#ifndef LIMONP_FILELOCK_HPP
|
#define LIMONP_FILELOCK_HPP
|
|
#include <unistd.h>
|
#include <stdlib.h>
|
#include <stdio.h>
|
#include <fcntl.h>
|
#include <errno.h>
|
#include <string>
|
#include <string.h>
|
#include <assert.h>
|
|
namespace limonp {
|
|
using std::string;
|
|
class FileLock {
|
public:
|
FileLock() : fd_(-1), ok_(true) {
|
}
|
~FileLock() {
|
if(fd_ > 0) {
|
Close();
|
}
|
}
|
void Open(const string& fname) {
|
assert(fd_ == -1);
|
fd_ = open(fname.c_str(), O_RDWR | O_CREAT, 0644);
|
if(fd_ < 0) {
|
ok_ = false;
|
err_ = strerror(errno);
|
}
|
}
|
void Close() {
|
::close(fd_);
|
}
|
void Lock() {
|
if(LockOrUnlock(fd_, true) < 0) {
|
ok_ = false;
|
err_ = strerror(errno);
|
}
|
}
|
void UnLock() {
|
if(LockOrUnlock(fd_, false) < 0) {
|
ok_ = false;
|
err_ = strerror(errno);
|
}
|
}
|
bool Ok() const {
|
return ok_;
|
}
|
string Error() const {
|
return err_;
|
}
|
private:
|
static int LockOrUnlock(int fd, bool lock) {
|
errno = 0;
|
struct flock f;
|
memset(&f, 0, sizeof(f));
|
f.l_type = (lock ? F_WRLCK : F_UNLCK);
|
f.l_whence = SEEK_SET;
|
f.l_start = 0;
|
f.l_len = 0; // Lock/unlock entire file
|
return fcntl(fd, F_SETLK, &f);
|
}
|
|
int fd_;
|
bool ok_;
|
string err_;
|
}; // class FileLock
|
|
}// namespace limonp
|
|
#endif // LIMONP_FILELOCK_HPP
|
