Check that the thread incrementing or decrementing

	the ref count of a Tcl_Obj is the thread that
	originally allocated the thread. This fail fast
	behavior will catch programming errors that
	allow a single Tcl_Obj to be accessed from multiple
	threads.

	* generic/tcl.h (Tcl_Obj): Add allocThread member
	to Tcl_Obj. This member records the thread id the
	Tcl_Obj was allocated. It is used to check that
	any future ref count incr or decr is done from
	the same thread that allocated the Tcl_Obj.
	This member is defined only when threads and
	mem debug are enabled.
	* generic/tclInt.h (TclNewObj, TclDbNewObj,
	TclDecrRefCount):
	Define TclNewObj and TclDbNewObj using TclDbInitNewObj
	when mem debug is enabled. This fixes a problem where
	TclNewObj calls did not work the same as TclDbNewObj
	when mem debug was enabled.
	* generic/tclObj.c (TclDbInitNewObj, Tcl_DbIncrRefCount,
	Tcl_DbDecrRefCount): Add new helper to init Tcl_Obj
	members when mem debug is enabled. Init the allocThread
	member in TclDbInitNewObj and check it in
	Tcl_DbIncrRefCount and Tcl_DbDecrRefCount to make sure
	a Tcl_Obj allocated in one thread is not being acted
	upon in another thread.

1 files changed, 18 insertions, 22 deletions

diff --git a/generic/tclInt.h b/generic/tclInt.h
index 02987c2..040e359 100644
--- a/generic/tclInt.h
+++ b/generic/tclInt.h
@@ -12,7 +12,7 @@
  * See the file "license.terms" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclInt.h,v 1.128 2003/06/09 22:48:32 andreas_kupries Exp $
+ * RCS: @(#) $Id: tclInt.h,v 1.129 2003/07/22 00:59:58 mdejong Exp $
  */
 
 #ifndef _TCLINT
@@ -2087,15 +2087,16 @@ EXTERN Tcl_Obj *TclPtrIncrWideVar _ANSI_ARGS_((Tcl_Interp *interp, Var *varPtr,
 #  define TclIncrObjsFreed()
 #endif /* TCL_COMPILE_STATS */
 
-#define TclNewObj(objPtr) \
-    TclAllocObjStorage(objPtr); \
+#ifndef TCL_MEM_DEBUG
+# define TclNewObj(objPtr) \
     TclIncrObjsAllocated(); \
+    TclAllocObjStorage(objPtr); \
     (objPtr)->refCount = 0; \
     (objPtr)->bytes    = tclEmptyStringRep; \
     (objPtr)->length   = 0; \
     (objPtr)->typePtr  = NULL
 
-#define TclDecrRefCount(objPtr) \
+# define TclDecrRefCount(objPtr) \
     if (--(objPtr)->refCount <= 0) { \
 	if (((objPtr)->typePtr != NULL) \
 		&& ((objPtr)->typePtr->freeIntRepProc != NULL)) { \
@@ -2108,27 +2109,22 @@ EXTERN Tcl_Obj *TclPtrIncrWideVar _ANSI_ARGS_((Tcl_Interp *interp, Var *varPtr,
         TclFreeObjStorage(objPtr); \
 	TclIncrObjsFreed(); \
     }
+#endif /* TCL_MEM_DEBUG */
 
 #ifdef TCL_MEM_DEBUG
-#  define TclAllocObjStorage(objPtr) \
-       (objPtr) = (Tcl_Obj *) \
-           Tcl_DbCkalloc(sizeof(Tcl_Obj), __FILE__, __LINE__)
+EXTERN void	TclDbInitNewObj _ANSI_ARGS_((Tcl_Obj *objPtr));
+
+# define TclDbNewObj(objPtr, file, line) \
+    TclIncrObjsAllocated(); \
+    (objPtr) = (Tcl_Obj *) Tcl_DbCkalloc(sizeof(Tcl_Obj), (file), (line)); \
+    TclDbInitNewObj(objPtr);
+
+# define TclNewObj(objPtr) \
+    TclDbNewObj(objPtr, __FILE__, __LINE__);
+
+# define TclDecrRefCount(objPtr) \
+    Tcl_DecrRefCount(objPtr);
 
-#  define TclFreeObjStorage(objPtr) \
-       if ((objPtr)->refCount < -1) { \
-           panic("Reference count for %lx was negative: %s line %d", \
-	           (objPtr), __FILE__, __LINE__); \
-       } \
-       ckfree((char *) (objPtr))
-     
-#  define TclDbNewObj(objPtr, file, line) \
-       (objPtr) = (Tcl_Obj *) Tcl_DbCkalloc(sizeof(Tcl_Obj), (file), (line)); \
-       (objPtr)->refCount = 0; \
-       (objPtr)->bytes    = tclEmptyStringRep; \
-       (objPtr)->length   = 0; \
-       (objPtr)->typePtr  = NULL; \
-       TclIncrObjsAllocated()
-     
 #elif defined(PURIFY)
 
 /*