2011-03-11 Anders Carlsson <andersca@apple.com>

Reviewed by Sam Weinig. Add a shared memory cache to the web process https://bugs.webkit.org/show_bug.cgi?id=56232 Add a very simple shared memory cache to the web process, so that we don't have to allocate and free memory over and over when painting. * Shared/ShareableBitmap.cpp: (WebKit::ShareableBitmap::create): (WebKit::ShareableBitmap::createShareable): (WebKit::ShareableBitmap::resize): * Shared/ShareableBitmap.h: (WebKit::ShareableBitmap::numBytesNeededForBitmapSize): (WebKit::ShareableBitmap::sizeInBytes): Rename numBytesForSize to numBytesNeededForBitmapSize. * UIProcess/DrawingAreaProxyImpl.cpp: (WebKit::DrawingAreaProxyImpl::update): Always send back a DidUpdate message, even if we didn't use the update info. This is needed so that the web process knows when the UI process is done with the shared memory inside the update info struct. * WebKit2.xcodeproj/project.pbxproj: Add new files. * WebProcess/WebPage/DrawingArea.h: (WebKit::DrawingArea::didUpdate): * WebProcess/WebPage/DrawingArea.messages.in: DidUpdate now takes a boolean. * WebProcess/WebPage/DrawingAreaImpl.cpp: (WebKit::sharedMemoryCache): Add shared memory cache. (WebKit::DrawingAreaImpl::~DrawingAreaImpl): Return the shared memory to the cache. (WebKit::DrawingAreaImpl::sendDidUpdateBackingStoreState): display now takes an extra boolean. (WebKit::DrawingAreaImpl::didUpdate): Return the shared memory to the cache. (WebKit::DrawingAreaImpl::display): If useSharedMemoryCache is true, get shared memory from the cache. * WebProcess/WebPage/SharedMemoryCache.cpp: Added. (WebKit::SharedMemoryCache::acquireSharedMemory): If the memory we currently hold on to is big enough, return it. (WebKit::SharedMemoryCache::releaseSharedMemory): If we're already holding on to shared memory, evict it if the returned shared memory object is bigger than the one we currently hold. (WebKit::SharedMemoryCache::clearCacheTimerFired): Null out the shared memory object. Canonical link: https://commits.webkit.org/70784@main git-svn-id: https://svn.webkit.org/repository/webkit/trunk@80899 268f45cc-cd09-0410-ab3c-d52691b4dbfc
WebKit · Mar 12, 2011 · cc1bbe0 · cc1bbe0
1 parent 56b7521
commit cc1bbe0
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diff --git a/Source/WebKit2/ChangeLog b/Source/WebKit2/ChangeLog
@@ -1,3 +1,63 @@
+2011-03-11  Anders Carlsson  <andersca@apple.com>
+
+        Reviewed by Sam Weinig.
+
+        Add a shared memory cache to the web process
+        https://bugs.webkit.org/show_bug.cgi?id=56232
+
+        Add a very simple shared memory cache to the web process, so that we don't have to allocate and
+        free memory over and over when painting.
+
+        * Shared/ShareableBitmap.cpp:
+        (WebKit::ShareableBitmap::create):
+        (WebKit::ShareableBitmap::createShareable):
+        (WebKit::ShareableBitmap::resize):
+        * Shared/ShareableBitmap.h:
+        (WebKit::ShareableBitmap::numBytesNeededForBitmapSize):
+        (WebKit::ShareableBitmap::sizeInBytes):
+        Rename numBytesForSize to numBytesNeededForBitmapSize.
+
+        * UIProcess/DrawingAreaProxyImpl.cpp:
+        (WebKit::DrawingAreaProxyImpl::update):
+        Always send back a DidUpdate message, even if we didn't use the update info.
+        This is needed so that the web process knows when the UI process is done with the shared memory inside
+        the update info struct.
+
+        * WebKit2.xcodeproj/project.pbxproj:
+        Add new files.
+
+        * WebProcess/WebPage/DrawingArea.h:
+        (WebKit::DrawingArea::didUpdate):
+        * WebProcess/WebPage/DrawingArea.messages.in:
+        DidUpdate now takes a boolean.
+
+        * WebProcess/WebPage/DrawingAreaImpl.cpp:
+        (WebKit::sharedMemoryCache):
+        Add shared memory cache.
+
+        (WebKit::DrawingAreaImpl::~DrawingAreaImpl):
+        Return the shared memory to the cache.
+
+        (WebKit::DrawingAreaImpl::sendDidUpdateBackingStoreState):
+        display now takes an extra boolean.
+
+        (WebKit::DrawingAreaImpl::didUpdate):
+        Return the shared memory to the cache.
+
+        (WebKit::DrawingAreaImpl::display):
+        If useSharedMemoryCache is true, get shared memory from the cache.
+
+        * WebProcess/WebPage/SharedMemoryCache.cpp: Added.
+        (WebKit::SharedMemoryCache::acquireSharedMemory):
+        If the memory we currently hold on to is big enough, return it.
+
+        (WebKit::SharedMemoryCache::releaseSharedMemory):
+        If we're already holding on to shared memory, evict it if the returned
+        shared memory object is bigger than the one we currently hold.
+
+        (WebKit::SharedMemoryCache::clearCacheTimerFired):
+        Null out the shared memory object.
+
 2011-03-11  Jessie Berlin  <jberlin@apple.com>
 
