } } status_t Layer::setToken(const sp& userClient, SharedClient* sharedClient, int32_t token) { sp lcblk = new SharedBufferServer( sharedClient, token, mBufferManager.getDefaultBufferCount(), getIdentity()); status_t err = mUserClientRef.setToken(userClient, lcblk, token); LOGE_IF(err != NO_ERROR, "ClientRef::setToken(%p, %p, %u) failed", userClient.get(), lcblk.get(), token); if (err == NO_ERROR) { // we need to free the buffers associated with this surface } return err; } int32_t Layer::getToken() const { return mUserClientRef.getToken(); } sp Layer::getClient() const { return mUserClientRef.getClient(); } // called with SurfaceFlinger::mStateLock as soon as the layer is entered // in the purgatory list void Layer::onRemoved() { ClientRef::Access sharedClient(mUserClientRef); SharedBufferServer* lcblk(sharedClient.get()); if (lcblk) { // wake up the condition lcblk->setStatus(NO_INIT); } } sp Layer::createSurface() const { sp sur(new SurfaceLayer(mFlinger, const_cast(this))); return sur; } status_t Layer::ditch() { // NOTE: Called from the main UI thread // the layer is not on screen anymore. free as much resources as possible mFreezeLock.clear(); Mutex::Autolock _l(mLock); mWidth = mHeight = 0; return NO_ERROR; } status_t Layer::setBuffers( uint32_t w, uint32_t h, PixelFormat format, uint32_t flags) { // this surfaces pixel format PixelFormatInfo info; status_t err = getPixelFormatInfo(format, &info); if (err) return err; // the display's pixel format const DisplayHardware& hw(graphicPlane(0).displayHardware()); uint32_t const maxSurfaceDims = min( hw.getMaxTextureSize(), hw.getMaxViewportDims()); // never allow a surface larger than what our underlying GL implementation // can handle. if ((uint32_t(w)>maxSurfaceDims) || (uint32_t(h)>maxSurfaceDims)) { return BAD_VALUE; } PixelFormatInfo displayInfo; getPixelFormatInfo(hw.getFormat(), &displayInfo); const uint32_t hwFlags = hw.getFlags(); mFormat = format; mWidth = w; mHeight = h; mReqFormat = format; mReqWidth = w; mReqHeight = h; mSecure = (flags & ISurfaceComposer::eSecure) ? true : false; mNeedsBlending = (info.h_alpha - info.l_alpha) > 0; // we use the red index int displayRedSize = displayInfo.getSize(PixelFormatInfo::INDEX_RED); int layerRedsize = info.getSize(PixelFormatInfo::INDEX_RED); mNeedsDithering = layerRedsize > displayRedSize; return NO_ERROR; } void Layer::reloadTexture(const Region& dirty) { sp buffer(mBufferManager.getActiveBuffer()); if (buffer == NULL) { // this situation can happen if we ran out of memory for instance. // not much we can do. continue to use whatever texture was bound // to this context. return; } if (mGLExtensions.haveDirectTexture()) { EGLDisplay dpy(mFlinger->graphicPlane(0).getEGLDisplay()); if (mBufferManager.initEglImage(dpy, buffer) != NO_ERROR) { // not sure what we can do here... goto slowpath; } } else { slowpath: GGLSurface t; if (buffer->usage & GRALLOC_USAGE_SW_READ_MASK) { status_t res = buffer->lock(&t, GRALLOC_USAGE_SW_READ_OFTEN); LOGE_IF(res, "error %d (%s) locking buffer %p", res, strerror(res), buffer.get()); if (res == NO_ERROR) { mBufferManager.loadTexture(dirty, t); buffer->unlock(); } } else { // we can't do anything } } } void Layer::drawForSreenShot() const { const bool currentFiltering = mNeedsFiltering; const_cast(this)->mNeedsFiltering = true; LayerBase::drawForSreenShot(); const_cast(this)->mNeedsFiltering = currentFiltering; } void Layer::onDraw(const Region& clip) const { Texture tex(mBufferManager.getActiveTexture()); if (tex.name == -1LU) { // the texture has not been created yet, this Layer has // in fact never been drawn into. This happens frequently with // SurfaceView because the WindowManager can't know