mirror of
https://github.com/MariaDB/server.git
synced 2025-03-07 11:43:08 +01:00
71 lines
1.6 KiB
C
71 lines
1.6 KiB
C
/*-
|
|
* See the file LICENSE for redistribution information.
|
|
*
|
|
* Copyright (c) 1997-2005
|
|
* Sleepycat Software. All rights reserved.
|
|
*
|
|
* $Id: os_flock.c,v 1.6 2005/06/16 20:23:28 bostic Exp $
|
|
*/
|
|
|
|
#include "db_config.h"
|
|
|
|
#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;
|
|
{
|
|
int ret;
|
|
DWORD low, high;
|
|
OVERLAPPED over;
|
|
|
|
DB_ASSERT(F_ISSET(fhp, DB_FH_OPENED) &&
|
|
fhp->handle != INVALID_HANDLE_VALUE);
|
|
|
|
/*
|
|
* Windows file locking interferes with read/write operations, so we
|
|
* map the ranges to an area past the end of the file.
|
|
*/
|
|
DB_ASSERT(offset < (u_int64_t)INT64_MAX);
|
|
offset = UINT64_MAX - offset;
|
|
low = (DWORD)offset;
|
|
high = (DWORD)(offset >> 32);
|
|
|
|
if (acquire) {
|
|
if (nowait)
|
|
RETRY_CHK_EINTR_ONLY(
|
|
!LockFile(fhp->handle, low, high, 1, 0), ret);
|
|
else if (__os_is_winnt()) {
|
|
memset(&over, 0, sizeof over);
|
|
over.Offset = low;
|
|
over.OffsetHigh = high;
|
|
RETRY_CHK_EINTR_ONLY(
|
|
!LockFileEx(fhp->handle, LOCKFILE_EXCLUSIVE_LOCK,
|
|
0, 1, 0, &over),
|
|
ret);
|
|
} else {
|
|
/* Windows 9x/ME doesn't support a blocking call. */
|
|
for (;;) {
|
|
RETRY_CHK_EINTR_ONLY(
|
|
!LockFile(fhp->handle, low, high, 1, 0),
|
|
ret);
|
|
if (ret != EAGAIN)
|
|
break;
|
|
__os_sleep(dbenv, 1, 0);
|
|
}
|
|
}
|
|
} else
|
|
RETRY_CHK_EINTR_ONLY(
|
|
!UnlockFile(fhp->handle, low, high, 1, 0), ret);
|
|
|
|
return (ret);
|
|
}
|