diff options
Diffstat (limited to 'io.c')
| -rw-r--r-- | io.c | 20 |
1 files changed, 16 insertions, 4 deletions
@@ -2168,7 +2168,16 @@ use_pipes: #ifndef PIPES_SIMULATED /* real pipes */ -/* wait_any --- wait for a child process, close associated pipe */ +/* + * wait_any --- if the argument pid is 0, wait for all child processes that + * have exited. We loop to make sure to reap all children that have exited to + * minimize the risk of running out of process slots. Since we don't process + * SIGCHLD, we do not immediately reap exited children. So when we get here, + * we want to reap any that have piled up. + * + * Note: on platforms that do not support waitpid with WNOHANG, when called with + * a zero argument, this function will hang until all children have exited. + */ static int wait_any(int interesting) /* pid of interest, if any */ @@ -2198,7 +2207,11 @@ wait_any(int interesting) /* pid of interest, if any */ hstat = signal(SIGHUP, SIG_IGN); qstat = signal(SIGQUIT, SIG_IGN); for (;;) { -# ifdef HAVE_SYS_WAIT_H /* POSIX compatible sys/wait.h */ +# if defined(HAVE_WAITPID) && defined(WNOHANG) + if ((pid = waitpid(-1, & status, WNOHANG)) == 0) + /* No children have exited */ + break; +# elif defined(HAVE_SYS_WAIT_H) /* POSIX compatible sys/wait.h */ pid = wait(& status); # else pid = wait((union wait *) & status); @@ -2210,13 +2223,12 @@ wait_any(int interesting) /* pid of interest, if any */ if (pid == redp->pid) { redp->pid = -1; redp->status = status; - goto finished; + break; } } if (pid == -1 && errno == ECHILD) break; } -finished: signal(SIGHUP, hstat); signal(SIGQUIT, qstat); #endif |