when the client // has drawn the first time. // If there is nothing under us, we paint the screen in black, otherwise // we just skip this update. // figure out if there is something below us Region under; const SurfaceFlinger::LayerVector& drawingLayers(mFlinger->mDrawingState.layersSortedByZ); const size_t count = drawingLayers.size(); for (size_t i=0 ; i& layer(drawingLayers[i]); if (layer.get() == static_cast(this)) break; under.orSelf(layer->visibleRegionScreen); } // if not everything below us is covered, we plug the holes! Region holes(clip.subtract(under)); if (!holes.isEmpty()) { clearWithOpenGL(holes, 0, 0, 0, 1); } return; } #ifdef USE_COMPOSITION_BYPASS sp buffer(mBufferManager.getActiveBuffer()); if ((buffer != NULL) && (buffer->transform)) { // Here we have a "bypass" buffer, but we need to composite it // most likely because it's not fullscreen anymore. // Since the buffer may have a transformation applied by the client // we need to inverse this transformation here. // calculate the inverse of the buffer transform const uint32_t mask = HAL_TRANSFORM_FLIP_V | HAL_TRANSFORM_FLIP_H; const uint32_t bufferTransformInverse = buffer->transform ^ mask; // To accomplish the inverse transform, we use "mBufferTransform" // which is not used by Layer.cpp const_cast(this)->mBufferTransform = bufferTransformInverse; drawWithOpenGL(clip, tex); // reset to "no transfrom" const_cast(this)->mBufferTransform = 0; return; } #endif drawWithOpenGL(clip, tex); } bool Layer::needsFiltering() const { if (!(mFlags & DisplayHardware::SLOW_CONFIG)) { // if our buffer is not the same size than ourselves, // we need filtering. Mutex::Autolock _l(mLock); if (mNeedsScaling) return true; } return LayerBase::needsFiltering(); } status_t Layer::setBufferCount(int bufferCount) { ClientRef::Access sharedClient(mUserClientRef); SharedBufferServer* lcblk(sharedClient.get()); if (!lcblk) { // oops, the client is already gone return DEAD_OBJECT; } // NOTE: lcblk->resize() is protected by an internal lock status_t err = lcblk->resize(bufferCount); if (err == NO_ERROR) mBufferManager.resize(bufferCount); return err; } sp Layer::requestBuffer(int index, uint32_t reqWidth, uint32_t reqHeight, uint32_t reqFormat, uint32_t usage) { sp buffer; if (int32_t(reqWidth | reqHeight | reqFormat) < 0) return buffer; if ((!reqWidth && reqHeight) || (reqWidth && !reqHeight)) return buffer; // this ensures our client doesn't go away while we're accessing // the shared area. ClientRef::Access sharedClient(mUserClientRef); SharedBufferServer* lcblk(sharedClient.get()); if (!lcblk) { // oops, the client is already gone return buffer; } /* * This is called from the client's Surface::dequeue(). This can happen * at any time, especially while we're in the middle of using the * buffer 'index' as our front buffer. */ uint32_t w, h, f, bypass; { // scope for the lock Mutex::Autolock _l(mLock); bypass = mBypassState; // zero means default mFixedSize = reqWidth && reqHeight; if (!reqFormat) reqFormat = mFormat; if (!reqWidth) reqWidth = mWidth; if (!reqHeight) reqHeight = mHeight; w = reqWidth; h = reqHeight; f = reqFormat; if ((reqWidth != mReqWidth) || (reqHeight != mReqHeight) || (reqFormat != mReqFormat)) { mReqWidth = reqWidth; mReqHeight = reqHeight; mReqFormat = reqFormat; mNeedsScaling = mWidth != mReqWidth || mHeight != mReqHeight; lcblk->reallocateAllExcept(index); } } // here we have to reallocate a new buffer because the buffer could be // used as the front buffer, or by a client in our process // (eg: status bar), and we can't release the handle under its feet. uint32_t effectiveUsage = getEffectiveUsage(usage); status_t err = NO_MEMORY; #ifdef USE_COMPOSITION_BYPASS if (!mSecure && bypass && (effectiveUsage & GRALLOC_USAGE_HW_RENDER)) { // always allocate a buffer matching the screen size. the size // may be different from (w,h) if the buffer is rotated. const DisplayHardware& hw(graphicPlane(0).displayHardware()); int32_t w = hw.getWidth(); int32_t h = hw.getHeight(); int32_t f = hw.getFormat(); buffer = new GraphicBuffer(w, h, f, effectiveUsage | GRALLOC_USAGE_HW_FB); err = buffer->initCheck(); buffer->transform = uint8_t(getOrientation()); if (err != NO_ERROR) { // allocation didn't succeed, probably because an older bypass // window hasn't released all its resources yet. ClientRef::Access sharedClient(mUserClientRef); SharedBufferServer* lcblk(sharedClient.get()); if (lcblk) { // all buffers need reallocation lcblk->reallocateAll(); } } } #endif if (err != NO_ERROR) { buffer = new GraphicBuffer(w, h, f, effectiveUsage); err = buffer->initCheck(); } if (err || buffer->handle == 0) { GraphicBuffer::dumpAllocationsToSystemLog(); LOGE_IF(err || buffer->handle == 0, "Layer::requestBuffer(this=%p), index=%d, w=%d, h=%d failed (%s)", this, index, w, h, strerror(-err)); } else { LOGD_IF(DEBUG_RESIZE, "Layer::requestBuffer(this=%p), index=%d, w=%d, h=%d, handle=%p", this, index, w, h, buffer->handle); } if (err == NO_ERROR && buffer->handle != 0) { Mutex::Autolock _l(mLock); mBufferManager.attachBuffer(index, buffer); } return buffer; } uint32_t Layer::getEffectiveUsage(uint32_t usage) const { /* * buffers used for software rendering, but h/w composition * are allocated with SW_READ_OFTEN | SW_WRITE_OFTEN | HW_TEXTURE * * buffers used for h/w rendering and h/w composition * are allocated with HW_RENDER | HW_TEXTURE * * buffers used with h/w rendering and either NPOT or no egl_image_ext * are allocated with SW_READ_RARELY | HW_RENDER * */ if (mSecure) { // secure buffer, don't store it into the GPU usage = GraphicBuffer::USAGE_SW_READ_OFTEN | GraphicBuffer::USAGE_SW_WRITE_OFTEN; } else { // it's allowed to modify the usage flags here, but generally // the requested flags should be honored. // request EGLImage for all buffers usage |= GraphicBuffer::USAGE_HW_TEXTURE; } return usage; } bool Layer::setBypass(bool enable) { Mutex::Autolock _l(mLock); if (mNeedsScaling || mNeedsFiltering) { return false; } if (mBypassState != enable) { mBypassState = enable; ClientRef::Access sharedClient(mUserClientRef); SharedBufferServer* lcblk(sharedClient.get()); if (lcblk) { // all buffers need reallocation lcblk->reallocateAll(); } } return true; } void Layer::updateBuffersOrientation() { sp buffer(getBypassBuffer()); if (buffer != NULL && mOrientation != buffer->transform) { ClientRef::Access sharedClient(mUserClientRef); SharedBufferServer* lcblk(sharedClient.get()); if (lcblk) { // all buffers need reallocation lcblk->reallocateAll(); } } } uint32_t Layer::doTransaction(uint32_t flags) { const Layer::State& front(drawingState()); const Layer::State& temp(currentState()); const bool sizeChanged = (front.requested_w != temp.requested_w) || (front.requested_h != temp.requested_h); if (sizeChanged) { // the size changed, we need to ask our client to request a new buffer LOGD_IF(DEBUG_RESIZE, "resize (layer=%p), requested (%dx%d), drawing (%d,%d)", this, int(temp.requested_w), int(temp.requested_h), int(front.requested_w), int(front.requested_h)); if (!isFixedSize()) { // we're being resized and there is a freeze display request, // acquire a freeze lock, so that the screen stays put // until we've redrawn at the new size; this is to avoid // glitches upon orientation changes. if (mFlinger->hasFreezeRequest()) { // if the surface is hidden, don't try to acquire the // freeze lock, since hidden surfaces may never redraw if (!