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