+#if HAVE_WAITID && defined WNOWAIT && 0
+ /* Commented out because waitid() without WEXITED and with WNOWAIT doesn't
+ work: On Solaris 7 and OSF/1 4.0, it returns -1 and sets errno = ECHILD,
+ and on HP-UX 10.20 it just hangs. */
+ /* Use of waitid() with WNOWAIT avoids a race condition: If slave_process is
+ true, and this process sleeps a very long time between the return from
+ waitpid() and the execution of unregister_slave_subprocess(), and
+ meanwhile another process acquires the same PID as child, and then - still
+ before unregister_slave_subprocess() - this process gets a fatal signal,
+ it would kill the other totally unrelated process. */
+ siginfo_t info;
+
+ if (termsigp != NULL)
+ *termsigp = 0;
+ for (;;)
+ {
+ if (waitid (P_PID, child, &info, WEXITED | (slave_process ? WNOWAIT : 0))
+ < 0)
+ {
+# ifdef EINTR
+ if (errno == EINTR)
+ continue;
+# endif
+ if (exit_on_error || !null_stderr)
+ error (exit_on_error ? EXIT_FAILURE : 0, errno,
+ _("%s subprocess"), progname);
+ return 127;
+ }
+
+ /* info.si_code is set to one of CLD_EXITED, CLD_KILLED, CLD_DUMPED,
+ CLD_TRAPPED, CLD_STOPPED, CLD_CONTINUED. Loop until the program
+ terminates. */
+ if (info.si_code == CLD_EXITED
+ || info.si_code == CLD_KILLED || info.si_code == CLD_DUMPED)
+ break;
+ }
+
+ /* The child process has exited or was signalled. */
+
+ if (slave_process)
+ {
+ /* Unregister the child from the list of slave subprocesses, so that
+ later, when we exit, we don't kill a totally unrelated process which
+ may have acquired the same pid. */
+ unregister_slave_subprocess (child);
+
+ /* Now remove the zombie from the process list. */
+ for (;;)
+ {
+ if (waitid (P_PID, child, &info, WEXITED) < 0)
+ {
+# ifdef EINTR
+ if (errno == EINTR)
+ continue;
+# endif
+ if (exit_on_error || !null_stderr)
+ error (exit_on_error ? EXIT_FAILURE : 0, errno,
+ _("%s subprocess"), progname);
+ return 127;
+ }
+ break;
+ }
+ }
+
+ switch (info.si_code)
+ {
+ case CLD_KILLED:
+ case CLD_DUMPED:
+ if (termsigp != NULL)
+ *termsigp = info.si_status; /* TODO: or info.si_signo? */
+# ifdef SIGPIPE
+ if (info.si_status == SIGPIPE && ignore_sigpipe)
+ return 0;
+# endif
+ if (exit_on_error || (!null_stderr && termsigp == NULL))
+ error (exit_on_error ? EXIT_FAILURE : 0, 0,
+ _("%s subprocess got fatal signal %d"),
+ progname, info.si_status);
+ return 127;
+ case CLD_EXITED:
+ if (info.si_status == 127)
+ {
+ if (exit_on_error || !null_stderr)
+ error (exit_on_error ? EXIT_FAILURE : 0, 0,
+ _("%s subprocess failed"), progname);
+ return 127;
+ }
+ return info.si_status;
+ default:
+ abort ();
+ }
+#else