89 lines
2.2 KiB
C++
89 lines
2.2 KiB
C++
/*============================================================================
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CMake - Cross Platform Makefile Generator
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Copyright 2014 Ruslan Baratov
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Distributed under the OSI-approved BSD License (the "License");
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see accompanying file Copyright.txt for details.
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This software is distributed WITHOUT ANY WARRANTY; without even the
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implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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See the License for more information.
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============================================================================*/
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#include "cmFileLock.h"
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#include "cmSystemTools.h"
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#include <errno.h> // errno
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#include <fcntl.h>
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#include <stdio.h> // SEEK_SET
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#include <unistd.h>
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cmFileLock::cmFileLock()
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: File(-1)
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{
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}
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cmFileLockResult cmFileLock::Release()
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{
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if (this->Filename.empty()) {
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return cmFileLockResult::MakeOk();
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}
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const int lockResult = this->LockFile(F_SETLK, F_UNLCK);
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this->Filename = "";
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::close(this->File);
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this->File = -1;
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if (lockResult == 0) {
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return cmFileLockResult::MakeOk();
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}
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return cmFileLockResult::MakeSystem();
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}
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cmFileLockResult cmFileLock::OpenFile()
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{
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this->File = ::open(this->Filename.c_str(), O_RDWR);
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if (this->File == -1) {
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return cmFileLockResult::MakeSystem();
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}
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return cmFileLockResult::MakeOk();
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}
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cmFileLockResult cmFileLock::LockWithoutTimeout()
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{
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if (this->LockFile(F_SETLKW, F_WRLCK) == -1) {
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return cmFileLockResult::MakeSystem();
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}
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return cmFileLockResult::MakeOk();
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}
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cmFileLockResult cmFileLock::LockWithTimeout(unsigned long seconds)
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{
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while (true) {
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if (this->LockFile(F_SETLK, F_WRLCK) == -1) {
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if (errno != EACCES && errno != EAGAIN) {
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return cmFileLockResult::MakeSystem();
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}
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} else {
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return cmFileLockResult::MakeOk();
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}
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if (seconds == 0) {
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return cmFileLockResult::MakeTimeout();
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}
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--seconds;
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cmSystemTools::Delay(1000);
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}
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}
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int cmFileLock::LockFile(int cmd, int type)
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{
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struct ::flock lock;
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lock.l_start = 0;
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lock.l_len = 0; // lock all bytes
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lock.l_pid = 0; // unused (for F_GETLK only)
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lock.l_type = static_cast<short>(type); // exclusive lock
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lock.l_whence = SEEK_SET;
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return ::fcntl(this->File, cmd, &lock);
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}
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