hg/stx-libbasic: comparison Context.st

equal deleted inserted replaced

-:48ddd376a992
+:1ae6dae275a2
 directly accessed by smalltalk code. The reason is that the sender field
 is lazily filled in by the VM, in the sender-accessor, and is usually
 invalid until needed."
 %{  /* NOCONTEXT */
+#ifdef __SCHTEAM__
+if (((STContinuation)self).caller == null) {
+	return __c__._RETURN_true();
+}
+return __c__._RETURN_false();
+/* NOTREACHED */
+#else
 if ( __INST(sender_) == nil ) {
 	RETURN (true);
 }
 RETURN (false);
+#endif
 %}.
 ^ self sender isNil
 !
 setLineNumber:aNumber
 return a replacement string. otherwise nil.
 This cares for invalid (free) objects which may appear with bad primitive code,
 and prevents a crash in such a case."
 %{
-#ifndef __SCHTEAM__
+#ifdef __SCHTEAM__
+return __c__._RETURN( ((STContinuation)self).stSelf(__c__) );
+#else
 /*
 * special handling for (invalid) free objects.
 * these only appear if some primitiveCode does not correctly use SEND macros,
 * which may lead to sends to free objects. In normal operation, this 'cannot' happen.
 */
 The VM needs this to know that some special action is to be performed with
 this context - a highly internal mechanism and not for public use."
 %{  /* NOCONTEXT */
 #ifdef __SCHTEAM__
-return context._RETURN (self.asSTContinuation().isMarkedForUnwind() ? STObject.True : STObject.False);
+return context._RETURN ( ((STContinuation)self).isMarkedForUnwind() );
 #else
 RETURN ( ((INT)__INST(flags) & __MASKSMALLINT(__UNWIND_MARK)) ? true : false );
 #endif
 %}
 "
 The VM needs this to know that some special action is to be performed with
 this context - a highly internal mechanism and not for public use."
 %{  /* NOCONTEXT */
 #ifdef __SCHTEAM__
-self.asSTContinuation().markForHandle();
+((STContinuation)self).markForHandle();
 #else
 __INST(flags) = (OBJ)((INT)__INST(flags) | __MASKSMALLINT(__HANDLE_MARK));
 #endif
 %}
 The VM needs this to know that some special action is to be performed with
 this context upon return - a highly internal mechanism and not for public use."
 %{  /* NOCONTEXT */
 #ifdef __SCHTEAM__
-self.asSTContinuation().markForInterrupt();
+((STContinuation)self).markForInterrupt();
 #else
 __markInterrupted(__ContextInstPtr(self));
 #endif
 %}
 !
 is unwound. This is used by the debugger for faster single-stepping;
 - a highly internal mechanism and not for public use."
 %{  /* NOCONTEXT */
 #ifdef __SCHTEAM__
-self.asSTContinuation().markForInterruptOnUnwind();
+((STContinuation)self).markForInterruptOnUnwind();
 #else
 __INST(flags) = (OBJ)((INT)__INST(flags) | __MASKSMALLINT(__IRQ_ON_UNWIND));
 #endif
 %}
 !
 The VM needs this to know that some special action is to be performed with
 this context - a highly internal mechanism and not for public use."
 %{  /* NOCONTEXT */
 #ifdef __SCHTEAM__
-self.asSTContinuation().markForRaise();
+((STContinuation)self).markForRaise();
 #else
 __INST(flags) = (OBJ)((INT)__INST(flags) | __MASKSMALLINT(__RAISE_MARK));
 #endif
 %}
 The VM needs this to know that some special action is to be performed with
 this context - a highly internal mechanism and not for public use."
 %{  /* NOCONTEXT */
 #ifdef __SCHTEAM__
-self.asSTContinuation().markForUnwind();
+((STContinuation)self).markForUnwind();
 #else
 __INST(flags) = (OBJ)((INT)__INST(flags) | __MASKSMALLINT(__UNWIND_MARK));
 #endif
 %}
 "set the sender of the context.
 DANGER: this is for experimental, internal use only (byteCode interpreters)"
 %{  /* NOCONTEXT */
 #ifdef __SCHTEAM__
-ERROR("unimplemented");
+((STContinuation)self).caller = aContext.asSTContinuation();
 #else
 __INST(sender_) = aContext;
 #endif
 %}
 !
 The VM needs this to know that some special action is to be performed with
 this context - a highly internal mechanism and not for public use."
