e349f2c0a3
POSIX file locks are essentially incompatible with multithreading. BSD locks have much saner semantics. We need this now that there can be multiple concurrent LocalStore::buildPaths() invocations.
39 lines
902 B
C++
39 lines
902 B
C++
#pragma once
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#include "util.hh"
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namespace nix {
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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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AutoCloseFD openLockFile(const Path & path, bool create);
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/* Delete an open lock file. */
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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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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 string & waitMsg = "");
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bool lockPaths(const PathSet & _paths,
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const 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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}
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