The Tor Browser: content/base/src/nsCCUncollectableMarker.cpp@6474c204b198 (annotated)

content/base/src/nsCCUncollectableMarker.cpp@6474c204b198 (annotated)

content/base/src/nsCCUncollectableMarker.cpp

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "nsCCUncollectableMarker.h"
 #include "nsIObserverService.h"
 #include "nsIDocShell.h"
 #include "nsServiceManagerUtils.h"
 #include "nsIContentViewer.h"
 #include "nsIDocument.h"
 #include "XULDocument.h"
 #include "nsIWindowMediator.h"
 #include "nsPIDOMWindow.h"
 #include "nsIWebNavigation.h"
 #include "nsISHistory.h"
 #include "nsISHEntry.h"
 #include "nsISHContainer.h"
 #include "nsIWindowWatcher.h"
 #include "mozilla/Services.h"
 #include "nsIXULWindow.h"
 #include "nsIAppShellService.h"
 #include "nsAppShellCID.h"
 #include "nsContentUtils.h"
 #include "nsGlobalWindow.h"
 #include "nsJSEnvironment.h"
 #include "nsInProcessTabChildGlobal.h"
 #include "nsFrameLoader.h"
 #include "mozilla/EventListenerManager.h"
 #include "mozilla/dom/Element.h"
 #include "xpcpublic.h"
 #include "nsObserverService.h"
 #include "nsFocusManager.h"
 using namespace mozilla;
 using namespace mozilla::dom;
 static bool sInited = 0;
 uint32_t nsCCUncollectableMarker::sGeneration = 0;
 #ifdef MOZ_XUL
 #include "nsXULPrototypeCache.h"
 #endif
 NS_IMPL_ISUPPORTS(nsCCUncollectableMarker, nsIObserver)
 /* static */
 nsresult
 nsCCUncollectableMarker::Init()
 {
   if (sInited) {
     return NS_OK;
   }
   nsCOMPtr<nsIObserver> marker = new nsCCUncollectableMarker;
   NS_ENSURE_TRUE(marker, NS_ERROR_OUT_OF_MEMORY);
   nsCOMPtr<nsIObserverService> obs =
     mozilla::services::GetObserverService();
   if (!obs)
     return NS_ERROR_FAILURE;
   nsresult rv;
   // This makes the observer service hold an owning reference to the marker
   rv = obs->AddObserver(marker, "xpcom-shutdown", false);
   NS_ENSURE_SUCCESS(rv, rv);
   rv = obs->AddObserver(marker, "cycle-collector-begin", false);
   NS_ENSURE_SUCCESS(rv, rv);
   rv = obs->AddObserver(marker, "cycle-collector-forget-skippable", false);
   NS_ENSURE_SUCCESS(rv, rv);
   sInited = true;
   return NS_OK;
 }
 static void
 MarkUserData(void* aNode, nsIAtom* aKey, void* aValue, void* aData)
 {
   nsIDocument* d = static_cast<nsINode*>(aNode)->GetCurrentDoc();
   if (d && nsCCUncollectableMarker::InGeneration(d->GetMarkedCCGeneration())) {
     Element::MarkUserData(aNode, aKey, aValue, aData);
   }
 }
 static void
 MarkUserDataHandler(void* aNode, nsIAtom* aKey, void* aValue, void* aData)
 {
   nsIDocument* d = static_cast<nsINode*>(aNode)->GetCurrentDoc();
   if (d && nsCCUncollectableMarker::InGeneration(d->GetMarkedCCGeneration())) {
     Element::MarkUserDataHandler(aNode, aKey, aValue, aData);
   }
 }
 static void
 MarkMessageManagers()
 {
   // The global message manager only exists in the root process.
   if (XRE_GetProcessType() != GeckoProcessType_Default) {
     return;
   }
   nsCOMPtr<nsIMessageBroadcaster> strongGlobalMM =
     do_GetService("@mozilla.org/globalmessagemanager;1");
   if (!strongGlobalMM) {
     return;
   }
   nsIMessageBroadcaster* globalMM = strongGlobalMM;
   strongGlobalMM = nullptr;
   globalMM->MarkForCC();
   uint32_t childCount = 0;
   globalMM->GetChildCount(&childCount);
   for (uint32_t i = 0; i < childCount; ++i) {
     nsCOMPtr<nsIMessageListenerManager> childMM;
     globalMM->GetChildAt(i, getter_AddRefs(childMM));
     if (!childMM) {
       continue;
     }
     nsCOMPtr<nsIMessageBroadcaster> strongWindowMM = do_QueryInterface(childMM);
     nsIMessageBroadcaster* windowMM = strongWindowMM;
     childMM = nullptr;
     strongWindowMM = nullptr;
     windowMM->MarkForCC();
     uint32_t tabChildCount = 0;
     windowMM->GetChildCount(&tabChildCount);
     for (uint32_t j = 0; j < tabChildCount; ++j) {
       nsCOMPtr<nsIMessageListenerManager> childMM;
       windowMM->GetChildAt(j, getter_AddRefs(childMM));
       if (!childMM) {
         continue;
       }
       nsCOMPtr<nsIMessageSender> strongTabMM = do_QueryInterface(childMM);
       nsIMessageSender* tabMM = strongTabMM;
       childMM = nullptr;
       strongTabMM = nullptr;
       tabMM->MarkForCC();
       //XXX hack warning, but works, since we know that
       //    callback is frameloader.
