summaryrefslogtreecommitdiff
path: root/proc/msg.c
blob: fe78a8958d1b3427261f7c553f0bf8f6e470b5cb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
/* Message port manipulations
   Copyright (C) 1994, 1995, 1996 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 "process_reply_U.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;
    }
}

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)
{
  *oldmsgport = p->p_msgport;
  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.  Reply to it before we expect it
	 to service requests.  */
      proc_setmsgport_reply (reply, replytype, 0, *oldmsgport);
      mach_port_deallocate (mach_task_self (), *oldmsgport);
      startup_essential_task (msgport, mach_task_self (), MACH_PORT_NULL,
			      "proc", master_host_port);
      return MIG_NO_REPLY;
    }
  else
    return 0;
}

/* Check to see if process P is blocked trying to get the message port of 
   process DYINGP; if so, return its call with ESRCH. */
void
check_message_dying (struct proc *p, struct proc *dyingp)
{
  if (p->p_msgportwait)
    {
      condition_broadcast (&p->p_wakeup);
      p->p_msgportwait = 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)
{
  struct proc *p = pid_find (pid);

  if (!p)
    return ESRCH;
  
  while (p->p_deadmsg)
    {
      callerp->p_msgportwait = 1;
      p->p_checkmsghangs = 1;
      condition_wait (&callerp->p_wakeup, &global_lock);
    }

  *msgport = p->p_msgport;
  return 0;
}

void
message_port_dead (struct proc *p)
{
  mach_port_deallocate (mach_task_self (), p->p_msgport);
  p->p_msgport = MACH_PORT_NULL;
  p->p_deadmsg = 1;
}