Bug 342854: Using JSContext callback to ensure that C stack limit is always set. r=brendan,mrbkap,sr=jst

git-svn-id: svn://10.0.0.236/trunk@205904 18797224-902f-48f8-a5cc-f745e15eee43

mozilla/dom/src/base/nsJSEnvironment.cpp

@@ -880,37 +880,6 @@ nsJSContext::JSOptionChangedCallback(const char *pref, void *data)
   return 0;
 }
 
-static jsuword
-GetThreadStackLimit()
-{
-  // Store the thread stack limit in a static local to ensure that all
-  // contexts get the same stack limit (they're all on the same thread
-  // anyways), and this also helps prevent returning a stack limit
-  // that is beyond the end of the stack if this method is called way
-  // deep on the stack.
-
-  static jsuword sThreadStackLimit;
-
-  if (sThreadStackLimit == 0) {
-    int stackDummy;
-    jsuword currentStackAddr = (jsuword)&stackDummy;
-
-    const jsuword kStackSize = 0x80000;   // 512k
-
-#if JS_STACK_GROWTH_DIRECTION < 0
-    sThreadStackLimit = (currentStackAddr > kStackSize)
-                        ? currentStackAddr - kStackSize
-                        : 0;
-#else
-    sThreadStackLimit = (currentStackAddr + kStackSize > currentStackAddr)
-                        ? currentStackAddr + kStackSize
-                        : (jsuword) -1;
-#endif
-  }
-
-  return sThreadStackLimit;
-}
-
 nsJSContext::nsJSContext(JSRuntime *aRuntime) : mGCOnDestruction(PR_TRUE)
 {
 
@@ -932,8 +901,6 @@ nsJSContext::nsJSContext(JSRuntime *aRuntime) : mGCOnDestruction(PR_TRUE)
   if (mContext) {
     ::JS_SetContextPrivate(mContext, NS_STATIC_CAST(nsIScriptContext *, this));
 
-    ::JS_SetThreadStackLimit(mContext, GetThreadStackLimit());
-
     // Make sure the new context gets the default context options
     ::JS_SetOptions(mContext, mDefaultJSOptions);
 

mozilla/js/src/xpconnect/src/xpcjsruntime.cpp

@@ -68,6 +68,9 @@ const char* XPCJSRuntime::mStrings[] = {
 
 /***************************************************************************/
 
+// ContextCallback calls are chained
+static JSContextCallback gOldJSContextCallback;
+
 // GCCallback calls are chained
 static JSGCCallback gOldJSGCCallback;
 
@@ -224,6 +227,28 @@ DetachedWrappedNativeProtoMarker(JSDHashTable *table, JSDHashEntryHdr *hdr,
     return JS_DHASH_NEXT;
 }
 
+// GCCallback calls are chained
+JS_STATIC_DLL_CALLBACK(JSBool)
+ContextCallback(JSContext *cx, uintN operation)
+{
+    XPCJSRuntime* self = nsXPConnect::GetRuntime();
+    if (self)
+    {
+        if (operation == JSCONTEXT_NEW)
+        {
+            XPCPerThreadData* tls = XPCPerThreadData::GetData();
+            if(tls)
+            {
+                JS_SetThreadStackLimit(cx, tls->GetStackLimit());
+            }
+        }
+    }
+
+    return gOldJSContextCallback
+           ? gOldJSContextCallback(cx, operation)
+           : JS_TRUE;
+}
+
 // static
 JSBool XPCJSRuntime::GCCallback(JSContext *cx, JSGCStatus status)
 {
@@ -768,6 +793,7 @@ XPCJSRuntime::~XPCJSRuntime()
     XPCConvert::RemoveXPCOMUCStringFinalizer();
 
     gOldJSGCCallback = NULL;
+    gOldJSContextCallback = NULL;
 }
 
 XPCJSRuntime::XPCJSRuntime(nsXPConnect* aXPConnect,
@@ -811,7 +837,11 @@ XPCJSRuntime::XPCJSRuntime(nsXPConnect* aXPConnect,
 
     NS_ASSERTION(!gOldJSGCCallback, "XPCJSRuntime created more than once");
     if(mJSRuntime)
+    {
+        gOldJSContextCallback = JS_SetContextCallback(mJSRuntime,
+                                                      ContextCallback);
         gOldJSGCCallback = JS_SetGCCallbackRT(mJSRuntime, GCCallback);
+    }
 
     // Install a JavaScript 'debugger' keyword handler in debug builds only
 #ifdef DEBUG

mozilla/js/src/xpconnect/src/xpcprivate.h

@@ -2893,6 +2893,8 @@ public:
     void MarkAutoRootsBeforeJSFinalize(JSContext* cx);
     void MarkAutoRootsAfterJSFinalize();
 
+    jsuword GetStackLimit() const { return mStackLimit; }
+
     static void InitStatics()
         { gLock = nsnull; gThreads = nsnull; gTLSIndex = BAD_TLS_INDEX; }
 
@@ -2921,6 +2923,8 @@ private:
     JSBool               mExceptionManagerNotAvailable;
     AutoMarkingPtr*      mAutoRoots;
 
+    jsuword              mStackLimit;
+
 #ifdef XPC_CHECK_WRAPPER_THREADSAFETY
     JSUint32             mWrappedNativeThreadsafetyReportDepth;
 #endif

mozilla/js/src/xpconnect/src/xpcthreadcontext.cpp

@@ -404,6 +404,27 @@ PRUintn           XPCPerThreadData::gTLSIndex = BAD_TLS_INDEX;
 PRLock*           XPCPerThreadData::gLock     = nsnull;
 XPCPerThreadData* XPCPerThreadData::gThreads  = nsnull;
 
+static jsuword
+GetThreadStackLimit()
+{
+    int stackDummy;
+    jsuword stackLimit, currentStackAddr = (jsuword)&stackDummy;
+
+    const jsuword kStackSize = 0x80000;   // 512k
+
+#if JS_STACK_GROWTH_DIRECTION < 0
+    stackLimit = (currentStackAddr > kStackSize)
+                 ? currentStackAddr - kStackSize
+                 : 0;
+#else
+    stackLimit = (currentStackAddr + kStackSize > currentStackAddr)
+                 ? currentStackAddr + kStackSize
+                 : (jsuword) -1;
+#endif
+
+  return stackLimit;
+}
+
 XPCPerThreadData::XPCPerThreadData()
     :   mJSContextStack(new XPCJSContextStack()),
         mNextThread(nsnull),
@@ -415,7 +436,8 @@ XPCPerThreadData::XPCPerThreadData()
         mExceptionManager(nsnull),
         mException(nsnull),
         mExceptionManagerNotAvailable(JS_FALSE),
-        mAutoRoots(nsnull)
+        mAutoRoots(nsnull),
+        mStackLimit(GetThreadStackLimit())
 #ifdef XPC_CHECK_WRAPPER_THREADSAFETY
       , mWrappedNativeThreadsafetyReportDepth(0)
 #endif