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-rw-r--r--nix/libstore/pathlocks.hh45
1 files changed, 45 insertions, 0 deletions
diff --git a/nix/libstore/pathlocks.hh b/nix/libstore/pathlocks.hh
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+++ b/nix/libstore/pathlocks.hh
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+#pragma once
+
+#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. */
+void deleteLockFile(const Path & path, int fd);
+
+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 = "");
+ bool lockPaths(const PathSet & _paths,
+ const string & waitMsg = "",
+ bool wait = true);
+ ~PathLocks();
+ void unlock();
+ void setDeletion(bool deletePaths);
+};
+
+
+bool pathIsLockedByMe(const Path & path);
+
+
+}