/* Set the process group ID of the process matching PID to PGID.
If PID is zero, the current process's process group ID is set.
If PGID is zero, the process ID of the process is used. */
int
__setpgid (pid_t pid, pid_t pgid)
{
error_t err;
unsigned int stamp;
stamp = _hurd_pids_changed_stamp; /* Atomic fetch. */
if (err = __USEPORT (PROC, __proc_setpgrp (port, pid, pgid)))
return __hurd_fail (err);
if (pid == 0 || pid == _hurd_pid)
/* Synchronize with the signal thread to make sure we have
received and processed proc_newids before returning to the user. */
while (_hurd_pids_changed_stamp == stamp)
{
#ifdef noteven
/* XXX we have no need for a mutex, but cthreads demands one. */
__condition_wait (&_hurd_pids_changed_sync, NULL);
#else
__swtch_pri(0);
#endif
}
return 0;
}
/* Create a new session with the calling process as its leader.
The process group IDs of the session and the calling process
are set to the process ID of the calling process, which is returned. */
pid_t
__setsid (void)
{
error_t err;
unsigned int stamp;
HURD_CRITICAL_BEGIN;
__mutex_lock (&_hurd_dtable_lock);
stamp = _hurd_pids_changed_stamp; /* Atomic fetch. */
/* Tell the proc server we want to start a new session. */
err = __USEPORT (PROC, __proc_setsid (port));
if (err)
__mutex_unlock (&_hurd_dtable_lock);
else
{
/* Punt our current ctty, and update the dtable accordingly. We hold
the dtable lock from before the proc_setsid call through clearing
the cttyid port and processing the dtable, so that we can be sure
that it's all done by the time the signal thread processes the
pgrp change notification. */
_hurd_locked_install_cttyid (MACH_PORT_NULL);
/* Synchronize with the signal thread to make sure we have received
and processed proc_newids before returning to the user.
This is necessary to ensure that _hurd_pgrp (and thus the value
returned by `getpgrp ()' in other threads) has been updated before
we return. */
while (_hurd_pids_changed_stamp == stamp)
{
#ifdef noteven
/* XXX we have no need for a mutex, but cthreads demands one. */
__condition_wait (&_hurd_pids_changed_sync, NULL);
#else
__swtch_pri (0);
#endif
}
}
HURD_CRITICAL_END;
return err ? __hurd_fail (err) : _hurd_pgrp;
}
