From 95660b09be94d6eb4b0482d33c78d8880e0c14cb Mon Sep 17 00:00:00 2001
From: dkf <donal.k.fellows@manchester.ac.uk>
Date: Mon, 1 Sep 2008 00:35:40 +0000
Subject: Improve the semantics of C-implemented destructors slightly.

---
 ChangeLog             |  8 ++++++++
 generic/tclOO.c       | 49 +++++++++++++++++++++++++++++++------------------
 generic/tclOOMethod.c | 12 +++++++++++-
 3 files changed, 50 insertions(+), 19 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index c9225ea..8f5fab5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2008-09-01  Donal K. Fellows  <dkf@users.sf.net>
+
+	* generic/tclOOMethod.c (InvokeProcedureMethod): 
+	* generic/tclOO.c (ObjectRenamedTrace): Arrange for only methods that
+	involve callbacks into the Tcl interpreter to be skipped when the
+	interpreter is being torn down. Allows the semantics of destructors in
+	a dying interpreter to be more useful when they're implemented in C.
+
 2008-08-29  Donal K. Fellows  <dkf@users.sf.net>
 
 	* unix/Makefile.in: Ensure that all TclOO headers get installed.
diff --git a/generic/tclOO.c b/generic/tclOO.c
index 95926f2..b25f070 100644
--- a/generic/tclOO.c
+++ b/generic/tclOO.c
@@ -8,7 +8,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclOO.c,v 1.15 2008/08/20 15:41:26 dkf Exp $
+ * RCS: @(#) $Id: tclOO.c,v 1.16 2008/09/01 00:35:42 dkf Exp $
  */
 
 #ifdef HAVE_CONFIG_H
@@ -548,6 +548,7 @@ ObjectRenamedTrace(
 {
     Object *oPtr = clientData;
     Class *clsPtr;
+    CallContext *contextPtr;
 
     /*
      * If this is a rename and not a delete of the object, we just flush the
@@ -570,24 +571,22 @@ ObjectRenamedTrace(
 
     AddRef(oPtr);
     oPtr->flags |= OBJECT_DELETED;
-    if (!Tcl_InterpDeleted(interp)) {
-	CallContext *contextPtr = TclOOGetCallContext(oPtr, NULL, DESTRUCTOR);
 
-	if (contextPtr != NULL) {
-	    int result;
-	    Tcl_InterpState state;
+    contextPtr = TclOOGetCallContext(oPtr, NULL, DESTRUCTOR);
+    if (contextPtr != NULL) {
+	int result;
+	Tcl_InterpState state;
 
-	    contextPtr->callPtr->flags |= DESTRUCTOR;
-	    contextPtr->skip = 0;
-	    state = Tcl_SaveInterpState(interp, TCL_OK);
-	    result = Tcl_NRCallObjProc(interp, TclOOInvokeContext, contextPtr,
-		    0, NULL);
-	    if (result != TCL_OK) {
-		Tcl_BackgroundError(interp);
-	    }
-	    Tcl_RestoreInterpState(interp, state);
-	    TclOODeleteContext(contextPtr);
+	contextPtr->callPtr->flags |= DESTRUCTOR;
+	contextPtr->skip = 0;
+	state = Tcl_SaveInterpState(interp, TCL_OK);
+	result = Tcl_NRCallObjProc(interp, TclOOInvokeContext, contextPtr, 0,
+		NULL);
+	if (result != TCL_OK) {
+	    Tcl_BackgroundError(interp);
 	}
+	Tcl_RestoreInterpState(interp, state);
+	TclOODeleteContext(contextPtr);
     }
 
     /*
@@ -2134,11 +2133,18 @@ Tcl_ObjectContextInvokeNext(
 
     if (contextPtr->index+1 >= contextPtr->callPtr->numChain) {
 	/*
-	 * We're at the end of the chain; generate an error message.
+	 * We're at the end of the chain; generate an error message unless the
+	 * interpreter is being torn down, in which case we might be getting
+	 * here because of methods/destructors doing a [next] (or equivalent)
+	 * unexpectedly.
 	 */
 
 	const char *methodType;
 
+	if (Tcl_InterpDeleted(interp)) {
+	    return TCL_OK;
+	}
+
 	if (contextPtr->callPtr->flags & CONSTRUCTOR) {
 	    methodType = "constructor";
 	} else if (contextPtr->callPtr->flags & DESTRUCTOR) {
@@ -2195,11 +2201,18 @@ TclNRObjectContextInvokeNext(
 
     if (contextPtr->index+1 >= contextPtr->callPtr->numChain) {
 	/*
-	 * We're at the end of the chain; generate an error message.
+	 * We're at the end of the chain; generate an error message unless the
+	 * interpreter is being torn down, in which case we might be getting
+	 * here because of methods/destructors doing a [next] (or equivalent)
+	 * unexpectedly.
 	 */
 
 	const char *methodType;
 
+	if (Tcl_InterpDeleted(interp)) {
+	    return TCL_OK;
+	}
+
 	if (contextPtr->callPtr->flags & CONSTRUCTOR) {
 	    methodType = "constructor";
 	} else if (contextPtr->callPtr->flags & DESTRUCTOR) {
diff --git a/generic/tclOOMethod.c b/generic/tclOOMethod.c
index 75aef73..5371719 100644
--- a/generic/tclOOMethod.c
+++ b/generic/tclOOMethod.c
@@ -8,7 +8,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclOOMethod.c,v 1.17 2008/08/23 18:53:12 msofer Exp $
+ * RCS: @(#) $Id: tclOOMethod.c,v 1.18 2008/09/01 00:35:42 dkf Exp $
  */
 
 #ifdef HAVE_CONFIG_H
@@ -643,6 +643,16 @@ InvokeProcedureMethod(
 				 * call frame's lifetime). */
 
     /*
+     * If the interpreter was deleted, we just skip to the next thing in the
+     * chain.
+     */
+
+    if (Tcl_InterpDeleted(interp)) {
+	return TclNRObjectContextInvokeNext(interp, context, objc, objv,
+		Tcl_ObjectContextSkippedArgs(context));
+    }
+
+    /*
      * Allocate the special frame data.
      */
 
-- 
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