--- /dev/null
+/*
+ * Amanda, The Advanced Maryland Automatic Network Disk Archiver
+ * Copyright (c) 1999 University of Maryland at College Park
+ * All Rights Reserved.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation, and that the name of U.M. not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission. U.M. makes no representations about the
+ * suitability of this software for any purpose. It is provided "as is"
+ * without express or implied warranty.
+ *
+ * U.M. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL U.M.
+ * BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Authors: the Amanda Development Team. Its members are listed in a
+ * file named AUTHORS, in the root directory of this distribution.
+ */
+/*
+ * $Id: event.h,v 1.6 2005/11/30 22:35:11 martinea Exp $
+ */
+#ifndef EVENT_H
+#define EVENT_H
+
+/*
+ * These functions define a generic event interface. One can register a
+ * function vector and the type of events to act on, and the event handler
+ * will dispatch as necessary.
+ */
+
+/*
+ * An opaque handle returned by the registry functions that can be
+ * used to unregister an event in the future.
+ */
+struct event_handle;
+typedef struct event_handle event_handle_t;
+
+/*
+ * The 'id' of the event. The meaning of this is dependant on the type
+ * of event we are registering. This is hopefully wide enough that
+ * callers can cast pointers to it and keep the value untruncated and
+ * unique.
+ */
+typedef unsigned long event_id_t;
+
+/*
+ * The types of events we can register.
+ */
+typedef enum {
+ EV_READFD, /* file descriptor is ready for reading */
+ EV_WRITEFD, /* file descriptor is ready for writing */
+ EV_SIG, /* signal has fired */
+ EV_TIME, /* n seconds have elapsed */
+ EV_WAIT, /* event_wakeup() was called with this id */
+ EV_DEAD /* internal use only */
+} event_type_t;
+
+/*
+ * The function signature for functions that get called when an event
+ * fires.
+ */
+typedef void (*event_fn_t) P((void *));
+
+/*
+ * Register an event handler.
+ *
+ * For readfd and writefd events, the first arg is the file descriptor.
+ * There can be multiple callers firing on the same file descriptor.
+ *
+ * For signal events, the first arg is the signal number as defined in
+ * <signal.h>. There can only be one signal handler. (do we need more?)
+ *
+ * For time events, the first arg is the interval in seconds between
+ * pulses. There can be multiple time events, of course. Don't
+ * count on the time events being too accurate. They depend on the
+ * caller calling event_loop() often enough.
+ */
+event_handle_t *event_register P((event_id_t, event_type_t,
+ event_fn_t, void *));
+
+/*
+ * Release an event handler.
+ */
+void event_release P((event_handle_t *));
+
+/*
+ * Wake up all EV_WAIT events waiting on a specific id
+ */
+int event_wakeup P((event_id_t));
+
+/*
+ * Process events. If the argument is nonzero, then the loop does
+ * not block.
+ */
+void event_loop P((const int));
+
+#endif /* EVENT_H */