1
2/*--------------------------------------------------------------------*/
3/*--- Generic scheduler lock implementation   sched-lock-generic.c ---*/
4/*---                                                              ---*/
5/*--- This implementation does not guarantee fair scheduling on    ---*/
6/*--- multicore systems but is sufficient to make the Valgrind     ---*/
7/*--- scheduler work reasonably.                                   ---*/
8/*--------------------------------------------------------------------*/
9
10/*
11   This file is part of Valgrind, a dynamic binary instrumentation
12   framework.
13
14   Copyright (C) 2011-2013 Bart Van Assche <bvanassche@acm.org>.
15
16   This program is free software; you can redistribute it and/or
17   modify it under the terms of the GNU General Public License as
18   published by the Free Software Foundation; either version 2 of the
19   License, or (at your option) any later version.
20
21   This program is distributed in the hope that it will be useful, but
22   WITHOUT ANY WARRANTY; without even the implied warranty of
23   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
24   General Public License for more details.
25
26   You should have received a copy of the GNU General Public License
27   along with this program; if not, write to the Free Software
28   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
29   02111-1307, USA.
30
31   The GNU General Public License is contained in the file COPYING.
32*/
33
34#include "pub_core_basics.h"
35#include "pub_core_mallocfree.h"
36#include "priv_sema.h"
37#include "priv_sched-lock.h"
38#include "priv_sched-lock-impl.h"
39
40struct sched_lock {
41   vg_sema_t sema;
42};
43
44static const HChar *get_sched_lock_name(void)
45{
46   return "generic";
47}
48
49static struct sched_lock *create_sched_lock(void)
50{
51   struct sched_lock *p;
52
53   p = VG_(malloc)("sched_lock", sizeof(*p));
54   if (p)
55      ML_(sema_init)(&p->sema);
56   return p;
57}
58
59static void destroy_sched_lock(struct sched_lock *p)
60{
61   ML_(sema_deinit)(&p->sema);
62   VG_(free)(p);
63}
64
65static int get_sched_lock_owner(struct sched_lock *p)
66{
67   return p->sema.owner_lwpid;
68}
69
70static void acquire_sched_lock(struct sched_lock *p)
71{
72   ML_(sema_down)(&p->sema, False);
73}
74
75static void release_sched_lock(struct sched_lock *p)
76{
77   ML_(sema_up)(&p->sema, False);
78}
79
80const struct sched_lock_ops ML_(generic_sched_lock_ops) = {
81   .get_sched_lock_name  = get_sched_lock_name,
82   .create_sched_lock    = create_sched_lock,
83   .destroy_sched_lock   = destroy_sched_lock,
84   .get_sched_lock_owner = get_sched_lock_owner,
85   .acquire_sched_lock   = acquire_sched_lock,
86   .release_sched_lock   = release_sched_lock,
87};
88