mirror of
https://github.com/MariaDB/server.git
synced 2025-01-17 20:42:30 +01:00
119 lines
3.4 KiB
C
119 lines
3.4 KiB
C
/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
|
|
|
|
This library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Library General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2 of the License, or (at your option) any later version.
|
|
|
|
This library 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
|
|
Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public
|
|
License along with this library; if not, write to the Free
|
|
Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
|
|
MA 02111-1307, USA */
|
|
|
|
#include "mysys_priv.h"
|
|
#include "mysys_err.h"
|
|
#include <errno.h>
|
|
#undef MY_HOW_OFTEN_TO_ALARM
|
|
#define MY_HOW_OFTEN_TO_ALARM ((int) my_time_to_wait_for_lock)
|
|
#ifdef NO_ALARM_LOOP
|
|
#undef NO_ALARM_LOOP
|
|
#endif
|
|
#include <my_alarm.h>
|
|
#ifdef __WIN__
|
|
#include <sys/locking.h>
|
|
#endif
|
|
#ifdef __EMX__
|
|
#define INCL_BASE
|
|
#define INCL_NOPMAPI
|
|
#include <os2emx.h>
|
|
#endif
|
|
|
|
/* Lock a part of a file */
|
|
|
|
int my_lock(File fd, int locktype, my_off_t start, my_off_t length,
|
|
myf MyFlags)
|
|
{
|
|
#ifdef HAVE_FCNTL
|
|
int value;
|
|
ALARM_VARIABLES;
|
|
#endif
|
|
DBUG_ENTER("my_lock");
|
|
DBUG_PRINT("my",("Fd: %d Op: %d start: %ld Length: %ld MyFlags: %d",
|
|
fd,locktype,(long) start,(long) length,MyFlags));
|
|
#ifdef VMS
|
|
DBUG_RETURN(0);
|
|
#else
|
|
if (my_disable_locking)
|
|
DBUG_RETURN(0);
|
|
|
|
#if defined(__EMX__) || defined(OS2)
|
|
|
|
if (!_lock64( fd, locktype, start, length, MyFlags))
|
|
DBUG_RETURN(0);
|
|
|
|
#elif defined(HAVE_LOCKING)
|
|
/* Windows */
|
|
{
|
|
my_bool error;
|
|
pthread_mutex_lock(&my_file_info[fd].mutex);
|
|
if (MyFlags & MY_SEEK_NOT_DONE)
|
|
VOID(my_seek(fd,start,MY_SEEK_SET,MYF(MyFlags & ~MY_SEEK_NOT_DONE)));
|
|
error= locking(fd,locktype,(ulong) length) && errno != EINVAL;
|
|
pthread_mutex_unlock(&my_file_info[fd].mutex);
|
|
if (!error)
|
|
DBUG_RETURN(0);
|
|
}
|
|
#else
|
|
#if defined(HAVE_FCNTL)
|
|
{
|
|
struct flock lock;
|
|
lock.l_type= (short) locktype;
|
|
lock.l_whence=0L;
|
|
lock.l_start=(long) start;
|
|
lock.l_len=(long) length;
|
|
if (MyFlags & MY_DONT_WAIT)
|
|
{
|
|
if (fcntl(fd,F_SETLK,&lock) != -1) /* Check if we can lock */
|
|
DBUG_RETURN(0); /* Ok, file locked */
|
|
DBUG_PRINT("info",("Was locked, trying with alarm"));
|
|
ALARM_INIT;
|
|
while ((value=fcntl(fd,F_SETLKW,&lock)) && ! ALARM_TEST &&
|
|
errno == EINTR)
|
|
{ /* Setup again so we don`t miss it */
|
|
ALARM_REINIT;
|
|
}
|
|
ALARM_END;
|
|
if (value != -1)
|
|
DBUG_RETURN(0);
|
|
if (errno == EINTR)
|
|
errno=EAGAIN;
|
|
}
|
|
else if (fcntl(fd,F_SETLKW,&lock) != -1) /* Wait until a lock */
|
|
DBUG_RETURN(0);
|
|
}
|
|
#else
|
|
if (MyFlags & MY_SEEK_NOT_DONE)
|
|
VOID(my_seek(fd,start,MY_SEEK_SET,MYF(MyFlags & ~MY_SEEK_NOT_DONE)));
|
|
if (lockf(fd,locktype,length) != -1)
|
|
DBUG_RETURN(0);
|
|
#endif /* HAVE_FCNTL */
|
|
#endif /* HAVE_LOCKING */
|
|
|
|
/* We got an error. We don't want EACCES errors */
|
|
my_errno=(errno == EACCES) ? EAGAIN : errno ? errno : -1;
|
|
if (MyFlags & MY_WME)
|
|
{
|
|
if (locktype == F_UNLCK)
|
|
my_error(EE_CANTUNLOCK,MYF(ME_BELL+ME_WAITTANG),my_errno);
|
|
else
|
|
my_error(EE_CANTLOCK,MYF(ME_BELL+ME_WAITTANG),my_errno);
|
|
}
|
|
DBUG_PRINT("error",("my_errno: %d (%d)",my_errno,errno));
|
|
DBUG_RETURN(-1);
|
|
#endif /* ! VMS */
|
|
} /* my_lock */
|