diff options
Diffstat (limited to 'proc/msg.c')
| -rw-r--r-- | proc/msg.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/proc/msg.c b/proc/msg.c new file mode 100644 index 00000000..b8413e3b --- /dev/null +++ b/proc/msg.c @@ -0,0 +1,148 @@ +/* Message port manipulations + Copyright (C) 1994, 1995, 1996, 1999 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> + +/* 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) + { + condition_broadcast (&p->p_wakeup); + p->p_msgportwait = 0; + } +} + +/* Register ourselves with init. */ +static any_t +tickle_init (any_t initport) +{ + startup_essential_task ((mach_port_t) initport, mach_task_self (), + MACH_PORT_NULL, "proc", master_host_port); + return 0; +} + +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) + /* Init is single threaded, so we can't delay our reply for + the essential task RPC; spawn a thread to do it. */ + cthread_detach (cthread_fork (tickle_init, (any_t) msgport)); + + 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) + { + condition_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 = pid_find_allow_zombie (pid); + + if (!callerp) + return EOPNOTSUPP; + +restart: + while (p && p->p_deadmsg && !p->p_dead) + { + callerp->p_msgportwait = 1; + p->p_checkmsghangs = 1; + cancel = hurd_condition_wait (&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; +} |