 %{  /* NOCONTEXT */
 #ifdef __SCHTEAM__
-self.asSTContinuation().unmarkForUnwind();
+((STContinuation)self).unmarkForUnwind();
 #else
 __INST(flags) = (OBJ)((INT)__INST(flags) & ~__MASKSMALLINT(__UNWIND_MARK));
 #endif
 %}
 ! !
 "/  although they aren't really - this is expert knowledge, no need to understand that ...)
 %{  /* NOCONTEXT */
 #ifdef __SCHTEAM__
 {
-	STContinuation caller = self.sender();
+	STContinuation lastCallee = (STContinuation)self;
+	STContinuation caller = lastCallee.caller;
 	while (caller != null) {
 	    if (caller.isExceptionalSmalltalkContext()) {
+		caller = lastCallee.sender();   // exposed
 		return context._RETURN(caller);
 	    }
-	    caller = caller.sender();
+	    lastCallee = caller;
+	    caller = lastCallee.caller;
 	}
 	return context._RETURN( STObject.Nil );
 }
 /* NOTREACHED */
 #else
 "/  although they aren't really - this is expert knowledge, no need to understand that ...)
 %{  /* NOCONTEXT */
 #ifdef __SCHTEAM__
 {
-	STContinuation cont = self.sender();
+	STContinuation lastCallee = (STContinuation)self;
+	STContinuation cont = lastCallee.caller;
 	STObject sel1 = context.stArg(0);
 	STObject sel2 = context.stArg(1);
 	STObject sel3 = context.stArg(2);
 	while (cont != null) {
 		 || (thisSelector == sel2)
 		 || (thisSelector == sel3)) {
 		    break;
 		}
 	    }
-	    cont = cont.sender();
+	    lastCallee = cont;
+	    cont = lastCallee.caller;
 	}
 	if (cont == null) {
 	    return __c__._RETURN_nil();
 	}
+	cont = lastCallee.sender();     // exposed
 	return __c__._RETURN(cont);
 }
 /* NOTREACHED */
 #else
 OBJ theContext;
 {
 	if (self == aContext) {
 	    return __c__._RETURN(self);
 	}
-	STContinuation theContext = self.sender();
+	STContinuation lastCallee = (STContinuation)self;
+	STContinuation theContext = lastCallee.caller;
 	while (theContext != null) {
 	    if ((theContext == aContext)
 	     || theContext.isMarkedForUnwind()) {
+		theContext = lastCallee.sender();   // exposed
 		return __c__._RETURN(theContext);
 	    }
-	    theContext = theContext.sender();
+	    lastCallee = theContext;
+	    theContext = lastCallee.caller;
 	}
 }
 #else
 OBJ theContext;
 "/  although they aren't really - this is expert knowledge, no need to understand that ...)
 %{  /* NOCONTEXT */
 #ifdef __SCHTEAM__
 {
-	STContinuation theContext = self.sender();
+	STContinuation lastCallee = (STContinuation)self;
+	STContinuation theContext = lastCallee.caller;
 	while (theContext != null) {
 	    if (theContext.isMarkedSpecial()) {
 		if ((findHandleContext == STObject.True)
 		    && theContext.isMarkedForHandle()) {
+		    theContext = lastCallee.sender();   // exposed
 		    return __c__._RETURN(theContext);
 		}
 		if ((findRaiseContext == STObject.True)
 		    && theContext.isMarkedForRaise()) {
+		    theContext = lastCallee.sender();   // exposed
 		    return __c__._RETURN(theContext);
 		}
 	    }
-	    theContext = theContext.sender();
+	    lastCallee = theContext;
+	    theContext = lastCallee.caller;
 	}
 }
 #else
 OBJ theContext;
 int flagMask = 0;
 "Modified: / 19-08-2013 / 12:13:20 / Jan Vrany <jan.vrany@fit.cvut.cz>"
 !
 canResume
 "return true, if the receiver allows to be resumed.
-Due to the implementation, this requires that the context which
+In ST/X, due to the implementation, this requires that the context which
-is right below the receiver is returnable."
+is right below the receiver is returnable and still active."
 |theContext|
 "
 starting with this context, find the one below
 (i.e. the one that I have called) and return from it.
 "
 %{
 #ifdef __SCHTEAM__
+// in the SCHTEAM-engine, all contexts are resumable
 return context._RETURN_true();
 #else
 OBJ sndr;
 theContext = __thisContext;
 was compiled (stc flag +/-optContext).
 If it was compiled with +optContext, methods are compiled
 non returnable, unless a return-pragma was present in the method.
 Since this saves some administrative work in every method
 invocation and makes overall execution faster, the system classes
-are all compiled with this flag turned on."
+are all compiled with this flag turned on.
