~drizzle-trunk/drizzle/development

1 by brian
clean slate
1
/* Copyright (C) 2000 MySQL AB
2
3
   This program is free software; you can redistribute it and/or modify
4
   it under the terms of the GNU General Public License as published by
5
   the Free Software Foundation; version 2 of the License.
6
7
   This program is distributed in the hope that it will be useful,
8
   but WITHOUT ANY WARRANTY; without even the implied warranty of
9
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
10
   GNU General Public License for more details.
11
12
   You should have received a copy of the GNU General Public License
13
   along with this program; if not, write to the Free Software
14
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
15
16
/* Alloc a block of locked memory */
17
18
#include "mysys_priv.h"
19
#include "mysys_err.h"
20
#include <my_list.h>
21
22
#ifdef HAVE_MLOCK
23
#include <sys/mman.h>
24
25
struct st_mem_list
26
{
27
  LIST list;
28
  uchar *page;
29
  uint size;
30
};
31
32
LIST *mem_list;
33
34
uchar *my_malloc_lock(uint size,myf MyFlags)
35
{
36
  int success;
37
  uint pagesize=sysconf(_SC_PAGESIZE);
38
  uchar *ptr;
39
  struct st_mem_list *element;
40
41
  size=((size-1) & ~(pagesize-1))+pagesize;
42
  if (!(ptr=memalign(pagesize,size)))
43
  {
44
    if (MyFlags & (MY_FAE+MY_WME))
45
      my_error(EE_OUTOFMEMORY, MYF(ME_BELL+ME_WAITTANG),size);
51.3.18 by Jay Pipes
Phase 5 - Remove DBUG from mysys
46
    return(0);
1 by brian
clean slate
47
  }
48
  success = mlock((uchar*) ptr,size);
49
  if (success != 0 && geteuid() == 0)
50
  {
51
    fprintf(stderr, "Warning: Failed to lock memory. errno %d\n",
52
	    errno);
53
  }
54
  else
55
  {
56
    /* Add block in a list for munlock */
57
    if (!(element=(struct st_mem_list*) my_malloc(sizeof(*element),MyFlags)))
58
    {
59
      VOID(munlock((uchar*) ptr,size));
60
      free(ptr);
51.3.18 by Jay Pipes
Phase 5 - Remove DBUG from mysys
61
      return(0);
1 by brian
clean slate
62
    }
63
    element->list.data=(uchar*) element;
64
    element->page=ptr;
65
    element->size=size;
66
    pthread_mutex_lock(&THR_LOCK_malloc);
67
    mem_list=list_add(mem_list,&element->list);
68
    pthread_mutex_unlock(&THR_LOCK_malloc);
69
  }
51.3.18 by Jay Pipes
Phase 5 - Remove DBUG from mysys
70
  return(ptr);
1 by brian
clean slate
71
}
72
73
74
void my_free_lock(uchar *ptr,myf Myflags __attribute__((unused)))
75
{
76
  LIST *list;
77
  struct st_mem_list *element=0;
78
79
  pthread_mutex_lock(&THR_LOCK_malloc);
80
  for (list=mem_list ; list ; list=list->next)
81
  {
82
    element=(struct st_mem_list*) list->data;
83
    if (ptr == element->page)
84
    {						/* Found locked mem */
85
      VOID(munlock((uchar*) ptr,element->size));
86
      mem_list=list_delete(mem_list,list);
87
      break;
88
    }
89
  }
90
  pthread_mutex_unlock(&THR_LOCK_malloc);
91
  if (element)
92
    my_free((uchar*) element,MYF(0));
93
  free(ptr);					/* Free even if not locked */
94
}
95
96
#endif /* HAVE_MLOCK */