Hi Jose,
yes, I've noticed that as well. It was, at a point, drastic (i.e. almost
allways lock-up) on my work development laptop; it now happens far less
often (but it does happens to me from time to time).
Dave Lewis, the author of OSProcess, fixed one issue which solved most of
the lockups I had, but not all of them. The lockup is in the interaction
between OSProcess inside Pharo and the external shell command (i.e. it
concerns anything which uses OSProcess), and seems like missing a signal.
It is also machine and linux version dependent (Ubuntu 14.10 was horrible,
14.04 and 15.04 on the same hardware are far less sensitive), and seems to
also depend on the load of the machine itself.
By the way, which version of OSProcess you are using?
Thierry
2015-06-02 11:10 GMT+02:00 Jose San Leandro <jose.sanlean...@osoco.es>:
> Hi,
>
> In one of our projects we are using Pharo4. The image gets built by
> gradle, which loads the Metacello project. Sometimes, we see the build
> process hangs. It just don't progress.
>
> When adding local gitfiletree:// dependencies manually through Monticello
> after a while Pharo gets frozen. It's not always the same repository, it's
> not always the same number of repositories before it hangs.
>
> I launched the image with strace, and attached gdb to the frozen process.
> It turns out It's waiting for a lock that gets never released.
>
> The environment is a 64b Gentoo Linux with enough of everything (multiple
> monitors, multiple cores, enough RAM).
>
> I hope anybody could point me how to dig deeper into this.
>
> # gdb
> (gdb) attach [pid]
> [..]
> Reading symbols from /usr/lib32/libbz2.so.1...(no debugging symbols
> found)...done.
> Loaded symbols for /usr/lib32/libbz2.so.1
> 0x0809d8bb in signalSemaphoreWithIndex ()
> (gdb) backtrace
> #0 0x0809d8bb in signalSemaphoreWithIndex ()
> #1 0x0810868c in handleSignal ()
> #2 <signal handler called>
> #3 0x0809d8c8 in signalSemaphoreWithIndex ()
> #4 0x0809f0af in aioPoll ()
> #5 0xf76f9671 in display_ioRelinquishProcessorForMicroseconds () from
> /home/chous/realhome/toolbox/pharo-5.0/pharo-vm/vm-display-X11
> #6 0x080a1887 in ioRelinquishProcessorForMicroseconds ()
> #7 0x080767fa in primitiveRelinquishProcessor ()
> #8 0xb6fc838c in ?? ()
> #9 0xb6fc3700 in ?? ()
> #10 0xb7952882 in ?? ()
> #11 0xb6fc3648 in ?? ()
> (gdb) disassemble
> Dump of assembler code for function handleSignal:
> 0x081085e0 <+0>: sub $0x9c,%esp
> 0x081085e6 <+6>: mov %ebx,0x90(%esp)
> 0x081085ed <+13>: mov 0xa0(%esp),%ebx
> 0x081085f4 <+20>: mov %esi,0x94(%esp)
> 0x081085fb <+27>: mov %edi,0x98(%esp)
> 0x08108602 <+34>: movzbl 0x8168420(%ebx),%esi
> 0x08108609 <+41>: mov %ebx,%eax
> 0x0810860b <+43>: mov %esi,%edx
> 0x0810860d <+45>: call 0x81070d0 <forwardSignaltoSemaphoreAt>
> 0x08108612 <+50>: call 0x805aae0 <pthread_self@plt>
> 0x08108617 <+55>: mov 0x8168598,%edi
> 0x0810861d <+61>: cmp %edi,%eax
> 0x0810861f <+63>: je 0x8108680 <handleSignal+160>
> 0x08108621 <+65>: lea 0x10(%esp),%esi
> 0x08108625 <+69>: mov %esi,(%esp)
> 0x08108628 <+72>: call 0x805b330 <sigemptyset@plt>
> 0x0810862d <+77>: mov %ebx,0x4(%esp)
> 0x08108631 <+81>: mov %esi,(%esp)
> 0x08108634 <+84>: call 0x805b0c0 <sigaddset@plt>
> 0x08108639 <+89>: movl $0x0,0x8(%esp)
> 0x08108641 <+97>: mov %esi,0x4(%esp)
> 0x08108645 <+101>: movl $0x0,(%esp)
> 0x0810864c <+108>: call 0x805ada0 <pthread_sigmask@plt>
> 0x08108651 <+113>: mov %ebx,0x4(%esp)
> 0x08108655 <+117>: mov %edi,(%esp)
> 0x08108658 <+120>: call 0x805b240 <pthread_kill@plt>
> 0x0810865d <+125>: mov 0x90(%esp),%ebx
> 0x08108664 <+132>: mov 0x94(%esp),%esi
> 0x0810866b <+139>: mov 0x98(%esp),%edi
> 0x08108672 <+146>: add $0x9c,%esp
> 0x08108678 <+152>: ret
> 0x08108679 <+153>: lea 0x0(%esi,%eiz,1),%esi
> 0x08108680 <+160>: test %esi,%esi
> 0x08108682 <+162>: je 0x810865d <handleSignal+125>
> 0x08108684 <+164>: mov %esi,(%esp)
> 0x08108687 <+167>: call 0x809d8a0 <signalSemaphoreWithIndex>
> => 0x0810868c <+172>: jmp 0x810865d <handleSignal+125>
> End of assembler dump.
