[M3devel] Ho hum... AtFork...
mika at async.caltech.edu
mika at async.caltech.edu
Wed Aug 13 19:04:59 CEST 2014
Sure, I understand. Just wasn't aware of it yesterday!
But I think there are two problems here: fork and FreeBSD.
The problems on AMD64_FREEBSD look like something different ..
there is custom FreeBSD code that is invoked and seems to screw things
up. The attached example doesn't use fork at all.
On the other hand, question about fork: what is the precise problem
with fork? My understanding was that it was an issue with held mutexes
on fork. But what if you don't hold any mutexes on fork?
Related question: how many times does fork appear in the cm3 tree? I
only ever use Process.Create ... can one build a custom solution for that
one routine, maybe with a forker thread somehow? Or do others use more
general forking patterns?
Mika
Tony Hosking writes:
>
>On Aug 13, 2014, at 12:37 PM, mika at async.caltech.edu wrote:
>
>> 1.262
>>=20
>> Short summary: 1.262 seems to work fine on AMD64_LINUX except for the
>> fork issue (a bummer because my parallelization of the backends of cm3
>> uses fork a lot...and it does speed up the compiler significantly if
>> you have fast disks and lots of cores) It does the attached on =
>AMD64_FREEBSD.
>
>Yes, that was the state of things. Subsequent revs were to address fork =
>issues.
>
>>=20
>> I see the intent of what you were doing in later version/s, but it was
>> a bit rough, I think... I think the three issues I reported (1. =
>locking
>> heapMu from AtFork; 2. the try-only-once bug in LockHeap itself; 3. =
>not
>> passing the lock to release from Wait) are all more or less real.
>
>Working on these right now. Sorry for hacked versions =97 no time right =
>now to do real testing before push.
>Getting closer now I think.
>
>>=20
>> Mika
>>=20
>> Tony Hosking writes:
>>> Which revision of ThreadPThread.m3 is this output from?
>>>=20
>>> On Aug 13, 2014, at 2:30 AM, mika at async.caltech.edu wrote:
>>>=20
>>>> =3D20
>>>> OK... deleted all the derived directories and rebuilt. Result on =3D
>>> FreeBSD is similar (or identical, hard to tell):
>>>> =3D20
>>>> I get a partial deadlock:
>>>> =3D20
>>>> PID USERNAME PRI NICE SIZE RES STATE C TIME WCPU =3D
>>> COMMAND
>>>> 48760 root 98 0 87836K 29104K CPU1 1 12:32 83.89% =3D
>>> threadtest{threadtest}
>>>> 48760 root 94 0 87836K 29104K CPU3 3 11:02 74.66% =3D
>>> threadtest{threadtest}
>>>> 48760 root 94 0 87836K 29104K CPU0 0 11:03 71.97% =3D
>>> threadtest{threadtest}
>>>> 48760 root 32 0 87836K 29104K umtxn 2 0:01 0.00% =3D
>>> threadtest{threadtest}
>>>> 48760 root 20 0 87836K 29104K umtxn 2 0:01 0.00% =3D
>>> threadtest{threadtest}
>>>> 48760 root 35 0 87836K 29104K uwait 2 0:01 0.00% =3D
>>> threadtest{threadtest}
>>>> 48760 root 27 0 87836K 29104K uwait 0 0:01 0.00% =3D
>>> threadtest{threadtest}
>>>> 48760 root 27 0 87836K 29104K umtxn 3 0:01 0.00% =3D
>>> threadtest{threadtest}
>>>> 48760 root 27 0 87836K 29104K umtxn 2 0:01 0.00% =3D
>>> threadtest{threadtest}
>>>> 48760 root 20 0 87836K 29104K umtxn 0 0:00 0.00% =3D
>>> threadtest{threadtest}
>>>> 48759 root 20 0 30276K 11064K wait 0 0:00 0.00% gdb
>>>> =3D20
>>>> one of the dead threads is the main thread, so now output. But =
>three
>>>> threads are still alive, interestingly enough.
>>>> =3D20
>>>> Looks like the same issue as before:
>>>> =3D20
>>>> Thread 5 (Thread 801807400 (LWP 100751/threadtest)):
>>>> #0 0x0000000800ae089c in __error () from /lib/libthr.so.3
>>>> #1 0x0000000800ad6261 in pthread_suspend_np () from =
>/lib/libthr.so.3
>>>> #2 0x00000000004511bc in ThreadPThread__SuspendThread (mt=3D3DError =
>=3D
>>> accessing memory address 0x8000ff5faa28: Bad address.
>>>> ) at ../src/thread/PTHREAD/ThreadFreeBSD.c:33
>>>> #3 0x000000000044ed8e in ThreadPThread__StopThread =3D
>>> (M3_DMxDjQ_act=3D3DError accessing memory address 0x8000ff5faa48: Bad =
>=3D
>>> address.
>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:909
>>>> #4 0x000000000044ef31 in ThreadPThread__StopWorld () at =3D
>>> ../src/thread/PTHREAD/ThreadPThread.m3:948
>>>> #5 0x000000000044e44e in RTThread__SuspendOthers () at =3D
>>> ../src/thread/PTHREAD/ThreadPThread.m3:713
>>>> #6 0x0000000000436386 in RTCollector__CollectSomeInStateZero () at =
>=3D
>>> ../src/runtime/common/RTCollector.m3:749
>>>> #7 0x0000000000436331 in RTCollector__CollectSome () at =3D
>>> ../src/runtime/common/RTCollector.m3:723
>>>> #8 0x0000000000435ff9 in RTHeapRep__CollectEnough () at =3D
>>> ../src/runtime/common/RTCollector.m3:657
>>>> #9 0x0000000000433233 in RTAllocator__AllocTraced =3D
>>> (M3_Cwb5VA_dataSize=3D3DError accessing memory address =
>0x8000ff5fac88: Bad =3D
>>> address.
>>>> ) at ../src/runtime/common/RTAllocator.m3:367
>>>> #10 0x0000000000432b55 in RTAllocator__GetOpenArray =3D
>>> (M3_Eic7CK_def=3D3DError accessing memory address 0x8000ff5fad48: Bad =
>=3D
>>> address.
>>>> ) at ../src/runtime/common/RTAllocator.m3:296
>>>> #11 0x0000000000431e8f in RTHooks__AllocateOpenArray =3D
>>> (M3_AJWxb1_defn=3D3DError accessing memory address 0x8000ff5fada8: =
>Bad =3D
>>> address.
>>>> ) at ../src/runtime/common/RTAllocator.m3:143
>>>> #12 0x00000000004052ea in Main__AApply (M3_AP7a1g_cl=3D3DError =
>accessing =3D
>>> memory address 0x8000ff5fade8: Bad address.
>>>> ) at ../src/Main.m3:283
>>>> #13 0x000000000044d243 in ThreadPThread__RunThread =
>(M3_DMxDjQ_me=3D3DError=3D
>>> accessing memory address 0x8000ff5faeb8: Bad address.
>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:449
>>>> #14 0x000000000044cf00 in ThreadPThread__ThreadBase =3D
>>> (M3_AJWxb1_param=3D3DError accessing memory address 0x8000ff5faf68: =
>Bad =3D
>>> address.
>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:422
>>>> #15 0x0000000800ad54a4 in pthread_create () from /lib/libthr.so.3
>>>> #16 0x0000000000000000 in ?? ()
>>>> =3D20
>>>> Interestingly the same test seems to work on AMD64_LINUX. That is
>>>> promising, at least. But of course, software testing never reveals =
>=3D
>>> the
>>>> absence of bugs.
>>>> =3D20
>>>> Mika
>>>> =3D20
>>>> Peter McKinna writes:
>>>>> --089e01183a1813188705007c3498
>>>>> Content-Type: text/plain; charset=3D3DUTF-8
>>>>> =3D20
>>>>> Oh, one other thing that seemed to help me in testing this stuff =3D
>>> especially
>>>>> things to do with m3core and libm3 which seem to get out of whack
>>>>> sometimes, is to totally remove the target directory of m3core then =
>=3D
>>> cm3;
>>>>> cm3 -ship Same with libm3. I'm not sure that clean actually removes =
>=3D
>>> the
>>>>> targets and I think there are leftover files that stuff things up =3D=
>
>>> since I
>>>>> would get segv in FileRd for no obvious reason.
>>>>> =3D20
>>>>> Peter
>>>>> =3D20
>>>>> =3D20
>>>>> =3D20
>>>>> On Wed, Aug 13, 2014 at 3:33 PM, Peter McKinna =3D
>>> <peter.mckinna at gmail.com>
>>>>> wrote:
>>>>> =3D20
>>>>>> That is weird. The thread tester works fine with the old version =
>of
>>>>>> ThreadPThread.m3 on linux amd_64 except if you have the fork test =
>in =3D
>>> the
>>>>>> mix of tests you see the pthread_mutex_destroy every now and =
>again, =3D
>>> the
>>>>>> fork bug in fact.
>>>>>> I was testing the pthread changes Tony has made over the past few =
>=3D
>>> days
>>>>>> using the thread tester program until I stupidly rebuilt the =3D
>>> compiler and
>>>>>> was getting all sorts of hangs as it dragged in the new version of
>>>>>> pthreads. So I rebuilt everything from a backup to get back where =
>I =3D
>>> was
>>>>>> with a decent compiler, then reintroduced the latest changes to
>>>>>> ThreadPThread.m3, which yesterday was just hanging in sigsuspend =
>but =3D
>>> today
>>>>>> is giving me an assert failure at line 1387 in UnlockHeap. So its =
>a =3D
>>> bit
>>>>>> unstable to say the least. Maybe there is something else wrong =
>with =3D
>>> freebsd.
>>>>>> =3D20
>>>>>> Peter
>>>>>> =3D20
>>>>>> =3D20
>>>>>> =3D20
>>>>>> On Wed, Aug 13, 2014 at 2:54 PM, <mika at async.caltech.edu> wrote:
>>>>>> =3D20
>>>>>>> =3D20
>>>>>>> Yeah OK 1.262 makes a lot more sense to me but I'm still not =3D
>>> getting
>>>>>>> things to work and now I'm really baffled because I think I =3D
>>> understand
>>>>>>> this code!
>>>>>>> =3D20
>>>>>>> What I did was I threw away all my changes and reverted =3D
>>> ThreadPThread.m3
>>>>>>> to 1.262 as you suggested.
>>>>>>> =3D20
>>>>>>> Rebuilt the compiler with upgrade.sh
>>>>>>> =3D20
>>>>>>> Then rebuilt the compiler again with itself.
>>>>>>> =3D20
>>>>>>> Then I realcleaned the world and buildshipped it. (I was afraid
>>>>>>> that parseparams, also imported by the thread tester, would =
>pollute
>>>>>>> it somehow.)
>>>>>>> =3D20
>>>>>>> When I look at the code in 1.262 it looks quite straightforward. =
>=3D
>>> heapMu
>>>>>>> is just a mutex, (Modula-3) mutexes are just (pthreads) mutexes.
>>>>>>> Condition
>>>>>>> variables are mutexes too, but that's no big deal.
>>>>>>> =3D20
>>>>>>> So, rebuild thread tester, run it:
>>>>>>> =3D20
>>>>>>> new source -> compiling Main.m3
>>>>>>> -> linking threadtest
>>>>>>> root at rover:~mika/cm3-cvs-anon/cm3/m3-libs/m3core/tests/thread #
>>>>>>> AMD64_FREEBSD/threadtest
>>>>>>> Writing file...done
>>>>>>> Creating read threads...done
>>>>>>> Creating fork threads...done
>>>>>>> Creating alloc threads...done
>>>>>>> Creating lock threads...done
>>>>>>> running...printing oldest/median age/newest
>>>>>>> .
>>>>>>> =3D20
>>>>>>> ***
>>>>>>> *** runtime error:
>>>>>>> *** Segmentation violation - possible attempt to dereference
>>>>>>> NIL.........laziest thread is 1407901189/1407901189/9 (tests: =
>read
>>>>>>> 1407901189/1407901189/1407901189 fork =3D
>>> 1407901189/1407901189/1407901189
>>>>>>> alloc 9/9/9 lock 1407901189/1407901189/9)
>>>>>>> =3D20
>>>>>>> =3D20
>>>>>>> =3D20
>>>>>>> =3D20
>>>>>>> ^C
>>>>>>> root at rover:~mika/cm3-cvs-anon/cm3/m3-libs/m3core/tests/thread # =
>gdb =3D
>>> !$
>>>>>>> gdb AMD64_FREEBSD/threadtest
>>>>>>> GNU gdb 6.1.1 [FreeBSD]
>>>>>>> Copyright 2004 Free Software Foundation, Inc.
>>>>>>> GDB is free software, covered by the GNU General Public License, =
>=3D
>>> and you
>>>>>>> are
>>>>>>> welcome to change it and/or distribute copies of it under certain
>>>>>>> conditions.
>>>>>>> Type "show copying" to see the conditions.
>>>>>>> There is absolutely no warranty for GDB. Type "show warranty" =
>for
>>>>>>> details.
>>>>>>> This GDB was configured as "amd64-marcel-freebsd"...
>>>>>>> (gdb) run
>>>>>>> Starting program:
>>>>>>> =3D
>>> =
>/big/home2/mika/2/cm3-cvs/cm3/m3-libs/m3core/tests/thread/AMD64_FREEBSD/th=
>=3D
>>> readtest
>>>>>>> [New LWP 100121]
>>>>>>> Writing file...done
>>>>>>> Creating read threads...done
>>>>>>> Creating fork threads...done
>>>>>>> Creating alloc threads...done
>>>>>>> Creating lock threads...done
>>>>>>> running...printing oldest/median age/newest
>>>>>>> .[New Thread 801807000 (LWP 100343/threadtest)]
>>>>>>> [New Thread 801807c00 (LWP 100667/threadtest)]
>>>>>>> [New Thread 801808800 (LWP 100816/threadtest)]
>>>>>>> [New Thread 801807400 (LWP 100349/threadtest)]
>>>>>>> [New Thread 801808400 (LWP 100815/threadtest)]
>>>>>>> [New Thread 801807800 (LWP 100352/threadtest)]
>>>>>>> [New Thread 801808c00 (LWP 100817/threadtest)]
>>>>>>> [New Thread 801809000 (LWP 100818/threadtest)]
>>>>>>> [New Thread 801809800 (LWP 100820/threadtest)]
>>>>>>> [New Thread 801808000 (LWP 100678/threadtest)]
>>>>>>> [New Thread 801806400 (LWP 100121/threadtest)]
>>>>>>> [New Thread 801806800 (LWP 100341/threadtest)]
>>>>>>> [New Thread 801806c00 (LWP 100342/threadtest)]
>>>>>>> .ERROR: pthread_mutex_lock:11
>>>>>>> =3D20
>>>>>>> Program received signal SIGABRT, Aborted.
>>>>>>> [Switching to Thread 801809800 (LWP 100820/threadtest)]
>>>>>>> 0x0000000800d5c26a in thr_kill () from /lib/libc.so.7
>>>>>>> (gdb) where
>>>>>>> #0 0x0000000800d5c26a in thr_kill () from /lib/libc.so.7
>>>>>>> #1 0x0000000800e23ac9 in abort () from /lib/libc.so.7
>>>>>>> #2 0x000000000045101f in ThreadPThread__pthread_mutex_lock =3D
>>> (mutex=3D3DError
>>>>>>> accessing memory address 0x8000fe5f2d98: Bad address.
>>>>>>> ) at ../src/thread/PTHREAD/ThreadPThreadC.c:513
>>>>>>> #3 0x000000000044b370 in ThreadPThread__LockMutex =3D
>>> (M3_AYIbX3_m=3D3DError
>>>>>>> accessing memory address 0x8000fe5f2dc8: Bad address.
