coregrind/m_scheduler/sched-lock-generic.c

   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) 2011-2017 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
  40 struct sched_lock {
  41    vg_sema_t sema;
  42 };
  43
  44 static const HChar *get_sched_lock_name(void)
  45 {
  46    return "generic";
  47 }
  48
  49 static struct sched_lock *create_sched_lock(void)
  50 {
  51    struct sched_lock *p;
  52
  53    p = VG_(malloc)("sched_lock", sizeof(*p));
  54    ML_(sema_init)(&p->sema);
  55    return p;
  56 }
  57
  58 static void destroy_sched_lock(struct sched_lock *p)
  59 {
  60    ML_(sema_deinit)(&p->sema);
  61    VG_(free)(p);
  62 }
  63
  64 static int get_sched_lock_owner(struct sched_lock *p)
  65 {
  66    return p->sema.owner_lwpid;
  67 }
  68
  69 static void acquire_sched_lock(struct sched_lock *p)
  70 {
  71    ML_(sema_down)(&p->sema, False);
  72 }
  73
  74 static void release_sched_lock(struct sched_lock *p)
  75 {
  76    ML_(sema_up)(&p->sema, False);
  77 }
  78
  79 const struct sched_lock_ops ML_(generic_sched_lock_ops) = {
  80    .get_sched_lock_name  = get_sched_lock_name,
  81    .create_sched_lock    = create_sched_lock,
  82    .destroy_sched_lock   = destroy_sched_lock,
  83    .get_sched_lock_owner = get_sched_lock_owner,
  84    .acquire_sched_lock   = acquire_sched_lock,
  85    .release_sched_lock   = release_sched_lock,
  86 };