         Reviewed by Adam Roben.

diff --git a/Source/WebKit2/Shared/ShareableBitmap.cpp b/Source/WebKit2/Shared/ShareableBitmap.cpp
@@ -35,7 +35,7 @@ namespace WebKit {
 
 PassRefPtr<ShareableBitmap> ShareableBitmap::create(const WebCore::IntSize& size)
 {
-    size_t numBytes = numBytesForSize(size);
+    size_t numBytes = numBytesNeededForBitmapSize(size);
 
     void* data = 0;
     if (!tryFastMalloc(numBytes).getValue(data))
@@ -46,7 +46,7 @@ PassRefPtr<ShareableBitmap> ShareableBitmap::create(const WebCore::IntSize& size
 
 PassRefPtr<ShareableBitmap> ShareableBitmap::createShareable(const IntSize& size)
 {
-    size_t numBytes = numBytesForSize(size);
+    size_t numBytes = numBytesNeededForBitmapSize(size);
 
     RefPtr<SharedMemory> sharedMemory = SharedMemory::create(numBytes);
     if (!sharedMemory)
@@ -59,7 +59,7 @@ PassRefPtr<ShareableBitmap> ShareableBitmap::create(const WebCore::IntSize& size
 {
     ASSERT(sharedMemory);
 
-    size_t numBytes = numBytesForSize(size);
+    size_t numBytes = numBytesNeededForBitmapSize(size);
     ASSERT_UNUSED(numBytes, sharedMemory->size() >= numBytes);
 
     return adoptRef(new ShareableBitmap(size, sharedMemory));
@@ -109,7 +109,7 @@ bool ShareableBitmap::resize(const IntSize& size)
     if (size == m_size)
         return true;
 
-    size_t newNumBytes = numBytesForSize(size);
+    size_t newNumBytes = numBytesNeededForBitmapSize(size);
 
     // Try to resize.
     char* newData = 0;

diff --git a/Source/WebKit2/Shared/ShareableBitmap.h b/Source/WebKit2/Shared/ShareableBitmap.h
@@ -58,6 +58,8 @@ class ShareableBitmap : public RefCounted<ShareableBitmap> {
 
     ~ShareableBitmap();
 
+    static size_t numBytesNeededForBitmapSize(const WebCore::IntSize& size) { return size.width() * size.height() * 4; }
+
     const WebCore::IntSize& size() const { return m_size; }
     WebCore::IntRect bounds() const { return WebCore::IntRect(WebCore::IntPoint(), size()); }
 
@@ -75,12 +77,10 @@ class ShareableBitmap : public RefCounted<ShareableBitmap> {
     ShareableBitmap(const WebCore::IntSize&, void*);
     ShareableBitmap(const WebCore::IntSize&, PassRefPtr<SharedMemory>);
 
-    static size_t numBytesForSize(const WebCore::IntSize& size) { return size.width() * size.height() * 4; }
-
     static void releaseData(void* typelessBitmap, void* typelessData);
 
     void* data() const;
-    size_t sizeInBytes() const { return numBytesForSize(m_size); }
+    size_t sizeInBytes() const { return numBytesNeededForBitmapSize(m_size); }
 