       mozilla::dom::ipc::MessageManagerCallback* cb =
         static_cast<nsFrameMessageManager*>(tabMM)->GetCallback();
       if (cb) {
         nsFrameLoader* fl = static_cast<nsFrameLoader*>(cb);
         EventTarget* et = fl->GetTabChildGlobalAsEventTarget();
         if (!et) {
           continue;
         }
         static_cast<nsInProcessTabChildGlobal*>(et)->MarkForCC();
         EventListenerManager* elm = et->GetExistingListenerManager();
         if (elm) {
           elm->MarkForCC();
         }
       }
     }
   }
   if (nsFrameMessageManager::sParentProcessManager) {
     nsFrameMessageManager::sParentProcessManager->MarkForCC();
     uint32_t childCount = 0;
     nsFrameMessageManager::sParentProcessManager->GetChildCount(&childCount);
     for (uint32_t i = 0; i < childCount; ++i) {
       nsCOMPtr<nsIMessageListenerManager> childMM;
       nsFrameMessageManager::sParentProcessManager->
         GetChildAt(i, getter_AddRefs(childMM));
       if (!childMM) {
         continue;
       }
       nsIMessageListenerManager* child = childMM;
       childMM = nullptr;
       child->MarkForCC();
     }
   }
   if (nsFrameMessageManager::sSameProcessParentManager) {
     nsFrameMessageManager::sSameProcessParentManager->MarkForCC();
   }
   if (nsFrameMessageManager::sChildProcessManager) {
     nsFrameMessageManager::sChildProcessManager->MarkForCC();
   }
 }
 void
 MarkContentViewer(nsIContentViewer* aViewer, bool aCleanupJS,
                   bool aPrepareForCC)
 {
   if (!aViewer) {
     return;
   }
   nsIDocument *doc = aViewer->GetDocument();
   if (doc &&
       doc->GetMarkedCCGeneration() != nsCCUncollectableMarker::sGeneration) {
     doc->MarkUncollectableForCCGeneration(nsCCUncollectableMarker::sGeneration);
     if (aCleanupJS) {
       EventListenerManager* elm = doc->GetExistingListenerManager();
       if (elm) {
         elm->MarkForCC();
       }
       nsCOMPtr<EventTarget> win = do_QueryInterface(doc->GetInnerWindow());
       if (win) {
         elm = win->GetExistingListenerManager();
         if (elm) {
           elm->MarkForCC();
         }
         static_cast<nsGlobalWindow*>(win.get())->UnmarkGrayTimers();
       }
       doc->PropertyTable(DOM_USER_DATA_HANDLER)->
         EnumerateAll(MarkUserDataHandler, &nsCCUncollectableMarker::sGeneration);
     } else if (aPrepareForCC) {
       // Unfortunately we need to still mark user data just before running CC so
       // that it has the right generation.
