bug 402763: cycle collect on memory-pressure notification, r/sr=stuart a=schrep

dom/src/base/nsDOMWindowUtils.cpp

@@ -53,7 +53,7 @@
 #include "nsIWidget.h"
 #include "nsGUIEvent.h"
 #include "nsIParser.h"
-#include "nsCycleCollector.h"
+#include "nsJSEnvironment.h"
 
 #ifdef MOZ_ENABLE_GTK2
 #include <gdk/gdkx.h>
@@ -341,8 +341,8 @@ nsDOMWindowUtils::GarbageCollect()
     return NS_ERROR_DOM_SECURITY_ERR;
 #endif
 
-  nsCycleCollector_collect();
-  nsCycleCollector_collect();
+  nsJSContext::CC();
+  nsJSContext::CC();
 
   return NS_OK;
 }

dom/src/base/nsJSEnvironment.cpp

@@ -281,6 +281,27 @@ nsUserActivityObserver::Observe(nsISupports* aSubject, const char* aTopic,
   return NS_OK;
 }
 
+// nsCCMemoryPressureObserver observes the memory-pressure notifications
+// and forces a cycle collection when it happens.
+
+class nsCCMemoryPressureObserver : public nsIObserver
+{
+public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIOBSERVER
+};
+
+NS_IMPL_ISUPPORTS1(nsCCMemoryPressureObserver, nsIObserver)
+
+NS_IMETHODIMP
+nsCCMemoryPressureObserver::Observe(nsISupports* aSubject, const char* aTopic,
+                                    const PRUnichar* aData)
+{
+  nsJSContext::CC();
+  return NS_OK;
+}
+
+
 /****************************************************************
  ************************** AutoFree ****************************
  ****************************************************************/
@@ -3620,6 +3641,10 @@ nsJSRuntime::Init()
   obs->AddObserver(activityObserver, "user-interaction-active", PR_FALSE);
   obs->AddObserver(activityObserver, "xpcom-shutdown", PR_FALSE);
 
+  nsIObserver* ccMemPressureObserver = new nsCCMemoryPressureObserver();
+  NS_ENSURE_TRUE(ccMemPressureObserver, NS_ERROR_OUT_OF_MEMORY);
+  obs->AddObserver(ccMemPressureObserver, "memory-pressure", PR_FALSE);
+
   rv = CallGetService(NS_SCRIPTSECURITYMANAGER_CONTRACTID, &sSecurityManager);
 
   sIsInitialized = NS_SUCCEEDED(rv);