(front.flags & ISurfaceComposer::eLayerHidden)) { mFreezeLock = mFlinger->getFreezeLock(); } } // this will make sure LayerBase::doTransaction doesn't update // the drawing state's size Layer::State& editDraw(mDrawingState); editDraw.requested_w = temp.requested_w; editDraw.requested_h = temp.requested_h; // record the new size, form this point on, when the client request // a buffer, it'll get the new size. setBufferSize(temp.requested_w, temp.requested_h); ClientRef::Access sharedClient(mUserClientRef); SharedBufferServer* lcblk(sharedClient.get()); if (lcblk) { // all buffers need reallocation lcblk->reallocateAll(); } } else { // record the new size setBufferSize(temp.requested_w, temp.requested_h); } } if (temp.sequence != front.sequence) { if (temp.flags & ISurfaceComposer::eLayerHidden || temp.alpha == 0) { // this surface is now hidden, so it shouldn't hold a freeze lock // (it may never redraw, which is fine if it is hidden) mFreezeLock.clear(); } } return LayerBase::doTransaction(flags); } void Layer::setBufferSize(uint32_t w, uint32_t h) { Mutex::Autolock _l(mLock); mWidth = w; mHeight = h; mNeedsScaling = mWidth != mReqWidth || mHeight != mReqHeight; } bool Layer::isFixedSize() const { Mutex::Autolock _l(mLock); return mFixedSize; } // ---------------------------------------------------------------------------- // pageflip handling... // ---------------------------------------------------------------------------- void Layer::lockPageFlip(bool& recomputeVisibleRegions) { ClientRef::Access sharedClient(mUserClientRef); SharedBufferServer* lcblk(sharedClient.get()); if (!lcblk) { // client died recomputeVisibleRegions = true; return; } ssize_t buf = lcblk->retireAndLock(); if (buf == NOT_ENOUGH_DATA) { // NOTE: This is not an error, it simply means there is nothing to // retire. The buffer is locked because we will use it // for composition later in the loop return; } if (buf < NO_ERROR) { LOGE("retireAndLock() buffer index (%d) out of range", int(buf)); mPostedDirtyRegion.clear(); return; } // we retired a buffer, which becomes the new front buffer if (mBufferManager.setActiveBufferIndex(buf) < NO_ERROR) { LOGE("retireAndLock() buffer index (%d) out of range", int(buf)); mPostedDirtyRegion.clear(); return; } sp newFrontBuffer(getBuffer(buf)); if (newFrontBuffer != NULL) { // get the dirty region // compute the posted region const Region dirty(lcblk->getDirtyRegion(buf)); mPostedDirtyRegion = dirty.intersect( newFrontBuffer->getBounds() ); // update the layer size and release freeze-lock const Layer::State& front(drawingState()); if (newFrontBuffer->getWidth() == front.requested_w && newFrontBuffer->getHeight() == front.requested_h) { if ((front.w != front.requested_w) || (front.h != front.requested_h)) { // Here we pretend the transaction happened by updating the // current and drawing states. Drawing state is only accessed // in this thread, no need to have it locked Layer::State& editDraw(mDrawingState); editDraw.w = editDraw.requested_w; editDraw.h = editDraw.requested_h; // We also need to update the current state so that we don't // end-up doing too much work during the next transaction. // NOTE: We actually don't need hold the transaction lock here // because State::w and State::h are only accessed from // this thread Layer::State& editTemp(currentState()); editTemp.w = editDraw.w; editTemp.h = editDraw.h; // recompute visible region recomputeVisibleRegions = true; } // we now have the correct size, unfreeze the screen mFreezeLock.clear(); } // get the crop region setBufferCrop( lcblk->getCrop(buf) ); // get the transformation setBufferTransform( lcblk->getTransform(buf) ); } else { // this should not happen unless we ran