Bug 1274516 - Add a helper to iterate over all ContentParents and use it to clear the image cache in both the parent and child processes. r=billm r=seth

dom/ipc/ContentChild.cpp

@@ -60,6 +60,7 @@
 #include "mozilla/media/MediaChild.h"
 #include "mozilla/BasePrincipal.h"
 #include "mozilla/WebBrowserPersistDocumentChild.h"
+#include "imgLoader.h"
 
 #if defined(MOZ_CONTENT_SANDBOX)
 #if defined(XP_WIN)
@@ -2243,6 +2244,16 @@ ContentChild::RecvRegisterChromeItem(const ChromeRegistryItem& item)
   return true;
 }
 
+bool
+ContentChild::RecvClearImageCache(const bool& privateLoader, const bool& chrome)
+{
+  imgLoader* loader = privateLoader ? imgLoader::PrivateBrowsingLoader() :
+                                      imgLoader::NormalLoader();
+
+  loader->ClearCache(chrome);
+  return true;
+}
+
 bool
 ContentChild::RecvSetOffline(const bool& offline)
 {

dom/ipc/ContentChild.h

@@ -388,6 +388,9 @@ public:
                                   const bool& reset) override;
   virtual bool RecvRegisterChromeItem(const ChromeRegistryItem& item) override;
 
+  virtual bool RecvClearImageCache(const bool& privateLoader,
+                                   const bool& chrome) override;
+
   virtual mozilla::jsipc::PJavaScriptChild* AllocPJavaScriptChild() override;
 
   virtual bool DeallocPJavaScriptChild(mozilla::jsipc::PJavaScriptChild*) override;

dom/ipc/ContentParent.cpp

@@ -1400,15 +1400,8 @@ ContentParent::GetAll(nsTArray<ContentParent*>& aArray)
 {
   aArray.Clear();
 
-  if (!sContentParents) {
-    return;
-  }
-
-  for (ContentParent* cp = sContentParents->getFirst(); cp;
-     cp = cp->LinkedListElement<ContentParent>::getNext()) {
-    if (cp->mIsAlive) {
-      aArray.AppendElement(cp);
-    }
+  for (auto* cp : AllProcesses(eLive)) {
+    aArray.AppendElement(cp);
   }
 }
 
@@ -1417,12 +1410,7 @@ ContentParent::GetAllEvenIfDead(nsTArray<ContentParent*>& aArray)
 {
   aArray.Clear();
 
-  if (!sContentParents) {
-    return;
-  }
-
-  for (ContentParent* cp = sContentParents->getFirst(); cp;
-     cp = cp->LinkedListElement<ContentParent>::getNext()) {
+  for (auto* cp : AllProcesses(eAll)) {
     aArray.AppendElement(cp);
   }
 }
@@ -5109,17 +5097,14 @@ ContentParent::IgnoreIPCPrincipal()
 void
 ContentParent::NotifyUpdatedDictionaries()
 {
-  AutoTArray<ContentParent*, 8> processes;
-  GetAll(processes);
-
   nsCOMPtr<nsISpellChecker> spellChecker(do_GetService(NS_SPELLCHECKER_CONTRACTID));
   MOZ_ASSERT(spellChecker, "No spell checker?");
 
   InfallibleTArray<nsString> dictionaries;
   spellChecker->GetDictionaryList(&dictionaries);
 
-  for (size_t i = 0; i < processes.Length(); ++i) {
-    Unused << processes[i]->SendUpdateDictionaryList(dictionaries);
+  for (auto* cp : AllProcesses(eLive)) {
+    Unused << cp->SendUpdateDictionaryList(dictionaries);
   }
 }
 

dom/ipc/ContentParent.h

@@ -166,6 +166,61 @@ public:
 
   static void GetAllEvenIfDead(nsTArray<ContentParent*>& aArray);
 
+  enum CPIteratorPolicy {
+    eLive,
+    eAll
+  };
+
+  class ContentParentIterator {
+  private:
+    ContentParent* mCurrent;
+    CPIteratorPolicy mPolicy;
+
+  public:
+    ContentParentIterator(CPIteratorPolicy aPolicy, ContentParent* aCurrent)
+      : mCurrent(aCurrent),
+        mPolicy(aPolicy)
+    {
+    }
+
+    ContentParentIterator begin()
+    {
+      return *this;
+    }
+    ContentParentIterator end()
+    {
+      return ContentParentIterator(mPolicy, nullptr);
+    }
+
+    const ContentParentIterator& operator++()
+    {
+      MOZ_ASSERT(mCurrent);
+      do {
+        mCurrent = mCurrent->LinkedListElement<ContentParent>::getNext();
+      } while (mPolicy != eAll && mCurrent && !mCurrent->mIsAlive);
+
+      return *this;
+    }
+
+    bool operator!=(const ContentParentIterator& aOther)
+    {
+      MOZ_ASSERT(mPolicy == aOther.mPolicy);
+      return mCurrent != aOther.mCurrent;
+    }
+
+    ContentParent* operator*()
+    {
+      return mCurrent;
+    }
+  };
+
+  static ContentParentIterator AllProcesses(CPIteratorPolicy aPolicy)
+  {
+    ContentParent* first =
+      sContentParents ? sContentParents->getFirst() : nullptr;
+    return ContentParentIterator(aPolicy, first);
+  }
+
   static bool IgnoreIPCPrincipal();
 
   static void NotifyUpdatedDictionaries();

dom/ipc/PContent.ipdl

@@ -514,6 +514,8 @@ child:
                          OverrideMapping[] overrides, nsCString locale, bool reset);
     async RegisterChromeItem(ChromeRegistryItem item);
 
+    async ClearImageCache(bool privateLoader, bool chrome);
+
     async SetOffline(bool offline);
     async SetConnectivity(bool connectivity);
 

image/imgLoader.cpp

@@ -8,7 +8,7 @@
 #include "mozilla/ClearOnShutdown.h"
 #include "mozilla/Move.h"
 #include "mozilla/Preferences.h"
- #include "mozilla/ChaosMode.h"
+#include "mozilla/ChaosMode.h"
 
 #include "ImageLogging.h"
 #include "nsImageModule.h"
@@ -37,6 +37,7 @@
 #include "nsIFile.h"
 #include "nsCRT.h"
 #include "nsINetworkPredictor.h"
+#include "mozilla/dom/ContentParent.h"
 #include "mozilla/dom/nsMixedContentBlocker.h"
 
 #include "nsIApplicationCache.h"
@@ -57,6 +58,7 @@
 #include "nsIDOMDocument.h"
 
 using namespace mozilla;
+using namespace mozilla::dom;
 using namespace mozilla::image;
 using namespace mozilla::net;
 
@@ -1344,6 +1346,13 @@ void imgLoader::ReadAcceptHeaderPref()
 NS_IMETHODIMP
 imgLoader::ClearCache(bool chrome)
 {
+  if (XRE_IsParentProcess()) {
+    bool privateLoader = this == gPrivateBrowsingLoader;
+    for (auto* cp : ContentParent::AllProcesses(ContentParent::eLive)) {
+      Unused << cp->SendClearImageCache(privateLoader, chrome);
+    }
+  }
+
   if (chrome) {
     return ClearChromeImageCache();
   } else {