1/* Licensed to the Apache Software Foundation (ASF) under one or more 2 * contributor license agreements. See the NOTICE file distributed with 3 * this work for additional information regarding copyright ownership. 4 * The ASF licenses this file to You under the Apache License, Version 2.0 5 * (the "License"); you may not use this file except in compliance with 6 * the License. You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#include "apr_arch_file_io.h" 18 19APR_DECLARE(apr_status_t) apr_file_lock(apr_file_t *thefile, int type) 20{ 21#ifdef _WIN32_WCE 22 /* The File locking is unsuported on WCE */ 23 return APR_ENOTIMPL; 24#else 25 const DWORD len = 0xffffffff; 26 DWORD flags; 27 28 flags = ((type & APR_FLOCK_NONBLOCK) ? LOCKFILE_FAIL_IMMEDIATELY : 0) 29 + (((type & APR_FLOCK_TYPEMASK) == APR_FLOCK_SHARED) 30 ? 0 : LOCKFILE_EXCLUSIVE_LOCK); 31 if (apr_os_level >= APR_WIN_NT) { 32 /* Syntax is correct, len is passed for LengthLow and LengthHigh*/ 33 OVERLAPPED offset; 34 memset (&offset, 0, sizeof(offset)); 35 if (!LockFileEx(thefile->filehand, flags, 0, len, len, &offset)) 36 return apr_get_os_error(); 37 } 38 else { 39 /* On Win9x, LockFile() never blocks. Hack in a crufty poll. 40 * 41 * Note that this hack exposes threads to being unserviced forever, 42 * in the situation that the given lock has low availability. 43 * When implemented in the kernel, LockFile will typically use 44 * FIFO or round robin distribution to ensure all threads get 45 * one crack at the lock; but in this case we can't emulate that. 46 * 47 * However Win9x are barely maintainable anyways, if the user does 48 * choose to build to them, this is the best we can do. 49 */ 50 while (!LockFile(thefile->filehand, 0, 0, len, 0)) { 51 DWORD err = GetLastError(); 52 if ((err == ERROR_LOCK_VIOLATION) && !(type & APR_FLOCK_NONBLOCK)) 53 { 54 Sleep(500); /* pause for a half second */ 55 continue; /* ... and then poll again */ 56 } 57 return APR_FROM_OS_ERROR(err); 58 } 59 } 60 61 return APR_SUCCESS; 62#endif /* !defined(_WIN32_WCE) */ 63} 64 65APR_DECLARE(apr_status_t) apr_file_unlock(apr_file_t *thefile) 66{ 67#ifdef _WIN32_WCE 68 return APR_ENOTIMPL; 69#else 70 DWORD len = 0xffffffff; 71 72 if (apr_os_level >= APR_WIN_NT) { 73 /* Syntax is correct, len is passed for LengthLow and LengthHigh*/ 74 OVERLAPPED offset; 75 memset (&offset, 0, sizeof(offset)); 76 if (!UnlockFileEx(thefile->filehand, 0, len, len, &offset)) 77 return apr_get_os_error(); 78 } 79 else { 80 if (!UnlockFile(thefile->filehand, 0, 0, len, 0)) 81 return apr_get_os_error(); 82 } 83 84 return APR_SUCCESS; 85#endif /* !defined(_WIN32_WCE) */ 86} 87