[Tcl-bugs] [ tcl-Bugs-604609 ] leak in command rename traces

[<no...@so...>]

Bugs item #604609, was opened at 2002-09-04 11:42
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=110894&aid=604609&group_id=10894

Category: 43. Parsing and Eval
Group: None
Status: Open
Resolution: None
Priority: 8
Submitted By: miguel sofer (msofer)
Assigned to: miguel sofer (msofer)
Summary: leak in command rename traces

Initial Comment:
The following scriptlet leaks two structs: a
TraceCommandInfo and a Command

# distilled from test trace-20.9 
#
# No leak if the trace really renames and does
# not delete

proc foo x {set x}
trace add command foo rename {rename foo "";#}
rename foo bar

Valgrind's complaint:

40 bytes in 1 blocks are definitely lost in loss record
3 of 7
 at 0x400467C4: malloc (vg_clientfuncs.c:100)
 by 0x80F9571: TclpAlloc (./../generic/tclAlloc.c:679)
 by 0x806B501: Tcl_Alloc (./../generic/tclCkalloc.c:1002)
 by 0x807A50B: TclTraceCommandObjCmd
(./../generic/tclCmdMZ.c:3385)
 by 0x80798D6: Tcl_TraceObjCmd
(./../generic/tclCmdMZ.c:2932)
 by 0x8066091: TclEvalObjvInternal
(./../generic/tclBasic.c:3033)

56 bytes in 1 blocks are definitely lost in loss record
4 of 7
 at 0x400467C4: malloc (vg_clientfuncs.c:100)
 by 0x80F9571: TclpAlloc (./../generic/tclAlloc.c:679)
 by 0x806B501: Tcl_Alloc (./../generic/tclCkalloc.c:1002)
 by 0x8064813: Tcl_CreateCommand
(./../generic/tclBasic.c:1512)
 by 0x80CC92E: Tcl_ProcObjCmd (./../generic/tclProc.c:136)
 by 0x8066091: TclEvalObjvInternal
(./../generic/tclBasic.c:3033)


----------------------------------------------------------------------

Comment By: Hemang Lavana (hemanglavana)
Date: 2002-09-05 11:20

Message:
Logged In: YES 
user_id=81875

The following patch should take care of the first complaint:

Index: tclBasic.c
===================================================================
RCS file: /cvsroot/tcl/tcl/generic/tclBasic.c,v
retrieving revision 1.69
diff -r1.69 tclBasic.c
2526,2527c2526,2532
<        * rename traces; while a delete trace is active we
will not
<        * process any more delete traces 
---
>        * rename traces; while if a delete trace is active
we will never
>        * reach here -- because Tcl_DeleteCommandFromToken
checks for the
>        * condition (cmdPtr->flags & CMD_IS_DELETED) and
returns immediately
>          * when a command deletion is in progress. For all
other traces,
>          * delete traces will not be invoked but a call to
TraceCommandProc
>          * will ensure that tracePtr->clientData is freed
whenever the
>          * command is "oldName" deleted.
2531,2533d2535
<       }
<       if (cmdPtr->flags & TCL_TRACE_DELETE) {
<           flags &= ~TCL_TRACE_DELETE;

Let me know if the 2nd complaint persists.

Hemang.

----------------------------------------------------------------------

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