     WebCore::IntSize m_size;
 

diff --git a/Source/WebKit2/UIProcess/DrawingAreaProxyImpl.cpp b/Source/WebKit2/UIProcess/DrawingAreaProxyImpl.cpp
@@ -144,13 +144,16 @@ void DrawingAreaProxyImpl::setPageIsVisible(bool)
 void DrawingAreaProxyImpl::update(uint64_t backingStoreStateID, const UpdateInfo& updateInfo)
 {
     ASSERT_ARG(backingStoreStateID, backingStoreStateID <= m_currentBackingStoreStateID);
-    if (backingStoreStateID < m_currentBackingStoreStateID)
+    if (backingStoreStateID < m_currentBackingStoreStateID) {
+        // We still want to send back a message so that the web process knows that it can reuse the shared memory used for the update info.
+        m_webPageProxy->process()->send(Messages::DrawingArea::DidUpdate(false), m_webPageProxy->pageID());
         return;
+    }
 
     // FIXME: Handle the case where the view is hidden.
 
     incorporateUpdate(updateInfo);
-    m_webPageProxy->process()->send(Messages::DrawingArea::DidUpdate(), m_webPageProxy->pageID());
+    m_webPageProxy->process()->send(Messages::DrawingArea::DidUpdate(true), m_webPageProxy->pageID());
 }
 
 void DrawingAreaProxyImpl::didUpdateBackingStoreState(uint64_t backingStoreStateID, const UpdateInfo& updateInfo, const LayerTreeContext& layerTreeContext)

diff --git a/Source/WebKit2/WebKit2.xcodeproj/project.pbxproj b/Source/WebKit2/WebKit2.xcodeproj/project.pbxproj
@@ -75,6 +75,8 @@
 		1A24B5F311F531E800C38269 /* MachUtilities.h in Headers */ = {isa = PBXBuildFile; fileRef = 1A24B5F111F531E800C38269 /* MachUtilities.h */; };
 		1A24BED5120894D100FBB059 /* SharedMemory.h in Headers */ = {isa = PBXBuildFile; fileRef = 1A24BED3120894D100FBB059 /* SharedMemory.h */; };
 		1A24BF3A120896A600FBB059 /* SharedMemoryMac.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 1A24BF39120896A600FBB059 /* SharedMemoryMac.cpp */; };
+		1A27A5C8132AC86A001138FB /* SharedMemoryCache.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 1A27A5C6132AC86A001138FB /* SharedMemoryCache.cpp */; };
+		1A27A5C9132AC86A001138FB /* SharedMemoryCache.h in Headers */ = {isa = PBXBuildFile; fileRef = 1A27A5C7132AC86A001138FB /* SharedMemoryCache.h */; };
 		1A2C307112D555450063DAA2 /* ContextMenuState.h in Headers */ = {isa = PBXBuildFile; fileRef = 1A2C306F12D555450063DAA2 /* ContextMenuState.h */; };
 		1A2D82A4127F4EAB001EB962 /* NPObjectMessageReceiver.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 1A1FA35C127A45BF0050E709 /* NPObjectMessageReceiver.cpp */; };
 		1A2D82A5127F4EAB001EB962 /* NPObjectMessageReceiver.h in Headers */ = {isa = PBXBuildFile; fileRef = 1A1FA35B127A45BF0050E709 /* NPObjectMessageReceiver.h */; };
@@ -900,6 +902,8 @@
 		1A24B5F111F531E800C38269 /* MachUtilities.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MachUtilities.h; sourceTree = "<group>"; };
 		1A24BED3120894D100FBB059 /* SharedMemory.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SharedMemory.h; sourceTree = "<group>"; };
 		1A24BF39120896A600FBB059 /* SharedMemoryMac.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = SharedMemoryMac.cpp; sourceTree = "<group>"; };
+		1A27A5C6132AC86A001138FB /* SharedMemoryCache.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = SharedMemoryCache.cpp; sourceTree = "<group>"; };
+		1A27A5C7132AC86A001138FB /* SharedMemoryCache.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SharedMemoryCache.h; sourceTree = "<group>"; };
 		1A2C306F12D555450063DAA2 /* ContextMenuState.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ContextMenuState.h; sourceTree = "<group>"; };
 		1A2D8411127F64E8001EB962 /* NPObjectMessageReceiver.messages.in */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text; path = NPObjectMessageReceiver.messages.in; sourceTree = "<group>"; };
 		1A2D8437127F65D5001EB962 /* NPObjectMessageReceiverMessageReceiver.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = NPObjectMessageReceiverMessageReceiver.cpp; sourceTree = "<group>"; };
@@ -2323,6 +2327,8 @@
 				1A186EE812EF7618008E5F37 /* LayerTreeHost.h */,
 				1A90C23612650717003E44D4 /* PageOverlay.cpp */,
 				1A90C23512650717003E44D4 /* PageOverlay.h */,
+				1A27A5C6132AC86A001138FB /* SharedMemoryCache.cpp */,
+				1A27A5C7132AC86A001138FB /* SharedMemoryCache.h */,
 				BC72B9F811E6476B001EB4EA /* WebBackForwardListProxy.cpp */,
 				BC72B9F911E6476B001EB4EA /* WebBackForwardListProxy.h */,
 				51871B59127CB89D00F76232 /* WebContextMenu.cpp */,
@@ -3455,6 +3461,7 @@
 				37C4E9F6131C6E7E0029BD5A /* config.h in Headers */,
 				E1BB16A413201B9B00F49431 /* FullKeyboardAccessWatcher.h in Headers */,
 				33AA1067131F060000D4A575 /* WebCookieManagerProxyClient.h in Headers */,
+				1A27A5C9132AC86A001138FB /* SharedMemoryCache.h in Headers */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -4059,6 +4066,7 @@
 				CD73BA4E131ACDB700EEDED2 /* WebFullScreenManagerMessageReceiver.cpp in Sources */,
 				CD73BA53131B645B00EEDED2 /* WebFullScreenManager.cpp in Sources */,
 				CD6F75F4131B66D000D6B21E /* WebFullScreenManagerProxy.cpp in Sources */,
+				1A27A5C8132AC86A001138FB /* SharedMemoryCache.cpp in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

