v1.4.4

source/core/StarLockFile.hpp

@@ -0,0 +1,42 @@
+#ifndef STAR_LOCK_FILE_HPP
+#define STAR_LOCK_FILE_HPP
+
+#include "StarMaybe.hpp"
+#include "StarString.hpp"
+
+namespace Star {
+
+class LockFile {
+public:
+  // Convenience function, tries to acquire a lock, and if succesfull returns an
+  // already locked
+  // LockFile.
+  static Maybe<LockFile> acquireLock(String const& filename, int64_t lockTimeout = 1000);
+
+  LockFile(String const& filename);
+  LockFile(LockFile&& lockFile);
+  // Automatically unlocks.
+  ~LockFile();
+
+  LockFile(LockFile const&) = delete;
+  LockFile& operator=(LockFile const&) = delete;
+
+  LockFile& operator=(LockFile&& lockFile);
+
+  // Wait at most timeout time to acquire the file lock, and return true if the
+  // lock was acquired.  If timeout is negative, wait forever.
+  bool lock(int64_t timeout = 0);
+  void unlock();
+
+  bool isLocked() const;
+
+private:
+  static int64_t const MaximumSleepMillis = 25;
+
+  String m_filename;
+  shared_ptr<void> m_handle;
+};
+
+}
+
+#endif