+This means, that by default, it is not possible to walk up the
+calling chain and return to an arbitrary context.
+For contexts which are known to require this (i.e. handlers as found
+by the exception walkers, these are marked specially (markForReturn),
+so compilers know that they should create full featured contexts."
 %{  /* NOCONTEXT */
 #ifdef __SCHTEAM__
+// in the SCHTEAM-engine, all contexts can be returned from
 return context._RETURN_true();
 #else
 RETURN ( ((INT)(__INST(flags)) & __MASKSMALLINT(__CANNOT_RETURN)) ? false : true );
 #endif
 %}.
 isHandleContext
 "return true, if this is a context with exception-handle flag set"
 %{  /* NOCONTEXT */
 #ifdef __SCHTEAM__
-ERROR("unimplemented");
+return __c__._RETURN ( ((STContinuation)self).isMarkedForHandle() );
 #else
 RETURN ( ((INT)__INST(flags) & __MASKSMALLINT(__HANDLE_MARK)) ? true : false );
 #endif
 %}
 !
 isNonLifo
 "return true, if this is a nonLifo context.
 A nonLifo context is one that is still on the machine stack,
 but has a reference taken and needs to be converted to a real
 object (in objectMemory) when the method/block returns.
-You dont have to understand this - this is a special ST/X
+You don't have to understand this - this is a special ST/X
 debug query, which may be removed without notice."
 %{  /* NOCONTEXT */
 #ifdef __SCHTEAM__
-ERROR("unimplemented");
+return __c__._RETURN ( ((STContinuation)self).isNonLifo() );
 #else
 RETURN ( ((INT)__INST(flags) & __MASKSMALLINT(__NONLIFO)) ? true : false );
 #endif
 %}
 !
 isOnMachineStack
 "return true, if this is a machine stack context as opposed to a
-real heap context.
+real heap context (i.e. if it has not been captured and returned from).
-You dont have to understand this - this is a special ST/X
+You don't have to understand this - this is a special ST/X
 debug query, which may be removed without notice."
 %{  /* NOCONTEXT */
 #ifdef __SCHTEAM__
-ERROR("unimplemented");
+return __c__._RETURN ( ! ((STContinuation)self).isCopiedToHeap() );
 #else
 RETURN ( (__qSpace(self) >= STACKSPACE) ? true : false );
 #endif
 %}
 !
 isRaiseContext
 "return true, if this is a context with exception-raise flag set"
 %{  /* NOCONTEXT */
 #ifdef __SCHTEAM__
-ERROR("unimplemented");
+return __c__._RETURN ( ((STContinuation)self).isMarkedForRaise() );
 #else
 RETURN ( ((INT)__INST(flags) & __MASKSMALLINT(__RAISE_MARK)) ? true : false );
 #endif
 %}
 !
 isSpecial
 "return true, if this is either a nonLifo or interrupted context"
 %{  /* NOCONTEXT */
 #ifdef __SCHTEAM__
-ERROR("unimplemented");
+return __c__._RETURN ( ((STContinuation)self).isMarkedSpecial() );
 #else
 RETURN ( ((INT)__INST(flags) & __MASKSMALLINT(__SPECIAL)) ? true : false );
 #endif
 %}
 !
 isUnwindContext
 "return true, if this is an unwindContext"
 %{  /* NOCONTEXT */
 #ifdef __SCHTEAM__
-ERROR("unimplemented");
+return __c__._RETURN ( ((STContinuation)self).isMarkedForUnwind() );
 #else
 RETURN ( ((INT)__INST(flags) & __MASKSMALLINT(__UNWIND_MARK)) ? true : false );
 #endif
 %}
 !
 tempNames
 ! !
 !Context class methodsFor:'documentation'!
 version
-^ '$Header: /cvs/stx/stx/libbasic/Context.st,v 1.223 2015-05-26 18:55:30 cg Exp $'
+^ '$Header: /cvs/stx/stx/libbasic/Context.st,v 1.224 2015-05-27 19:09:55 cg Exp $'
 !
 version_CVS
-^ '$Header: /cvs/stx/stx/libbasic/Context.st,v 1.223 2015-05-26 18:55:30 cg Exp $'
+^ '$Header: /cvs/stx/stx/libbasic/Context.st,v 1.224 2015-05-27 19:09:55 cg Exp $'
 !
 version_HG
 ^ '$Changeset: <not expanded> $'

branch	jv
changeset 18413	1ae6dae275a2
parent 18409	48ddd376a992
parent 18412	dc22d0d82e28
child 18442	bd42fa983e3f