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-rw-r--r--dom/base/nsCCUncollectableMarker.cpp550
1 files changed, 550 insertions, 0 deletions
diff --git a/dom/base/nsCCUncollectableMarker.cpp b/dom/base/nsCCUncollectableMarker.cpp
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index 000000000..861cda521
--- /dev/null
+++ b/dom/base/nsCCUncollectableMarker.cpp
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 "nsITabChild.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/CycleCollectedJSContext.h"
+#include "mozilla/EventListenerManager.h"
+#include "mozilla/dom/Element.h"
+#include "mozilla/dom/ProcessGlobal.h"
+#include "xpcpublic.h"
+#include "nsObserverService.h"
+#include "nsFocusManager.h"
+#include "nsIInterfaceRequestorUtils.h"
+
+using namespace mozilla;
+using namespace mozilla::dom;
+
+static bool sInited = 0;
+// The initial value of sGeneration should not be the same as the
+// value it is given at xpcom-shutdown, because this will make any GCs
+// before we first CC benignly violate the black-gray invariant, due
+// to dom::TraceBlackJS().
+uint32_t nsCCUncollectableMarker::sGeneration = 1;
+#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;
+
+ 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)->GetUncomposedDoc();
+ if (d && nsCCUncollectableMarker::InGeneration(d->GetMarkedCCGeneration())) {
+ Element::MarkUserData(aNode, aKey, aValue, aData);
+ }
+}
+
+static void
+MarkChildMessageManagers(nsIMessageBroadcaster* aMM)
+{
+ aMM->MarkForCC();
+
+ uint32_t tabChildCount = 0;
+ aMM->GetChildCount(&tabChildCount);
+ for (uint32_t j = 0; j < tabChildCount; ++j) {
+ nsCOMPtr<nsIMessageListenerManager> childMM;
+ aMM->GetChildAt(j, getter_AddRefs(childMM));
+ if (!childMM) {
+ continue;
+ }
+
+ nsCOMPtr<nsIMessageBroadcaster> strongNonLeafMM = do_QueryInterface(childMM);
+ nsIMessageBroadcaster* nonLeafMM = strongNonLeafMM;
+
+ nsCOMPtr<nsIMessageSender> strongTabMM = do_QueryInterface(childMM);
+ nsIMessageSender* tabMM = strongTabMM;
+
+ strongNonLeafMM = nullptr;
+ strongTabMM = nullptr;
+ childMM = nullptr;
+
+ if (nonLeafMM) {
+ MarkChildMessageManagers(nonLeafMM);
+ continue;
+ }
+
+ 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();
+ }
+ }
+ }
+}
+
+static void
+MarkMessageManagers()
+{
+ if (nsFrameMessageManager::GetChildProcessManager()) {
+ // ProcessGlobal's MarkForCC marks also ChildProcessManager.
+ ProcessGlobal* pg = ProcessGlobal::Get();
+ if (pg) {
+ pg->MarkForCC();
+ }
+ }
+
+ // The global message manager only exists in the root process.
+ if (!XRE_IsParentProcess()) {
+ return;
+ }
+ nsCOMPtr<nsIMessageBroadcaster> strongGlobalMM =
+ do_GetService("@mozilla.org/globalmessagemanager;1");
+ if (!strongGlobalMM) {
+ return;
+ }
+ nsIMessageBroadcaster* globalMM = strongGlobalMM;
+ strongGlobalMM = nullptr;
+ MarkChildMessageManagers(globalMM);
+
+ 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();
+ }
+}
+
+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();
+ }
+ } 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) {
+ if (nsPIDOMWindowInner* inner = doc->GetInnerWindow()) {
+ inner->MarkUncollectableForCCGeneration(nsCCUncollectableMarker::sGeneration);
+ }
+ if (nsPIDOMWindowOuter* outer = doc->GetWindow()) {
+ 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) {
+ if (nsCOMPtr<nsPIDOMWindowOuter> window = do_QueryInterface(iter)) {
+ nsCOMPtr<nsIDocShell> rootDocShell = window->GetDocShell();
+
+ MarkDocShell(rootDocShell, aCleanupJS, aPrepareForCC);
+
+ nsCOMPtr<nsITabChild> tabChild =
+ rootDocShell ? rootDocShell->GetTabChild() : nullptr;
+ if (tabChild) {
+ nsCOMPtr<nsIContentFrameMessageManager> mm;
+ tabChild->GetMessageManager(getter_AddRefs(mm));
+ if (mm) {
+ // MarkForCC ends up calling UnmarkGray on message listeners, which
+ // TraceBlackJS can't do yet.
