1 /* 2 * libjingle 3 * Copyright 2009, Google Inc. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright notice, 9 * this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include "talk/base/filelock.h" 29 30 #include "talk/base/fileutils.h" 31 #include "talk/base/logging.h" 32 #include "talk/base/pathutils.h" 33 #include "talk/base/stream.h" 34 35 namespace talk_base { 36 37 FileLock::FileLock(const std::string& path, FileStream* file) 38 : path_(path), file_(file) { 39 } 40 41 FileLock::~FileLock() { 42 MaybeUnlock(); 43 } 44 45 void FileLock::Unlock() { 46 LOG_F(LS_INFO); 47 MaybeUnlock(); 48 } 49 50 void FileLock::MaybeUnlock() { 51 if (file_) { 52 LOG(LS_INFO) << "Unlocking:" << path_; 53 file_->Close(); 54 Filesystem::DeleteFile(path_); 55 file_.reset(); 56 } 57 } 58 59 FileLock* FileLock::TryLock(const std::string& path) { 60 FileStream* stream = new FileStream(); 61 bool ok = false; 62 #ifdef WIN32 63 // Open and lock in a single operation. 64 ok = stream->OpenShare(path, "a", _SH_DENYRW, NULL); 65 #else // Linux and OSX 66 ok = stream->Open(path, "a", NULL) && stream->TryLock(); 67 #endif 68 if (ok) { 69 return new FileLock(path, stream); 70 } else { 71 // Something failed, either we didn't succeed to open the 72 // file or we failed to lock it. Anyway remove the heap 73 // allocated object and then return NULL to indicate failure. 74 delete stream; 75 return NULL; 76 } 77 } 78 79 } // namespace talk_base 80