diff --git a/Source/WebKit2/WebProcess/WebPage/DrawingArea.h b/Source/WebKit2/WebProcess/WebPage/DrawingArea.h
@@ -86,7 +86,7 @@ class DrawingArea {
     // CoreIPC message handlers.
     // FIXME: These should be pure virtual.
     virtual void updateBackingStoreState(uint64_t backingStoreStateID, bool respondImmediately, const WebCore::IntSize& size, const WebCore::IntSize& scrollOffset) { }
-    virtual void didUpdate() { }
+    virtual void didUpdate(bool didIncorporateBackingStore) { }
     virtual void suspendPainting() { }
     virtual void resumePainting() { }
 };

diff --git a/Source/WebKit2/WebProcess/WebPage/DrawingArea.messages.in b/Source/WebKit2/WebProcess/WebPage/DrawingArea.messages.in
@@ -22,7 +22,7 @@
 
 messages -> DrawingArea {
     UpdateBackingStoreState(uint64_t backingStoreStateID, bool respondImmediately, WebCore::IntSize size, WebCore::IntSize scrollOffset)
-    DidUpdate()
+    DidUpdate(bool didIncorporateBackingStore)
     SuspendPainting()
     ResumePainting()
 }
diff --git a/Source/WebKit2/WebProcess/WebPage/DrawingAreaImpl.cpp b/Source/WebKit2/WebProcess/WebPage/DrawingAreaImpl.cpp
@@ -29,6 +29,7 @@
 #include "DrawingAreaProxyMessages.h"
 #include "LayerTreeContext.h"
 #include "ShareableBitmap.h"
+#include "SharedMemoryCache.h"
 #include "UpdateInfo.h"
 #include "WebPage.h"
 #include "WebPageCreationParameters.h"
@@ -45,13 +46,23 @@ using namespace WebCore;
 
 namespace WebKit {
 
+static SharedMemoryCache& sharedMemoryCache()
+{
+    DEFINE_STATIC_LOCAL(SharedMemoryCache, sharedMemoryCache, ());
+
+    return sharedMemoryCache;
+}
+
 PassOwnPtr<DrawingAreaImpl> DrawingAreaImpl::create(WebPage* webPage, const WebPageCreationParameters& parameters)
 {
     return adoptPtr(new DrawingAreaImpl(webPage, parameters));
 }
 
 DrawingAreaImpl::~DrawingAreaImpl()
 {
+    if (m_sharedMemoryUsedForLastUpdate)
+        sharedMemoryCache().releaseSharedMemory(m_sharedMemoryUsedForLastUpdate.release());
+
     if (m_layerTreeHost)
         m_layerTreeHost->invalidate();
 }
@@ -296,7 +307,7 @@ void DrawingAreaImpl::sendDidUpdateBackingStoreState()
     UpdateInfo updateInfo;
 
     if (!m_isPaintingSuspended && !m_layerTreeHost)
-        display(updateInfo);
+        display(updateInfo, false);
 
 #if USE(ACCELERATED_COMPOSITING)
     LayerTreeContext layerTreeContext;
@@ -319,8 +330,14 @@ void DrawingAreaImpl::sendDidUpdateBackingStoreState()
 #endif
 }
 
