xref: /freebsd/contrib/ntp/sntp/libevent/defer-internal.h (revision 783d3ff6d7fae619db8a7990b8a6387de0c677b5)
1 /*
2  * Copyright (c) 2009-2012 Niels Provos and Nick Mathewson
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  * 3. The name of the author may not be used to endorse or promote products
13  *    derived from this software without specific prior written permission.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 #ifndef DEFER_INTERNAL_H_INCLUDED_
27 #define DEFER_INTERNAL_H_INCLUDED_
28 
29 #ifdef __cplusplus
30 extern "C" {
31 #endif
32 
33 #include "event2/event-config.h"
34 #include "evconfig-private.h"
35 
36 #include <sys/queue.h>
37 
38 struct event_callback;
39 typedef void (*deferred_cb_fn)(struct event_callback *, void *);
40 
41 /**
42    Initialize an empty, non-pending event_callback.
43 
44    @param deferred The struct event_callback structure to initialize.
45    @param priority The priority that the callback should run at.
46    @param cb The function to run when the struct event_callback executes.
47    @param arg The function's second argument.
48  */
49 EVENT2_EXPORT_SYMBOL
50 void event_deferred_cb_init_(struct event_callback *, ev_uint8_t, deferred_cb_fn, void *);
51 /**
52    Change the priority of a non-pending event_callback.
53  */
54 void event_deferred_cb_set_priority_(struct event_callback *, ev_uint8_t);
55 /**
56    Cancel a struct event_callback if it is currently scheduled in an event_base.
57  */
58 EVENT2_EXPORT_SYMBOL
59 void event_deferred_cb_cancel_(struct event_base *, struct event_callback *);
60 /**
61    Activate a struct event_callback if it is not currently scheduled in an event_base.
62 
63    Return true if it was not previously scheduled.
64  */
65 EVENT2_EXPORT_SYMBOL
66 int event_deferred_cb_schedule_(struct event_base *, struct event_callback *);
67 
68 #ifdef __cplusplus
69 }
70 #endif
71 
72 #endif /* EVENT_INTERNAL_H_INCLUDED_ */
73 
74