>>>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:119
>>>>>>> #4 0x0000000000405b5d in Main__LApply (M3_AP7a1g_cl=3D3DError =3D
>>> accessing
>>>>>>> memory address 0x8000fe5f2df8: Bad address.
>>>>>>> ) at ../src/Main.m3:319
>>>>>>> #5 0x000000000044d243 in ThreadPThread__RunThread =3D
>>> (M3_DMxDjQ_me=3D3DError
>>>>>>> accessing memory address 0x8000fe5f2eb8: Bad address.
>>>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:449
>>>>>>> #6 0x000000000044cf00 in ThreadPThread__ThreadBase
>>>>>>> (M3_AJWxb1_param=3D3DError accessing memory address =
>0x8000fe5f2f68: =3D
>>> Bad address.
>>>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:422
>>>>>>> #7 0x0000000800ad54a4 in pthread_create () from /lib/libthr.so.3
>>>>>>> #8 0x0000000000000000 in ?? ()
>>>>>>> (gdb) set lang c
>>>>>>> (gdb) thread apply all bt
>>>>>>> ... not that interesting ...
>>>>>>> =3D20
>>>>>>> Segfault is segfault---error 11 is EDEADLK (locking against =3D
>>> myself?)
>>>>>>> =3D20
>>>>>>> ????? the code is very straightforward, as I said.
>>>>>>> =3D20
>>>>>>> I thought people had the thread tester working with pthreads? =3D
>>> Which set
>>>>>>> of files, then? Anyone on FreeBSD/amd64?
>>>>>>> =3D20
>>>>>>> Could it be an issue with "volatile"? Not even sure where to =
>look.
>>>>>>> =3D20
>>>>>>> The code calling the lock is just this:
>>>>>>> =3D20
>>>>>>> PROCEDURE GetChar (rd: T): CHAR
>>>>>>> RAISES {EndOfFile, Failure, Alerted} =3D3D
>>>>>>> BEGIN
>>>>>>> LOCK rd DO
>>>>>>> RETURN FastGetChar(rd);
>>>>>>> END
>>>>>>> END GetChar;
>>>>>>> =3D20
>>>>>>> No mysteries there...
>>>>>>> =3D20
>>>>>>> Ah is this the fork bug? Looks like the Init routine is called =
>on =3D
>>> a
>>>>>>> lot of NIL mutexes around the fork. But the subprocesses aren't =
>=3D
>>> meant
>>>>>>> to accesses the mutexes... humm
>>>>>>> =3D20
>>>>>>> Hmm, and it's not entirely a fork issue. Even with "threadtest =3D=
>
>>> -tests
>>>>>>> STD,-fork,-forktoomuch" it misbehaves. Hangs....
>>>>>>> =3D20
>>>>>>> Looks like a deadlock this time.
>>>>>>> =3D20
>>>>>>> Some stacks...
>>>>>>> =3D20
>>>>>>> Thread 4 (Thread 800c0b400 (LWP 100477/threadtest)):
>>>>>>> #0 0x00000000004b4e2b in __vdso_gettimeofday ()
>>>>>>> #1 0x00000000004ab8d2 in gettimeofday ()
>>>>>>> #2 0x0000000000452e4b in TimePosix__Now () at
>>>>>>> ../src/time/POSIX/TimePosixC.c:50
>>>>>>> #3 0x0000000000452d72 in Time__Now () at
>>>>>>> ../src/time/POSIX/TimePosix.m3:14
>>>>>>> #4 0x00000000004029a3 in Main__LApply (M3_AP7a1g_cl=3D3DError =3D
>>> accessing
>>>>>>> memory address 0x8000fedf6df8: Bad address.
>>>>>>> ) at ../src/Main.m3:327
>>>>>>> #5 0x0000000000449f93 in ThreadPThread__RunThread =3D
>>> (M3_DMxDjQ_me=3D3DError
>>>>>>> accessing memory address 0x8000fedf6eb8: Bad address.
>>>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:449
>>>>>>> #6 0x0000000000449c50 in ThreadPThread__ThreadBase
>>>>>>> (M3_AJWxb1_param=3D3DError accessing memory address =
>0x8000fedf6f68: =3D
>>> Bad address.
>>>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:422
>>>>>>> #7 0x000000000047c7d4 in thread_start ()
>>>>>>> #8 0x0000000000000000 in ?? ()
>>>>>>> =3D20
>>>>>>> Thread 3 (Thread 800c0b000 (LWP 100476/threadtest)):
>>>>>>> #0 0x000000000047e53c in _umtx_op_err ()
>>>>>>> #1 0x0000000000475f14 in __thr_umutex_lock ()
>>>>>>> #2 0x0000000000479404 in mutex_lock_common ()
>>>>>>> #3 0x000000000044dd15 in ThreadPThread__pthread_mutex_lock =3D
>>> (mutex=3D3DError
>>>>>>> accessing memory address 0x8000feff7d98: Bad address.
>>>>>>> ) at ../src/thread/PTHREAD/ThreadPThreadC.c:506
>>>>>>> #4 0x00000000004480c0 in ThreadPThread__LockMutex =3D
>>> (M3_AYIbX3_m=3D3DError
>>>>>>> accessing memory address 0x8000feff7dc8: Bad address.
>>>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:119
>>>>>>> #5 0x00000000004028ad in Main__LApply (M3_AP7a1g_cl=3D3DError =3D
>>> accessing
>>>>>>> memory address 0x8000feff7df8: Bad address.
>>>>>>> ) at ../src/Main.m3:319
>>>>>>> #6 0x0000000000449f93 in ThreadPThread__RunThread =3D
>>> (M3_DMxDjQ_me=3D3DError
>>>>>>> accessing memory address 0x8000feff7eb8: Bad address.
>>>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:449
>>>>>>> #7 0x0000000000449c50 in ThreadPThread__ThreadBase
>>>>>>> (M3_AJWxb1_param=3D3DError accessing memory address =
>0x8000feff7f68: =3D
>>> Bad address.
>>>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:422
>>>>>>> #8 0x000000000047c7d4 in thread_start ()
>>>>>>> #9 0x0000000000000000 in ?? ()
>>>>>>> =3D20
>>>>>>> Thread 6 (Thread 800c09800 (LWP 100470/threadtest)):
>>>>>>> #0 0x000000000047e53c in _umtx_op_err ()
>>>>>>> #1 0x0000000000475759 in suspend_common ()
>>>>>>> #2 0x00000000004755c1 in pthread_suspend_np ()
>>>>>>> #3 0x000000000044df0c in ThreadPThread__SuspendThread =
>(mt=3D3DError
>>>>>>> accessing memory address 0x8000ffbfd6f8: Bad address.
>>>>>>> ) at ../src/thread/PTHREAD/ThreadFreeBSD.c:33
>>>>>>> #4 0x000000000044bade in ThreadPThread__StopThread =3D
>>> (M3_DMxDjQ_act=3D3DError
>>>>>>> accessing memory address 0x8000ffbfd718: Bad address.
>>>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:909
>>>>>>> #5 0x000000000044bc81 in ThreadPThread__StopWorld () at
>>>>>>> ../src/thread/PTHREAD/ThreadPThread.m3:948
>>>>>>> #6 0x000000000044b19e in RTThread__SuspendOthers () at
>>>>>>> ../src/thread/PTHREAD/ThreadPThread.m3:713
>>>>>>> #7 0x00000000004330d6 in RTCollector__CollectSomeInStateZero () =
>at
>>>>>>> ../src/runtime/common/RTCollector.m3:749
>>>>>>> #8 0x0000000000433081 in RTCollector__CollectSome () at
>>>>>>> ../src/runtime/common/RTCollector.m3:723
>>>>>>> #9 0x0000000000432d49 in RTHeapRep__CollectEnough () at
>>>>>>> ../src/runtime/common/RTCollector.m3:657
>>>>>>> #10 0x000000000042ff83 in RTAllocator__AllocTraced
>>>>>>> (M3_Cwb5VA_dataSize=3D3DError accessing memory address =3D
>>> 0x8000ffbfd958: Bad
>>>>>>> address.
>>>>>>> ) at ../src/runtime/common/RTAllocator.m3:367
>>>>>>> #11 0x000000000042f8a5 in RTAllocator__GetOpenArray =3D
>>> (M3_Eic7CK_def=3D3DError
>>>>>>> accessing memory address 0x8000ffbfda18: Bad address.
>>>>>>> ) at ../src/runtime/common/RTAllocator.m3:296
>>>>>>> #12 0x000000000042ebdf in RTHooks__AllocateOpenArray
>>>>>>> (M3_AJWxb1_defn=3D3DError accessing memory address =
>0x8000ffbfda78: =3D
>>> Bad address.
>>>>>>> ) at ../src/runtime/common/RTAllocator.m3:143
>>>>>>> #13 0x000000000040ca4e in Rd__NextBuff (M3_EkTcCb_rd=3D3DError =3D
>>> accessing
>>>>>>> memory address 0x8000ffbfdab8: Bad address.
>>>>>>> ) at ../src/rw/Rd.m3:159
>>>>>>> #14 0x000000000040cd43 in UnsafeRd__FastGetChar =
>(M3_EkTcCb_rd=3D3DError=3D
>>>=20
>>>>>>> accessing memory address 0x8000ffbfdb88: Bad address.
>>>>>>> ) at ../src/rw/Rd.m3:187
>>>>>>> #15 0x000000000040cc4a in Rd__GetChar (M3_EkTcCb_rd=3D3DError =3D
>>> accessing
>>>>>>> memory address 0x8000ffbfdbd8: Bad address.
>>>>>>> ) at ../src/rw/Rd.m3:176
>>>>>>> #16 0x000000000040095c in Main__RApply (M3_AP7a1g_cl=3D3DError =3D
>>> accessing
>>>>>>> memory address 0x8000ffbfdc58: Bad address.
>>>>>>> ) at ../src/Main.m3:185
>>>>>>> =3D20
>>>>>>> #17 0x0000000000449f93 in ThreadPThread__RunThread =3D
>>> (M3_DMxDjQ_me=3D3DError
>>>>>>> accessing memory address 0x8000ffbfdeb8: Bad address.
>>>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:449
>>>>>>> #18 0x0000000000449c50 in ThreadPThread__ThreadBase
>>>>>>> (M3_AJWxb1_param=3D3DError accessing memory address =
>0x8000ffbfdf68: =3D
>>> Bad address.
>>>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:422
>>>>>>> #19 0x000000000047c7d4 in thread_start ()
>>>>>>> #20 0x0000000000000000 in ?? ()
>>>>>>> =3D20
>>>>>>> Thread 5 (Thread 800c09400 (LWP 101035/threadtest)):
>>>>>>> #0 0x000000000047e53c in _umtx_op_err ()
>>>>>>> #1 0x0000000000475f14 in __thr_umutex_lock ()
>>>>>>> #2 0x0000000000479404 in mutex_lock_common ()
>>>>>>> #3 0x000000000044dd15 in ThreadPThread__pthread_mutex_lock =3D
>>> (mutex=3D3DError
>>>>>>> accessing memory address 0x8000ffffc678: Bad address.
>>>>>>> ) at ../src/thread/PTHREAD/ThreadPThreadC.c:506
>>>>>>> #4 0x000000000044d039 in RTOS__LockHeap () at
>>>>>>> ../src/thread/PTHREAD/ThreadPThread.m3:1337
>>>>>>> ---Type <return> to continue, or q <return> to quit---
>>>>>>> #5 0x000000000042ff79 in RTAllocator__AllocTraced
>>>>>>> (M3_Cwb5VA_dataSize=3D3DError accessing memory address =3D
>>> 0x8000ffffc6e8: Bad
>>>>>>> address.
>>>>>>> ) at ../src/runtime/common/RTAllocator.m3:365
>>>>>>> #6 0x000000000042f15b in RTAllocator__GetTracedObj =3D
>>> (M3_Eic7CK_def=3D3DError
>>>>>>> accessing memory address 0x8000ffffc7a8: Bad address.
>>>>>>> ) at ../src/runtime/common/RTAllocator.m3:224
>>>>>>> #7 0x000000000042eb23 in RTHooks__AllocateTracedObj
>>>>>>> (M3_AJWxb1_defn=3D3DError accessing memory address =
>0x8000ffffc7f8: =3D
>>> Bad address.
>>>>>>> ) at ../src/runtime/common/RTAllocator.m3:122
>>>>>>> #8 0x000000000045fbe4 in TextCat__Flat (M3_Bd56fi_LText=3D3DError =
>=3D
>>> accessing
>>>>>>> memory address 0x8000ffffc858: Bad address.
>>>>>>> ) at ../src/text/TextCat.m3:562
>>>>>>> #9 0x000000000045ed5d in TextCat__Balance =3D
>>> (M3_Bd56fi_LText=3D3D0x800c490b0,
>>>>>>> M3_BUgnwf_LInfo=3D3DError accessing memory address =
>0x8000ffffc8f8: =3D
>>> Bad address.
>>>>>>> ) at ../src/text/TextCat.m3:488
>>>>>>> #10 0x000000000045d64f in RTHooks__Concat (M3_Bd56fi_t=3D3DError =
>=3D
>>> accessing
>>>>>>> memory address 0x8000ffffcbb8: Bad address.
>>>>>>> ) at ../src/text/TextCat.m3:40
>>>>>>> #11 0x000000000040639e in Main_M3 (M3_AcxOUs_mode=3D3DError =
>accessing =3D
>>> memory
>>>>>>> address 0x8000ffffcc38: Bad address.
>>>>>>> ) at ../src/Main.m3:593
>>>>>>> #12 0x000000000043d55d in RTLinker__RunMainBody =
>(M3_DjPxE3_m=3D3DError
>>>>>>> accessing memory address 0x8000ffffcf88: Bad address.
>>>>>>> ) at ../src/runtime/common/RTLinker.m3:408
>>>>>>> #13 0x000000000043c8e8 in RTLinker__AddUnitI (M3_DjPxE3_m=3D3DError=
> =3D
>>> accessing
>>>>>>> memory address 0x8000ffffd008: Bad address.
>>>>>>> ) at ../src/runtime/common/RTLinker.m3:115
>>>>>>> #14 0x000000000043c97c in RTLinker__AddUnit (M3_DjPxE5_b=3D3DError =
>=3D
>>> accessing
>>>>>>> memory address 0x8000ffffd028: Bad address.
>>>>>>> ) at ../src/runtime/common/RTLinker.m3:124
>>>>>>> #15 0x00000000004004a6 in main (argc=3D3DError accessing memory =3D=
>
>>> address
>>>>>>> 0x8000ffffd07c: Bad address.
>>>>>>> ) at _m3main.c:22
>>>>>>> =3D20
>>>>>>> Thread 9 (Thread 800c0a400 (LWP 100473/threadtest)):
>>>>>>> #0 0x000000000047e53c in _umtx_op_err ()
>>>>>>> #1 0x0000000000477e8a in check_suspend ()
>>>>>>> #2 0x00000000004780a2 in sigcancel_handler ()
>>>>>>> #3 <signal handler called>
>>>>>>> #4 0x000000000047e53c in _umtx_op_err ()
>>>>>>> #5 0x0000000000475f14 in __thr_umutex_lock ()
>>>>>>> #6 0x0000000000479404 in mutex_lock_common ()
>>>>>>> #7 0x000000000044dd15 in ThreadPThread__pthread_mutex_lock =3D
>>> (mutex=3D3DError
>>>>>>> accessing memory address 0x8000ff5fac18: Bad address.