-void DrawingAreaImpl::didUpdate()
+void DrawingAreaImpl::didUpdate(bool didIncorporateBackingStore)
 {
+    ASSERT(m_sharedMemoryUsedForLastUpdate);
+    sharedMemoryCache().releaseSharedMemory(m_sharedMemoryUsedForLastUpdate.release());
+
+    if (!didIncorporateBackingStore)
+        return;
+
     // We might get didUpdate messages from the UI process even after we've
     // entered accelerated compositing mode. Ignore them.
     if (m_layerTreeHost)
@@ -395,7 +412,7 @@ void DrawingAreaImpl::exitAcceleratedCompositingMode()
     if (m_isPaintingSuspended)
         updateInfo.viewSize = m_webPage->size();
     else
-        display(updateInfo);
+        display(updateInfo, false);
 
 #if USE(ACCELERATED_COMPOSITING)
     // Send along a complete update of the page so we can paint the contents right after we exit the
@@ -462,7 +479,7 @@ void DrawingAreaImpl::display()
     }
 
     UpdateInfo updateInfo;
-    display(updateInfo);
+    display(updateInfo, true);
 
     if (m_layerTreeHost) {
         // The call to update caused layout which turned on accelerated compositing.
@@ -495,7 +512,7 @@ static bool shouldPaintBoundsRect(const IntRect& bounds, const Vector<IntRect>&
     return wastedSpace <= wastedSpaceThreshold;
 }
 
-void DrawingAreaImpl::display(UpdateInfo& updateInfo)
+void DrawingAreaImpl::display(UpdateInfo& updateInfo, bool useSharedMemoryCache)
 {
     ASSERT(!m_isPaintingSuspended);
     ASSERT(!m_layerTreeHost);
@@ -515,7 +532,19 @@ void DrawingAreaImpl::display(UpdateInfo& updateInfo)
     IntRect bounds = m_dirtyRegion.bounds();
     ASSERT(m_webPage->bounds().contains(bounds));
 
-    RefPtr<ShareableBitmap> bitmap = ShareableBitmap::createShareable(bounds.size());
+    RefPtr<ShareableBitmap> bitmap;
+    if (useSharedMemoryCache) {
+        size_t size = ShareableBitmap::numBytesNeededForBitmapSize(bounds.size());
+
+        ASSERT(!m_sharedMemoryUsedForLastUpdate);
+
+        m_sharedMemoryUsedForLastUpdate = sharedMemoryCache().acquireSharedMemory(size);
+        bitmap = ShareableBitmap::create(bounds.size(), m_sharedMemoryUsedForLastUpdate);
+    } else {
+        // Just create a new shareable bitmap.
+        bitmap = ShareableBitmap::createShareable(bounds.size());
+    }
+
     if (!bitmap->createHandle(updateInfo.bitmapHandle))
         return;
 

diff --git a/Source/WebKit2/WebProcess/WebPage/DrawingAreaImpl.h b/Source/WebKit2/WebProcess/WebPage/DrawingAreaImpl.h
@@ -33,6 +33,7 @@
 
 namespace WebKit {
 
+class SharedMemory;
 class UpdateInfo;
 
 class DrawingAreaImpl : public DrawingArea {
@@ -61,7 +62,7 @@ class DrawingAreaImpl : public DrawingArea {
 
     // CoreIPC message handlers.
     virtual void updateBackingStoreState(uint64_t backingStoreStateID, bool respondImmediately, const WebCore::IntSize&, const WebCore::IntSize& scrollOffset);
-    virtual void didUpdate();
+    virtual void didUpdate(bool didIncorporateBackingStore);
     virtual void suspendPainting();
     virtual void resumePainting();
 
@@ -74,7 +75,7 @@ class DrawingAreaImpl : public DrawingArea {
     void scheduleDisplay();
     void displayTimerFired();
     void display();
-    void display(UpdateInfo&);
+    void display(UpdateInfo&, bool useSharedMemoryCache);
 
     uint64_t m_backingStoreStateID;
 
@@ -105,6 +106,12 @@ class DrawingAreaImpl : public DrawingArea {
 
     // The layer tree host that handles accelerated compositing.
     RefPtr<LayerTreeHost> m_layerTreeHost;
+
+    // The shared memory we used for the last update. If possible, we'll try
+    // to reuse it for subsequent paints to avoid allocating/freeeing shared memory
+    // for every paint.
+    RefPtr<SharedMemory> m_sharedMemoryUsedForLastUpdate;
+
 };
 
 } // namespace WebKit