Experimental Physics and
Industrial Control System

Michael Abbott <[email protected]> · Mon, 12 May 2008 13:15:48 +0000 (GMT)

> To reproduce this, create an EPICS IOC with the following code:
> 
> 	int main()
> 	{
>	    printf("Running iocsh\n");
> 	    iocsh("/dev/null");
>	    printf("Calling epicsThreadExitMain\n");
> 	    epicsThreadExitMain();
> 	}

For what it's worth, here are the last few lines from running

	strace bin/linux-x86/softIoc

on the offending process:

...
write(1, "Running iocsh\n", 14Running iocsh
)         = 14
open("/dev/null", O_RDONLY)             = 3
fstat64(3, {st_mode=S_IFCHR|0666, st_rdev=makedev(1, 3), ...}) = 0
ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbfe9c790) = -1 ENOTTY (Inappropriate ioctl for device)
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7f60000
read(3, "", 4096)                       = 0
close(3)                                = 0
munmap(0xb7f60000, 4096)                = 0
rt_sigprocmask(SIG_SETMASK, ~[RTMIN RT_1], [], 8) = 0
mmap2(NULL, 135168, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7f1f000
mprotect(0xb7f1f000, 4096, PROT_NONE)   = 0
clone(child_stack=0xb7f3f4c4, flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|CLONE_SYSVSEM|CLONE_SETTLS|CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID|CLONE_DETACHED, parent_tidptr=0xb7f3fbe8, {entry_number:6, base_addr:0xb7f3fba0, limit:1048575, seg_32bit:1, contents:0, read_exec_only:0, limit_in_pages:1, seg_not_present:0, useable:1}, child_tidptr=0xb7f3fbe8) = 5730
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
write(1, "Calling epicsThreadExitMain\n", 28Calling epicsThreadExitMain
) = 28
futex(0x7f81a0, FUTEX_WAKE, 2147483647) = 0
_exit(0)                                = ?

Curious.  I would have expected the _exit(0) call to have done everything 
that's necessary.  As far as I can tell from the man page, _exit is pretty 
well guaranteed to terminate the program.

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System