>>>>>>> ) at ../src/thread/PTHREAD/ThreadPThreadC.c:506
>>>>>>> #8 0x000000000044d039 in RTOS__LockHeap () at
>>>>>>> ../src/thread/PTHREAD/ThreadPThread.m3:1337
>>>>>>> #9 0x000000000042ff79 in RTAllocator__AllocTraced
>>>>>>> (M3_Cwb5VA_dataSize=3D3DError accessing memory address =3D
>>> 0x8000ff5fac88: Bad
>>>>>>> address.
>>>>>>> ) at ../src/runtime/common/RTAllocator.m3:365
>>>>>>> #10 0x000000000042f8a5 in RTAllocator__GetOpenArray =3D
>>> (M3_Eic7CK_def=3D3DError
>>>>>>> accessing memory address 0x8000ff5fad48: Bad address.
>>>>>>> ) at ../src/runtime/common/RTAllocator.m3:296
>>>>>>> #11 0x000000000042ebdf in RTHooks__AllocateOpenArray
>>>>>>> (M3_AJWxb1_defn=3D3DError accessing memory address =
>0x8000ff5fada8: =3D
>>> Bad address.
>>>>>>> ) at ../src/runtime/common/RTAllocator.m3:143
>>>>>>> #12 0x000000000040203a in Main__AApply (M3_AP7a1g_cl=3D3DError =3D
>>> accessing
>>>>>>> memory address 0x8000ff5fade8: Bad address.
>>>>>>> ) at ../src/Main.m3:283
>>>>>>> #13 0x0000000000449f93 in ThreadPThread__RunThread =3D
>>> (M3_DMxDjQ_me=3D3DError
>>>>>>> accessing memory address 0x8000ff5faeb8: Bad address.
>>>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:449
>>>>>>> #14 0x0000000000449c50 in ThreadPThread__ThreadBase
>>>>>>> (M3_AJWxb1_param=3D3DError accessing memory address =
>0x8000ff5faf68: =3D
>>> Bad address.
>>>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:422
>>>>>>> #15 0x000000000047c7d4 in thread_start ()
>>>>>>> #16 0x0000000000000000 in ?? ()
>>>>>>> =3D20
>>>>>>> (others are similar)
>>>>>>> =3D20
>>>>>>> Hmm looks like a FreeBSD issue now. It's here...
>>>>>>> =3D20
>>>>>>> int
>>>>>>> __cdecl
>>>>>>> ThreadPThread__SuspendThread (m3_pthread_t mt)
>>>>>>> {
>>>>>>> ThreadFreeBSD__Fatal(pthread_suspend_np(PTHREAD_FROM_M3(mt)),
>>>>>>> "pthread_suspend_np");
>>>>>>> return 1;
>>>>>>> }
>>>>>>> =3D20
>>>>>>> Now this suspend can wait:
>>>>>>> =3D20
>>>>>>> static int
>>>>>>> suspend_common(struct pthread *curthread, struct pthread *thread,
>>>>>>> int waitok)
>>>>>>> {
>>>>>>> uint32_t tmp;
>>>>>>> =3D20
>>>>>>> while (thread->state !=3D3D PS_DEAD &&
>>>>>>> !(thread->flags & THR_FLAGS_SUSPENDED)) {
>>>>>>> thread->flags |=3D3D THR_FLAGS_NEED_SUSPEND;
>>>>>>> /* Thread is in creation. */
>>>>>>> if (thread->tid =3D3D=3D3D TID_TERMINATED)
>>>>>>> return (1);
>>>>>>> tmp =3D3D thread->cycle;
>>>>>>> _thr_send_sig(thread, SIGCANCEL);
>>>>>>> THR_THREAD_UNLOCK(curthread, thread);
>>>>>>> if (waitok) {
>>>>>>> _thr_umtx_wait_uint(&thread->cycle, tmp, =3D
>>> NULL,
>>>>>>> 0); <=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D
>>>>>>> THR_THREAD_LOCK(curthread, thread);
>>>>>>> } else {
>>>>>>> THR_THREAD_LOCK(curthread, thread);
>>>>>>> return (0);
>>>>>>> }
>>>>>>> }
>>>>>>> =3D20
>>>>>>> return (1);
>>>>>>> }
>>>>>>> =3D20
>>>>>>> ... but what it can wait for I am not clear on.
>>>>>>> =3D20
>>>>>>> Do things work better on Linux?
>>>>>>> =3D20
>>>>>>> What is the status of the fork bug? Can it be worked around by =3D=
>
>>> only
>>>>>>> forking via Process.Create with no mutexes held (outside of all =3D=
>
>>> LOCK
>>>>>>> blocks)?
>>>>>>> =3D20
>>>>>>> Mika
>>>>>>> =3D20
>>>>>>> =3D20
>>>>>>> =3D20
>>>>>>> Peter McKinna writes:
>>>>>>>> --001a11c2ced4471a2e050079db82
>>>>>>>> Content-Type: text/plain; charset=3D3DUTF-8
>>>>>>>> =3D20
>>>>>>>> Mika
>>>>>>>> =3D20
>>>>>>>> I think you need to back out Tony's changes to fix the fork bug, =
>=3D
>>> at
>>>>>>> least
>>>>>>>> for now. Need to reload from cvs version 1.262 for =3D
>>> ThreadPThread.m3 If
>>>>>>>> you're using git you're on your own.
>>>>>>>> Do a cvs log ThreadPThread.m3 for an explanation for some of the =
>=3D
>>> design
>>>>>>>> principles.
>>>>>>>> Also if you use gdb then you need to set lanc c before =
>backtraces =3D
>>> so at
>>>>>>>> least you can see address names and values even if they are =3D
>>> contorted you
>>>>>>>> can extract the M3 name in the parm lists. Also in gdb thread =3D
>>> apply all
>>>>>>> bt
>>>>>>>> gives all thread backtraces which can be handy to see whose got =
>=3D
>>> the locks
>>>>>>>> held.
>>>>>>>> =3D20
>>>>>>>> Regards Peter
>>>>>>>> =3D20
>>>>>>>> =3D20
>>>>>>>> =3D20
>>>>>>>> On Wed, Aug 13, 2014 at 12:14 PM, <mika at async.caltech.edu> =
>wrote:
>>>>>>>> =3D20
>>>>>>>>> =3D20
>>>>>>>>> Question... is there something odd about my pthreads? Are =3D
>>> pthreads
>>>>>>>>> normally reentrant? I didn't think so.
>>>>>>>>> =3D20
>>>>>>>>> My compiler is much happier with the following changes I =
>already
>>>>>>> outlined:
>>>>>>>>> =3D20
>>>>>>>>> 1. a dirty, disgusting hack to keep from locking against myself =
>=3D
>>> going
>>>>>>> from
>>>>>>>>> XWait with self.mutex locked to m.release().
>>>>>>>>> =3D20
>>>>>>>>> 2. the change to LockHeap I described in previous email
>>>>>>>>> =3D20
>>>>>>>>> But now...
>>>>>>>>> =3D20
>>>>>>>>> (gdb) cont
>>>>>>>>> Continuing.
>>>>>>>>> ERROR: pthread_mutex_lock:11
>>>>>>>>> ERROR: pthread_mutex_lock:11
>>>>>>>>> =3D20
>>>>>>>>> Program received signal SIGABRT, Aborted.
>>>>>>>>> 0x000000080107626a in thr_kill () from /lib/libc.so.7
>>>>>>>>> (gdb) where
>>>>>>>>> #0 0x000000080107626a in thr_kill () from /lib/libc.so.7
>>>>>>>>> #1 0x000000080113dac9 in abort () from /lib/libc.so.7
>>>>>>>>> #2 0x000000000071e37a in ThreadPThread__pthread_mutex_lock
>>>>>>> (mutex=3D3DError
>>>>>>>>> accessing memory address 0x8000ffffb508: Bad address.
>>>>>>>>> ) at ../src/thread/PTHREAD/ThreadPThreadC.c:543
>>>>>>>>> #3 0x000000000071d48d in RTOS__LockHeap () at
>>>>>>>>> ../src/thread/PTHREAD/ThreadPThread.m3:1377
>>>>>>>>> #4 0x0000000000706b9d in RTHooks__CheckLoadTracedRef
>>>>>>> (M3_Af40ku_ref=3D3DError
>>>>>>>>> accessing memory address 0x8000ffffb568: Bad address.
>>>>>>>>> ) at ../src/runtime/common/RTCollector.m3:2234
>>>>>>>>> #5 0x000000000071d284 in ThreadPThread__AtForkParent () at
>>>>>>>>> ../src/thread/PTHREAD/ThreadPThread.m3:1348
>>>>>>>>> #6 0x0000000800df8733 in fork () from /lib/libthr.so.3
>>>>>>>>> #7 0x000000000070dd8b in RTProcess__Fork () at
>>>>>>>>> ../src/runtime/common/RTProcessC.c:152
>>>>>>>>> #8 0x00000000006c52f2 in ProcessPosixCommon__Create_ForkExec
>>>>>>>>> (M3_Bd56fi_cmd=3D3DError accessing memory address =
>0x8000ffffb6f8: =3D
>>> Bad
>>>>>>> address.
>>>>>>>>> ) at ../src/os/POSIX/ProcessPosixCommon.m3:75
>>>>>>>>> #9 0x00000000006c6c6c in Process__Create =
>(M3_Bd56fi_cmd=3D3DError
>>>>>>> accessing
>>>>>>>>> memory address 0x8000ffffb7f8: Bad address.
>>>>>>>>> ) at ../src/os/POSIX/ProcessPosix.m3:21
>>>>>>>>> #10 0x00000000004d6826 in QMachine__FulfilExecPromise
>>>>>>> (M3_D6rRrg_ep=3D3DError
>>>>>>>>> accessing memory address 0x8000ffffb838: Bad address.
>>>>>>>>> ) at ../src/QMachine.m3:1666
>>>>>>>>> #11 0x00000000004d6220 in QMachine__ExecCommand =3D
>>> (M3_An02H2_t=3D3DError
>>>>>>>>> accessing memory address 0x8000ffffb9f8: Bad address.
>>>>>>>>> ) at ../src/QMachine.m3:1605
>>>>>>>>> #12 0x00000000004d537e in QMachine__DoTryExec =
>(M3_An02H2_t=3D3DError
>>>>>>> accessing
>>>>>>>>> memory address 0x8000ffffbee8: Bad address.
>>>>>>>>> ) at ../src/QMachine.m3:1476
>>>>>>>>> =3D20
>>>>>>>>> What am I doing wrong here?
>>>>>>>>> =3D20
>>>>>>>>> The error doesn't look unreasonable! Looking more closely at =
>the =3D
>>> code:
>>>>>>>>> =3D20
>>>>>>>>> First, AtForkPrepare has been called:
>>>>>>>>> =3D20
>>>>>>>>> PROCEDURE AtForkPrepare() =3D3D
>>>>>>>>> VAR me :=3D3D GetActivation();
>>>>>>>>> act: Activation;
>>>>>>>>> BEGIN
>>>>>>>>> PThreadLockMutex(slotsMu, ThisLine());
>>>>>>>>> PThreadLockMutex(perfMu, ThisLine());
>>>>>>>>> PThreadLockMutex(initMu, ThisLine()); (* InitMutex =3D3D>
>>>>>>>>> RegisterFinalCleanup =3D3D> LockHeap *)
>>>>>>>>> PThreadLockMutex(heapMu, ThisLine());
>>>>>>>>> PThreadLockMutex(activeMu, ThisLine()); (* LockHeap =3D3D>
>>>>>>> SuspendOthers
>>>>>>>>> =3D3D> activeMu *)
>>>>>>>>> (* Walk activations and lock all threads.
>>>>>>>>> * NOTE: We have initMu, activeMu, so slots won't change,
>>>>>>> conditions
>>>>>>>>> and
>>>>>>>>> * mutexes won't be initialized on-demand.
>>>>>>>>> *)
>>>>>>>>> act :=3D3D me;
>>>>>>>>> REPEAT
>>>>>>>>> PThreadLockMutex(act.mutex, ThisLine());
>>>>>>>>> act :=3D3D act.next;
>>>>>>>>> UNTIL act =3D3D me;
>>>>>>>>> END AtForkPrepare;
>>>>>>>>> =3D20
>>>>>>>>> a postcondition of this routine is that heapMu is locked.
>>>>>>>>> =3D20
>>>>>>>>> now we get into AtForkParent:
>>>>>>>>> =3D20
>>>>>>>>> PROCEDURE AtForkParent() =3D3D
>>>>>>>>> VAR me :=3D3D GetActivation();
>>>>>>>>> act: Activation;
>>>>>>>>> cond: Condition;
>>>>>>>>> BEGIN
>>>>>>>>> (* Walk activations and unlock all threads, conditions. *)
>>>>>>>>> act :=3D3D me;
>>>>>>>>> REPEAT
>>>>>>>>> cond :=3D3D slots[act.slot].join;
>>>>>>>>> IF cond # NIL THEN PThreadUnlockMutex(cond.mutex, =3D
>>> ThisLine())
>>>>>>> END;
>>>>>>>>> PThreadUnlockMutex(act.mutex, ThisLine());
>>>>>>>>> act :=3D3D act.next;
>>>>>>>>> UNTIL act =3D3D me;
>>>>>>>>> PThreadUnlockMutex(activeMu, ThisLine());
>>>>>>>>> PThreadUnlockMutex(heapMu, ThisLine());
>>>>>>>>> PThreadUnlockMutex(initMu, ThisLine());
>>>>>>>>> PThreadUnlockMutex(perfMu, ThisLine());
>>>>>>>>> PThreadUnlockMutex(slotsMu, ThisLine());
>>>>>>>>> END AtForkParent;
>>>>>>>>> =3D20
>>>>>>>>> We can see by inspecting the code that a necessary precondition =
>=3D
>>> for
>>>>>>>>> this routine is that heapMu is locked! (Since it's going to =3D
>>> unlock it,
>>>>>>>>> it had BETTER be locked on entry.)
>>>>>>>>> =3D20
>>>>>>>>> But the cond :=3D3D ... causes a RTHooks.CheckLoadTracedRef
>>>>>>>>> =3D20
>>>>>>>>> which causes an RTOS.LockHeap
>>>>>>>>> =3D20
>>>>>>>>> the code of which we just saw:
>>>>>>>>> =3D20
>>>>>>>>> PROCEDURE LockHeap () =3D3D
>>>>>>>>> VAR self :=3D3D pthread_self();
>>>>>>>>> BEGIN
>>>>>>>>> WITH r =3D3D pthread_mutex_lock(heapMu,ThisLine()) DO =
><*ASSERT =3D
>>> r=3D3D0*>
>>>>>>> END;
>>>>>>>>> ...
>>>>>>>>> =3D20
>>>>>>>>> we try to lock heapMu. kaboom! No surprise there, really?
>>>>>>>>> =3D20
>>>>>>>>> Am I going about this totally the wrong way? Other people are =
>=3D
>>> running
>>>>>>>>> Modula-3
>>>>>>>>> with pthreads, right? Right?? Somewhere out there in =3D
>>> m3devel-land?
