[Tcl-bugs] [ tcl-Bugs-2869384 ] Tcl_AsyncMark does not work with --enable-threads

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

Bugs item #2869384, was opened at 2009-09-28 18:33
Message generated for change (Settings changed) made by eugene_cdn
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=110894&aid=2869384&group_id=10894

Please note that this message will contain a full copy of the comment thread,
including the initial issue submission, for this request,
not just the latest update.
Category: 04. Async Events
Group: obsolete: 8.5.5
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: Yevgen Ryazanov (eugene_cdn)
Assigned to: Joe Mistachkin (mistachkin)
>Summary: Tcl_AsyncMark does not work with --enable-threads

Initial Comment:
OS: sparc Solaris 10
Tcl_AsynMark cannot be called in a signal handler because it locks the same mutex (notifierMutex) as Tcl_WaitForEvent. If a signal is handled in main thread when it serves Tcl events, then deadlock is very probable. Attached example will produce a stack like this
     -----------------  lwp# 1 / thread# 1  --------------------
     feb40408 lwp_park (0, 0, 0)
     ff0385fc Tcl_MutexLock (ff08247c, 0, 0, 1000, 0, 0) + b4
     ff039624 Tcl_AlertNotifier (2bda8, 0, 0, 1000, 0, 0) + 34
     fefd83a8 Tcl_ThreadAlert (1, 0, 0, 0, 0, 0) + a8
     feedf7e0 Tcl_AsyncMark (1a80d8, 0, 0, 0, 0, 0) + 60
     fee306a8 GotAlarm (e, 0, ffbfeb10, 1, 21c30, 21c2c) + 30
     feb40494 __sighndlr (e, 0, ffbfeb10, fee30678, 0, 1) + c
     feb3558c call_user_handler (e, 0, 4, 0, ff0c2000, ffbfeb10) + 3b8
     feb4187c _write   (4, ff05ce88, 1, 0, 0, 2c0b5) + c
     ff03a2f0 Tcl_WaitForEvent (224e8, fffffffd, ff1966e4, ff3ee0f8, ff3f06e0, 0) + 3c0
     fefd7f74 Tcl_DoOneEvent (0, 6e7f8, 0, 0, 1, 0) + 1ec
     ff17c738 Tk_MainLoop (2c1a8, 31188, 0, 1, 1, 5400) + 48
     ff1966e4 Tk_MainEx (2, ffbff2ac, 10e90, 2c1a8, 4, 4) + b1c
     00010e60 main     (2, ffbff2ac, ffbff2b8, 21000, ff0c0100, ff0c0140) + 50
     000109e0 _start   (0, 0, 0, 0, 0, 0) + 108
     -----------------  lwp# 2 / thread# 2  --------------------
     feb40408 lwp_park (0, 0, 0)
     ff0385fc Tcl_MutexLock (ff08247c, fea7bf1c, fea7be9c, fea7be1c, 0, fea7bea5) + b4
     ff03a8e4 NotifierThreadProc (0, fea7c000, 0, 0, ff03a4a8, 1) + 43c
     feb40368 _lwp_start (0, 0, 0, 0, 0, 0)
in a few seconds. To reproduce the problem, use regular wish built with --enable-threads and use attached script as input:
    wish run.tcl
It will hang shortly. To speed up hanging, one can decrease timeouts. Tk must serve some events to make the application hanging faster, so the script changes text widget in loop. Build script is attached (need to modify paths).

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

You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=110894&aid=2869384&group_id=10894