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
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
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;
}
|
