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/* Copyright (C) 2000 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/* Alloc a block of locked memory */
#include "mysys_priv.h"
#include "mysys_err.h"
#include <my_list.h>
#ifdef HAVE_MLOCK
#include <sys/mman.h>
struct st_mem_list
{
LIST list;
uchar *page;
uint size;
};
LIST *mem_list;
uchar *my_malloc_lock(uint size,myf MyFlags)
{
int success;
uint pagesize=sysconf(_SC_PAGESIZE);
uchar *ptr;
struct st_mem_list *element;
DBUG_ENTER("my_malloc_lock");
size=((size-1) & ~(pagesize-1))+pagesize;
if (!(ptr=memalign(pagesize,size)))
{
if (MyFlags & (MY_FAE+MY_WME))
my_error(EE_OUTOFMEMORY, MYF(ME_BELL+ME_WAITTANG),size);
DBUG_RETURN(0);
}
success = mlock((uchar*) ptr,size);
if (success != 0 && geteuid() == 0)
{
DBUG_PRINT("warning",("Failed to lock memory. errno %d\n",
errno));
fprintf(stderr, "Warning: Failed to lock memory. errno %d\n",
errno);
}
else
{
/* Add block in a list for munlock */
if (!(element=(struct st_mem_list*) my_malloc(sizeof(*element),MyFlags)))
{
VOID(munlock((uchar*) ptr,size));
free(ptr);
DBUG_RETURN(0);
}
element->list.data=(uchar*) element;
element->page=ptr;
element->size=size;
pthread_mutex_lock(&THR_LOCK_malloc);
mem_list=list_add(mem_list,&element->list);
pthread_mutex_unlock(&THR_LOCK_malloc);
}
DBUG_RETURN(ptr);
}
void my_free_lock(uchar *ptr,myf Myflags __attribute__((unused)))
{
LIST *list;
struct st_mem_list *element=0;
pthread_mutex_lock(&THR_LOCK_malloc);
for (list=mem_list ; list ; list=list->next)
{
element=(struct st_mem_list*) list->data;
if (ptr == element->page)
{ /* Found locked mem */
VOID(munlock((uchar*) ptr,element->size));
mem_list=list_delete(mem_list,list);
break;
}
}
pthread_mutex_unlock(&THR_LOCK_malloc);
if (element)
my_free((uchar*) element,MYF(0));
free(ptr); /* Free even if not locked */
}
#endif /* HAVE_MLOCK */
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