out of memory while // allocating the buffer. we're hoping that things will get back // to normal the next time the app tries to draw into this buffer. // meanwhile, pretend the screen didn't update. mPostedDirtyRegion.clear(); } if (lcblk->getQueuedCount()) { // signal an event if we have more buffers waiting mFlinger->signalEvent(); } /* a buffer was posted, so we need to call reloadTexture(), which * will update our internal data structures (eg: EGLImageKHR or * texture names). we need to do this even if mPostedDirtyRegion is * empty -- it's orthogonal to the fact that a new buffer was posted, * for instance, a degenerate case could be that the user did an empty * update but repainted the buffer with appropriate content (after a * resize for instance). */ reloadTexture( mPostedDirtyRegion ); } void Layer::unlockPageFlip( const Transform& planeTransform, Region& outDirtyRegion) { Region dirtyRegion(mPostedDirtyRegion); if (!dirtyRegion.isEmpty()) { mPostedDirtyRegion.clear(); // The dirty region is given in the layer's coordinate space // transform the dirty region by the surface's transformation // and the global transformation. const Layer::State& s(drawingState()); const Transform tr(planeTransform * s.transform); dirtyRegion = tr.transform(dirtyRegion); // At this point, the dirty region is in screen space. // Make sure it's constrained by the visible region (which // is in screen space as well). dirtyRegion.andSelf(visibleRegionScreen); outDirtyRegion.orSelf(dirtyRegion); } if (visibleRegionScreen.isEmpty()) { // an invisible layer should not hold a freeze-lock // (because it may never be updated and therefore never release it) mFreezeLock.clear(); } } void Layer::dump(String8& result, char* buffer, size_t SIZE) const { LayerBaseClient::dump(result, buffer, SIZE); ClientRef::Access sharedClient(mUserClientRef); SharedBufferServer* lcblk(sharedClient.get()); uint32_t totalTime = 0; if (lcblk) { SharedBufferStack::Statistics stats = lcblk->getStats(); totalTime= stats.totalTime; result.append( lcblk->dump(" ") ); } sp buf0(getBuffer(0)); sp buf1(getBuffer(1)); uint32_t w0=0, h0=0, s0=0; uint32_t w1=0, h1=0, s1=0; if (buf0 != 0) { w0 = buf0->getWidth(); h0 = buf0->getHeight(); s0 = buf0->getStride(); } if (buf1 != 0) { w1 = buf1->getWidth(); h1 = buf1->getHeight(); s1 = buf1->getStride(); } snprintf(buffer, SIZE, " " "format=%2d, [%3ux%3u:%3u] [%3ux%3u:%3u]," " freezeLock=%p, bypass=%d, dq-q-time=%u us\n", mFormat, w0, h0, s0, w1, h1, s1, getFreezeLock().get(), mBypassState, totalTime); result.append(buffer); } // --------------------------------------------------------------------------- Layer::ClientRef::ClientRef() : mControlBlock(0), mToken(-1) { } Layer::ClientRef::~ClientRef() { } int32_t Layer::ClientRef::getToken() const { Mutex::Autolock _l(mLock); return mToken; } sp Layer::ClientRef::getClient() const { Mutex::Autolock _l(mLock); return mUserClient.promote(); } status_t Layer::ClientRef::setToken(const sp& uc, const sp& sharedClient, int32_t token) { Mutex::Autolock _l(mLock); { // scope for strong mUserClient reference sp userClient(mUserClient.promote()); if (mUserClient != 0 && mControlBlock != 0) { mControlBlock->setStatus(NO_INIT); } } mUserClient = uc; mToken = token; mControlBlock = sharedClient; return NO_ERROR; } sp Layer::ClientRef::getUserClientUnsafe() const { return mUserClient.promote(); } // this class gives us access to SharedBufferServer safely // it makes sure the UserClient (and its associated shared memory) // won't go away while we're accessing it. Layer::ClientRef::Access::Access(const ClientRef& ref) : mControlBlock(0) { Mutex::Autolock _l(ref.mLock); mUserClientStrongRef = ref.mUserClient.promote(); if (mUserClientStrongRef != 0) mControlBlock = ref.mControlBlock; } Layer::ClientRef::Access::~Access() { } // --------------------------------------------------------------------------- Layer::BufferManager::BufferManager(TextureManager& tm) : mNumBuffers(NUM_BUFFERS), mTextureManager(tm), mActiveBuffer(-1), mFailover(false) { } Layer::BufferManager::~BufferManager() { } status_t Layer::BufferManager::resize(size_t size) { Mutex::Autolock _l(mLock); mNumBuffers = size; return NO_ERROR; } // only for debugging sp Layer::BufferManager::getBuffer(size_t index) const { return mBufferData[index].buffer; } status_t Layer::BufferManager::setActiveBufferIndex(size_t index) { mActiveBuffer = index; return NO_ERROR; } size_t Layer::BufferManager::getActiveBufferIndex() const { return mActiveBuffer; } Texture Layer::BufferManager::getActiveTexture() const { Texture res; if (mFailover || mActiveBuffer<0) { res = mFailoverTexture; } else { static_cast(res) = mBufferData[mActiveBuffer].texture; } return res; } sp Layer::BufferManager::getActiveBuffer() const { sp result; const ssize_t activeBuffer = mActiveBuffer; if (activeBuffer >= 0) { BufferData const * const buffers = mBufferData; Mutex::Autolock _l(mLock); result = buffers[activeBuffer].buffer; } return result; } sp Layer::BufferManager::detachBuffer(size_t index) { BufferData* const buffers = mBufferData; sp buffer; Mutex::Autolock _l(mLock); buffer = buffers[index].buffer; buffers[index].buffer = 0; return buffer; } status_t Layer::BufferManager::attachBuffer(size_t index, const sp& buffer) { BufferData* const buffers = mBufferData; Mutex::Autolock _l(mLock); buffers[index].buffer = buffer; buffers[index].texture.dirty = true; return NO_ERROR; } status_t Layer::BufferManager::destroy(EGLDisplay dpy) { BufferData* const buffers = mBufferData; size_t num; { // scope for the lock Mutex::Autolock _l(mLock); num = mNumBuffers; for (size_t i=0 ; i& buffer) { status_t err = NO_INIT; ssize_t index = mActiveBuffer; if (index >= 0) { if (!mFailover) { Image& texture(mBufferData[index].texture); err = mTextureManager.initEglImage(&texture, dpy, buffer); // if EGLImage fails, we switch to regular texture mode, and we // free all resources associated with using EGLImages. if (err == NO_ERROR) { mFailover = false; destroyTexture(&mFailoverTexture, dpy); } else { mFailover = true; const size_t num = mNumBuffers; for (size_t i=0 ; iname != -1U) { glDeleteTextures(1, &tex->name); tex->name = -1U; } if (tex->image != EGL_NO_IMAGE_KHR) { eglDestroyImageKHR(dpy, tex->image); tex->image = EGL_NO_IMAGE_KHR; } return NO_ERROR; } // --------------------------------------------------------------------------- Layer::SurfaceLayer::SurfaceLayer(const sp& flinger, const sp& owner) : Surface(flinger, owner->getIdentity(), owner) { } Layer::SurfaceLayer::~SurfaceLayer() { } sp Layer::SurfaceLayer::requestBuffer(int index, uint32_t w, uint32_t h, uint32_t format, uint32_t usage) { sp buffer; sp owner(getOwner()); if (owner != 0) { /* * requestBuffer() cannot be called from the main thread * as it could cause a dead-lock, since it may have to wait * on conditions updated my the main thread. */ buffer = owner->requestBuffer(index, w, h, format, usage); } return buffer; } status_t Layer::SurfaceLayer::setBufferCount(int bufferCount) { status_t err = DEAD_OBJECT; sp owner(getOwner()); if (owner != 0) { /* * setBufferCount() cannot be called from the main thread * as it could cause a dead-lock, since it may have to wait * on conditions updated my the main thread. */ err = owner->setBufferCount(bufferCount); } return err; } // --------------------------------------------------------------------------- }; // namespace android