libs/pbd/debug_rt_alloc.c

   1 /*
   2     Copyright (C) 2011 Paul Davis
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18 */
  19
  20 #ifdef DEBUG_RT_ALLOC
  21
  22 #define _GNU_SOURCE
  23 #include <dlfcn.h>
  24 #include <stdio.h>
  25 #include <pthread.h>
  26 #include <stdlib.h>
  27
  28 int (*pbd_alloc_allowed) () = 0;
  29
  30 /** Thread-local key whose value is set to 1 if malloc checking is disabled
  31  *  for this thread, 0 otherwise.
  32  */
  33
  34 static pthread_key_t disabled;
  35
  36 static pthread_once_t once;
  37
  38 static void
  39 make_key (void)
  40 {
  41         (void) pthread_key_create (&disabled, NULL);
  42 }
  43
  44 /** This is our malloc which overrides the system one */
  45 void* malloc (size_t s)
  46 {
  47         static void * (*real_malloc) (size_t) = NULL;
  48         if (!real_malloc) {
  49                 /* find the system malloc */
  50                 real_malloc = dlsym (RTLD_NEXT, "malloc");
  51         }
  52
  53         (void) pthread_once (&once, make_key);
  54
  55         if (pthread_getspecific (disabled) == NULL && pbd_alloc_allowed && !pbd_alloc_allowed ()) {
  56                 /* pbd_alloc_allowed says that this malloc is not permitted */
  57                 abort ();
  58         }
  59
  60         /* Pass through to the system malloc */
  61         return real_malloc (s);
  62 }
  63
  64 void
  65 suspend_rt_malloc_checks ()
  66 {
  67         (void) pthread_once (&once, make_key);
  68         pthread_setspecific (disabled, (void *) 1);
  69 }
  70
  71 void
  72 resume_rt_malloc_checks ()
  73 {
  74         (void) pthread_once (&once, make_key);
  75         pthread_setspecific (disabled, (void *) 0);
  76 }
  77
  78 #endif