ac89bb064a
All OS and IO operations should be moved out, leaving only some misc portable pure functions. This is useful to avoid copious CPP when doing things like Windows and Emscripten ports. Newly exposed functions to break cycles: - `restoreSignals` - `updateWindowSize`
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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