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, see <http://www.gnu.org/licenses/>.
  28
  29    The GNU General Public License is contained in the file COPYING.
  30 */
  31
  32 #include "pub_core_basics.h"
  33 #include "pub_core_mallocfree.h"
  34 #include "priv_sema.h"
  35 #include "priv_sched-lock.h"
  36 #include "priv_sched-lock-impl.h"
  37
  38 struct sched_lock {
  39    vg_sema_t sema;
  40 };
  41
  42 static const HChar *get_sched_lock_name(void)
  43 {
  44    return "generic";
  45 }
  46
  47 static struct sched_lock *create_sched_lock(void)
  48 {
  49    struct sched_lock *p;
  50
  51    p = VG_(malloc)("sched_lock", sizeof(*p));
  52    ML_(sema_init)(&p->sema);
  53    return p;
  54 }
  55
  56 static void destroy_sched_lock(struct sched_lock *p)
  57 {
  58    ML_(sema_deinit)(&p->sema);
  59    VG_(free)(p);
  60 }
  61
  62 static int get_sched_lock_owner(struct sched_lock *p)
  63 {
  64    return p->sema.owner_lwpid;
  65 }
  66
  67 static void acquire_sched_lock(struct sched_lock *p)
  68 {
  69    ML_(sema_down)(&p->sema, False);
  70 }
  71
  72 static void release_sched_lock(struct sched_lock *p)
  73 {
  74    ML_(sema_up)(&p->sema, False);
  75 }
  76
  77 const struct sched_lock_ops ML_(generic_sched_lock_ops) = {
  78    .get_sched_lock_name  = get_sched_lock_name,
  79    .create_sched_lock    = create_sched_lock,
  80    .destroy_sched_lock   = destroy_sched_lock,
  81    .get_sched_lock_owner = get_sched_lock_owner,
  82    .acquire_sched_lock   = acquire_sched_lock,
  83    .release_sched_lock   = release_sched_lock,
  84 };