>>>>>>>>> =3D20
>>>>>>>>> Mika
>>>>>>>>> =3D20
>>>>>>>>> =3D20
>>>>>>>> =3D20
>>>>>>>> --001a11c2ced4471a2e050079db82
>>>>>>>> Content-Type: text/html; charset=3D3DUTF-8
>>>>>>>> Content-Transfer-Encoding: quoted-printable
>>>>>>>> =3D20
>>>>>>>> <div dir=3D3D3D"ltr">Mika<div><br></div><div>=3D3DC2=3D3DA0 I =
>think you =3D
>>> need to back
>>>>>>> ou=3D3D
>>>>>>>> t Tony's changes to fix the fork bug, at least for now. Need =
>=3D
>>> to
>>>>>>> reload =3D3D
>>>>>>>> from cvs version 1.262 for ThreadPThread.m3 If you're using =
>=3D
>>> git
>>>>>>> you'=3D3D
>>>>>>>> ;re on your own.</div>
>>>>>>>> =3D20
>>>>>>>> <div>=3D3DC2=3D3DA0 Do a cvs log ThreadPThread.m3 for an =
>explanation =3D
>>> for some of
>>>>>>> th=3D3D
>>>>>>>> e design principles.=3D3DC2=3D3DA0</div><div>=3D3DC2=3D3DA0 Also =
>if you =3D
>>> use gdb then you
>>>>>>> ne=3D3D
>>>>>>>> ed to set lanc c before backtraces so at least you can see =
>address =3D
>>> names
>>>>>>> an=3D3D
>>>>>>>> d values even if they are contorted you can extract the M3 name =
>in =3D
>>> the
>>>>>>> parm=3D3D
>>>>>>>> lists. Also in gdb thread apply all bt gives all thread =
>backtraces
>>>>>>> which c=3D3D
>>>>>>>> an be handy to see whose got the locks held.</div>
>>>>>>>> =3D20
>>>>>>>> <div><br></div><div>Regards Peter</div><div><br></div><div
>>>>>>> class=3D3D3D"gmail_e=3D3D
>>>>>>>> xtra"><br><br><div class=3D3D3D"gmail_quote">On Wed, Aug 13, =
>2014 at =3D
>>> 12:14
>>>>>>> PM, =3D3D
>>>>>>>> <span dir=3D3D3D"ltr"><<a =
>href=3D3D3D"mailto:mika at async.caltech.edu"
>>>>>>> target=3D3D3D"=3D3D
>>>>>>>> _blank">mika at async.caltech.edu</a>></span> wrote:<br>
>>>>>>>> =3D20
>>>>>>>> <blockquote class=3D3D3D"gmail_quote" style=3D3D3D"margin:0 0 0
>>>>>>> .8ex;border-left:1p=3D3D
>>>>>>>> x #ccc solid;padding-left:1ex"><br>
>>>>>>>> Question... is there something odd about my pthreads? =
>=3D3DC2=3D3DA0Are =3D
>>> pthreads
>>>>>>> no=3D3D
>>>>>>>> rmally reentrant? =3D3DC2=3D3DA0I didn't think so.<br>
>>>>>>>> <br>
>>>>>>>> My compiler is much happier with the following changes I already
>>>>>>> outlined:<=3D3D
>>>>>>>> br>
>>>>>>>> <br>
>>>>>>>> 1. a dirty, disgusting hack to keep from locking against myself =
>=3D
>>> going
>>>>>>> from =3D3D
>>>>>>>> XWait with self.mutex locked to m.release().<br>
>>>>>>>> <br>
>>>>>>>> 2. the change to LockHeap I described in previous email<br>
>>>>>>>> <br>
>>>>>>>> But now...<br>
>>>>>>>> <br>
>>>>>>>> (gdb) cont<br>
>>>>>>>> Continuing.<br>
>>>>>>>> ERROR: pthread_mutex_lock:11<br>
>>>>>>>> ERROR: pthread_mutex_lock:11<br>
>>>>>>>> <br>
>>>>>>>> Program received signal SIGABRT, Aborted.<br>
>>>>>>>> 0x000000080107626a in thr_kill () from /lib/libc.so.7<br>
>>>>>>>> (gdb) where<br>
>>>>>>>> #0 =3D3DC2=3D3DA00x000000080107626a in thr_kill () from =3D
>>> /lib/libc.so.7<br>
>>>>>>>> #1 =3D3DC2=3D3DA00x000000080113dac9 in abort () from =3D
>>> /lib/libc.so.7<br>
>>>>>>>> #2 =3D3DC2=3D3DA00x000000000071e37a in =3D
>>> ThreadPThread__pthread_mutex_lock
>>>>>>> (mutex=3D3D3DE=3D3D
>>>>>>>> rror accessing memory address 0x8000ffffb508: Bad address.<br>
>>>>>>>> ) at ../src/thread/PTHREAD/ThreadPThreadC.c:543<br>
>>>>>>>> #3 =3D3DC2=3D3DA00x000000000071d48d in RTOS__LockHeap () at
>>>>>>> ../src/thread/PTHREAD/T=3D3D
>>>>>>>> hreadPThread.m3:1377<br>
>>>>>>>> #4 =3D3DC2=3D3DA00x0000000000706b9d in =
>RTHooks__CheckLoadTracedRef
>>>>>>> (M3_Af40ku_ref=3D3D
>>>>>>>> =3D3D3DError accessing memory address 0x8000ffffb568: Bad =3D
>>> address.<br>
>>>>>>>> ) at ../src/runtime/common/RTCollector.m3:2234<br>
>>>>>>>> #5 =3D3DC2=3D3DA00x000000000071d284 in =
>ThreadPThread__AtForkParent () =3D
>>> at
>>>>>>> ../src/thr=3D3D
>>>>>>>> ead/PTHREAD/ThreadPThread.m3:1348<br>
>>>>>>>> #6 =3D3DC2=3D3DA00x0000000800df8733 in fork () from =3D
>>> /lib/libthr.so.3<br>
>>>>>>>> #7 =3D3DC2=3D3DA00x000000000070dd8b in RTProcess__Fork () at
>>>>>>> ../src/runtime/common/=3D3D
>>>>>>>> RTProcessC.c:152<br>
>>>>>>>> #8 =3D3DC2=3D3DA00x00000000006c52f2 in =3D
>>> ProcessPosixCommon__Create_ForkExec
>>>>>>> (M3_Bd56=3D3D
>>>>>>>> fi_cmd=3D3D3DError accessing memory address 0x8000ffffb6f8: Bad =
>=3D
>>> address.<br>
>>>>>>>> ) at ../src/os/POSIX/ProcessPosixCommon.m3:75<br>
>>>>>>>> #9 =3D3DC2=3D3DA00x00000000006c6c6c in Process__Create =3D
>>> (M3_Bd56fi_cmd=3D3D3DError
>>>>>>> acces=3D3D
>>>>>>>> sing memory address 0x8000ffffb7f8: Bad address.<br>
>>>>>>>> ) at ../src/os/POSIX/ProcessPosix.m3:21<br>
>>>>>>>> #10 0x00000000004d6826 in QMachine__FulfilExecPromise
>>>>>>> (M3_D6rRrg_ep=3D3D3DError=3D3D
>>>>>>>> accessing memory address 0x8000ffffb838: Bad address.<br>
>>>>>>>> ) at ../src/QMachine.m3:1666<br>
>>>>>>>> #11 0x00000000004d6220 in QMachine__ExecCommand =3D
>>> (M3_An02H2_t=3D3D3DError
>>>>>>> access=3D3D
>>>>>>>> ing memory address 0x8000ffffb9f8: Bad address.<br>
>>>>>>>> ) at ../src/QMachine.m3:1605<br>
>>>>>>>> #12 0x00000000004d537e in QMachine__DoTryExec =
>(M3_An02H2_t=3D3D3DError=3D
>>>=20
>>>>>>> accessin=3D3D
>>>>>>>> g memory address 0x8000ffffbee8: Bad address.<br>
>>>>>>>> ) at ../src/QMachine.m3:1476<br>
>>>>>>>> <br>
>>>>>>>> What am I doing wrong here?<br>
>>>>>>>> <br>
>>>>>>>> The error doesn't look unreasonable! =3D3DC2=3D3DA0Looking =
>more =3D
>>> closely at
>>>>>>> the =3D3D
>>>>>>>> code:<br>
>>>>>>>> <br>
>>>>>>>> First, AtForkPrepare has been called:<br>
>>>>>>>> <br>
>>>>>>>> PROCEDURE AtForkPrepare() =3D3D3D<br>
>>>>>>>> =3D3DC2=3D3DA0 VAR me :=3D3D3D GetActivation();<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 act: =
>Activation;<br>
>>>>>>>> =3D3DC2=3D3DA0 BEGIN<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 PThreadLockMutex(slotsMu, =
>ThisLine());<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 PThreadLockMutex(perfMu, =
>ThisLine());<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 PThreadLockMutex(initMu, =
>ThisLine()); (* =3D
>>> InitMutex =3D3D3D>
>>>>>>> Re=3D3D
>>>>>>>> gisterFinalCleanup =3D3D3D> LockHeap *)<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 PThreadLockMutex(heapMu, =
>ThisLine());<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 PThreadLockMutex(activeMu, =
>ThisLine()); (* =3D
>>> LockHeap
>>>>>>> =3D3D3D> S=3D3D
>>>>>>>> uspendOthers =3D3D3D> activeMu *)<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 (* Walk activations and lock all =3D=
>
>>> threads.<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0* NOTE: We have =
>initMu, activeMu, =3D
>>> so slots won't
>>>>>>> ch=3D3D
>>>>>>>> ange, conditions and<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0* mutexes won't =
>be initialized =3D
>>> on-demand.<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0*)<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 act :=3D3D3D me;<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 REPEAT<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =
>PThreadLockMutex(act.mutex, =3D
>>> ThisLine());<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 act :=3D3D3D =
>act.next;<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 UNTIL act =3D3D3D me;<br>
>>>>>>>> =3D3DC2=3D3DA0 END AtForkPrepare;<br>
>>>>>>>> <br>
>>>>>>>> a postcondition of this routine is that heapMu is locked.<br>
>>>>>>>> <br>
>>>>>>>> now we get into AtForkParent:<br>
>>>>>>>> <br>
>>>>>>>> PROCEDURE AtForkParent() =3D3D3D<br>
>>>>>>>> =3D3DC2=3D3DA0 VAR me :=3D3D3D GetActivation();<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 act: =
>Activation;<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 cond: =
>Condition;<br>
>>>>>>>> =3D3DC2=3D3DA0 BEGIN<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 (* Walk activations and unlock all =
>threads, =3D
>>> conditions.
>>>>>>> *)<br=3D3D
>>>>>>>>> =3D20
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 act :=3D3D3D me;<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 REPEAT<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 cond :=3D3D3D =3D
>>> slots[act.slot].join;<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 IF cond # NIL THEN =
>=3D
>>> PThreadUnlockMutex(cond.mutex,
>>>>>>> This=3D3D
>>>>>>>> Line()) END;<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =
>PThreadUnlockMutex(act.mutex, =3D
>>> ThisLine());<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 act :=3D3D3D =
>act.next;<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 UNTIL act =3D3D3D me;<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 PThreadUnlockMutex(activeMu, =3D
>>> ThisLine());<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 PThreadUnlockMutex(heapMu, =
>ThisLine());<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 PThreadUnlockMutex(initMu, =
>ThisLine());<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 PThreadUnlockMutex(perfMu, =
>ThisLine());<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 PThreadUnlockMutex(slotsMu, =
>ThisLine());<br>
>>>>>>>> =3D3DC2=3D3DA0 END AtForkParent;<br>
>>>>>>>> <br>
>>>>>>>> We can see by inspecting the code that a necessary precondition =
>=3D
>>> for<br>
>>>>>>>> this routine is that heapMu is locked! =3D3DC2=3D3DA0(Since =
>it's =3D
>>> going to
>>>>>>> unloc=3D3D
>>>>>>>> k it,<br>
>>>>>>>> it had BETTER be locked on entry.)<br>
>>>>>>>> <br>
>>>>>>>> But the cond :=3D3D3D ... causes a =
>RTHooks.CheckLoadTracedRef<br>
>>>>>>>> <br>
>>>>>>>> which causes an RTOS.LockHeap<br>
>>>>>>>> <br>
>>>>>>>> the code of which we just saw:<br>
>>>>>>>> <br>
>>>>>>>> PROCEDURE LockHeap () =3D3D3D<br>
>>>>>>>> =3D3DC2=3D3DA0 VAR self :=3D3D3D pthread_self();<br>
>>>>>>>> =3D3DC2=3D3DA0 BEGIN<br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 WITH r =3D3D3D =3D
>>> pthread_mutex_lock(heapMu,ThisLine()) DO
>>>>>>> <*ASSE=3D3D
>>>>>>>> RT r=3D3D3D0*> END;<br>
>>>>>>>> ...<br>
>>>>>>>> <br>
>>>>>>>> we try to lock heapMu. =3D3DC2=3D3DA0kaboom! =3D3DC2=3D3DA0No =
>surprise =3D
>>> there, really?<br>
>>>>>>>> <br>
>>>>>>>> Am I going about this totally the wrong way? =3D3DC2=3D3DA0Other =
>=3D
>>> people are
>>>>>>> running=3D3D
>>>>>>>> Modula-3<br>
>>>>>>>> with pthreads, right? =3D3DC2=3D3DA0Right?? =3D3DC2=3D3DA0Somewher=
>e out =3D
>>> there in
>>>>>>> m3devel-la=3D3D
>>>>>>>> nd?<br>
>>>>>>>> <span><font color=3D3D3D"#888888"><br>
>>>>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0Mika<br>
>>>>>>>> <br>
>>>>>>>> </font></span></blockquote></div><br></div></div>
>>>>>>>> =3D20
>>>>>>>> --001a11c2ced4471a2e050079db82--
>>>>>>> =3D20
>>>>>> =3D20
>>>>>> =3D20
>>>>> =3D20
>>>>> --089e01183a1813188705007c3498
>>>>> Content-Type: text/html; charset=3D3DUTF-8
>>>>> Content-Transfer-Encoding: quoted-printable
>>>>> =3D20
>>>>> <div dir=3D3D3D"ltr">Oh, one other thing that seemed to help me in =
>=3D
>>> testing this=3D3D
>>>>> stuff especially things to do with m3core and libm3 which seem to =
>get =3D
>>> out =3D3D
>>>>> of whack sometimes, is to totally remove the target directory of =3D
>>> m3core the=3D3D
>>>>> n cm3; cm3 -ship Same with libm3. I'm not sure that clean =3D
>>> actually remo=3D3D
>>>>> ves the targets and I think there are leftover files that stuff =3D
>>> things up s=3D3D
>>>>> ince I would get segv in FileRd for no obvious reason.<div>
>>>>> <br></div><div>Peter</div><div><br></div></div><div =3D
>>> class=3D3D3D"gmail_extra"><=3D3D
>>>>> br><br><div class=3D3D3D"gmail_quote">On Wed, Aug 13, 2014 at 3:33 =
>PM, =3D
>>> Peter Mc=3D3D
>>>>> Kinna <span dir=3D3D3D"ltr"><<a =3D
>>> href=3D3D3D"mailto:peter.mckinna at gmail.com" targ=3D3D
>>>>> et=3D3D3D"_blank">peter.mckinna at gmail.com</a>></span> wrote:<br>
>>>>> <blockquote class=3D3D3D"gmail_quote" style=3D3D3D"margin:0 0 0 =3D
>>> .8ex;border-left:1p=3D3D
>>>>> x #ccc solid;padding-left:1ex"><div dir=3D3D3D"ltr">That is weird. =
>The =3D
>>> thread t=3D3D
>>>>> ester works fine with the old version of ThreadPThread.m3 on linux =
>=3D
>>> amd_64 e=3D3D
