Bug 700835 - Restore plugin caching to work around bad crash in lates…

…t Apple Java updates. r=josh a=akeybl
mozilla · Nov 12, 2011 · 2741cc5 · 2741cc5
1 parent d7d8529
commit 2741cc5
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Showing 5 changed files with 99 additions and 8 deletions.
diff --git a/dom/plugins/base/nsNPAPIPlugin.cpp b/dom/plugins/base/nsNPAPIPlugin.cpp
@@ -2480,9 +2480,8 @@ _setvalue(NPP npp, NPPVariable variable, void *result)
       }
 
     case NPPVpluginKeepLibraryInMemory: {
-      // This variable is not supported any more but we'll pretend it is
-      // so that plugins don't fail on an error return.
-      return NS_OK;
+      NPBool bCached = (result != nsnull);
+      return inst->SetCached(bCached);
     }
 
     case NPPVpluginUsesDOMForCursorBool: {

diff --git a/dom/plugins/base/nsNPAPIPluginInstance.cpp b/dom/plugins/base/nsNPAPIPluginInstance.cpp
@@ -95,6 +95,7 @@ nsNPAPIPluginInstance::nsNPAPIPluginInstance(nsNPAPIPlugin* plugin)
     mWindowless(PR_FALSE),
     mWindowlessLocal(PR_FALSE),
     mTransparent(PR_FALSE),
+    mCached(PR_FALSE),
     mUsesDOMForCursor(PR_FALSE),
     mInPluginInitCall(PR_FALSE),
     mPlugin(plugin),
@@ -142,6 +143,12 @@ nsNPAPIPluginInstance::Destroy()
   mPlugin = nsnull;
 }
 
+TimeStamp
+nsNPAPIPluginInstance::StopTime()
+{
+  return mStopTime;
+}
+
 nsresult nsNPAPIPluginInstance::Initialize(nsIPluginInstanceOwner* aOwner, const char* aMIMEType)
 {
   PLUGIN_LOG(PLUGIN_LOG_NORMAL, ("nsNPAPIPluginInstance::Initialize this=%p\n",this));
@@ -200,6 +207,7 @@ nsresult nsNPAPIPluginInstance::Stop()
   {
     AsyncCallbackAutoLock lock;
     mRunning = DESTROYING;
+    mStopTime = TimeStamp::Now();
   }
 
   OnPluginDestroy(&mNPP);
@@ -873,6 +881,19 @@ nsNPAPIPluginInstance::DefineJavaProperties()
   return NS_OK;
 }
 
+nsresult
+nsNPAPIPluginInstance::SetCached(PRBool aCache)
+{
+  mCached = aCache;
+  return NS_OK;
+}
+
+PRBool
+nsNPAPIPluginInstance::ShouldCache()
+{
+  return mCached;
+}
+
 nsresult
 nsNPAPIPluginInstance::IsWindowless(PRBool* isWindowless)
 {

diff --git a/dom/plugins/base/nsNPAPIPluginInstance.h b/dom/plugins/base/nsNPAPIPluginInstance.h
@@ -95,6 +95,7 @@ class nsNPAPIPluginInstance : public nsISupports
   nsresult IsRemoteDrawingCoreAnimation(PRBool* aDrawing);
   nsresult GetJSObject(JSContext *cx, JSObject** outObject);
   nsresult DefineJavaProperties();
+  PRBool ShouldCache();
   nsresult IsWindowless(PRBool* isWindowless);
   nsresult AsyncSetWindow(NPWindow* window);
   nsresult GetImage(ImageContainer* aContainer, Image** aImage);
@@ -173,6 +174,12 @@ class nsNPAPIPluginInstance : public nsISupports
     return mRunning == RUNNING || mRunning == DESTROYING;
   }
 
+  // return is only valid when the plugin is not running
+  mozilla::TimeStamp StopTime();
+
+  // cache this NPAPI plugin
+  nsresult SetCached(PRBool aCache);
+
   already_AddRefed<nsPIDOMWindow> GetDOMWindow();
 
   nsresult PrivateModeStateChanged();
@@ -232,6 +239,7 @@ class nsNPAPIPluginInstance : public nsISupports
   PRPackedBool mWindowless;
   PRPackedBool mWindowlessLocal;
   PRPackedBool mTransparent;
+  PRPackedBool mCached;
   PRPackedBool mUsesDOMForCursor;
 
 public:
@@ -260,6 +268,10 @@ class nsNPAPIPluginInstance : public nsISupports
   // non-null during a HandleEvent call
   void* mCurrentPluginEvent;
 
+  // Timestamp for the last time this plugin was stopped.
+  // This is only valid when the plugin is actually stopped!
+  mozilla::TimeStamp mStopTime;
+
   nsCOMPtr<nsIURI> mURI;
 
