Bug 1329331 - Leave the Large-Allocation process after subsequent navigations, r=smaug

MozReview-Commit-ID: DfivmSEvzBu

browser/base/content/tabbrowser.xml

@@ -1688,7 +1688,8 @@
 
             // Abort if we're not going to change anything
             if (isRemote == aShouldBeRemote && !aOptions.newFrameloader && !aOptions.freshProcess &&
-                (!isRemote || aBrowser.getAttribute("remoteType") == aOptions.remoteType)) {
+                (!isRemote || aBrowser.getAttribute("remoteType") == aOptions.remoteType) &&
+                !aBrowser.frameLoader.isFreshProcess) {
               return false;
             }
 
@@ -1835,7 +1836,8 @@
               E10SUtils.getRemoteTypeForURI(aURL, gMultiProcessBrowser,
                                             currentRemoteType);
             if (currentRemoteType != aOptions.remoteType ||
-                aOptions.freshProcess || aOptions.newFrameloader) {
+                aOptions.freshProcess || aOptions.newFrameloader ||
+                aBrowser.frameLoader.isFreshProcess) {
               let remote = aOptions.remoteType != E10SUtils.NOT_REMOTE;
               return this.updateBrowserRemoteness(aBrowser, remote, aOptions);
             }

browser/modules/E10SUtils.jsm

@@ -152,6 +152,13 @@ this.E10SUtils = {
     if (aDocShell.QueryInterface(Ci.nsIDocShellTreeItem).sameTypeParent)
       return true;
 
+    // If we are in a fresh process, and it wouldn't be content visible to
+    // change processes, we want to load into a new process so that we can throw
+    // this one out.
+    if (aDocShell.inFreshProcess && aDocShell.isOnlyToplevelInTabGroup) {
+      return false;
+    }
+
     // If the URI can be loaded in the current process then continue
     return this.shouldLoadURIInThisProcess(aURI);
   },

docshell/base/nsDocShell.cpp

@@ -14758,3 +14758,10 @@ nsDocShell::GetIsOnlyToplevelInTabGroup(bool* aResult)
   *aResult = true;
   return NS_OK;
 }
+
+NS_IMETHODIMP
+nsDocShell::GetInFreshProcess(bool* aResult)
+{
+  *aResult = TabChild::GetWasFreshProcess();
+  return NS_OK;
+}

docshell/base/nsIDocShell.idl

@@ -1124,4 +1124,9 @@ interface nsIDocShell : nsIDocShellTreeItem
    * occuring in this docshell to be performed within a different docshell.
    */
   [infallible] readonly attribute boolean isOnlyToplevelInTabGroup;
+
+  /**
+   * Returns `true` if this docshell was created by a Large-Allocation load.
+   */
+  [infallible] readonly attribute boolean inFreshProcess;
 };

dom/base/nsFrameLoader.cpp

@@ -3668,6 +3668,13 @@ nsFrameLoader::GetIsDead(bool* aIsDead)
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsFrameLoader::GetIsFreshProcess(bool* aIsFreshProcess)
+{
+  *aIsFreshProcess = mFreshProcess;
+  return NS_OK;
+}
+
 nsIMessageSender*
 nsFrameLoader::GetProcessMessageManager() const
 {

dom/base/nsIFrameLoader.idl

@@ -268,6 +268,12 @@ interface nsIFrameLoader : nsISupports
    * Is `true` if the frameloader is dead (destroy has been called on it)
    */
   [infallible] readonly attribute boolean isDead;
+
+  /**
+   * Is `true` if the <xul:browser> which created this frameloader had the
+   * freshProcess attribute set when it was created.
+   */
+  [infallible] readonly attribute boolean isFreshProcess;
 };
 
 %{C++

dom/ipc/TabChild.cpp

@@ -157,6 +157,7 @@ static const char BEFORE_FIRST_PAINT[] = "before-first-paint";
 
 typedef nsDataHashtable<nsUint64HashKey, TabChild*> TabChildMap;
 static TabChildMap* sTabChildren;
+bool TabChild::sWasFreshProcess = false;
 
 TabChildBase::TabChildBase()
   : mTabChildGlobal(nullptr)
@@ -3070,6 +3071,7 @@ TabChild::RecvThemeChanged(nsTArray<LookAndFeelInt>&& aLookAndFeelIntCache)
 mozilla::ipc::IPCResult
 TabChild::RecvSetFreshProcess()
 {
+  MOZ_ASSERT(!sWasFreshProcess, "Can only be a fresh process once!");
   mIsFreshProcess = true;
   return IPC_OK();
 }

dom/ipc/TabChild.h

@@ -660,15 +660,28 @@ public:
 
   bool TakeIsFreshProcess()
   {
-    bool wasFreshProcess = mIsFreshProcess;
-    mIsFreshProcess = false;
-    return wasFreshProcess;
+    if (mIsFreshProcess) {
+      MOZ_ASSERT(!sWasFreshProcess,
+                 "At most one tabGroup may be a fresh process per process");
+      sWasFreshProcess = true;
+      mIsFreshProcess = false;
+      return true;
+    }
+    return false;
   }
 
   already_AddRefed<nsISHistory> GetRelatedSHistory();
 
   mozilla::dom::TabGroup* TabGroup();
 
+  // Returns `true` if this this process was created to load a docshell in a
+  // "Fresh Process". This value is initialized to `false`, and is set to `true`
+  // in RecvSetFreshProcess.
+  static bool GetWasFreshProcess()
+  {
+    return sWasFreshProcess;
+  }
+
 protected:
   virtual ~TabChild();
 
@@ -818,6 +831,8 @@ private:
   uintptr_t mNativeWindowHandle;
 #endif // defined(XP_WIN)
 
+  static bool sWasFreshProcess;
+
   DISALLOW_EVIL_CONSTRUCTORS(TabChild);
 };
 

dom/tests/browser/browser_largeAllocation.js

@@ -153,7 +153,9 @@ add_task(function*() {
 
     let pid3 = yield getPID(aBrowser);
 
-    is(pid2, pid3);
+    // We should have been kicked out of the large-allocation process by the
+    // load, meaning we're back in the first process.
+    is(pid1, pid3); // XXX: This may be flakey in multiple content process e10s?
 
     yield ContentTask.spawn(aBrowser, TEST_URI, TEST_URI => {
       content.document.location = TEST_URI;
@@ -197,18 +199,26 @@ add_task(function*() {
 
     let pid3 = yield getPID(aBrowser);
 
-    is(pid2, pid3, "PIDs 2 and 3 should match");
+    // We should have been kicked out of the large-allocation process by the
+    // load, meaning we're back in the first process.
+    is(pid1, pid3, "PIDs 1 and 3 should match");
 
-    // Navigate back to the previous page, loading it from bfcache
+    stopExpectNoProcess();
+
+    epc = expectProcessCreated();
+
+    // Navigate back to the previous page. As the large alloation process was
+    // left, it won't be in bfcache and will have to be loaded fresh.
     yield ContentTask.spawn(aBrowser, TEST_URI, TEST_URI => {
       content.window.history.back();
     });
 
+    yield epc;
+
     let pid4 = yield getPID(aBrowser);
 
     isnot(pid1, pid4, "PID 4 shouldn't match PID 1");
-    is(pid2, pid4, "PID 4 should match PID 2");
+    isnot(pid2, pid4, "PID 4 shouldn't match PID 2");
 
-    stopExpectNoProcess();
   });
 });