       doc->PropertyTable(DOM_USER_DATA)->
         EnumerateAll(MarkUserData, &nsCCUncollectableMarker::sGeneration);
     }
   }
   if (doc) {
     nsPIDOMWindow* inner = doc->GetInnerWindow();
     if (inner) {
       inner->MarkUncollectableForCCGeneration(nsCCUncollectableMarker::sGeneration);
     }
     nsPIDOMWindow* outer = doc->GetWindow();
     if (outer) {
       outer->MarkUncollectableForCCGeneration(nsCCUncollectableMarker::sGeneration);
     }
   }
 }
 void MarkDocShell(nsIDocShellTreeItem* aNode, bool aCleanupJS,
                   bool aPrepareForCC);
 void
 MarkSHEntry(nsISHEntry* aSHEntry, bool aCleanupJS, bool aPrepareForCC)
 {
   if (!aSHEntry) {
     return;
   }
   nsCOMPtr<nsIContentViewer> cview;
   aSHEntry->GetContentViewer(getter_AddRefs(cview));
   MarkContentViewer(cview, aCleanupJS, aPrepareForCC);
   nsCOMPtr<nsIDocShellTreeItem> child;
   int32_t i = 0;
   while (NS_SUCCEEDED(aSHEntry->ChildShellAt(i++, getter_AddRefs(child))) &&
          child) {
     MarkDocShell(child, aCleanupJS, aPrepareForCC);
   }
   nsCOMPtr<nsISHContainer> shCont = do_QueryInterface(aSHEntry);
   int32_t count;
   shCont->GetChildCount(&count);
   for (i = 0; i < count; ++i) {
     nsCOMPtr<nsISHEntry> childEntry;
     shCont->GetChildAt(i, getter_AddRefs(childEntry));
     MarkSHEntry(childEntry, aCleanupJS, aPrepareForCC);
   }
 }
 void
 MarkDocShell(nsIDocShellTreeItem* aNode, bool aCleanupJS, bool aPrepareForCC)
 {
   nsCOMPtr<nsIDocShell> shell = do_QueryInterface(aNode);
   if (!shell) {
     return;
   }
   nsCOMPtr<nsIContentViewer> cview;
   shell->GetContentViewer(getter_AddRefs(cview));
   MarkContentViewer(cview, aCleanupJS, aPrepareForCC);
   nsCOMPtr<nsIWebNavigation> webNav = do_QueryInterface(shell);
   nsCOMPtr<nsISHistory> history;
   webNav->GetSessionHistory(getter_AddRefs(history));
   if (history) {
     int32_t i, historyCount;
     history->GetCount(&historyCount);
     for (i = 0; i < historyCount; ++i) {
       nsCOMPtr<nsISHEntry> shEntry;
       history->GetEntryAtIndex(i, false, getter_AddRefs(shEntry));
       MarkSHEntry(shEntry, aCleanupJS, aPrepareForCC);
     }
   }
   int32_t i, childCount;
   aNode->GetChildCount(&childCount);
   for (i = 0; i < childCount; ++i) {
     nsCOMPtr<nsIDocShellTreeItem> child;
     aNode->GetChildAt(i, getter_AddRefs(child));
     MarkDocShell(child, aCleanupJS, aPrepareForCC);
   }
 }
 void
 MarkWindowList(nsISimpleEnumerator* aWindowList, bool aCleanupJS,
                bool aPrepareForCC)
 {
   nsCOMPtr<nsISupports> iter;
   while (NS_SUCCEEDED(aWindowList->GetNext(getter_AddRefs(iter))) &&
          iter) {
     nsCOMPtr<nsPIDOMWindow> window = do_QueryInterface(iter);
     if (window) {
       nsCOMPtr<nsIDocShell> rootDocShell = window->GetDocShell();
       MarkDocShell(rootDocShell, aCleanupJS, aPrepareForCC);
     }
   }
 }
 nsresult
 nsCCUncollectableMarker::Observe(nsISupports* aSubject, const char* aTopic,
                                  const char16_t* aData)
 {
   if (!strcmp(aTopic, "xpcom-shutdown")) {
     Element::ClearContentUnbinder();
     nsCOMPtr<nsIObserverService> obs =
       mozilla::services::GetObserverService();
     if (!obs)
       return NS_ERROR_FAILURE;
     // No need for kungFuDeathGrip here, yay observerservice!
     obs->RemoveObserver(this, "xpcom-shutdown");
     obs->RemoveObserver(this, "cycle-collector-begin");
     obs->RemoveObserver(this, "cycle-collector-forget-skippable");
     sGeneration = 0;
     return NS_OK;
   }
   NS_ASSERTION(!strcmp(aTopic, "cycle-collector-begin") ||
                !strcmp(aTopic, "cycle-collector-forget-skippable"), "wrong topic");
   // JS cleanup can be slow. Do it only if there has been a GC.
