58 lines
1.1 KiB
C++
58 lines
1.1 KiB
C++
#pragma once
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///@file
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#include "file-descriptor.hh"
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namespace nix {
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/**
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* Open (possibly create) a lock file and return the file descriptor.
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* -1 is returned if create is false and the lock could not be opened
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* because it doesn't exist. Any other error throws an exception.
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*/
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AutoCloseFD openLockFile(const Path & path, bool create);
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/**
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* Delete an open lock file.
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*/
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void deleteLockFile(const Path & path, int fd);
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enum LockType { ltRead, ltWrite, ltNone };
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bool lockFile(int fd, LockType lockType, bool wait);
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class PathLocks
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{
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private:
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typedef std::pair<int, Path> FDPair;
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std::list<FDPair> fds;
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bool deletePaths;
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public:
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PathLocks();
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PathLocks(const PathSet & paths,
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const std::string & waitMsg = "");
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bool lockPaths(const PathSet & _paths,
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const std::string & waitMsg = "",
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bool wait = true);
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~PathLocks();
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void unlock();
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void setDeletion(bool deletePaths);
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};
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struct FdLock
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{
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int fd;
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bool acquired = false;
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FdLock(int fd, LockType lockType, bool wait, std::string_view waitMsg);
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~FdLock()
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{
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if (acquired)
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lockFile(fd, ltNone, false);
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}
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};
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}
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