+ mm->MarkForCC();
+ }
+ }
+ }
+ }
+}
+
+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
+
+ enum ForgetSkippableCleanupState
+ {
+ eInitial = 0,
+ eUnmarkJSEventListeners = 1,
+ eUnmarkMessageManagers = 2,
+ eUnmarkStrongObservers = 3,
+ eUnmarkJSHolders = 4,
+ eDone = 5
+ };
+
+ static_assert(eDone == NS_MAJOR_FORGET_SKIPPABLE_CALLS,
+ "There must be one forgetSkippable call per cleanup state.");
+
+ static uint32_t sFSState = eDone;
+ if (prepareForCC) {
+ sFSState = eDone;
+ return NS_OK;
+ }
+
+ if (cleanupJS) {
+ // After a GC we start clean up phases from the beginning,
+ // but we don't want to do the additional clean up phases here
+ // since we have done already plenty of gray unmarking while going through
+ // frame message managers and docshells.
+ sFSState = eInitial;
+ return NS_OK;
+ } else {
+ ++sFSState;
+ }
+
+ switch(sFSState) {
+ case eUnmarkJSEventListeners: {
+ nsContentUtils::UnmarkGrayJSListenersInCCGenerationDocuments();
+ break;
+ }
+ case eUnmarkMessageManagers: {
+ MarkMessageManagers();
+ break;
+ }
+ case eUnmarkStrongObservers: {
+ nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+ static_cast<nsObserverService *>(obs.get())->UnmarkGrayStrongObservers();
+ break;
+ }
+ case eUnmarkJSHolders: {
+ xpc_UnmarkSkippableJSHolders();
+ break;
+ }
+ default: {
+ break;
+ }
+ }
+
+ return NS_OK;
+}
+
+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;
+ }
+
+ if (nsFrameMessageManager::GetChildProcessManager()) {
+ nsIContentProcessMessageManager* pg = ProcessGlobal::Get();
+ if (pg) {
+ mozilla::TraceScriptHolder(pg, aTrc);
+ }
+ }
+
+ // Mark globals of active windows black.
+ nsGlobalWindow::WindowByIdTable* windowsById =
+ nsGlobalWindow::GetWindowsTable();
+ if (windowsById) {
+ for (auto iter = windowsById->Iter(); !iter.Done(); iter.Next()) {
+ nsGlobalWindow* window = iter.Data();
+ if (window->GetDocShell() && window->IsOuterWindow()) {
+ window->TraceGlobalJSObject(aTrc);
+ EventListenerManager* elm = window->GetExistingListenerManager();
+ if (elm) {
+ elm->TraceListeners(aTrc);
+ }
+
+ if (window->IsRootOuterWindow()) {
+ // In child process trace all the TabChildGlobals.
+ // Since there is one root outer window per TabChildGlobal, we need
+ // to look for only those windows, not all.
+ nsIDocShell* ds = window->GetDocShell();
+ if (ds) {
+ nsCOMPtr<nsITabChild> tabChild = ds->GetTabChild();
+ if (tabChild) {
+ nsCOMPtr<nsIContentFrameMessageManager> mm;
+ tabChild->GetMessageManager(getter_AddRefs(mm));
+ nsCOMPtr<EventTarget> et = do_QueryInterface(mm);
+ if (et) {
+ nsCOMPtr<nsISupports> tabChildAsSupports =
+ do_QueryInterface(tabChild);
+ mozilla::TraceScriptHolder(tabChildAsSupports, aTrc);
+ EventListenerManager* elm = et->GetExistingListenerManager();
+ if (elm) {
+ elm->TraceListeners(aTrc);
+ }
+ // As of now there isn't an easy way to trace message listeners.
+ }
+ }
+ }
+ }
+
+#ifdef MOZ_XUL
+ nsIDocument* doc = window->GetExtantDoc();
+ if (doc && doc->IsXULDocument()) {
+ XULDocument* xulDoc = static_cast<XULDocument*>(doc);
+ xulDoc->TraceProtos(aTrc, aGCNumber);
+ }
+#endif
+ }
+ }
+ }
+}