[Tcl-Threads] Interpreter crashes when using thread pools

[Ken M. <ken...@sp...>]

Hello,

I am trying to use thread pools to run jobs concurrently on OS X  
10.6. The tclsh says that patchlevel is 8.5.7, and the Thread package  
is version 2.6.5. I had to patch the Thread package because  
tpool::create would always crash, due to a buffer being too small (I  
believe this is already patched in CVS - see http://sourceforge.net/ 
tracker/?func=detail&aid=2833864&group_id=10894&atid=110894).

Here is a simplified version of my code:

package require Thread
set pool [tpool::create -maxworkers 4]
set joblist [list]

foreach job <jobs to do> {
	lappend joblist [tpool::post $pool $job]
}

foreach job $joblist {
	tpool::wait $pool $job
	if {[catch {tpool::get $pool $job} m]} {
		puts "Error: $m"
		exit 1
	}
}

while {[tpool::release $pool]} {}

Usually everything works fine. However, occasionally the interpreter  
will crash in Tcl_FinalizeThread - either a segfault or an abort. Is  
there something I am doing wrong? I have crash dump output:

======== Segfault: ========

Process:         tclsh8.5 [36473]
Path:            /System/Library/Frameworks/Tcl.framework/Versions/ 
8.5/tclsh8.5
Identifier:      tclsh8.5
Version:         ??? (???)
Code Type:       X86-64 (Native)
Parent Process:  tclsh8.5 [36454]

Date/Time:       2010-06-30 12:55:19.890 -0700
OS Version:      Mac OS X 10.6.3 (10D573)
Report Version:  6

Exception Type:  EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x0000000000000017
Crashed Thread:  4

Thread 0:  Dispatch queue: com.apple.main-thread
0   dyld                                0x00007fff5fc0d6ab  
ImageLoaderMachO::getExportedSymbolAddress(ImageLoader::Symbol  
const*, ImageLoader::LinkContext const&, ImageLoader const*) const + 1
1   dyld                                0x00007fff5fc12dc0  
ImageLoaderMachOCompressed::resolve(ImageLoader::LinkContext const&,  
char const*, unsigned char, int, ImageLoader const**,  
ImageLoaderMachOCompressed::LastLookup*) + 208
2   dyld                                0x00007fff5fc1698e  
ImageLoaderMachOCompressed::doBindFastLazySymbol(unsigned int,  
ImageLoader::LinkContext const&) + 238
3   dyld                                0x00007fff5fc04783  
dyld::fastBindLazySymbol(ImageLoader**, unsigned long) + 98
4   libSystem.B.dylib                   0x00007fff864bf01e  
dyld_stub_binder + 118
5   ???                                 0x00000001000e4010 0 +  
4295901200
6   Tcl                                 0x000000010004b31f  
Tcl_Finalize + 249
7   Tcl                                 0x000000010004b414 Tcl_Exit + 89
8   Tcl                                 0x000000010001c0c1 Tcl_Alloc  
+ 8021
9   Tcl                                 0x0000000100016559  
Tcl_CreateInterp + 4820
10  Tcl                                 0x000000010004e2eb  
TclStackAlloc + 6637
11  Tcl                                 0x0000000100054fae  
TclStackAlloc + 34480
12  Tcl                                 0x0000000100017ad7  
TclEvalObjEx + 714
13  Tcl                                 0x000000010007339c Tcl_Main +  
2237
14  tclsh                               0x00000001000019d0  
0x100000000 + 6608
15  tclsh                               0x0000000100001978  
0x100000000 + 6520

Thread 1:  Dispatch queue: com.apple.libdispatch-manager
0   libSystem.B.dylib                   0x00007fff863d04ea kevent + 10
1   libSystem.B.dylib                   0x00007fff863d23bd  
_dispatch_mgr_invoke + 154
2   libSystem.B.dylib                   0x00007fff863d2094  
_dispatch_queue_invoke + 185
3   libSystem.B.dylib                   0x00007fff863d1bbe  
_dispatch_worker_thread2 + 252
4   libSystem.B.dylib                   0x00007fff863d14e8  
_pthread_wqthread + 353
5   libSystem.B.dylib                   0x00007fff863d1385  
start_wqthread + 13

Thread 2:
0   libSystem.B.dylib                   0x00007fff863d130a  
__workq_kernreturn + 10
1   libSystem.B.dylib                   0x00007fff863d171c  
_pthread_wqthread + 917
2   libSystem.B.dylib                   0x00007fff863d1385  
start_wqthread + 13

Thread 3:
0   libSystem.B.dylib                   0x00007fff863fb286 select 
$DARWIN_EXTSN + 10
1   Tcl                                 0x00000001000abd86  
Tcl_InitNotifier + 1520
2   libSystem.B.dylib                   0x00007fff863f08b6  
_pthread_start + 331
3   libSystem.B.dylib                   0x00007fff863f0769  
thread_start + 13

Thread 4 Crashed:
0   Tcl                                 0x0000000100059ae5  
Tcl_CreateHashEntry + 231
1   Tcl                                 0x0000000100093b37  
TclpRealloc + 1270
2   Tcl                                 0x0000000100092b84  
Tcl_GetThreadData + 31
3   Tcl                                 0x000000010007a4bb  
Tcl_CreateEventSource + 137
4   Tcl                                 0x000000010004b046  
Tcl_FinalizeThread + 77
5   Tcl                                 0x00000001000928f1  
Tcl_ExitThread + 16
6   libthread2.6.5.dylib                0x00000001001caa3d  
TpoolWorker + 860
7   libSystem.B.dylib                   0x00007fff863f08b6  
_pthread_start + 331
8   libSystem.B.dylib                   0x00007fff863f0769  
thread_start + 13