> (gdb) up 3
> (gdb) disassemble
> Dump of assembler code for function signalSemaphoreWithIndex:
> 0x0809d8a0 <+0>: push %esi
> 0x0809d8a1 <+1>: xor %eax,%eax
> 0x0809d8a3 <+3>: push %ebx
> 0x0809d8a4 <+4>: sub $0x24,%esp
> 0x0809d8a7 <+7>: mov 0x30(%esp),%esi
> 0x0809d8ab <+11>: test %esi,%esi
> 0x0809d8ad <+13>: jle 0x809d918 <signalSemaphoreWithIndex+120>
> 0x0809d8af <+15>: mov $0x1,%edx
> 0x0809d8b4 <+20>: lea 0x0(%esi,%eiz,1),%esi
> 0x0809d8b8 <+24>: mfence
> 0x0809d8bb <+27>: mov $0x0,%eax
> 0x0809d8c0 <+32>: lock cmpxchg %edx,0x8152d80
> => 0x0809d8c8 <+40>: mov %eax,0x1c(%esp)
> 0x0809d8cc <+44>: mov 0x1c(%esp),%eax
> 0x0809d8d0 <+48>: test %eax,%eax
> 0x0809d8d2 <+50>: jne 0x809d8b8 <signalSemaphoreWithIndex+24>
> 0x0809d8d4 <+52>: mov 0x8152d84,%edx
> 0x0809d8da <+58>: cmp $0x1ff,%edx
> 0x0809d8e0 <+64>: lea 0x1(%edx),%ebx
> 0x0809d8e3 <+67>: cmove %eax,%ebx
> 0x0809d8e6 <+70>: mov 0x8152d88,%eax
> 0x0809d8eb <+75>: cmp %ebx,%eax
> 0x0809d8ed <+77>: je 0x809d920 <signalSemaphoreWithIndex+128>
> 0x0809d8ef <+79>: mov 0x8152d84,%eax
> 0x0809d8f4 <+84>: mov %esi,0x8152da0(,%eax,4)
> 0x0809d8fb <+91>: mfence
> 0x0809d8fe <+94>: mov %ebx,0x8152d84
> 0x0809d904 <+100>: movl $0x0,0x8152d80
> 0x0809d90e <+110>: call 0x807c2c0 <forceInterruptCheck>
> 0x0809d913 <+115>: mov $0x1,%eax
> 0x0809d918 <+120>: add $0x24,%esp
> 0x0809d91b <+123>: pop %ebx
> 0x0809d91c <+124>: pop %esi
> 0x0809d91d <+125>: ret
> 0x0809d91e <+126>: xchg %ax,%ax
> 0x0809d920 <+128>: movl $0x810c888,(%esp)
> 0x0809d927 <+135>: movl $0x0,0x8152d80
> 0x0809d931 <+145>: call 0x80a3720 <error>
> 0x0809d936 <+150>: jmp 0x809d8ef <signalSemaphoreWithIndex+79>
> End of assembler dump.
>
> Meanwhile, strace gets frozen showing this:
> [..]
> clone(child_stack=0,
> flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD,
> child_tidptr=0x7f63665cd9d0) = 3736
> rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
> rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
> rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
> rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
> rt_sigaction(SIGINT, {0x42a8a0, [], SA_RESTORER, 0x7f6365ba3ad0},
> {SIG_DFL, [], SA_RESTORER, 0x7f6365ba3ad0}, 8) = 0
> wait4(-1, 0x7ffc4ef7f7e8, 0, NULL) = ? ERESTARTSYS (To be restarted
> if SA_RESTART is set)
> --- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
> wait4(-1,
>
