Bug 545455, part 2: Expose override-able hooks for top-level IPDL actors to be notified on stack entrance/exit. r=bent

--HG--
extra : rebase_source : e50ede6dbffc9d864ba62eda6d2a622c8b99dece

ipc/glue/RPCChannel.h

@@ -68,6 +68,16 @@ public:
                                          Message*& aReply) = 0;
         virtual Result OnCallReceived(const Message& aMessage,
                                       Message*& aReply) = 0;
+
+        virtual void OnEnteredCxxStack()
+        {
+            NS_RUNTIMEABORT("default impl shouldn't be invoked");
+        }
+
+        virtual void OnExitedCxxStack()
+        {
+            NS_RUNTIMEABORT("default impl shouldn't be invoked");
+        }   
     };
 
     // What happens if RPC calls race?
@@ -166,14 +176,12 @@ protected:
     // for when the depth goes from non-zero to zero;
     void EnteredCxxStack()
     {
-        // FIXME/bug 545455: call mListener hook
-        printf("[%s] +++ CXX STACK\n", mChild ? "child" : "parent");
+        static_cast<RPCListener*>(mListener)->OnEnteredCxxStack();
     }
 
     void ExitedCxxStack()
     {
-        // FIXME/bug 545455: call mListener hook
-        printf("[%s] --- CXX STACK\n", mChild ? "child" : "parent");
+        static_cast<RPCListener*>(mListener)->OnExitedCxxStack();
     }
 
     class NS_STACK_CLASS CxxStackFrame

ipc/ipdl/ipdl/lower.py

@@ -1348,6 +1348,14 @@ class Protocol(ipdl.ast.Protocol):
         assert self.decl.type.isToplevel()
         return ExprVar('ShouldContinueFromReplyTimeout')
 
+    def enteredCxxStackVar(self):
+        assert self.decl.type.isToplevel()
+        return ExprVar('EnteredCxxStack')
+
+    def exitedCxxStackVar(self):
+        assert self.decl.type.isToplevel()
+        return ExprVar('ExitedCxxStack')
+
     def nextActorIdExpr(self, side):
         assert self.decl.type.isToplevel()
         if side is 'parent':   op = '++'
@@ -2639,7 +2647,15 @@ class _GenerateProtocolActorCode(ipdl.ast.Visitor):
                 MethodDecl(p.shouldContinueFromTimeoutVar().name,
                            ret=Type.BOOL, virtual=1))
             shouldcontinue.addstmt(StmtReturn(ExprLiteral.TRUE))
-            self.cls.addstmts([ shouldcontinue, Whitespace.NL ])
+
+            # void EnteredCxxStack(); default to no-op
+            entered = MethodDefn(
+                MethodDecl(p.enteredCxxStackVar().name, virtual=1))
+            exited = MethodDefn(
+                MethodDecl(p.exitedCxxStackVar().name, virtual=1))
+
+            self.cls.addstmts([ shouldcontinue, entered, exited,
+                                Whitespace.NL ])
 
         self.cls.addstmts((
             [ Label.PRIVATE ]
@@ -2860,6 +2876,16 @@ class _GenerateProtocolActorCode(ipdl.ast.Visitor):
 
             self.cls.addstmts([ ontimeout, Whitespace.NL ])
 
+        # On[Entered/Exited]CxxStack()
+        if ptype.isToplevel() and toplevel.talksRpc():
+            onentered = MethodDefn(MethodDecl('OnEnteredCxxStack'))
+            onentered.addstmt(StmtReturn(ExprCall(p.enteredCxxStackVar())))
+
+            onexited = MethodDefn(MethodDecl('OnExitedCxxStack'))
+            onexited.addstmt(StmtReturn(ExprCall(p.exitedCxxStackVar())))
+
+            self.cls.addstmts([ onentered, onexited, Whitespace.NL ])
+
         # OnChannelClose()
         onclose = MethodDefn(MethodDecl('OnChannelClose'))
         if ptype.isToplevel():