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Viewing changes to libjack/driver.c

  • Committer: Bazaar Package Importer
  • Author(s): Luca Falavigna
  • Date: 2008-12-06 11:05:15 UTC
  • mfrom: (4.1.3 sid)
  • Revision ID: james.westby@ubuntu.com-20081206110515-xa9v9pajr9jqvfvg
Tags: 0.115.6-1ubuntu1
* Merge from Debian unstable, remaining Ubuntu changes:
  - Redirect stderr in bash completion (Debian #504488).

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libjack/driver.c
 
1
/* -*- mode: c; c-file-style: "linux"; -*- */
 
2
/*
 
3
    Copyright (C) 2001-2003 Paul Davis
 
4
    
 
5
    This program is free software; you can redistribute it and/or modify
 
6
    it under the terms of the GNU Lesser General Public License as published by
 
7
    the Free Software Foundation; either version 2.1 of the License, or
 
8
    (at your option) any later version.
 
9
    
 
10
    This program is distributed in the hope that it will be useful,
 
11
    but WITHOUT ANY WARRANTY; without even the implied warranty of
 
12
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 
13
    GNU Lesser General Public License for more details.
 
14
    
 
15
    You should have received a copy of the GNU Lesser General Public License
 
16
    along with this program; if not, write to the Free Software 
 
17
    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 
18
    
 
19
*/
 
20
 
 
21
#include <config.h>
 
22
#include <stdio.h>
 
23
#include <string.h>
 
24
#include <stdarg.h>
 
25
#include <stdlib.h>
 
26
#include <stdio.h>
 
27
#include <errno.h>
 
28
 
 
29
#include <jack/internal.h>
 
30
#include <jack/driver.h>
 
31
#include <jack/engine.h>
 
32
#include <jack/thread.h>
 
33
 
 
34
#ifdef USE_MLOCK
 
35
#include <sys/mman.h>
 
36
#endif /* USE_MLOCK */
 
37
 
 
38
static int dummy_attach (jack_driver_t *drv, jack_engine_t *eng) { return 0; }
 
39
static int dummy_detach (jack_driver_t *drv, jack_engine_t *eng) { return 0; }
 
40
static int dummy_write (jack_driver_t *drv,
 
41
                        jack_nframes_t nframes) { return 0; }
 
42
static int dummy_read (jack_driver_t *drv, jack_nframes_t nframes) { return 0; }
 
43
static int dummy_null_cycle (jack_driver_t *drv,
 
44
                             jack_nframes_t nframes) { return 0; }
 
45
static int dummy_bufsize (jack_driver_t *drv,
 
46
                          jack_nframes_t nframes) {return 0;}
 
47
static int dummy_stop (jack_driver_t *drv) { return 0; }
 
48
static int dummy_start (jack_driver_t *drv) { return 0; }
 
49
 
 
50
void
 
51
jack_driver_init (jack_driver_t *driver)
 
52
{
 
53
        memset (driver, 0, sizeof (*driver));
 
54
 
 
55
        driver->attach = dummy_attach;
 
56
        driver->detach = dummy_detach;
 
57
        driver->write = dummy_write;
 
58
        driver->read = dummy_read;
 
59
        driver->null_cycle = dummy_null_cycle;
 
60
        driver->bufsize = dummy_bufsize;
 
61
        driver->start = dummy_start;
 
62
        driver->stop = dummy_stop;
 
63
}
 
64
 
 
65
 
 
66
 
 
67
/****************************
 
68
 *** Non-Threaded Drivers ***
 
69
 ****************************/
 
70
 
 
71
static int dummy_nt_run_cycle (jack_driver_nt_t *drv) { return 0; }
 
72
static int dummy_nt_attach    (jack_driver_nt_t *drv) { return 0; }
 
73
static int dummy_nt_detach    (jack_driver_nt_t *drv) { return 0; }
 
74
 
 
75
 
 
76
/*
 
77
 * These are used in driver->nt_run for controlling whether or not
 
78
 * driver->engine->driver_exit() gets called (EXIT = call it, PAUSE = don't)
 
79
 */
 
80
#define DRIVER_NT_RUN   0
 
81
#define DRIVER_NT_EXIT  1
 
82
#define DRIVER_NT_PAUSE 2
 
83
#define DRIVER_NT_DYING 3
 
84
 
 
85
static int
 
86
jack_driver_nt_attach (jack_driver_nt_t * driver, jack_engine_t * engine)
 
87
{
 
88
        driver->engine = engine;
 
89
        return driver->nt_attach (driver);
 