   bool cleanupJS =
     nsJSContext::CleanupsSinceLastGC() == 0 &&
     !strcmp(aTopic, "cycle-collector-forget-skippable");
   bool prepareForCC = !strcmp(aTopic, "cycle-collector-begin");
   if (prepareForCC) {
     Element::ClearContentUnbinder();
   }
   // Increase generation to effectively unmark all current objects
   if (!++sGeneration) {
     ++sGeneration;
   }
   nsFocusManager::MarkUncollectableForCCGeneration(sGeneration);
   nsresult rv;
   // Iterate all toplevel windows
   nsCOMPtr<nsISimpleEnumerator> windowList;
   nsCOMPtr<nsIWindowMediator> med =
     do_GetService(NS_WINDOWMEDIATOR_CONTRACTID);
   if (med) {
     rv = med->GetEnumerator(nullptr, getter_AddRefs(windowList));
     NS_ENSURE_SUCCESS(rv, rv);
     MarkWindowList(windowList, cleanupJS, prepareForCC);
   }
   nsCOMPtr<nsIWindowWatcher> ww =
     do_GetService(NS_WINDOWWATCHER_CONTRACTID);
   if (ww) {
     rv = ww->GetWindowEnumerator(getter_AddRefs(windowList));
     NS_ENSURE_SUCCESS(rv, rv);
     MarkWindowList(windowList, cleanupJS, prepareForCC);
   }
   nsCOMPtr<nsIAppShellService> appShell =
     do_GetService(NS_APPSHELLSERVICE_CONTRACTID);
   if (appShell) {
     nsCOMPtr<nsIXULWindow> hw;
     appShell->GetHiddenWindow(getter_AddRefs(hw));
     if (hw) {
       nsCOMPtr<nsIDocShell> shell;
       hw->GetDocShell(getter_AddRefs(shell));
       MarkDocShell(shell, cleanupJS, prepareForCC);
     }
     bool hasHiddenPrivateWindow = false;
     appShell->GetHasHiddenPrivateWindow(&hasHiddenPrivateWindow);
     if (hasHiddenPrivateWindow) {
       appShell->GetHiddenPrivateWindow(getter_AddRefs(hw));
       if (hw) {
         nsCOMPtr<nsIDocShell> shell;
         hw->GetDocShell(getter_AddRefs(shell));
         MarkDocShell(shell, cleanupJS, prepareForCC);
       }
     }
   }
 #ifdef MOZ_XUL
   nsXULPrototypeCache* xulCache = nsXULPrototypeCache::GetInstance();
   if (xulCache) {
     xulCache->MarkInCCGeneration(sGeneration);
   }
 #endif
   static bool previousWasJSCleanup = false;
   if (cleanupJS) {
     nsContentUtils::UnmarkGrayJSListenersInCCGenerationDocuments(sGeneration);
     MarkMessageManagers();
     nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
     static_cast<nsObserverService *>(obs.get())->UnmarkGrayStrongObservers();
     previousWasJSCleanup = true;
   } else if (previousWasJSCleanup) {
     previousWasJSCleanup = false;
     if (!prepareForCC) {
       xpc_UnmarkSkippableJSHolders();
     }
   }
   return NS_OK;
 }
 struct TraceClosure
 {
   TraceClosure(JSTracer* aTrc, uint32_t aGCNumber)
     : mTrc(aTrc), mGCNumber(aGCNumber)
   {}
   JSTracer* mTrc;
   uint32_t mGCNumber;
 };
 static PLDHashOperator
 TraceActiveWindowGlobal(const uint64_t& aId, nsGlobalWindow*& aWindow, void* aClosure)
 {
   if (aWindow->GetDocShell() && aWindow->IsOuterWindow()) {
     TraceClosure* closure = static_cast<TraceClosure*>(aClosure);
     aWindow->TraceGlobalJSObject(closure->mTrc);
 #ifdef MOZ_XUL
     nsIDocument* doc = aWindow->GetExtantDoc();
     if (doc && doc->IsXUL()) {
       XULDocument* xulDoc = static_cast<XULDocument*>(doc);
       xulDoc->TraceProtos(closure->mTrc, closure->mGCNumber);
     }
 #endif
   }
   return PL_DHASH_NEXT;
 }
 void
 mozilla::dom::TraceBlackJS(JSTracer* aTrc, uint32_t aGCNumber, bool aIsShutdownGC)
 {
 #ifdef MOZ_XUL
   // Mark the scripts held in the XULPrototypeCache. This is required to keep
   // the JS script in the cache live across GC.
   nsXULPrototypeCache* cache = nsXULPrototypeCache::MaybeGetInstance();
   if (cache) {
     if (aIsShutdownGC) {
       cache->FlushScripts();
     } else {
       cache->MarkInGC(aTrc);
     }
   }
 #endif
   if (!nsCCUncollectableMarker::sGeneration) {
     return;
   }
   TraceClosure closure(aTrc, aGCNumber);
   // Mark globals of active windows black.
   nsGlobalWindow::WindowByIdTable* windowsById =
     nsGlobalWindow::GetWindowsTable();
   if (windowsById) {
     windowsById->Enumerate(TraceActiveWindowGlobal, &closure);
   }
   // Mark the safe context black
   nsContentUtils::TraceSafeJSContext(aTrc);
 }

The Tor Browser / annotate

content/base/src/nsCCUncollectableMarker.cpp@6474c204b198 (annotated)

content/base/src/nsCCUncollectableMarker.cpp