mirror of
https://github.com/MariaDB/server.git
synced 2025-01-20 14:02:32 +01:00
56 lines
1.1 KiB
C
56 lines
1.1 KiB
C
/*-
|
|
* See the file LICENSE for redistribution information.
|
|
*
|
|
* Copyright (c) 1997-2005
|
|
* Sleepycat Software. All rights reserved.
|
|
*
|
|
* $Id: os_flock.c,v 12.4 2005/06/20 14:59:01 bostic Exp $
|
|
*/
|
|
|
|
#include "db_config.h"
|
|
|
|
#ifndef NO_SYSTEM_INCLUDES
|
|
#include <sys/types.h>
|
|
|
|
#include <fcntl.h>
|
|
#include <string.h>
|
|
#endif
|
|
|
|
#include "db_int.h"
|
|
|
|
/*
|
|
* __os_fdlock --
|
|
* Acquire/release a lock on a byte in a file.
|
|
*
|
|
* PUBLIC: int __os_fdlock __P((DB_ENV *, DB_FH *, off_t, int, int));
|
|
*/
|
|
int
|
|
__os_fdlock(dbenv, fhp, offset, acquire, nowait)
|
|
DB_ENV *dbenv;
|
|
DB_FH *fhp;
|
|
int acquire, nowait;
|
|
off_t offset;
|
|
{
|
|
struct flock fl;
|
|
int ret;
|
|
|
|
DB_ASSERT(F_ISSET(fhp, DB_FH_OPENED) && fhp->fd != -1);
|
|
|
|
#ifdef HAVE_FCNTL
|
|
fl.l_start = offset;
|
|
fl.l_len = 1;
|
|
fl.l_type = acquire ? F_WRLCK : F_UNLCK;
|
|
fl.l_whence = SEEK_SET;
|
|
|
|
RETRY_CHK_EINTR_ONLY(
|
|
(fcntl(fhp->fd, nowait ? F_SETLK : F_SETLKW, &fl)), ret);
|
|
|
|
if (ret != 0 && ret != EACCES && ret != EAGAIN)
|
|
__db_err(dbenv, "fcntl: %s", strerror(ret));
|
|
return (ret);
|
|
#else
|
|
__db_err(dbenv,
|
|
"advisory file locking unavailable: %s", strerror(DB_OPNOTSUP));
|
|
return (DB_OPNOTSUP);
|
|
#endif
|
|
}
|