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/* Copyright 2000-2005 The Apache Software Foundation or its licensors, as
* applicable.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "apr_arch_file_io.h"
APR_DECLARE(apr_status_t) apr_file_lock(apr_file_t *thefile, int type)
{
#ifdef _WIN32_WCE
/* The File locking is unsuported on WCE */
return APR_ENOTIMPL;
#else
const DWORD len = 0xffffffff;
DWORD flags;
flags = ((type & APR_FLOCK_NONBLOCK) ? LOCKFILE_FAIL_IMMEDIATELY : 0)
+ (((type & APR_FLOCK_TYPEMASK) == APR_FLOCK_SHARED)
? 0 : LOCKFILE_EXCLUSIVE_LOCK);
if (apr_os_level >= APR_WIN_NT) {
/* Syntax is correct, len is passed for LengthLow and LengthHigh*/
OVERLAPPED offset;
memset (&offset, 0, sizeof(offset));
if (!LockFileEx(thefile->filehand, flags, 0, len, len, &offset))
return apr_get_os_error();
}
else {
/* On Win9x, LockFile() never blocks. Hack in a crufty poll.
*
* Note that this hack exposes threads to being unserviced forever,
* in the situation that the given lock has low availability.
* When implemented in the kernel, LockFile will typically use
* FIFO or round robin distribution to ensure all threads get
* one crack at the lock; but in this case we can't emulate that.
*
* However Win9x are barely maintainable anyways, if the user does
* choose to build to them, this is the best we can do.
*/
while (!LockFile(thefile->filehand, 0, 0, len, 0)) {
DWORD err = GetLastError();
if ((err == ERROR_LOCK_VIOLATION) && !(type & APR_FLOCK_NONBLOCK))
{
Sleep(500); /* pause for a half second */
continue; /* ... and then poll again */
}
return APR_FROM_OS_ERROR(err);
}
}
return APR_SUCCESS;
#endif /* !defined(_WIN32_WCE) */
}
APR_DECLARE(apr_status_t) apr_file_unlock(apr_file_t *thefile)
{
#ifdef _WIN32_WCE
return APR_ENOTIMPL;
#else
DWORD len = 0xffffffff;
if (apr_os_level >= APR_WIN_NT) {
/* Syntax is correct, len is passed for LengthLow and LengthHigh*/
OVERLAPPED offset;
memset (&offset, 0, sizeof(offset));
if (!UnlockFileEx(thefile->filehand, 0, len, len, &offset))
return apr_get_os_error();
}
else {
if (!UnlockFile(thefile->filehand, 0, 0, len, 0))
return apr_get_os_error();
}
return APR_SUCCESS;
#endif /* !defined(_WIN32_WCE) */
}
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