Question

On Solaris 9 and 10, both x86 and Sparc, we have a process that is hanging during exit:

fe0b5994 lwp_park (0, 0, 0)
fe0b206c slow_lock (ff388908, fe080400, 0, 0, 98, fe0abe00) + 58
ff376aa8 __deregister_frame_info_bases (2a518, 1, 0, 2daf0, 0, ff376be4) + 4c
00014858 ???????? (0, ff000000, 0, 0, 0, 0)
00019920 _fini    (0, 0, 210fc, fe21cbf0, 5, fe25897c) + 4
fe21cbf0 _exithandle (fee66a4c, 0, 40, 0, 0, fe2bc000) + 70
fe2a0564 exit     (0, fdefb47c, 40, fdefb8ff, 2c, 0) + 24
fee66a4c (our code) (4e280, 5ab5c, 5aa60, 2ed0, 81010100, fdefb988) + 244

Our code is compiled on the Solaris 9 machine, using gcc 3.4.6.

The process in question is a single-threaded child from a multi-threaded parent, forked but not execed.

Has anyone seen anything similar?

Do you know if a more recent version of gcc would fix the problem?

Answer 1

You could try calling _exit() to exit the child process, rather than exit(). exit() is a library function that does various forms of library cleanup before exiting–for example, it flushes stdio buffers to disk. _exit() is the actual system call which terminates the process. Even in single-threaded programs, you normally used _exit() inside forked children to prevent library cleanup from happening twice.