>>>>> xcept if you have the fork test in the mix of tests you see the =3D
>>> pthread_mut=3D3D
>>>>> ex_destroy every now and again, the fork bug in =
>fact.=3D3DC2=3D3DA0<div>
>>>>> =3D20
>>>>> I was testing the pthread changes Tony has made over the past few =3D=
>
>>> days usin=3D3D
>>>>> g the thread tester program until I stupidly rebuilt the compiler =
>and =3D
>>> was g=3D3D
>>>>> etting all sorts of hangs as it dragged in the new version of =3D
>>> pthreads. So =3D3D
>>>>> I rebuilt everything from a backup to get back where I was with a =3D=
>
>>> decent co=3D3D
>>>>> mpiler, then reintroduced the latest changes to ThreadPThread.m3, =3D=
>
>>> which yes=3D3D
>>>>> terday was just hanging in sigsuspend but today is giving me an =3D
>>> assert fail=3D3D
>>>>> ure at line 1387 in UnlockHeap. So its a bit unstable to say the =3D
>>> least. May=3D3D
>>>>> be there is something else wrong with freebsd.</div>
>>>>> <span class=3D3D3D"HOEnZb"><font color=3D3D3D"#888888">
>>>>> =3D
>>> =
><div><br></div><div>Peter</div><div><br></div></font></span></div><div =3D=
>
>>> clas=3D3D
>>>>> s=3D3D3D"HOEnZb"><div class=3D3D3D"h5"><div =3D
>>> class=3D3D3D"gmail_extra"><br><br><div clas=3D3D
>>>>> s=3D3D3D"gmail_quote">On Wed, Aug 13, 2014 at 2:54 PM, <span =3D
>>> dir=3D3D3D"ltr"><<=3D3D
>>>>> a href=3D3D3D"mailto:mika at async.caltech.edu" =3D
>>> target=3D3D3D"_blank">mika at async.calte=3D3D
>>>>> ch.edu</a>></span> wrote:<br>
>>>>> =3D20
>>>>> <blockquote class=3D3D3D"gmail_quote" style=3D3D3D"margin:0 0 0 =3D
>>> .8ex;border-left:1p=3D3D
>>>>> x #ccc solid;padding-left:1ex"><br>
>>>>> Yeah OK 1.262 makes a lot more sense to me but I'm still not =3D
>>> getting<br=3D3D
>>>>>> =3D20
>>>>> things to work and now I'm really baffled because I think I =3D
>>> understand<=3D3D
>>>>> br>
>>>>> this code!<br>
>>>>> <br>
>>>>> What I did was I threw away all my changes and reverted =3D
>>> ThreadPThread.m3<br=3D3D
>>>>>> =3D20
>>>>> to 1.262 as you suggested.<br>
>>>>> <br>
>>>>> Rebuilt the compiler with upgrade.sh<br>
>>>>> <br>
>>>>> Then rebuilt the compiler again with itself.<br>
>>>>> <br>
>>>>> Then I realcleaned the world and buildshipped it. =3D3DC2=3D3DA0(I =
>was =3D
>>> afraid<br>
>>>>> that parseparams, also imported by the thread tester, would =3D
>>> pollute<br>
>>>>> it somehow.)<br>
>>>>> <br>
>>>>> When I look at the code in 1.262 it looks quite straightforward. =3D
>>> =3D3DC2=3D3DA0heap=3D3D
>>>>> Mu<br>
>>>>> is just a mutex, (Modula-3) mutexes are just (pthreads) mutexes. =3D
>>> =3D3DC2=3D3DA0Cond=3D3D
>>>>> ition<br>
>>>>> variables are mutexes too, but that's no big deal.<br>
>>>>> <br>
>>>>> So, rebuild thread tester, run it:<br>
>>>>> <br>
>>>>> new source -> compiling Main.m3<br>
>>>>> =3D3DC2=3D3DA0-> linking threadtest<br>
>>>>> root at rover:~mika/cm3-cvs-anon/cm3/m3-libs/m3core/tests/thread # =3D
>>> AMD64_FREEB=3D3D
>>>>> SD/threadtest<br>
>>>>> Writing file...done<br>
>>>>> Creating read threads...done<br>
>>>>> Creating fork threads...done<br>
>>>>> Creating alloc threads...done<br>
>>>>> Creating lock threads...done<br>
>>>>> running...printing oldest/median age/newest<br>
>>>>> .<br>
>>>>> <br>
>>>>> ***<br>
>>>>> *** runtime error:<br>
>>>>> *** =3D3DC2=3D3DA0 =3D3DC2=3D3DA0Segmentation violation - possible =
>attempt to =3D
>>> dereference N=3D3D
>>>>> IL.........laziest thread is 1407901189/<a =3D
>>> href=3D3D3D"tel:1407901189%2F9" valu=3D3D
>>>>> e=3D3D3D"+14079011899" target=3D3D3D"_blank">1407901189/9</a> =
>(tests: =3D
>>> read 14079011=3D3D
>>>>> 89/1407901189/1407901189 fork 1407901189/1407901189/1407901189 =
>alloc =3D
>>> 9/9/9 =3D3D
>>>>> lock 1407901189/1407901189/9)<br>
>>>>> =3D20
>>>>> =3D20
>>>>> <br>
>>>>> <br>
>>>>> <br>
>>>>> <br>
>>>>> ^C<br>
>>>>> root at rover:~mika/cm3-cvs-anon/cm3/m3-libs/m3core/tests/thread # gdb =
>=3D
>>> !$<br>
>>>>> gdb AMD64_FREEBSD/threadtest<br>
>>>>> GNU gdb 6.1.1 [FreeBSD]<br>
>>>>> Copyright 2004 Free Software Foundation, Inc.<br>
>>>>> GDB is free software, covered by the GNU General Public License, =
>and =3D
>>> you ar=3D3D
>>>>> e<br>
>>>>> welcome to change it and/or distribute copies of it under certain =3D=
>
>>> condition=3D3D
>>>>> s.<br>
>>>>> Type "show copying" to see the conditions.<br>
>>>>> There is absolutely no warranty for GDB. =3D3DC2=3D3DA0Type =
>"show =3D
>>> warranty&quo=3D3D
>>>>> t; for details.<br>
>>>>> This GDB was configured as "amd64-marcel-freebsd"...<br>
>>>>> (gdb) run<br>
>>>>> Starting program: =3D
>>> /big/home2/mika/2/cm3-cvs/cm3/m3-libs/m3core/tests/thread=3D3D
>>>>> /AMD64_FREEBSD/threadtest<br>
>>>>> [New LWP 100121]<br>
>>>>> Writing file...done<br>
>>>>> Creating read threads...done<br>
>>>>> Creating fork threads...done<br>
>>>>> Creating alloc threads...done<br>
>>>>> Creating lock threads...done<br>
>>>>> running...printing oldest/median age/newest<br>
>>>>> .[New Thread 801807000 (LWP 100343/threadtest)]<br>
>>>>> [New Thread 801807c00 (LWP 100667/threadtest)]<br>
>>>>> [New Thread 801808800 (LWP 100816/threadtest)]<br>
>>>>> [New Thread 801807400 (LWP 100349/threadtest)]<br>
>>>>> [New Thread 801808400 (LWP 100815/threadtest)]<br>
>>>>> [New Thread 801807800 (LWP 100352/threadtest)]<br>
>>>>> [New Thread 801808c00 (LWP 100817/threadtest)]<br>
>>>>> [New Thread 801809000 (LWP 100818/threadtest)]<br>
>>>>> [New Thread 801809800 (LWP 100820/threadtest)]<br>
>>>>> [New Thread 801808000 (LWP 100678/threadtest)]<br>
>>>>> [New Thread 801806400 (LWP 100121/threadtest)]<br>
>>>>> [New Thread 801806800 (LWP 100341/threadtest)]<br>
>>>>> [New Thread 801806c00 (LWP 100342/threadtest)]<br>
>>>>> .ERROR: pthread_mutex_lock:11<br>
>>>>> <div><br>
>>>>> Program received signal SIGABRT, Aborted.<br>
>>>>> </div>[Switching to Thread 801809800 (LWP 100820/threadtest)]<br>
>>>>> 0x0000000800d5c26a in thr_kill () from /lib/libc.so.7<br>
>>>>> (gdb) where<br>
>>>>> #0 =3D3DC2=3D3DA00x0000000800d5c26a in thr_kill () from =3D
>>> /lib/libc.so.7<br>
>>>>> #1 =3D3DC2=3D3DA00x0000000800e23ac9 in abort () from =
>/lib/libc.so.7<br>
>>>>> #2 =3D3DC2=3D3DA00x000000000045101f in =
>ThreadPThread__pthread_mutex_lock =3D
>>> (mutex=3D3D3DE=3D3D
>>>>> rror accessing memory address 0x8000fe5f2d98: Bad address.<br>
>>>>> ) at ../src/thread/PTHREAD/ThreadPThreadC.c:513<br>
>>>>> #3 =3D3DC2=3D3DA00x000000000044b370 in ThreadPThread__LockMutex =3D
>>> (M3_AYIbX3_m=3D3D3DErro=3D3D
>>>>> r accessing memory address 0x8000fe5f2dc8: Bad address.<br>
>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:119<br>
>>>>> #4 =3D3DC2=3D3DA00x0000000000405b5d in Main__LApply =
>(M3_AP7a1g_cl=3D3D3DError=3D
>>> accessing=3D3D
>>>>> memory address 0x8000fe5f2df8: Bad address.<br>
>>>>> ) at ../src/Main.m3:319<br>
>>>>> #5 =3D3DC2=3D3DA00x000000000044d243 in ThreadPThread__RunThread =3D
>>> (M3_DMxDjQ_me=3D3D3DErr=3D3D
>>>>> or accessing memory address 0x8000fe5f2eb8: Bad address.<br>
>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:449<br>
>>>>> #6 =3D3DC2=3D3DA00x000000000044cf00 in ThreadPThread__ThreadBase =3D
>>> (M3_AJWxb1_param=3D3D
>>>>> =3D3D3DError accessing memory address 0x8000fe5f2f68: Bad =
>address.<br>
>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:422<br>
>>>>> #7 =3D3DC2=3D3DA00x0000000800ad54a4 in pthread_create () from =3D
>>> /lib/libthr.so.3<br>
>>>>> #8 =3D3DC2=3D3DA00x0000000000000000 in ?? ()<br>
>>>>> (gdb) set lang c<br>
>>>>> (gdb) thread apply all bt<br>
>>>>> ... not that interesting ...<br>
>>>>> <br>
>>>>> Segfault is segfault---error 11 is EDEADLK (locking against =3D
>>> myself?)<br>
>>>>> <br>
>>>>> ????? the code is very straightforward, as I said.<br>
>>>>> <br>
>>>>> I thought people had the thread tester working with pthreads? =3D
>>> =3D3DC2=3D3DA0Which s=3D3D
>>>>> et of files, then? =3D3DC2=3D3DA0Anyone on FreeBSD/amd64?<br>
>>>>> <br>
>>>>> Could it be an issue with "volatile"? =3D3DC2=3D3DA0Not =
>even =3D
>>> sure where t=3D3D
>>>>> o look.<br>
>>>>> <br>
>>>>> The code calling the lock is just this:<br>
>>>>> <br>
>>>>> PROCEDURE GetChar (rd: T): CHAR<br>
>>>>> =3D3DC2=3D3DA0 RAISES {EndOfFile, Failure, Alerted} =3D3D3D<br>
>>>>> =3D3DC2=3D3DA0 BEGIN<br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 LOCK rd DO<br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 RETURN =
>FastGetChar(rd);<br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 END<br>
>>>>> =3D3DC2=3D3DA0 END GetChar;<br>
>>>>> <br>
>>>>> No mysteries there...<br>
>>>>> <br>
>>>>> Ah is this the fork bug? =3D3DC2=3D3DA0Looks like the Init routine =
>is =3D
>>> called on a<b=3D3D
>>>>> r>
>>>>> lot of NIL mutexes around the fork. =3D3DC2=3D3DA0But the =
>subprocesses =3D
>>> aren't m=3D3D
>>>>> eant<br>
>>>>> to accesses the mutexes... humm<br>
>>>>> <br>
>>>>> Hmm, and it's not entirely a fork issue. =3D3DC2=3D3DA0Even =
>with =3D
>>> "threadte=3D3D
>>>>> st -tests STD,-fork,-forktoomuch" it misbehaves. =3D
>>> =3D3DC2=3D3DA0Hangs....<br>
>>>>> <br>
>>>>> Looks like a deadlock this time.<br>
>>>>> <br>
>>>>> Some stacks...<br>
>>>>> <br>
>>>>> Thread 4 (Thread 800c0b400 (LWP 100477/threadtest)):<br>
>>>>> #0 =3D3DC2=3D3DA00x00000000004b4e2b in __vdso_gettimeofday ()<br>
>>>>> #1 =3D3DC2=3D3DA00x00000000004ab8d2 in gettimeofday ()<br>
>>>>> #2 =3D3DC2=3D3DA00x0000000000452e4b in TimePosix__Now () at =3D
>>> ../src/time/POSIX/TimeP=3D3D
>>>>> osixC.c:50<br>
>>>>> #3 =3D3DC2=3D3DA00x0000000000452d72 in Time__Now () at =3D
>>> ../src/time/POSIX/TimePosix.=3D3D
>>>>> m3:14<br>
>>>>> #4 =3D3DC2=3D3DA00x00000000004029a3 in Main__LApply =
>(M3_AP7a1g_cl=3D3D3DError=3D
>>> accessing=3D3D
>>>>> memory address 0x8000fedf6df8: Bad address.<br>
>>>>> ) at ../src/Main.m3:327<br>
>>>>> #5 =3D3DC2=3D3DA00x0000000000449f93 in ThreadPThread__RunThread =3D
>>> (M3_DMxDjQ_me=3D3D3DErr=3D3D
>>>>> or accessing memory address 0x8000fedf6eb8: Bad address.<br>
>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:449<br>
>>>>> #6 =3D3DC2=3D3DA00x0000000000449c50 in ThreadPThread__ThreadBase =3D
>>> (M3_AJWxb1_param=3D3D
>>>>> =3D3D3DError accessing memory address 0x8000fedf6f68: Bad =
>address.<br>
>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:422<br>
>>>>> #7 =3D3DC2=3D3DA00x000000000047c7d4 in thread_start ()<br>
>>>>> #8 =3D3DC2=3D3DA00x0000000000000000 in ?? ()<br>
>>>>> <br>
>>>>> Thread 3 (Thread 800c0b000 (LWP 100476/threadtest)):<br>
>>>>> #0 =3D3DC2=3D3DA00x000000000047e53c in _umtx_op_err ()<br>
>>>>> #1 =3D3DC2=3D3DA00x0000000000475f14 in __thr_umutex_lock ()<br>
>>>>> #2 =3D3DC2=3D3DA00x0000000000479404 in mutex_lock_common ()<br>
>>>>> #3 =3D3DC2=3D3DA00x000000000044dd15 in =
>ThreadPThread__pthread_mutex_lock =3D
>>> (mutex=3D3D3DE=3D3D
>>>>> rror accessing memory address 0x8000feff7d98: Bad address.<br>
>>>>> ) at ../src/thread/PTHREAD/ThreadPThreadC.c:506<br>
>>>>> #4 =3D3DC2=3D3DA00x00000000004480c0 in ThreadPThread__LockMutex =3D
>>> (M3_AYIbX3_m=3D3D3DErro=3D3D
>>>>> r accessing memory address 0x8000feff7dc8: Bad address.<br>
>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:119<br>
>>>>> #5 =3D3DC2=3D3DA00x00000000004028ad in Main__LApply =
>(M3_AP7a1g_cl=3D3D3DError=3D
>>> accessing=3D3D
>>>>> memory address 0x8000feff7df8: Bad address.<br>
>>>>> ) at ../src/Main.m3:319<br>
>>>>> #6 =3D3DC2=3D3DA00x0000000000449f93 in ThreadPThread__RunThread =3D
>>> (M3_DMxDjQ_me=3D3D3DErr=3D3D
>>>>> or accessing memory address 0x8000feff7eb8: Bad address.<br>
>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:449<br>
>>>>> #7 =3D3DC2=3D3DA00x0000000000449c50 in ThreadPThread__ThreadBase =3D
>>> (M3_AJWxb1_param=3D3D
>>>>> =3D3D3DError accessing memory address 0x8000feff7f68: Bad =
>address.<br>
>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:422<br>
>>>>> #8 =3D3DC2=3D3DA00x000000000047c7d4 in thread_start ()<br>
>>>>> #9 =3D3DC2=3D3DA00x0000000000000000 in ?? ()<br>
>>>>> <br>
>>>>> Thread 6 (Thread 800c09800 (LWP 100470/threadtest)):<br>
