Bug 1663486 - Synchronize ChildSHistory state when sending a browsing context to a new process. r=smaug

Differential Revision: https://phabricator.services.mozilla.com/D89419

docshell/base/BrowsingContext.cpp

@@ -409,8 +409,12 @@ void BrowsingContext::CreateFromIPC(BrowsingContext::IPCInitializer&& aInit,
   }
 
   context->mWindowless = aInit.mWindowless;
-  if (aInit.mHasSessionHistory) {
-    context->InitSessionHistory();
+  if (context->GetHasSessionHistory()) {
+    context->CreateChildSHistory();
+    if (StaticPrefs::fission_sessionHistoryInParent()) {
+      context->GetChildSessionHistory()->SetIndexAndLength(
+          aInit.mSessionHistoryIndex, aInit.mSessionHistoryCount, nsID());
+    }
   }
 
   // NOTE: Call through the `Set` methods for these values to ensure that any
@@ -607,7 +611,7 @@ void BrowsingContext::Attach(bool aFromIPC, ContentParent* aOriginProcess) {
     PopupBlocker::RegisterOpenPopupSpam();
   }
 
-  if (IsTop() && GetHasSessionHistory()) {
+  if (IsTop() && GetHasSessionHistory() && !mChildSessionHistory) {
     CreateChildSHistory();
   }
 
@@ -2069,7 +2073,10 @@ BrowsingContext::IPCInitializer BrowsingContext::GetIPCInitializer() {
   init.mUseRemoteTabs = mUseRemoteTabs;
   init.mUseRemoteSubframes = mUseRemoteSubframes;
   init.mOriginAttributes = mOriginAttributes;
-  init.mHasSessionHistory = mChildSessionHistory != nullptr;
+  if (mChildSessionHistory && StaticPrefs::fission_sessionHistoryInParent()) {
+    init.mSessionHistoryIndex = mChildSessionHistory->Index();
+    init.mSessionHistoryCount = mChildSessionHistory->Count();
+  }
   init.mRequestContextId = mRequestContextId;
   init.mFields = mFields.RawValues();
   return init;
@@ -2726,6 +2733,12 @@ void BrowsingContext::HistoryGo(int32_t aIndex,
   }
 }
 
+void BrowsingContext::SetChildSHistory(ChildSHistory* aChildSHistory) {
+  mChildSessionHistory = aChildSHistory;
+  mChildSessionHistory->SetBrowsingContext(this);
+  mFields.SetWithoutSyncing<IDX_HasSessionHistory>(true);
+}
+
 }  // namespace dom
 
 namespace ipc {
@@ -2768,6 +2781,8 @@ void IPDLParamTraits<dom::BrowsingContext::IPCInitializer>::Write(
   WriteIPDLParam(aMessage, aActor, aInit.mUseRemoteSubframes);
   WriteIPDLParam(aMessage, aActor, aInit.mOriginAttributes);
   WriteIPDLParam(aMessage, aActor, aInit.mRequestContextId);
+  WriteIPDLParam(aMessage, aActor, aInit.mSessionHistoryIndex);
+  WriteIPDLParam(aMessage, aActor, aInit.mSessionHistoryCount);
   WriteIPDLParam(aMessage, aActor, aInit.mFields);
 }
 
@@ -2783,6 +2798,10 @@ bool IPDLParamTraits<dom::BrowsingContext::IPCInitializer>::Read(
                      &aInit->mUseRemoteSubframes) ||
       !ReadIPDLParam(aMessage, aIterator, aActor, &aInit->mOriginAttributes) ||
       !ReadIPDLParam(aMessage, aIterator, aActor, &aInit->mRequestContextId) ||
+      !ReadIPDLParam(aMessage, aIterator, aActor,
+                     &aInit->mSessionHistoryIndex) ||
+      !ReadIPDLParam(aMessage, aIterator, aActor,
+                     &aInit->mSessionHistoryCount) ||
       !ReadIPDLParam(aMessage, aIterator, aActor, &aInit->mFields)) {
     return false;
   }

docshell/base/BrowsingContext.h

@@ -591,7 +591,8 @@ class BrowsingContext : public nsILoadContext, public nsWrapperCache {
     bool mWindowless = false;
     bool mUseRemoteTabs = false;
     bool mUseRemoteSubframes = false;
-    bool mHasSessionHistory = false;
+    int32_t mSessionHistoryIndex = -1;
+    int32_t mSessionHistoryCount = 0;
     OriginAttributes mOriginAttributes;
     uint64_t mRequestContextId = 0;
 
@@ -679,6 +680,12 @@ class BrowsingContext : public nsILoadContext, public nsWrapperCache {
   BrowsingContext(WindowContext* aParentWindow, BrowsingContextGroup* aGroup,
                   uint64_t aBrowsingContextId, Type aType, FieldValues&& aInit);
 
+  void SetChildSHistory(ChildSHistory* aChildSHistory);
+  already_AddRefed<ChildSHistory> ForgetChildSHistory() {
+    // FIXME Do we need to unset mHasSessionHistory?
+    return mChildSessionHistory.forget();
+  }
+
  private:
   void Attach(bool aFromIPC, ContentParent* aOriginProcess);
 

docshell/base/CanonicalBrowsingContext.cpp

@@ -164,6 +164,8 @@ void CanonicalBrowsingContext::ReplacedBy(
   if (mSessionHistory) {
     mSessionHistory->SetBrowsingContext(aNewContext);
     mSessionHistory.swap(aNewContext->mSessionHistory);
+    RefPtr<ChildSHistory> childSHistory = ForgetChildSHistory();
+    aNewContext->SetChildSHistory(childSHistory);
   }
 
   MOZ_ASSERT(aNewContext->mLoadingEntries.IsEmpty());

docshell/shistory/ChildSHistory.cpp

@@ -21,6 +21,10 @@ namespace dom {
 ChildSHistory::ChildSHistory(BrowsingContext* aBrowsingContext)
     : mBrowsingContext(aBrowsingContext) {}
 
+void ChildSHistory::SetBrowsingContext(BrowsingContext* aBrowsingContext) {
+  mBrowsingContext = aBrowsingContext;
+}
+
 void ChildSHistory::SetIsInProcess(bool aIsInProcess) {
   if (!aIsInProcess) {
     mHistory = nullptr;

docshell/shistory/ChildSHistory.h

@@ -44,6 +44,8 @@ class ChildSHistory : public nsISupports, public nsWrapperCache {
 
   explicit ChildSHistory(BrowsingContext* aBrowsingContext);
 
+  void SetBrowsingContext(BrowsingContext* aBrowsingContext);
+
   // Create or destroy the session history implementation in the child process.
   // This can be removed once session history is stored exclusively in the
   // parent process.