OpenMPI  0.1.1
defer-internal.h
1 /*
2  * Copyright (c) 2009-2010 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_
27 #define _DEFER_INTERNAL_H_
28 
29 #ifdef __cplusplus
30 extern "C" {
31 #endif
32 
33 #include "event2/event-config.h"
34 #include <sys/queue.h>
35 
36 struct deferred_cb;
37 
38 typedef void (*deferred_cb_fn)(struct deferred_cb *, void *);
39 
40 /** A deferred_cb is a callback that can be scheduled to run as part of
41  * an event_base's event_loop, rather than running immediately. */
42 struct deferred_cb {
43  /** Links to the adjacent active (pending) deferred_cb objects. */
44  TAILQ_ENTRY (deferred_cb) cb_next;
45  /** True iff this deferred_cb is pending in an event_base. */
46  unsigned queued : 1;
47  /** The function to execute when the callback runs. */
48  deferred_cb_fn cb;
49  /** The function's second argument. */
50  void *arg;
51 };
52 
53 /** A deferred_cb_queue is a list of deferred_cb that we can add to and run. */
55  /** Lock used to protect the queue. */
56  void *lock;
57 
58  /** How many entries are in the queue? */
60 
61  /** Function called when adding to the queue from another thread. */
62  void (*notify_fn)(struct deferred_cb_queue *, void *);
63  void *notify_arg;
64 
65  /** Deferred callback management: a list of deferred callbacks to
66  * run active the active events. */
67  TAILQ_HEAD (deferred_cb_list, deferred_cb) deferred_cb_list;
68 };
69 
70 /**
71  Initialize an empty, non-pending deferred_cb.
72 
73  @param deferred The deferred_cb structure to initialize.
74  @param cb The function to run when the deferred_cb executes.
75  @param arg The function's second argument.
76  */
77 void event_deferred_cb_init(struct deferred_cb *, deferred_cb_fn, void *);
78 /**
79  Cancel a deferred_cb if it is currently scheduled in an event_base.
80  */
81 void event_deferred_cb_cancel(struct deferred_cb_queue *, struct deferred_cb *);
82 /**
83  Activate a deferred_cb if it is not currently scheduled in an event_base.
84  */
85 void event_deferred_cb_schedule(struct deferred_cb_queue *, struct deferred_cb *);
86 
87 #define LOCK_DEFERRED_QUEUE(q) \
88  EVLOCK_LOCK((q)->lock, 0)
89 #define UNLOCK_DEFERRED_QUEUE(q) \
90  EVLOCK_UNLOCK((q)->lock, 0)
91 
92 #ifdef __cplusplus
93 }
94 #endif
95 
96 void event_deferred_cb_queue_init(struct deferred_cb_queue *);
97 struct deferred_cb_queue *event_base_get_deferred_cb_queue(struct event_base *);
98 
99 #endif /* _EVENT_INTERNAL_H_ */
100 
unsigned queued
True iff this deferred_cb is pending in an event_base.
Definition: defer-internal.h:46
deferred_cb_fn cb
The function to execute when the callback runs.
Definition: defer-internal.h:48
void(* notify_fn)(struct deferred_cb_queue *, void *)
Function called when adding to the queue from another thread.
Definition: defer-internal.h:62
TAILQ_ENTRY(deferred_cb) cb_next
Links to the adjacent active (pending) deferred_cb objects.
TAILQ_HEAD(deferred_cb_list, deferred_cb) deferred_cb_list
Deferred callback management: a list of deferred callbacks to run active the active events...
void * arg
The function's second argument.
Definition: defer-internal.h:50
A deferred_cb is a callback that can be scheduled to run as part of an event_base's event_loop...
Definition: defer-internal.h:42
int active_count
How many entries are in the queue?
Definition: defer-internal.h:59
Definition: event-internal.h:167
A deferred_cb_queue is a list of deferred_cb that we can add to and run.
Definition: defer-internal.h:54
void * lock
Lock used to protect the queue.
Definition: defer-internal.h:56