1/* Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 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
25struct st_mem_list
26{
27 LIST list;
28 uchar *page;
29 uint size;
30};
31
32LIST *mem_list;
33
34uchar *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 DBUG_ENTER("my_malloc_lock");
41
42 size=((size-1) & ~(pagesize-1))+pagesize;
43 if (!(ptr=memalign(pagesize,size)))
44 {
45 if (MyFlags & (MY_FAE+MY_WME))
46 my_error(EE_OUTOFMEMORY, MYF(ME_BELL+ME_WAITTANG+ME_FATALERROR), size);
47 DBUG_RETURN(0);
48 }
49 success = mlock((uchar*) ptr,size);
50 if (success != 0 && geteuid() == 0)
51 {
52 DBUG_PRINT("warning",("Failed to lock memory. errno %d\n",
53 errno));
54 fprintf(stderr, "Warning: Failed to lock memory. errno %d\n",
55 errno);
56 }
57 else
58 {
59 /* Add block in a list for munlock */
60 if (!(element=(struct st_mem_list*) my_malloc(sizeof(*element),MyFlags)))
61 {
62 (void) munlock((uchar*) ptr,size);
63 free(ptr);
64 DBUG_RETURN(0);
65 }
66 element->list.data=(uchar*) element;
67 element->page=ptr;
68 element->size=size;
69 mysql_mutex_lock(&THR_LOCK_malloc);
70 mem_list=list_add(mem_list,&element->list);
71 mysql_mutex_unlock(&THR_LOCK_malloc);
72 }
73 DBUG_RETURN(ptr);
74}
75
76
77void my_free_lock(uchar *ptr)
78{
79 LIST *list;
80 struct st_mem_list *element=0;
81
82 mysql_mutex_lock(&THR_LOCK_malloc);
83 for (list=mem_list ; list ; list=list->next)
84 {
85 element=(struct st_mem_list*) list->data;
86 if (ptr == element->page)
87 { /* Found locked mem */
88 (void) munlock((uchar*) ptr,element->size);
89 mem_list=list_delete(mem_list,list);
90 break;
91 }
92 }
93 mysql_mutex_unlock(&THR_LOCK_malloc);
94 my_free(element);
95 free(ptr); /* Free even if not locked */
96}
97
98#endif /* HAVE_MLOCK */
99