1 /* GStreamer
2 * Copyright (C) 2009 Wim Taymans <wim.taymans@gmail.com>
3 *
4 * gsttaskpool.c: Pool for streaming threads
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
15 *
16 * You should have received a copy of the GNU Library General Public
17 * License along with this library; if not, write to the
18 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
19 * Boston, MA 02110-1301, USA.
20 */
21
22 /**
23 * SECTION:gsttaskpool
24 * @title: GstTaskPool
25 * @short_description: Pool of GStreamer streaming threads
26 * @see_also: #GstTask, #GstPad
27 *
28 * This object provides an abstraction for creating threads. The default
29 * implementation uses a regular GThreadPool to start tasks.
30 *
31 * Subclasses can be made to create custom threads.
32 */
33
34 #include "gst_private.h"
35
36 #include "gstinfo.h"
37 #include "gsttaskpool.h"
38 #include "gsterror.h"
39
40 GST_DEBUG_CATEGORY_STATIC (taskpool_debug);
41 #define GST_CAT_DEFAULT (taskpool_debug)
42
43 #ifndef GST_DISABLE_GST_DEBUG
44 static void gst_task_pool_finalize (GObject * object);
45 #endif
46
47 #define _do_init \
48 { \
49 GST_DEBUG_CATEGORY_INIT (taskpool_debug, "taskpool", 0, "Thread pool"); \
50 }
51
52 G_DEFINE_TYPE_WITH_CODE (GstTaskPool, gst_task_pool, GST_TYPE_OBJECT, _do_init);
53
54 typedef struct
55 {
56 GstTaskPoolFunction func;
57 gpointer user_data;
58 } TaskData;
59
60 static void
default_func(TaskData * tdata,GstTaskPool * pool)61 default_func (TaskData * tdata, GstTaskPool * pool)
62 {
63 GstTaskPoolFunction func;
64 gpointer user_data;
65
66 func = tdata->func;
67 user_data = tdata->user_data;
68 g_slice_free (TaskData, tdata);
69
70 func (user_data);
71 }
72
73 static void
default_prepare(GstTaskPool * pool,GError ** error)74 default_prepare (GstTaskPool * pool, GError ** error)
75 {
76 GST_OBJECT_LOCK (pool);
77 pool->pool = g_thread_pool_new ((GFunc) default_func, pool, -1, FALSE, error);
78 GST_OBJECT_UNLOCK (pool);
79 }
80
81 static void
default_cleanup(GstTaskPool * pool)82 default_cleanup (GstTaskPool * pool)
83 {
84 GThreadPool *pool_;
85
86 GST_OBJECT_LOCK (pool);
87 pool_ = pool->pool;
88 pool->pool = NULL;
89 GST_OBJECT_UNLOCK (pool);
90
91 if (pool_) {
92 /* Shut down all the threads, we still process the ones scheduled
93 * because the unref happens in the thread function.
94 * Also wait for currently running ones to finish. */
95 g_thread_pool_free (pool_, FALSE, TRUE);
96 }
97 }
98
99 static gpointer
default_push(GstTaskPool * pool,GstTaskPoolFunction func,gpointer user_data,GError ** error)100 default_push (GstTaskPool * pool, GstTaskPoolFunction func,
101 gpointer user_data, GError ** error)
102 {
103 TaskData *tdata;
104
105 tdata = g_slice_new (TaskData);
106 tdata->func = func;
107 tdata->user_data = user_data;
108
109 GST_OBJECT_LOCK (pool);
110 if (pool->pool)
111 g_thread_pool_push (pool->pool, tdata, error);
112 else {
113 g_slice_free (TaskData, tdata);
114 g_set_error_literal (error, GST_CORE_ERROR, GST_CORE_ERROR_FAILED,
115 "No thread pool");
116
117 }
118 GST_OBJECT_UNLOCK (pool);
119
120 return NULL;
121 }
122
123 static void
default_join(GstTaskPool * pool,gpointer id)124 default_join (GstTaskPool * pool, gpointer id)
125 {
126 /* we do nothing here, we can't join from the pools */
127 }
128
129 static void
gst_task_pool_class_init(GstTaskPoolClass * klass)130 gst_task_pool_class_init (GstTaskPoolClass * klass)
131 {
132 GObjectClass *gobject_class;
133 GstTaskPoolClass *gsttaskpool_class;
134
135 gobject_class = (GObjectClass *) klass;
136 gsttaskpool_class = (GstTaskPoolClass *) klass;
137
138 #ifndef GST_DISABLE_GST_DEBUG
139 gobject_class->finalize = gst_task_pool_finalize;
140 #endif
141
142 gsttaskpool_class->prepare = default_prepare;
143 gsttaskpool_class->cleanup = default_cleanup;
144 gsttaskpool_class->push = default_push;
145 gsttaskpool_class->join = default_join;
146 }
147
148 static void
gst_task_pool_init(GstTaskPool * pool)149 gst_task_pool_init (GstTaskPool * pool)
150 {
151 }
152
153 #ifndef GST_DISABLE_GST_DEBUG
154 static void
gst_task_pool_finalize(GObject * object)155 gst_task_pool_finalize (GObject * object)
156 {
157 GST_DEBUG ("taskpool %p finalize", object);
158
159 G_OBJECT_CLASS (gst_task_pool_parent_class)->finalize (object);
160 }
161 #endif
162 /**
163 * gst_task_pool_new:
164 *
165 * Create a new default task pool. The default task pool will use a regular
166 * GThreadPool for threads.