>>>>> #0 =3D3DC2=3D3DA00x000000000047e53c in _umtx_op_err ()<br>
>>>>> #1 =3D3DC2=3D3DA00x0000000000475759 in suspend_common ()<br>
>>>>> #2 =3D3DC2=3D3DA00x00000000004755c1 in pthread_suspend_np ()<br>
>>>>> #3 =3D3DC2=3D3DA00x000000000044df0c in ThreadPThread__SuspendThread =
>=3D
>>> (mt=3D3D3DError acc=3D3D
>>>>> essing memory address 0x8000ffbfd6f8: Bad address.<br>
>>>>> ) at ../src/thread/PTHREAD/ThreadFreeBSD.c:33<br>
>>>>> #4 =3D3DC2=3D3DA00x000000000044bade in ThreadPThread__StopThread =3D
>>> (M3_DMxDjQ_act=3D3D3DE=3D3D
>>>>> rror accessing memory address 0x8000ffbfd718: Bad address.<br>
>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:909<br>
>>>>> #5 =3D3DC2=3D3DA00x000000000044bc81 in ThreadPThread__StopWorld () =
>at =3D
>>> ../src/thread=3D3D
>>>>> /PTHREAD/ThreadPThread.m3:948<br>
>>>>> #6 =3D3DC2=3D3DA00x000000000044b19e in RTThread__SuspendOthers () =
>at =3D
>>> ../src/thread/=3D3D
>>>>> PTHREAD/ThreadPThread.m3:713<br>
>>>>> #7 =3D3DC2=3D3DA00x00000000004330d6 in =3D
>>> RTCollector__CollectSomeInStateZero () at ..=3D3D
>>>>> /src/runtime/common/RTCollector.m3:749<br>
>>>>> #8 =3D3DC2=3D3DA00x0000000000433081 in RTCollector__CollectSome () =
>at =3D
>>> ../src/runtim=3D3D
>>>>> e/common/RTCollector.m3:723<br>
>>>>> #9 =3D3DC2=3D3DA00x0000000000432d49 in RTHeapRep__CollectEnough () =
>at =3D
>>> ../src/runtim=3D3D
>>>>> e/common/RTCollector.m3:657<br>
>>>>> #10 0x000000000042ff83 in RTAllocator__AllocTraced =3D
>>> (M3_Cwb5VA_dataSize=3D3D3DEr=3D3D
>>>>> ror accessing memory address 0x8000ffbfd958: Bad address.<br>
>>>>> ) at ../src/runtime/common/RTAllocator.m3:367<br>
>>>>> #11 0x000000000042f8a5 in RTAllocator__GetOpenArray =3D
>>> (M3_Eic7CK_def=3D3D3DError =3D3D
>>>>> accessing memory address 0x8000ffbfda18: Bad address.<br>
>>>>> ) at ../src/runtime/common/RTAllocator.m3:296<br>
>>>>> #12 0x000000000042ebdf in RTHooks__AllocateOpenArray =3D
>>> (M3_AJWxb1_defn=3D3D3DErro=3D3D
>>>>> r accessing memory address 0x8000ffbfda78: Bad address.<br>
>>>>> ) at ../src/runtime/common/RTAllocator.m3:143<br>
>>>>> #13 0x000000000040ca4e in Rd__NextBuff (M3_EkTcCb_rd=3D3D3DError =3D
>>> accessing memo=3D3D
>>>>> ry address 0x8000ffbfdab8: Bad address.<br>
>>>>> ) at ../src/rw/Rd.m3:159<br>
>>>>> #14 0x000000000040cd43 in UnsafeRd__FastGetChar =
>(M3_EkTcCb_rd=3D3D3DError=3D
>>> acces=3D3D
>>>>> sing memory address 0x8000ffbfdb88: Bad address.<br>
>>>>> ) at ../src/rw/Rd.m3:187<br>
>>>>> #15 0x000000000040cc4a in Rd__GetChar (M3_EkTcCb_rd=3D3D3DError =3D
>>> accessing memor=3D3D
>>>>> y address 0x8000ffbfdbd8: Bad address.<br>
>>>>> ) at ../src/rw/Rd.m3:176<br>
>>>>> #16 0x000000000040095c in Main__RApply (M3_AP7a1g_cl=3D3D3DError =3D
>>> accessing memo=3D3D
>>>>> ry address 0x8000ffbfdc58: Bad address.<br>
>>>>> ) at ../src/Main.m3:185<br>
>>>>> <br>
>>>>> #17 0x0000000000449f93 in ThreadPThread__RunThread =3D
>>> (M3_DMxDjQ_me=3D3D3DError ac=3D3D
>>>>> cessing memory address 0x8000ffbfdeb8: Bad address.<br>
>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:449<br>
>>>>> #18 0x0000000000449c50 in ThreadPThread__ThreadBase =3D
>>> (M3_AJWxb1_param=3D3D3DErro=3D3D
>>>>> r accessing memory address 0x8000ffbfdf68: Bad address.<br>
>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:422<br>
>>>>> #19 0x000000000047c7d4 in thread_start ()<br>
>>>>> #20 0x0000000000000000 in ?? ()<br>
>>>>> <br>
>>>>> Thread 5 (Thread 800c09400 (LWP 101035/threadtest)):<br>
>>>>> #0 =3D3DC2=3D3DA00x000000000047e53c in _umtx_op_err ()<br>
>>>>> #1 =3D3DC2=3D3DA00x0000000000475f14 in __thr_umutex_lock ()<br>
>>>>> #2 =3D3DC2=3D3DA00x0000000000479404 in mutex_lock_common ()<br>
>>>>> #3 =3D3DC2=3D3DA00x000000000044dd15 in =
>ThreadPThread__pthread_mutex_lock =3D
>>> (mutex=3D3D3DE=3D3D
>>>>> rror accessing memory address 0x8000ffffc678: Bad address.<br>
>>>>> ) at ../src/thread/PTHREAD/ThreadPThreadC.c:506<br>
>>>>> #4 =3D3DC2=3D3DA00x000000000044d039 in RTOS__LockHeap () at =3D
>>> ../src/thread/PTHREAD/T=3D3D
>>>>> hreadPThread.m3:1337<br>
>>>>> ---Type <return> to continue, or q <return> to =3D
>>> quit---<br>
>>>>> #5 =3D3DC2=3D3DA00x000000000042ff79 in RTAllocator__AllocTraced =3D
>>> (M3_Cwb5VA_dataSize=3D3D
>>>>> =3D3D3DError accessing memory address 0x8000ffffc6e8: Bad =
>address.<br>
>>>>> ) at ../src/runtime/common/RTAllocator.m3:365<br>
>>>>> #6 =3D3DC2=3D3DA00x000000000042f15b in RTAllocator__GetTracedObj =3D
>>> (M3_Eic7CK_def=3D3D3DE=3D3D
>>>>> rror accessing memory address 0x8000ffffc7a8: Bad address.<br>
>>>>> ) at ../src/runtime/common/RTAllocator.m3:224<br>
>>>>> #7 =3D3DC2=3D3DA00x000000000042eb23 in RTHooks__AllocateTracedObj =3D=
>
>>> (M3_AJWxb1_defn=3D3D
>>>>> =3D3D3DError accessing memory address 0x8000ffffc7f8: Bad =
>address.<br>
>>>>> ) at ../src/runtime/common/RTAllocator.m3:122<br>
>>>>> #8 =3D3DC2=3D3DA00x000000000045fbe4 in TextCat__Flat =3D
>>> (M3_Bd56fi_LText=3D3D3DError acces=3D3D
>>>>> sing memory address 0x8000ffffc858: Bad address.<br>
>>>>> ) at ../src/text/TextCat.m3:562<br>
>>>>> #9 =3D3DC2=3D3DA00x000000000045ed5d in TextCat__Balance =3D
>>> (M3_Bd56fi_LText=3D3D3D0x800c49=3D3D
>>>>> 0b0, M3_BUgnwf_LInfo=3D3D3DError accessing memory address =3D
>>> 0x8000ffffc8f8: Bad a=3D3D
>>>>> ddress.<br>
>>>>> ) at ../src/text/TextCat.m3:488<br>
>>>>> #10 0x000000000045d64f in RTHooks__Concat (M3_Bd56fi_t=3D3D3DError =
>=3D
>>> accessing me=3D3D
>>>>> mory address 0x8000ffffcbb8: Bad address.<br>
>>>>> ) at ../src/text/TextCat.m3:40<br>
>>>>> #11 0x000000000040639e in Main_M3 (M3_AcxOUs_mode=3D3D3DError =
>accessing =3D
>>> memory =3D3D
>>>>> address 0x8000ffffcc38: Bad address.<br>
>>>>> ) at ../src/Main.m3:593<br>
>>>>> #12 0x000000000043d55d in RTLinker__RunMainBody =
>(M3_DjPxE3_m=3D3D3DError =3D
>>> access=3D3D
>>>>> ing memory address 0x8000ffffcf88: Bad address.<br>
>>>>> ) at ../src/runtime/common/RTLinker.m3:408<br>
>>>>> #13 0x000000000043c8e8 in RTLinker__AddUnitI (M3_DjPxE3_m=3D3D3DError=
> =3D
>>> accessing=3D3D
>>>>> memory address 0x8000ffffd008: Bad address.<br>
>>>>> ) at ../src/runtime/common/RTLinker.m3:115<br>
>>>>> #14 0x000000000043c97c in RTLinker__AddUnit (M3_DjPxE5_b=3D3D3DError =
>=3D
>>> accessing =3D3D
>>>>> memory address 0x8000ffffd028: Bad address.<br>
>>>>> ) at ../src/runtime/common/RTLinker.m3:124<br>
>>>>> #15 0x00000000004004a6 in main (argc=3D3D3DError accessing memory =3D=
>
>>> address 0x800=3D3D
>>>>> 0ffffd07c: Bad address.<br>
>>>>> ) at _m3main.c:22<br>
>>>>> <br>
>>>>> Thread 9 (Thread 800c0a400 (LWP 100473/threadtest)):<br>
>>>>> #0 =3D3DC2=3D3DA00x000000000047e53c in _umtx_op_err ()<br>
>>>>> #1 =3D3DC2=3D3DA00x0000000000477e8a in check_suspend ()<br>
>>>>> #2 =3D3DC2=3D3DA00x00000000004780a2 in sigcancel_handler ()<br>
>>>>> #3 =3D3DC2=3D3DA0<signal handler called><br>
>>>>> #4 =3D3DC2=3D3DA00x000000000047e53c in _umtx_op_err ()<br>
>>>>> #5 =3D3DC2=3D3DA00x0000000000475f14 in __thr_umutex_lock ()<br>
>>>>> #6 =3D3DC2=3D3DA00x0000000000479404 in mutex_lock_common ()<br>
>>>>> #7 =3D3DC2=3D3DA00x000000000044dd15 in =
>ThreadPThread__pthread_mutex_lock =3D
>>> (mutex=3D3D3DE=3D3D
>>>>> rror accessing memory address 0x8000ff5fac18: Bad address.<br>
>>>>> ) at ../src/thread/PTHREAD/ThreadPThreadC.c:506<br>
>>>>> #8 =3D3DC2=3D3DA00x000000000044d039 in RTOS__LockHeap () at =3D
>>> ../src/thread/PTHREAD/T=3D3D
>>>>> hreadPThread.m3:1337<br>
>>>>> #9 =3D3DC2=3D3DA00x000000000042ff79 in RTAllocator__AllocTraced =3D
>>> (M3_Cwb5VA_dataSize=3D3D
>>>>> =3D3D3DError accessing memory address 0x8000ff5fac88: Bad =
>address.<br>
>>>>> ) at ../src/runtime/common/RTAllocator.m3:365<br>
>>>>> #10 0x000000000042f8a5 in RTAllocator__GetOpenArray =3D
>>> (M3_Eic7CK_def=3D3D3DError =3D3D
>>>>> accessing memory address 0x8000ff5fad48: Bad address.<br>
>>>>> ) at ../src/runtime/common/RTAllocator.m3:296<br>
>>>>> #11 0x000000000042ebdf in RTHooks__AllocateOpenArray =3D
>>> (M3_AJWxb1_defn=3D3D3DErro=3D3D
>>>>> r accessing memory address 0x8000ff5fada8: Bad address.<br>
>>>>> ) at ../src/runtime/common/RTAllocator.m3:143<br>
>>>>> #12 0x000000000040203a in Main__AApply (M3_AP7a1g_cl=3D3D3DError =3D
>>> accessing memo=3D3D
>>>>> ry address 0x8000ff5fade8: Bad address.<br>
>>>>> ) at ../src/Main.m3:283<br>
>>>>> #13 0x0000000000449f93 in ThreadPThread__RunThread =3D
>>> (M3_DMxDjQ_me=3D3D3DError ac=3D3D
>>>>> cessing memory address 0x8000ff5faeb8: Bad address.<br>
>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:449<br>
>>>>> #14 0x0000000000449c50 in ThreadPThread__ThreadBase =3D
>>> (M3_AJWxb1_param=3D3D3DErro=3D3D
>>>>> r accessing memory address 0x8000ff5faf68: Bad address.<br>
>>>>> ) at ../src/thread/PTHREAD/ThreadPThread.m3:422<br>
>>>>> #15 0x000000000047c7d4 in thread_start ()<br>
>>>>> #16 0x0000000000000000 in ?? ()<br>
>>>>> <br>
>>>>> (others are similar)<br>
>>>>> <br>
>>>>> Hmm looks like a FreeBSD issue now. =3D3DC2=3D3DA0It's =
>here...<br>
>>>>> <br>
>>>>> int<br>
>>>>> __cdecl<br>
>>>>> ThreadPThread__SuspendThread (m3_pthread_t mt)<br>
>>>>> {<br>
>>>>> =3D3DC2=3D3DA0 =3D
>>> ThreadFreeBSD__Fatal(pthread_suspend_np(PTHREAD_FROM_M3(mt)), =
>"=3D3D
>>>>> pthread_suspend_np");<br>
>>>>> =3D3DC2=3D3DA0 return 1;<br>
>>>>> }<br>
>>>>> <br>
>>>>> Now this suspend can wait:<br>
>>>>> <br>
>>>>> static int<br>
>>>>> suspend_common(struct pthread *curthread, struct pthread =
>*thread,<br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 int =
>waitok)<br>
>>>>> {<br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =
>uint32_t tmp;<br>
>>>>> <br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 while =
>(thread->state =3D
>>> !=3D3D3D PS_DEAD &&=3D3D
>>>>> <br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =
>=3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D
>>> =3D3DC2=3D3DA0 !(thread->flags & T=3D3D
>>>>> HR_FLAGS_SUSPENDED)) {<br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =
>=3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D
>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 thread->flags |=3D3D
>>>>> =3D3D3D THR_FLAGS_NEED_SUSPEND;<br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =
>=3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D
>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 /* Thread is in cre=3D3D
>>>>> ation. */<br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =
>=3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D
>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 if (thread->tid =3D3D
>>>>> =3D3D3D=3D3D3D TID_TERMINATED)<br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =
>=3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D
>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3=
>D
>>>>> =3D3DA0 =3D3DC2=3D3DA0 return (1);<br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =
>=3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D
>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 tmp =3D3D3D thread->=3D3D
>>>>> cycle;<br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =
>=3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D
>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 _thr_send_sig(threa=3D3D
>>>>> d, SIGCANCEL);<br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =
>=3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D
>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 THR_THREAD_UNLOCK(c=3D3D
>>>>> urthread, thread);<br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =
>=3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D
>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 if (waitok) {<br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =
>=3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D
>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3=
>D
>>>>> =3D3DA0 =3D3DC2=3D3DA0 _thr_umtx_wait_uint(&thread->cycle, =
>tmp, =3D
>>> NULL, 0); =3D3DC2=3D3DA0=3D3D
>>>>> <=3D3D3D=3D3D3D=3D3D3D=3D3D3D=3D3D3D=3D3D3D=3D3D3D=3D3D3D=3D3D3D=3D=
