+extern boost::filesystem::path shared_path ();
+extern FILE * fopen_boost (boost::filesystem::path, std::string);
+extern int dcpomatic_fseek (FILE *, int64_t, int);
+extern void start_batch_converter (boost::filesystem::path dcpomatic);
+extern int thread_id ();
+
+/** @class Waker
+ * @brief A class which tries to keep the computer awake on various operating systems.
+ *
+ * Create a Waker to prevent sleep, and call ::nudge every so often (every minute or so).
+ * Destroy the Waker to allow sleep again.
+ */
+class Waker
+{
+public:
+ Waker ();
+ ~Waker ();
+
+ void nudge ();
+
+private:
+#ifdef DCPOMATIC_OSX
+ IOPMAssertionID _assertion_id;
+#endif
+};
+
+#endif