--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=630, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=636, si_uid=0, si_status=0, si_utime=0, si_stime=1 /* 0.01 s */} ---
--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=638, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=628, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
+++ exited with 0 +++