>3D3D<br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =
>=3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D
>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3=
>D
>>>>> =3D3DA0 =3D3DC2=3D3DA0 THR_THREAD_LOCK(curthread, thread);<br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =
>=3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D
>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 } else {<br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =
>=3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D
>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3=
>D
>>>>> =3D3DA0 =3D3DC2=3D3DA0 THR_THREAD_LOCK(curthread, thread);<br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =
>=3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D
>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3=
>D
>>>>> =3D3DA0 =3D3DC2=3D3DA0 return (0);<br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =
>=3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D
>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 }<br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 }<br>
>>>>> <br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 return =
>(1);<br>
>>>>> }<br>
>>>>> <br>
>>>>> ... but what it can wait for I am not clear on.<br>
>>>>> <br>
>>>>> Do things work better on Linux?<br>
>>>>> <br>
>>>>> What is the status of the fork bug? =3D3DC2=3D3DA0Can it be worked =
>around =3D
>>> by only f=3D3D
>>>>> orking via Process.Create with no mutexes held (outside of all LOCK =
>=3D
>>> blocks)=3D3D
>>>>> ?<br>
>>>>> <br>
>>>>> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0Mika<br>
>>>>> <br>
>>>>> <br>
>>>>> <br>
>>>>> Peter McKinna writes:<br>
>>>>> >--001a11c2ced4471a2e050079db82<br>
>>>>> >Content-Type: text/plain; charset=3D3D3DUTF-8<br>
>>>>> <div><div>><br>
>>>>> >Mika<br>
>>>>> ><br>
>>>>> > =3D3DC2=3D3DA0I think you need to back out Tony's changes =
>to fix =3D
>>> the fork =3D3D
>>>>> bug, at least<br>
>>>>> >for now. Need to reload from cvs version 1.262 for =3D
>>> ThreadPThread.m3 If<=3D3D
>>>>> br>
>>>>> >you're using git you're on your own.<br>
>>>>> > =3D3DC2=3D3DA0Do a cvs log ThreadPThread.m3 for an explanation =
>for =3D
>>> some of the=3D3D
>>>>> design<br>
>>>>> >principles.<br>
>>>>> > =3D3DC2=3D3DA0Also if you use gdb then you need to set lanc c =
>before =3D
>>> backtrace=3D3D
>>>>> s so at<br>
>>>>> >least you can see address names and values even if they are =3D
>>> contorted y=3D3D
>>>>> ou<br>
>>>>> >can extract the M3 name in the parm lists. Also in gdb thread =3D=
>
>>> apply all=3D3D
>>>>> bt<br>
>>>>> >gives all thread backtraces which can be handy to see whose got =
>=3D
>>> the loc=3D3D
>>>>> ks<br>
>>>>> >held.<br>
>>>>> ><br>
>>>>> >Regards Peter<br>
>>>>> ><br>
>>>>> ><br>
>>>>> ><br>
>>>>> >On Wed, Aug 13, 2014 at 12:14 PM, <<a =3D
>>> href=3D3D3D"mailto:mika at async.calt=3D3D
>>>>> ech.edu" target=3D3D3D"_blank">mika at async.caltech.edu</a>> =3D
>>> wrote:<br>
>>>>> ><br>
>>>>> >><br>
>>>>> >> Question... is there something odd about my pthreads? =3D
>>> =3D3DC2=3D3DA0Are pt=3D3D
>>>>> hreads<br>
>>>>> >> normally reentrant? =3D3DC2=3D3DA0I didn't think =
>so.<br>
>>>>> >><br>
>>>>> >> My compiler is much happier with the following changes I =3D=
>
>>> already o=3D3D
>>>>> utlined:<br>
>>>>> >><br>
>>>>> >> 1. a dirty, disgusting hack to keep from locking against =3D=
>
>>> myself go=3D3D
>>>>> ing from<br>
>>>>> >> XWait with self.mutex locked to m.release().<br>
>>>>> >><br>
>>>>> >> 2. the change to LockHeap I described in previous =
>email<br>
>>>>> >><br>
>>>>> >> But now...<br>
>>>>> >><br>
>>>>> >> (gdb) cont<br>
>>>>> >> Continuing.<br>
>>>>> >> ERROR: pthread_mutex_lock:11<br>
>>>>> >> ERROR: pthread_mutex_lock:11<br>
>>>>> >><br>
>>>>> >> Program received signal SIGABRT, Aborted.<br>
>>>>> >> 0x000000080107626a in thr_kill () from /lib/libc.so.7<br>
>>>>> >> (gdb) where<br>
>>>>> >> #0 =3D3DC2=3D3DA00x000000080107626a in thr_kill () from =3D
>>> /lib/libc.so.7<br>
>>>>> >> #1 =3D3DC2=3D3DA00x000000080113dac9 in abort () from =3D
>>> /lib/libc.so.7<br>
>>>>> >> #2 =3D3DC2=3D3DA00x000000000071e37a in =3D
>>> ThreadPThread__pthread_mutex_lock (=3D3D
>>>>> mutex=3D3D3DError<br>
>>>>> >> accessing memory address 0x8000ffffb508: Bad address.<br>
>>>>> >> ) at ../src/thread/PTHREAD/ThreadPThreadC.c:543<br>
>>>>> >> #3 =3D3DC2=3D3DA00x000000000071d48d in RTOS__LockHeap () =
>at<br>
>>>>> >> ../src/thread/PTHREAD/ThreadPThread.m3:1377<br>
>>>>> >> #4 =3D3DC2=3D3DA00x0000000000706b9d in =3D
>>> RTHooks__CheckLoadTracedRef (M3_Af4=3D3D
>>>>> 0ku_ref=3D3D3DError<br>
>>>>> >> accessing memory address 0x8000ffffb568: Bad address.<br>
>>>>> >> ) at ../src/runtime/common/RTCollector.m3:2234<br>
>>>>> >> #5 =3D3DC2=3D3DA00x000000000071d284 in =3D
>>> ThreadPThread__AtForkParent () at<b=3D3D
>>>>> r>
>>>>> >> ../src/thread/PTHREAD/ThreadPThread.m3:1348<br>
>>>>> >> #6 =3D3DC2=3D3DA00x0000000800df8733 in fork () from =3D
>>> /lib/libthr.so.3<br>
>>>>> >> #7 =3D3DC2=3D3DA00x000000000070dd8b in RTProcess__Fork () =
>at<br>
>>>>> >> ../src/runtime/common/RTProcessC.c:152<br>
>>>>> >> #8 =3D3DC2=3D3DA00x00000000006c52f2 in =3D
>>> ProcessPosixCommon__Create_ForkExec=3D3D
>>>>> <br>
>>>>> >> (M3_Bd56fi_cmd=3D3D3DError accessing memory address =3D
>>> 0x8000ffffb6f8: Ba=3D3D
>>>>> d address.<br>
>>>>> >> ) at ../src/os/POSIX/ProcessPosixCommon.m3:75<br>
>>>>> >> #9 =3D3DC2=3D3DA00x00000000006c6c6c in Process__Create =3D
>>> (M3_Bd56fi_cmd=3D3D3DEr=3D3D
>>>>> ror accessing<br>
>>>>> >> memory address 0x8000ffffb7f8: Bad address.<br>
>>>>> >> ) at ../src/os/POSIX/ProcessPosix.m3:21<br>
>>>>> >> #10 0x00000000004d6826 in QMachine__FulfilExecPromise =3D
>>> (M3_D6rRrg_e=3D3D
>>>>> p=3D3D3DError<br>
>>>>> >> accessing memory address 0x8000ffffb838: Bad address.<br>
>>>>> >> ) at ../src/QMachine.m3:1666<br>
>>>>> >> #11 0x00000000004d6220 in QMachine__ExecCommand =3D
>>> (M3_An02H2_t=3D3D3DErr=3D3D
>>>>> or<br>
>>>>> >> accessing memory address 0x8000ffffb9f8: Bad address.<br>
>>>>> >> ) at ../src/QMachine.m3:1605<br>
>>>>> >> #12 0x00000000004d537e in QMachine__DoTryExec =3D
>>> (M3_An02H2_t=3D3D3DError=3D3D
>>>>> accessing<br>
>>>>> >> memory address 0x8000ffffbee8: Bad address.<br>
>>>>> >> ) at ../src/QMachine.m3:1476<br>
>>>>> >><br>
>>>>> >> What am I doing wrong here?<br>
>>>>> >><br>
>>>>> >> The error doesn't look unreasonable! =3D3DC2=3D3DA0Looki=
>ng =3D
>>> more closel=3D3D
>>>>> y at the code:<br>
>>>>> >><br>
>>>>> >> First, AtForkPrepare has been called:<br>
>>>>> >><br>
>>>>> >> PROCEDURE AtForkPrepare() =3D3D3D<br>
>>>>> >> =3D3DC2=3D3DA0 VAR me :=3D3D3D GetActivation();<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 act: =
>Activation;<br>
>>>>> >> =3D3DC2=3D3DA0 BEGIN<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 PThreadLockMutex(slotsMu, =3D
>>> ThisLine());<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 PThreadLockMutex(perfMu, =3D
>>> ThisLine());<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 PThreadLockMutex(initMu, =
>ThisLine()); =3D
>>> (* InitMutex =3D3D
>>>>> =3D3D3D><br>
>>>>> >> RegisterFinalCleanup =3D3D3D> LockHeap *)<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 PThreadLockMutex(heapMu, =3D
>>> ThisLine());<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 PThreadLockMutex(activeMu, =3D=
>
>>> ThisLine()); (* LockHeap =3D3D
>>>>> =3D3D3D> SuspendOthers<br>
>>>>> >> =3D3D3D> activeMu *)<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 (* Walk activations and lock =
>all =3D
>>> threads.<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0* NOTE: We =
>have initMu, =3D
>>> activeMu, so slots won=3D3D
>>>>> 't change, conditions<br>
>>>>> >> and<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0* mutexes =
>won't be =3D
>>> initialized on-demand.<=3D3D
>>>>> br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0*)<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 act :=3D3D3D me;<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 REPEAT<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =
>PThreadLockMutex(act.mutex, =3D
>>> ThisLine());<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 act :=3D3D3D =
>act.next;<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 UNTIL act =3D3D3D me;<br>
>>>>> >> =3D3DC2=3D3DA0 END AtForkPrepare;<br>
>>>>> >><br>
>>>>> >> a postcondition of this routine is that heapMu is =3D
>>> locked.<br>
>>>>> >><br>
>>>>> >> now we get into AtForkParent:<br>
>>>>> >><br>
>>>>> >> PROCEDURE AtForkParent() =3D3D3D<br>
>>>>> >> =3D3DC2=3D3DA0 VAR me :=3D3D3D GetActivation();<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 act: =
>Activation;<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 cond: =
>Condition;<br>
>>>>> >> =3D3DC2=3D3DA0 BEGIN<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 (* Walk activations and =
>unlock all =3D
>>> threads, conditio=3D3D
>>>>> ns. *)<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 act :=3D3D3D me;<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 REPEAT<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 cond :=3D3D3D =
>=3D
>>> slots[act.slot].join;<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 IF cond # NIL =
>THEN =3D
>>> PThreadUnlockMutex(cond.mu=3D3D
>>>>> tex, ThisLine()) END;<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D
>>> PThreadUnlockMutex(act.mutex, ThisLine());<br=3D3D
>>>>>> =3D20
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 act :=3D3D3D =
>act.next;<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 UNTIL act =3D3D3D me;<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 PThreadUnlockMutex(activeMu, =
>=3D
>>> ThisLine());<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 PThreadUnlockMutex(heapMu, =3D=
>
>>> ThisLine());<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 PThreadUnlockMutex(initMu, =3D=
>
>>> ThisLine());<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 PThreadUnlockMutex(perfMu, =3D=
>
>>> ThisLine());<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 PThreadUnlockMutex(slotsMu, =
>=3D
>>> ThisLine());<br>
>>>>> >> =3D3DC2=3D3DA0 END AtForkParent;<br>
>>>>> >><br>
>>>>> >> We can see by inspecting the code that a necessary =3D
>>> precondition fo=3D3D
>>>>> r<br>
>>>>> >> this routine is that heapMu is locked! =3D3DC2=3D3DA0(Since =
>=3D
>>> it's going=3D3D
>>>>> to unlock it,<br>
>>>>> >> it had BETTER be locked on entry.)<br>
>>>>> >><br>
>>>>> >> But the cond :=3D3D3D ... causes a =3D
>>> RTHooks.CheckLoadTracedRef<br>
>>>>> >><br>
>>>>> >> which causes an RTOS.LockHeap<br>
>>>>> >><br>
>>>>> >> the code of which we just saw:<br>
>>>>> >><br>
>>>>> >> PROCEDURE LockHeap () =3D3D3D<br>
>>>>> >> =3D3DC2=3D3DA0 VAR self :=3D3D3D pthread_self();<br>
>>>>> >> =3D3DC2=3D3DA0 BEGIN<br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 WITH r =3D3D3D =3D
>>> pthread_mutex_lock(heapMu,ThisLine()) DO =3D3D
>>>>> <*ASSERT r=3D3D3D0*> END;<br>
>>>>> >> ...<br>
>>>>> >><br>
>>>>> >> we try to lock heapMu. =3D3DC2=3D3DA0kaboom! =3D3DC2=3D3DA0N=
>o =3D
>>> surprise there, real=3D3D
>>>>> ly?<br>
>>>>> >><br>
>>>>> >> Am I going about this totally the wrong way? =
>=3D3DC2=3D3DA0Other =3D
>>> people ar=3D3D
>>>>> e running<br>
>>>>> >> Modula-3<br>
>>>>> >> with pthreads, right? =3D3DC2=3D3DA0Right?? =
>=3D3DC2=3D3DA0Somewhere =3D
>>> out there in m=3D3D
>>>>> 3devel-land?<br>
>>>>> >><br>
>>>>> >> =3D3DC2=3D3DA0 =3D3DC2=3D3DA0 =3D3DC2=3D3DA0Mika<br>
>>>>> >><br>
>>>>> >><br>
>>>>> ><br>
>>>>> </div></div>>--001a11c2ced4471a2e050079db82<br>
>>>>> >Content-Type: text/html; charset=3D3D3DUTF-8<br>
>>>>> >Content-Transfer-Encoding: quoted-printable<br>
>>>>> ><br>
>>>>> ><div =3D
>>> dir=3D3D3D3D"ltr">Mika<div><br></div>=3D3=
>D
>>>>> ;<div>=3D3D3DC2=3D3D3DA0 I think you need to back ou=3D3D3D<br>=
>
