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/* Message port manipulations
Copyright (C) 1994, 1995, 1996, 1999, 2001 Free Software Foundation
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2, or (at
your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
#include <mach.h>
#include <hurd.h>
#include "proc.h"
#include <hurd/startup.h>
#include <assert.h>
#include <stdlib.h>
#include <stdio.h>
/* Check to see if process P is blocked trying to get the message
port of process AVAILP; if so, return its call. */
void
check_message_return (struct proc *p, void *availpaddr)
{
if (p->p_msgportwait)
{
pthread_cond_broadcast (&p->p_wakeup);
p->p_msgportwait = 0;
}
}
/* Register ourselves with statup. */
static void *
tickle_statup (void *statupport)
{
startup_essential_task ((mach_port_t) statupport, mach_task_self (),
MACH_PORT_NULL, "proc", _hurd_host_priv);
return NULL;
}
error_t
S_proc_setmsgport (struct proc *p,
mach_port_t reply, mach_msg_type_name_t replytype,
mach_port_t msgport,
mach_port_t *oldmsgport,
mach_msg_type_name_t *oldmsgport_type)
{
if (!p)
return EOPNOTSUPP;
*oldmsgport = p->p_msgport;
*oldmsgport_type = MACH_MSG_TYPE_MOVE_SEND;
p->p_msgport = msgport;
p->p_deadmsg = 0;
if (p->p_checkmsghangs)
prociterate (check_message_return, p);
p->p_checkmsghangs = 0;
if (p == startup_proc && startup_fallback)
{
/* Statup is single threaded, so we can't delay our reply for
the essential task RPC; spawn a thread to do it. */
pthread_t thread;
error_t err;
err = pthread_create (&thread, NULL, tickle_statup,
(void*) (uintptr_t) msgport);
if (!err)
pthread_detach (thread);
else
{
errno = err;
perror ("pthread_create");
}
}
return 0;
}
/* Check to see if process P is blocked trying to get the message port of
process DYINGP; if so, wake it up. */
void
check_message_dying (struct proc *p, struct proc *dyingp)
{
if (p->p_msgportwait)
{
pthread_cond_broadcast (&p->p_wakeup);
p->p_msgportwait = 0;
}
}
/* Check if the message port of process P has died. Return nonzero if
this has indeed happened. */
int
check_msgport_death (struct proc *p)
{
/* Only check if the message port passed away, if we know that it
was ever alive. */
if (p->p_msgport != MACH_PORT_NULL)
{
mach_port_type_t type;
error_t err;
err = mach_port_type (mach_task_self (), p->p_msgport, &type);
if (err || (type & MACH_PORT_TYPE_DEAD_NAME))
{
/* The port appears to be dead; throw it away. */
mach_port_deallocate (mach_task_self (), p->p_msgport);
p->p_msgport = MACH_PORT_NULL;
p->p_deadmsg = 1;
return 1;
}
}
return 0;
}
error_t
S_proc_getmsgport (struct proc *callerp,
mach_port_t reply_port,
mach_msg_type_name_t reply_port_type,
pid_t pid,
mach_port_t *msgport)
{
int cancel;
struct proc *p;
if (!callerp)
return EOPNOTSUPP;
p = pid_find_allow_zombie (pid);
restart:
while (p && p->p_deadmsg && !p->p_dead)
{
callerp->p_msgportwait = 1;
p->p_checkmsghangs = 1;
cancel = pthread_hurd_cond_wait_np (&callerp->p_wakeup, &global_lock);
if (callerp->p_dead)
return EOPNOTSUPP;
if (cancel)
return EINTR;
/* Refetch P in case it went away while we were waiting. */
p = pid_find_allow_zombie (pid);
}
if (!p)
return ESRCH;
if (check_msgport_death (p))
goto restart;
*msgport = p->p_msgport;
return 0;
}
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