1 /* GStreamer
2 * Copyright (C) 2017 Matthew Waters <matthew@centricular.com>
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Library General Public License for more details.
13 *
14 * You should have received a copy of the GNU Library General Public
15 * License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
17 * Boston, MA 02110-1301, USA.
18 */
19
20 #ifndef __GST_PROMISE_H__
21 #define __GST_PROMISE_H__
22
23 #include <gst/gst.h>
24
25 G_BEGIN_DECLS
26
27 GST_API
28 GType gst_promise_get_type(void);
29 #define GST_TYPE_PROMISE (gst_promise_get_type())
30 #define GST_PROMISE(obj) ((GstPromise *) obj)
31
32 typedef struct _GstPromise GstPromise;
33
34 /**
35 * GstPromiseResult:
36 * @GST_PROMISE_RESULT_PENDING: Initial state. Waiting for transition to any
37 * other state.
38 * @GST_PROMISE_RESULT_INTERRUPTED: Interrupted by the consumer as it doesn't
39 * want the value anymore.
40 * @GST_PROMISE_RESULT_REPLIED: A producer marked a reply
41 * @GST_PROMISE_RESULT_EXPIRED: The promise expired (the carrying object
42 * lost all refs) and the promise will never be fulfilled.
43 *
44 * The result of a #GstPromise
45 *
46 * Since: 1.14
47 */
48 typedef enum
49 {
50 GST_PROMISE_RESULT_PENDING,
51 GST_PROMISE_RESULT_INTERRUPTED,
52 GST_PROMISE_RESULT_REPLIED,
53 GST_PROMISE_RESULT_EXPIRED,
54 } GstPromiseResult;
55
56 /**
57 * GstPromiseChangeFunc:
58 * @promise: a #GstPromise
59 * @user_data: (closure): user data
60 *
61 * Since: 1.14
62 */
63 typedef void (*GstPromiseChangeFunc) (GstPromise * promise, gpointer user_data);
64
65 /**
66 * GstPromise:
67 * @parent: parent #GstMiniObject
68 *
69 * Since: 1.14
70 */
71 struct _GstPromise
72 {
73 GstMiniObject parent;
74 };
75
76 GST_API
77 GstPromise * gst_promise_new (void);
78 GST_API
79 GstPromise * gst_promise_new_with_change_func (GstPromiseChangeFunc func,
80 gpointer user_data,
81 GDestroyNotify notify);
82
83 GST_API
84 GstPromiseResult gst_promise_wait (GstPromise * promise);
85 GST_API
86 void gst_promise_reply (GstPromise * promise,
87 GstStructure * s);
88 GST_API
89 void gst_promise_interrupt (GstPromise * promise);
90 GST_API
91 void gst_promise_expire (GstPromise * promise);
92
93 GST_API
94 const GstStructure * gst_promise_get_reply (GstPromise * promise);
95
96 /**
97 * gst_promise_ref:
98 * @promise: a #GstPromise.
99 *
100 * Increases the refcount of the given @promise by one.
101 *
102 * Returns: (transfer full): @promise
103 *
104 * Since: 1.14
105 */
106 static inline GstPromise *
gst_promise_ref(GstPromise * promise)107 gst_promise_ref (GstPromise * promise)
108 {
109 return (GstPromise *) gst_mini_object_ref (GST_MINI_OBJECT_CAST (promise));
110 }
111
112 /**
113 * gst_promise_unref:
114 * @promise: (transfer full): a #GstPromise.
115 *
116 * Decreases the refcount of the promise. If the refcount reaches 0, the
117 * promise will be freed.
118 *
119 * Since: 1.14
120 */
121 static inline void
gst_promise_unref(GstPromise * promise)122 gst_promise_unref (GstPromise * promise)
123 {
124 gst_mini_object_unref (GST_MINI_OBJECT_CAST (promise));
125 }
126
127 #ifdef G_DEFINE_AUTOPTR_CLEANUP_FUNC
128 G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstPromise, gst_promise_unref)
129 #endif
130
131 G_END_DECLS
132
133 #endif /* __GST_PROMISE_H__ */
134