>>>>> >t Tony's changes to fix the fork bug, at least for now. =
>=3D
>>> Need to=3D3D
>>>>> reload =3D3D3D<br>
>>>>> >from cvs version 1.262 for ThreadPThread.m3 If you're =3D=
>
>>> using git=3D3D
>>>>> you'=3D3D3D<br>
>>>>> >;re on your own.</div><br>
>>>>> ><br>
>>>>> ><div>=3D3D3DC2=3D3D3DA0 Do a cvs log ThreadPThread.m3 for =
>an =3D
>>> explanation =3D3D
>>>>> for some of th=3D3D3D<br>
>>>>> >e design =
>principles.=3D3D3DC2=3D3D3DA0</div><div>=3D3D3DC2=3D3D=3D
>>> 3DA0 Also if=3D3D
>>>>> you use gdb then you ne=3D3D3D<br>
>>>>> >ed to set lanc c before backtraces so at least you can see =3D
>>> address name=3D3D
>>>>> s an=3D3D3D<br>
>>>>> >d values even if they are contorted you can extract the M3 name =
>=3D
>>> in the =3D3D
>>>>> parm=3D3D3D<br>
>>>>> > lists. Also in gdb thread apply all bt gives all thread =3D
>>> backtraces whi=3D3D
>>>>> ch c=3D3D3D<br>
>>>>> >an be handy to see whose got the locks held.</div><br>
>>>>> ><br>
>>>>> ><div><br></div><div>Regards =3D
>>> Peter</div>&l=3D3D
>>>>> t;div><br></div><div =
>class=3D3D3D3D"gmail_e=3D3D3D<b=3D
>>> r>
>>>>> >xtra"><br><br><div =3D
>>> class=3D3D3D3D"gmail_quote&q=3D3D
>>>>> uot;>On Wed, Aug 13, 2014 at 12:14 PM, =3D3D3D<br>
>>>>> > <span dir=3D3D3D3D"ltr"><<a =3D
>>> href=3D3D3D3D"mailt=3D3D
>>>>> o:<a href=3D3D3D"mailto:mika at async.caltech.edu" =3D
>>> target=3D3D3D"_blank">mika at async.ca=3D3D
>>>>> ltech.edu</a>" target=3D3D3D3D"=3D3D3D<br>
>>>>> >_blank"><a href=3D3D3D"mailto:mika at async.caltech.edu" =3D=
>
>>> target=3D3D3D"_bl=3D3D
>>>>> ank">mika at async.caltech.edu</a></a>></span> =3D
>>> wrote:<br=3D3D
>>>>> ><br>
>>>>> ><br>
>>>>> ><blockquote class=3D3D3D3D"gmail_quote" =3D
>>> style=3D3D3D3D"margin=3D3D
>>>>> :0 0 0 .8ex;border-left:1p=3D3D3D<br>
>>>>> >x #ccc solid;padding-left:1ex"><br><br>
>>>>> >Question... is there something odd about my pthreads? =3D
>>> =3D3D3DC2=3D3D3DA0Are pth=3D3D
>>>>> reads no=3D3D3D<br>
>>>>> >rmally reentrant? =3D3D3DC2=3D3D3DA0I didn't think =3D
>>> so.<br><br>
>>>>> ><br><br>
>>>>> >My compiler is much happier with the following changes I =
>already =3D
>>> outlin=3D3D
>>>>> ed:<=3D3D3D<br>
>>>>> >br><br>
>>>>> ><br><br>
>>>>> >1. a dirty, disgusting hack to keep from locking against myself =
>=3D
>>> going f=3D3D
>>>>> rom =3D3D3D<br>
>>>>> >XWait with self.mutex locked to m.release().<br><br>
>>>>> ><br><br>
>>>>> >2. the change to LockHeap I described in previous =3D
>>> email<br><br>
>>>>> ><br><br>
>>>>> >But now...<br><br>
>>>>> ><br><br>
>>>>> >(gdb) cont<br><br>
>>>>> >Continuing.<br><br>
>>>>> >ERROR: pthread_mutex_lock:11<br><br>
>>>>> >ERROR: pthread_mutex_lock:11<br><br>
>>>>> ><br><br>
>>>>> >Program received signal SIGABRT, Aborted.<br><br>
>>>>> >0x000000080107626a in thr_kill () from =3D
>>> /lib/libc.so.7<br><br>
>>>>> >(gdb) where<br><br>
>>>>> >#0 =3D3D3DC2=3D3D3DA00x000000080107626a in thr_kill () from =3D
>>> /lib/libc.so.7<b=3D3D
>>>>> r><br>
>>>>> >#1 =3D3D3DC2=3D3D3DA00x000000080113dac9 in abort () from =3D
>>> /lib/libc.so.7<br&g=3D3D
>>>>> t;<br>
>>>>> >#2 =3D3D3DC2=3D3D3DA00x000000000071e37a in =3D
>>> ThreadPThread__pthread_mutex_lock (m=3D3D
>>>>> utex=3D3D3D3DE=3D3D3D<br>
>>>>> >rror accessing memory address 0x8000ffffb508: Bad =3D
>>> address.<br><br=3D3D
>>>>>> =3D20
>>>>> >) at ../src/thread/PTHREAD/ThreadPThreadC.c:543<br><br>
>>>>> >#3 =3D3D3DC2=3D3D3DA00x000000000071d48d in RTOS__LockHeap () at =
>=3D
>>> ../src/thread/P=3D3D
>>>>> THREAD/T=3D3D3D<br>
>>>>> >hreadPThread.m3:1377<br><br>
>>>>> >#4 =3D3D3DC2=3D3D3DA00x0000000000706b9d in =3D
>>> RTHooks__CheckLoadTracedRef (M3_Af40=3D3D
>>>>> ku_ref=3D3D3D<br>
>>>>> >=3D3D3D3DError accessing memory address 0x8000ffffb568: Bad =3D
>>> address.<br&=3D3D
>>>>> gt;<br>
>>>>> >) at ../src/runtime/common/RTCollector.m3:2234<br><br>
>>>>> >#5 =3D3D3DC2=3D3D3DA00x000000000071d284 in =3D
>>> ThreadPThread__AtForkParent () at ..=3D3D
>>>>> /src/thr=3D3D3D<br>
>>>>> >ead/PTHREAD/ThreadPThread.m3:1348<br><br>
>>>>> >#6 =3D3D3DC2=3D3D3DA00x0000000800df8733 in fork () from =3D
>>> /lib/libthr.so.3<br&=3D3D
>>>>> gt;<br>
>>>>> >#7 =3D3D3DC2=3D3D3DA00x000000000070dd8b in RTProcess__Fork () =
>at =3D
>>> ../src/runtime=3D3D
>>>>> /common/=3D3D3D<br>
>>>>> >RTProcessC.c:152<br><br>
>>>>> >#8 =3D3D3DC2=3D3D3DA00x00000000006c52f2 in =3D
>>> ProcessPosixCommon__Create_ForkExec =3D3D
>>>>> (M3_Bd56=3D3D3D<br>
>>>>> >fi_cmd=3D3D3D3DError accessing memory address 0x8000ffffb6f8: =
>Bad =3D
>>> address.&=3D3D
>>>>> lt;br><br>
>>>>> >) at ../src/os/POSIX/ProcessPosixCommon.m3:75<br><br>
>>>>> >#9 =3D3D3DC2=3D3D3DA00x00000000006c6c6c in Process__Create =3D
>>> (M3_Bd56fi_cmd=3D3D3D3DE=3D3D
>>>>> rror acces=3D3D3D<br>
>>>>> >sing memory address 0x8000ffffb7f8: Bad address.<br><br>
>>>>> >) at ../src/os/POSIX/ProcessPosix.m3:21<br><br>
>>>>> >#10 0x00000000004d6826 in QMachine__FulfilExecPromise =3D
>>> (M3_D6rRrg_ep=3D3D3D3=3D3D
>>>>> DError=3D3D3D<br>
>>>>> > accessing memory address 0x8000ffffb838: Bad =3D
>>> address.<br><br>
>>>>> >) at ../src/QMachine.m3:1666<br><br>
>>>>> >#11 0x00000000004d6220 in QMachine__ExecCommand =3D
>>> (M3_An02H2_t=3D3D3D3DError =3D3D
>>>>> access=3D3D3D<br>
>>>>> >ing memory address 0x8000ffffb9f8: Bad address.<br><br>
>>>>> >) at ../src/QMachine.m3:1605<br><br>
>>>>> >#12 0x00000000004d537e in QMachine__DoTryExec =3D
>>> (M3_An02H2_t=3D3D3D3DError ac=3D3D
>>>>> cessin=3D3D3D<br>
>>>>> >g memory address 0x8000ffffbee8: Bad address.<br><br>
>>>>> >) at ../src/QMachine.m3:1476<br><br>
>>>>> ><br><br>
>>>>> >What am I doing wrong here?<br><br>
>>>>> ><br><br>
>>>>> >The error doesn't look unreasonable! =
>=3D3D3DC2=3D3D3DA0Looking =3D
>>> more clo=3D3D
>>>>> sely at the =3D3D3D<br>
>>>>> >code:<br><br>
>>>>> ><br><br>
>>>>> >First, AtForkPrepare has been called:<br><br>
>>>>> ><br><br>
>>>>> >PROCEDURE AtForkPrepare() =3D3D3D3D<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 VAR me :=3D3D3D3D =
>GetActivation();<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 act: =3D=
>
>>> Activation;<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 BEGIN<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 PThreadLockMutex(slotsMu, =
>=3D
>>> ThisLine());<br><=3D3D
>>>>> br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 PThreadLockMutex(perfMu, =
>=3D
>>> ThisLine());<br><b=3D3D
>>>>> r>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 PThreadLockMutex(initMu, =
>=3D
>>> ThisLine()); (* InitMute=3D3D
>>>>> x =3D3D3D3D> Re=3D3D3D<br>
>>>>> >gisterFinalCleanup =3D3D3D3D> LockHeap *)<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 PThreadLockMutex(heapMu, =
>=3D
>>> ThisLine());<br><b=3D3D
>>>>> r>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 =
>PThreadLockMutex(activeMu, =3D
>>> ThisLine()); (* LockHe=3D3D
>>>>> ap =3D3D3D3D> S=3D3D3D<br>
>>>>> >uspendOthers =3D3D3D3D> activeMu *)<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 (* Walk activations and =
>lock all =3D
>>> threads.<br&g=3D3D
>>>>> t;<br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0* NOTE: =
>We have =3D
>>> initMu, activeMu, so sl=3D3D
>>>>> ots won't ch=3D3D3D<br>
>>>>> >ange, conditions and<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0* =
>mutexes =3D
>>> won't be initialized =3D3D
>>>>> on-demand.<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 =
>=3D3D3DC2=3D3D3DA0*)<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 act :=3D3D3D3D =
>me;<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 REPEAT<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 =3D
>>> PThreadLockMutex(act.mutex, ThisLine()=3D3D
>>>>> );<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 act =
>:=3D3D3D3D =3D
>>> act.next;<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 UNTIL act =3D3D3D3D =
>me;<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 END AtForkPrepare;<br><br>
>>>>> ><br><br>
>>>>> >a postcondition of this routine is that heapMu is =3D
>>> locked.<br><br>
>>>>> ><br><br>
>>>>> >now we get into AtForkParent:<br><br>
>>>>> ><br><br>
>>>>> >PROCEDURE AtForkParent() =3D3D3D3D<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 VAR me :=3D3D3D3D =
>GetActivation();<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 act: =3D=
>
>>> Activation;<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 cond: =
>=3D
>>> Condition;<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 BEGIN<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 (* Walk activations and =
>unlock all =3D
>>> threads, condi=3D3D
>>>>> tions. *)<br=3D3D3D<br>
>>>>> >><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 act :=3D3D3D3D =
>me;<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 REPEAT<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 cond =
>:=3D3D3D3D =3D
>>> slots[act.slot].join;<b=3D3D
>>>>> r><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 IF =
>cond # NIL THEN =3D
>>> PThreadUnlockMutex(=3D3D
>>>>> cond.mutex, This=3D3D3D<br>
>>>>> >Line()) END;<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 =3D
>>> PThreadUnlockMutex(act.mutex, ThisLine=3D3D
>>>>> ());<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 act =
>:=3D3D3D3D =3D
>>> act.next;<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 UNTIL act =3D3D3D3D =
>me;<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 =
>PThreadUnlockMutex(activeMu, =3D
>>> ThisLine());<br&g=3D3D
>>>>> t;<br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 =
>PThreadUnlockMutex(heapMu, =3D
>>> ThisLine());<br>=3D3D
>>>>> <br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 =
>PThreadUnlockMutex(initMu, =3D
>>> ThisLine());<br>=3D3D
>>>>> <br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 =
>PThreadUnlockMutex(perfMu, =3D
>>> ThisLine());<br>=3D3D
>>>>> <br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 =
>PThreadUnlockMutex(slotsMu, =3D
>>> ThisLine());<br>=3D3D
>>>>> ;<br>
>>>>> >=3D3D3DC2=3D3D3DA0 END AtForkParent;<br><br>
>>>>> ><br><br>
>>>>> >We can see by inspecting the code that a necessary precondition =
>=3D
>>> for<=3D3D
>>>>> br><br>
>>>>> >this routine is that heapMu is locked! =3D3D3DC2=3D3D3DA0(Since =
>=3D
>>> it's go=3D3D
>>>>> ing to unloc=3D3D3D<br>
>>>>> >k it,<br><br>
>>>>> >it had BETTER be locked on entry.)<br><br>
>>>>> ><br><br>
>>>>> >But the cond :=3D3D3D3D ... causes a =3D
>>> RTHooks.CheckLoadTracedRef<br><b=3D3D
>>>>> r>
>>>>> ><br><br>
>>>>> >which causes an RTOS.LockHeap<br><br>
>>>>> ><br><br>
>>>>> >the code of which we just saw:<br><br>
>>>>> ><br><br>
>>>>> >PROCEDURE LockHeap () =3D3D3D3D<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 VAR self :=3D3D3D3D =
>pthread_self();<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 BEGIN<br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 WITH r =3D3D3D3D =3D
>>> pthread_mutex_lock(heapMu,ThisLine()=3D3D
>>>>> ) DO <*ASSE=3D3D3D<br>
>>>>> >RT r=3D3D3D3D0*> END;<br><br>
>>>>> >...<br><br>
>>>>> ><br><br>
>>>>> >we try to lock heapMu. =3D3D3DC2=3D3D3DA0kaboom! =
>=3D3D3DC2=3D3D3DA0No =3D
>>> surprise there, r=3D3D
>>>>> eally?<br><br>
>>>>> ><br><br>
>>>>> >Am I going about this totally the wrong way? =
>=3D3D3DC2=3D3D3DA0Other =3D
>>> people are=3D3D
>>>>> running=3D3D3D<br>
>>>>> > Modula-3<br><br>
>>>>> >with pthreads, right? =3D3D3DC2=3D3D3DA0Right?? =
>=3D3D3DC2=3D3D3DA0Somewhere=3D
>>> out there i=3D3D
>>>>> n m3devel-la=3D3D3D<br>
>>>>> >nd?<br><br>
>>>>> ><span><font =3D
>>> color=3D3D3D3D"#888888"><br><br>
>>>>> >=3D3D3DC2=3D3D3DA0 =3D3D3DC2=3D3D3DA0 =
>=3D3D3DC2=3D3D3DA0Mika<br><br>
>>>>> ><br><br>
>>>>> =3D
>>> =
>></font></span></blockquote></div><br><=
>=3D
>>> ;=3D3D
>>>>> /div></div><br>
>>>>> ><br>
>>>>> >--001a11c2ced4471a2e050079db82--<br>
>>>>> </blockquote></div><br></div>
>>>>> </div></div></blockquote></div><br></div>
>>>>> =3D20
>>>>> --089e01183a1813188705007c3498--
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