Thread 4 crashed with X86 Thread State (64-bit):
   rax: 0x0000000100308610  rbx: 0x0000000100307ba0  rcx:  
0x000000000000001a  rdx: 0x0000000000000000
   rdi: 0x0000000100307ba0  rsi: 0x00000001000edce0  rbp:  
0x0000000100698d90  rsp: 0x0000000100698d40
    r8: 0x0000000101035618   r9: 0x0000000000000001  r10:  
0x00007fff863b77a2  r11: 0x0000000000000246
   r12: 0x0000000000000007  r13: 0x00000000000edce0  r14:  
0x0000000000000000  r15: 0x00000001000edce0
   rip: 0x0000000100059ae5  rfl: 0x0000000000010202  cr2:  
0x0000000000000017


======== Abort: ========

Process:         tclsh8.5 [36499]
Path:            /System/Library/Frameworks/Tcl.framework/Versions/ 
8.5/tclsh8.5
Identifier:      tclsh8.5
Version:         ??? (???)
Code Type:       X86-64 (Native)
Parent Process:  tclsh8.5 [36498]

Date/Time:       2010-06-30 12:55:24.311 -0700
OS Version:      Mac OS X 10.6.3 (10D573)
Report Version:  6

Exception Type:  EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Crashed Thread:  4

Application Specific Information:
abort() called

Thread 0:  Dispatch queue: com.apple.main-thread
0   Tcl                                 0x0000000100093501 TclpFree +  
165
1   Tcl                                 0x000000010007135c  
TclAddLiteralObj + 791
2   Tcl                                 0x000000010004b324  
Tcl_Finalize + 254
3   Tcl                                 0x000000010004b414 Tcl_Exit + 89
4   Tcl                                 0x000000010001c0c1 Tcl_Alloc  
+ 8021
5   Tcl                                 0x0000000100016559  
Tcl_CreateInterp + 4820
6   Tcl                                 0x000000010004e2eb  
TclStackAlloc + 6637
7   Tcl                                 0x0000000100054fae  
TclStackAlloc + 34480
8   Tcl                                 0x0000000100017ad7  
TclEvalObjEx + 714
9   Tcl                                 0x000000010007339c Tcl_Main +  
2237
10  tclsh                               0x00000001000019d0  
0x100000000 + 6608
11  tclsh                               0x0000000100001978  
0x100000000 + 6520

Thread 1:  Dispatch queue: com.apple.libdispatch-manager
0   libSystem.B.dylib                   0x00007fff863d04ea kevent + 10
1   libSystem.B.dylib                   0x00007fff863d23bd  
_dispatch_mgr_invoke + 154
2   libSystem.B.dylib                   0x00007fff863d2094  
_dispatch_queue_invoke + 185
3   libSystem.B.dylib                   0x00007fff863d1bbe  
_dispatch_worker_thread2 + 252
4   libSystem.B.dylib                   0x00007fff863d14e8  
_pthread_wqthread + 353
5   libSystem.B.dylib                   0x00007fff863d1385  
start_wqthread + 13

Thread 2:
0   libSystem.B.dylib                   0x00007fff863d130a  
__workq_kernreturn + 10
1   libSystem.B.dylib                   0x00007fff863d171c  
_pthread_wqthread + 917
2   libSystem.B.dylib                   0x00007fff863d1385  
start_wqthread + 13

Thread 3:
0   libSystem.B.dylib                   0x00007fff863fb286 select 
$DARWIN_EXTSN + 10
1   Tcl                                 0x00000001000abd86  
Tcl_InitNotifier + 1520
2   libSystem.B.dylib                   0x00007fff863f08b6  
_pthread_start + 331
3   libSystem.B.dylib                   0x00007fff863f0769  
thread_start + 13

Thread 4 Crashed:
0   libSystem.B.dylib                   0x00007fff8642a01e  
__semwait_signal_nocancel + 10
1   libSystem.B.dylib                   0x00007fff86429f20 nanosleep 
$NOCANCEL + 129
2   libSystem.B.dylib                   0x00007fff86486902 usleep 
$NOCANCEL + 57
3   libSystem.B.dylib                   0x00007fff864a5eb8 abort + 93
4   Tcl                                 0x000000010007cbb8 Tcl_Panic + 0
5   Tcl                                 0x000000010007cc5a Tcl_Panic  
+ 162
6   Tcl                                 0x0000000100059dbe  
Tcl_DeleteHashTable + 250
7   Tcl                                 0x0000000100093a2f  
TclpRealloc + 1006
8   Tcl                                 0x0000000100093b2e  
TclpRealloc + 1261
9   Tcl                                 0x000000010004b00c  
Tcl_FinalizeThread + 19
10  Tcl                                 0x00000001000928f1  
Tcl_ExitThread + 16
11  libthread2.6.5.dylib                0x00000001001caa3d  
TpoolWorker + 860
12  libSystem.B.dylib                   0x00007fff863f08b6  
_pthread_start + 331
13  libSystem.B.dylib                   0x00007fff863f0769  
thread_start + 13

Thread 4 crashed with X86 Thread State (64-bit):
   rax: 0x000000000000003c  rbx: 0x000000010071bc30  rcx:  
0x000000010071bbe8  rdx: 0x0000000000000001
   rdi: 0x0000000000000c03  rsi: 0x0000000000000000  rbp:  
0x000000010071bc20  rsp: 0x000000010071bbe8
    r8: 0x0000000000000000   r9: 0x0000000000989680  r10:  
0x0000000000000001  r11: 0x0000000000000246
   r12: 0x0000000000000000  r13: 0x00000001000b66b7  r14:  
0x00000001000b669c  r15: 0x000000000000004c
   rip: 0x00007fff8642a01e  rfl: 0x0000000000000247  cr2:  
0x0000000101178700

Thanks,

-Ken