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
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
|
/* Thread Priority Protect helpers.
Copyright (C) 2006-2013 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Jakub Jelinek <jakub@redhat.com>, 2006.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <assert.h>
#include <atomic.h>
#include <errno.h>
#include <pthreadP.h>
#include <sched.h>
#include <stdlib.h>
int __sched_fifo_min_prio = -1;
int __sched_fifo_max_prio = -1;
void
__init_sched_fifo_prio (void)
{
__sched_fifo_max_prio = sched_get_priority_max (SCHED_FIFO);
atomic_write_barrier ();
__sched_fifo_min_prio = sched_get_priority_min (SCHED_FIFO);
}
int
__pthread_tpp_change_priority (int previous_prio, int new_prio)
{
struct pthread *self = THREAD_SELF;
struct priority_protection_data *tpp = THREAD_GETMEM (self, tpp);
if (tpp == NULL)
{
if (__sched_fifo_min_prio == -1)
__init_sched_fifo_prio ();
size_t size = sizeof *tpp;
size += (__sched_fifo_max_prio - __sched_fifo_min_prio + 1)
* sizeof (tpp->priomap[0]);
tpp = calloc (size, 1);
if (tpp == NULL)
return ENOMEM;
tpp->priomax = __sched_fifo_min_prio - 1;
THREAD_SETMEM (self, tpp, tpp);
}
assert (new_prio == -1
|| (new_prio >= __sched_fifo_min_prio
&& new_prio <= __sched_fifo_max_prio));
assert (previous_prio == -1
|| (previous_prio >= __sched_fifo_min_prio
&& previous_prio <= __sched_fifo_max_prio));
int priomax = tpp->priomax;
int newpriomax = priomax;
if (new_prio != -1)
{
if (tpp->priomap[new_prio - __sched_fifo_min_prio] + 1 == 0)
return EAGAIN;
++tpp->priomap[new_prio - __sched_fifo_min_prio];
if (new_prio > priomax)
newpriomax = new_prio;
}
if (previous_prio != -1)
{
if (--tpp->priomap[previous_prio - __sched_fifo_min_prio] == 0
&& priomax == previous_prio
&& previous_prio > new_prio)
{
int i;
for (i = previous_prio - 1; i >= __sched_fifo_min_prio; --i)
if (tpp->priomap[i - __sched_fifo_min_prio])
break;
newpriomax = i;
}
}
if (priomax == newpriomax)
return 0;
lll_lock (self->lock, LLL_PRIVATE);
tpp->priomax = newpriomax;
int result = 0;
if ((self->flags & ATTR_FLAG_SCHED_SET) == 0)
{
if (__sched_getparam (self->tid, &self->schedparam) != 0)
result = errno;
else
self->flags |= ATTR_FLAG_SCHED_SET;
}
if ((self->flags & ATTR_FLAG_POLICY_SET) == 0)
{
self->schedpolicy = __sched_getscheduler (self->tid);
if (self->schedpolicy == -1)
result = errno;
else
self->flags |= ATTR_FLAG_POLICY_SET;
}
if (result == 0)
{
struct sched_param sp = self->schedparam;
if (sp.sched_priority < newpriomax || sp.sched_priority < priomax)
{
if (sp.sched_priority < newpriomax)
sp.sched_priority = newpriomax;
if (__sched_setscheduler (self->tid, self->schedpolicy, &sp) < 0)
result = errno;
}
}
lll_unlock (self->lock, LLL_PRIVATE);
return result;
}
int
__pthread_current_priority (void)
{
struct pthread *self = THREAD_SELF;
if ((self->flags & (ATTR_FLAG_POLICY_SET | ATTR_FLAG_SCHED_SET))
== (ATTR_FLAG_POLICY_SET | ATTR_FLAG_SCHED_SET))
return self->schedparam.sched_priority;
int result = 0;
lll_lock (self->lock, LLL_PRIVATE);
if ((self->flags & ATTR_FLAG_SCHED_SET) == 0)
{
if (__sched_getparam (self->tid, &self->schedparam) != 0)
result = -1;
else
self->flags |= ATTR_FLAG_SCHED_SET;
}
if ((self->flags & ATTR_FLAG_POLICY_SET) == 0)
{
self->schedpolicy = __sched_getscheduler (self->tid);
if (self->schedpolicy == -1)
result = -1;
else
self->flags |= ATTR_FLAG_POLICY_SET;
}
if (result != -1)
result = self->schedparam.sched_priority;
lll_unlock (self->lock, LLL_PRIVATE);
return result;
}
|
