guix/src/libstore/pathlocks.hh

51 lines
1.1 KiB
C++

#ifndef __PATHLOCKS_H
#define __PATHLOCKS_H
#include "types.hh"
namespace nix {
/* Open (possibly create) a lock file and return the file descriptor.
-1 is returned if create is false and the lock could not be opened
because it doesn't exist. Any other error throws an exception. */
int openLockFile(const Path & path, bool create);
/* Delete an open lock file. Both must be called to be fully portable
between Unix and Windows. */
void deleteLockFilePreClose(const Path & path, int fd);
void deleteLockFilePostClose(const Path & path);
enum LockType { ltRead, ltWrite, ltNone };
bool lockFile(int fd, LockType lockType, bool wait);
class PathLocks
{
private:
typedef std::pair<int, Path> FDPair;
list<FDPair> fds;
bool deletePaths;
public:
PathLocks();
PathLocks(const PathSet & paths,
const string & waitMsg = "");
void lockPaths(const PathSet & _paths,
const string & waitMsg = "");
~PathLocks();
void unlock();
void setDeletion(bool deletePaths);
};
bool pathIsLockedByMe(const Path & path);
}
#endif /* !__PATHLOCKS_H */