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/* Copyright (C) 2000-2003 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 */
#if defined(__NETWARE__)
#include "../mysys/my_lock.c"
#else
#undef MAP_TO_USE_RAID /* Avoid RAID mappings */
#include <my_global.h>
#include <my_sys.h>
#include <mysys_err.h>
#include <my_pthread.h>
#include <thr_alarm.h>
#include <errno.h>
/**
@breif Lock a part of a file
@note
This works like mysys/my_lock.c, with the exception that this function
uses the thr_alarm() to break long lock statements.
(mysys can't use thr_alarm() as by default the alarm handling doesn't
exists)
*/
int my_lock(File fd,int locktype,my_off_t start,my_off_t length,myf MyFlags)
{
thr_alarm_t alarmed;
ALARM alarm_buff;
uint wait_for_alarm;
struct flock m_lock;
DBUG_ENTER("my_lock");
DBUG_PRINT("my",("Fd: %d Op: %d start: %ld Length: %ld MyFlags: %d",
fd,locktype,(ulong) start,(ulong) length,MyFlags));
if (my_disable_locking && ! (MyFlags & MY_FORCE_LOCK))
DBUG_RETURN(0); /* purecov: inspected */
m_lock.l_type=(short) locktype;
m_lock.l_whence=0L;
m_lock.l_start=(long) start;
m_lock.l_len=(long) length;
if (fcntl(fd,F_SETLK,&m_lock) != -1) /* Check if we can lock */
DBUG_RETURN(0); /* Ok, file locked */
if (!(MyFlags & MY_NO_WAIT))
{
wait_for_alarm= (MyFlags & MY_SHORT_WAIT ? MY_HOW_OFTEN_TO_ALARM :
(uint) 12*60*60);
DBUG_PRINT("info",("Was locked, trying with alarm"));
if (!thr_alarm(&alarmed,wait_for_alarm,&alarm_buff))
{
int value;
while ((value=fcntl(fd,F_SETLKW,&m_lock)) && !thr_got_alarm(&alarmed) &&
errno == EINTR) ;
thr_end_alarm(&alarmed);
if (value != -1)
DBUG_RETURN(0);
}
else
{
errno=EINTR;
}
}
if (errno == EINTR || errno == EACCES)
my_errno=EAGAIN; /* Easier to check for this */
else
my_errno=errno;
if (MyFlags & MY_WME)
{
if (locktype == F_UNLCK)
my_error(EE_CANTUNLOCK,MYF(ME_BELL+ME_WAITTANG),errno);
else
my_error(EE_CANTLOCK,MYF(ME_BELL+ME_WAITTANG),errno);
}
DBUG_PRINT("error",("errno: %d",errno));
DBUG_RETURN(-1);
}
#endif
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