   PRPackedBool mUsePluginLayersPref;

diff --git a/dom/plugins/base/nsPluginHost.cpp b/dom/plugins/base/nsPluginHost.cpp
@@ -230,6 +230,10 @@ PRLogModuleInfo* nsPluginLogging::gPluginLog = nsnull;
 #define BRAND_PROPERTIES_URL "chrome://branding/locale/brand.properties"
 #define PLUGIN_PROPERTIES_URL "chrome://global/locale/downloadProgress.properties"
 
+// #defines for plugin cache and prefs
+#define NS_PREF_MAX_NUM_CACHED_INSTANCES "browser.plugins.max_num_cached_plugins"
+#define DEFAULT_NUMBER_OF_STOPPED_INSTANCES 10
+
 #ifdef CALL_SAFETY_ON
 // By default we run OOPP, so we don't want to cover up crashes.
 PRBool gSkipPluginSafeCalls = PR_TRUE;
@@ -3198,13 +3202,34 @@ nsPluginHost::StopPluginInstance(nsNPAPIPluginInstance* aInstance)
     return NS_OK;
   }
 
-  nsPluginTag* pluginTag = TagForPlugin(aInstance->GetPlugin());
-
   aInstance->Stop();
-  aInstance->Destroy();
-  mInstances.RemoveElement(aInstance);
 
-  OnPluginInstanceDestroyed(pluginTag);
+  // if the instance does not want to be 'cached' just remove it
+  PRBool doCache = aInstance->ShouldCache();
+  if (doCache) {
+    // try to get the max cached instances from a pref or use default
+    PRUint32 cachedInstanceLimit;
+    nsresult rv = NS_ERROR_FAILURE;
+    if (mPrefService)
+      rv = mPrefService->GetIntPref(NS_PREF_MAX_NUM_CACHED_INSTANCES, (int*)&cachedInstanceLimit);
+    if (NS_FAILED(rv))
+      cachedInstanceLimit = DEFAULT_NUMBER_OF_STOPPED_INSTANCES;
+
+    if (StoppedInstanceCount() >= cachedInstanceLimit) {
+      nsNPAPIPluginInstance *oldestInstance = FindOldestStoppedInstance();
+      if (oldestInstance) {
+        nsPluginTag* pluginTag = TagForPlugin(oldestInstance->GetPlugin());
+        oldestInstance->Destroy();
+        mInstances.RemoveElement(oldestInstance);
+        OnPluginInstanceDestroyed(pluginTag);
+      }
+    }
+  } else {
+    nsPluginTag* pluginTag = TagForPlugin(aInstance->GetPlugin());
+    aInstance->Destroy();
+    mInstances.RemoveElement(aInstance);
+    OnPluginInstanceDestroyed(pluginTag);
+  }
 
   return NS_OK;
 }
@@ -3930,6 +3955,38 @@ nsPluginHost::FindInstance(const char *mimetype)
   return nsnull;
 }
 
+nsNPAPIPluginInstance*
+nsPluginHost::FindOldestStoppedInstance()
+{
+  nsNPAPIPluginInstance *oldestInstance = nsnull;
+  TimeStamp oldestTime = TimeStamp::Now();
+  for (PRUint32 i = 0; i < mInstances.Length(); i++) {
+    nsNPAPIPluginInstance *instance = mInstances[i];
+    if (instance->IsRunning())
+      continue;
+
+    TimeStamp time = instance->StopTime();
+    if (time < oldestTime) {
+      oldestTime = time;
+      oldestInstance = instance;
+    }
+  }
+
+  return oldestInstance;
+}
+
+PRUint32
+nsPluginHost::StoppedInstanceCount()
+{
+  PRUint32 stoppedCount = 0;
+  for (PRUint32 i = 0; i < mInstances.Length(); i++) {
+    nsNPAPIPluginInstance *instance = mInstances[i];
+    if (!instance->IsRunning())
+      stoppedCount++;
+  }
+  return stoppedCount;
+}
+
 nsTArray< nsRefPtr<nsNPAPIPluginInstance> >*
 nsPluginHost::InstanceArray()
 {

diff --git a/dom/plugins/base/nsPluginHost.h b/dom/plugins/base/nsPluginHost.h
@@ -205,6 +205,8 @@ class nsPluginHost : public nsIPluginHost,
                      const nsAString& browserDumpID);
 
   nsNPAPIPluginInstance *FindInstance(const char *mimetype);
+  nsNPAPIPluginInstance *FindOldestStoppedInstance();
+  PRUint32 StoppedInstanceCount();
 
   nsTArray< nsRefPtr<nsNPAPIPluginInstance> > *InstanceArray();