167 *
168 * Returns: (transfer full): a new #GstTaskPool. gst_object_unref() after usage.
169 */
170 GstTaskPool *
gst_task_pool_new(void)171 gst_task_pool_new (void)
172 {
173 GstTaskPool *pool;
174
175 pool = g_object_new (GST_TYPE_TASK_POOL, NULL);
176
177 /* clear floating flag */
178 gst_object_ref_sink (pool);
179
180 return pool;
181 }
182
183 /**
184 * gst_task_pool_prepare:
185 * @pool: a #GstTaskPool
186 * @error: an error return location
187 *
188 * Prepare the taskpool for accepting gst_task_pool_push() operations.
189 *
190 * MT safe.
191 */
192 void
gst_task_pool_prepare(GstTaskPool * pool,GError ** error)193 gst_task_pool_prepare (GstTaskPool * pool, GError ** error)
194 {
195 GstTaskPoolClass *klass;
196
197 g_return_if_fail (GST_IS_TASK_POOL (pool));
198
199 klass = GST_TASK_POOL_GET_CLASS (pool);
200
201 if (klass->prepare)
202 klass->prepare (pool, error);
203 }
204
205 /**
206 * gst_task_pool_cleanup:
207 * @pool: a #GstTaskPool
208 *
209 * Wait for all tasks to be stopped. This is mainly used internally
210 * to ensure proper cleanup of internal data structures in test suites.
211 *
212 * MT safe.
213 */
214 void
gst_task_pool_cleanup(GstTaskPool * pool)215 gst_task_pool_cleanup (GstTaskPool * pool)
216 {
217 GstTaskPoolClass *klass;
218
219 g_return_if_fail (GST_IS_TASK_POOL (pool));
220
221 klass = GST_TASK_POOL_GET_CLASS (pool);
222
223 if (klass->cleanup)
224 klass->cleanup (pool);
225 }
226
227 /**
228 * gst_task_pool_push:
229 * @pool: a #GstTaskPool
230 * @func: (scope async): the function to call
231 * @user_data: (closure): data to pass to @func
232 * @error: return location for an error
233 *
234 * Start the execution of a new thread from @pool.
235 *
236 * Returns: (transfer none) (nullable): a pointer that should be used
237 * for the gst_task_pool_join function. This pointer can be %NULL, you
238 * must check @error to detect errors.
239 */
240 gpointer
gst_task_pool_push(GstTaskPool * pool,GstTaskPoolFunction func,gpointer user_data,GError ** error)241 gst_task_pool_push (GstTaskPool * pool, GstTaskPoolFunction func,
242 gpointer user_data, GError ** error)
243 {
244 GstTaskPoolClass *klass;
245
246 g_return_val_if_fail (GST_IS_TASK_POOL (pool), NULL);
247
248 klass = GST_TASK_POOL_GET_CLASS (pool);
249
250 if (klass->push == NULL)
251 goto not_supported;
252
253 return klass->push (pool, func, user_data, error);
254
255 /* ERRORS */
256 not_supported:
257 {
258 g_warning ("pushing tasks on pool %p is not supported", pool);
259 return NULL;
260 }
261 }
262
263 /**
264 * gst_task_pool_join:
265 * @pool: a #GstTaskPool
266 * @id: the id
267 *
268 * Join a task and/or return it to the pool. @id is the id obtained from
269 * gst_task_pool_push().
270 */
271 void
gst_task_pool_join(GstTaskPool * pool,gpointer id)272 gst_task_pool_join (GstTaskPool * pool, gpointer id)
273 {
274 GstTaskPoolClass *klass;
275
276 g_return_if_fail (GST_IS_TASK_POOL (pool));
277
278 klass = GST_TASK_POOL_GET_CLASS (pool);
279
280 if (klass->join)
281 klass->join (pool, id);
282 }
283