90
}
 
91
 
 
92
static int
 
93
jack_driver_nt_detach (jack_driver_nt_t * driver, jack_engine_t * engine)
 
94
{
 
95
        int ret;
 
96
 
 
97
        ret = driver->nt_detach (driver);
 
98
        driver->engine = NULL;
 
99
 
 
100
        return ret;
 
101
}
 
102
 
 
103
static void *
 
104
jack_driver_nt_thread (void * arg)
 
105
{
 
106
        jack_driver_nt_t * driver = (jack_driver_nt_t *) arg;
 
107
        int rc = 0;
 
108
        int run;
 
109
 
 
110
        /* This thread may start running before pthread_create()
 
111
         * actually stores the driver->nt_thread value.  It's safer to
 
112
         * store it here as well. 
 
113
         */
 
114
 
 
115
        driver->nt_thread = pthread_self();
 
116
 
 
117
        pthread_mutex_lock (&driver->nt_run_lock);
 
118
 
 
119
        while ((run = driver->nt_run) == DRIVER_NT_RUN) {
 
120
                pthread_mutex_unlock (&driver->nt_run_lock);
 
121
 
 
122
                if ((rc = driver->nt_run_cycle (driver)) != 0) {
 
123
                        jack_error ("DRIVER NT: could not run driver cycle");
 
124
                        goto out;
 
125
                }
 
126
 
 
127
                pthread_mutex_lock (&driver->nt_run_lock);
 
128
        }
 
129
 
 
130
        pthread_mutex_unlock (&driver->nt_run_lock);
 
131
 
 
132
 out:
 
133
        if (rc) {
 
134
                driver->nt_run = DRIVER_NT_DYING;
 
135
                driver->engine->driver_exit (driver->engine);
 
136
        }
 
137
        pthread_exit (NULL);
 
138
}
 
139
 
 
140
static int
 
141
jack_driver_nt_start (jack_driver_nt_t * driver)
 
142
{
 
143
        int err;
 
144
 
 
145
        /* stop the new thread from really starting until the driver has
 
146
           been started.
 
147
        */
 
148
 
 
149
        pthread_mutex_lock (&driver->nt_run_lock);
 
150
        driver->nt_run = DRIVER_NT_RUN;
 
151
 
 
152
        if ((err = jack_client_create_thread (NULL,
 
153
                                              &driver->nt_thread, 
 
154
                                              driver->engine->rtpriority,
 
155
                                              driver->engine->control->real_time,
 
156
                                              jack_driver_nt_thread, driver)) != 0) {
 
157
                jack_error ("DRIVER NT: could not start driver thread!");
 
158
                return err;
 
159
        }
 
160
 
 
161
        if ((err = driver->nt_start (driver)) != 0) {
 
162
                /* make the thread run and exit immediately */
 
163
                driver->nt_run = DRIVER_NT_EXIT;
 
164
                pthread_mutex_unlock (&driver->nt_run_lock);
 
165
                jack_error ("DRIVER NT: could not start driver");
 
166
                return err;
 
167
        }
 
168
 
 
169
        /* let the thread run, since the underlying "device" has now been started */
 
170
 
 
171
        pthread_mutex_unlock (&driver->nt_run_lock);
 
172
 
 
173
        return 0;
 
174
}
 
175
 
 
176
static int
 
177
jack_driver_nt_do_stop (jack_driver_nt_t * driver, int run)
 
178
{
 
179
        int err;
 
180
 
 
181
        pthread_mutex_lock (&driver->nt_run_lock);
 
182
        if(driver->nt_run != DRIVER_NT_DYING) {
 
183
                driver->nt_run = run;
 
184
        }
 
185
        pthread_mutex_unlock (&driver->nt_run_lock);
 
186
 
 
187
        /* detect when called while the thread is shutting itself down */
 
188
        if (driver->nt_thread && driver->nt_run != DRIVER_NT_DYING
 
189
            && (err = pthread_join (driver->nt_thread, NULL)) != 0) {
 
190
                jack_error ("DRIVER NT: error waiting for driver thread: %s",
 
191
                            strerror (err));
 
192
                return err;
 
193
        }
 
194
 
 
195
        if ((err = driver->nt_stop (driver)) != 0) {
 
196
                jack_error ("DRIVER NT: error stopping driver");
 
197
                return err;
 
198
        }
 
199
 
 
200
        return 0;
 
201
}
 
202
 
 
203
static int
 
204
jack_driver_nt_stop (jack_driver_nt_t * driver)
 
205
{
 
206
        return jack_driver_nt_do_stop (driver, DRIVER_NT_EXIT);
 
207
}
 
208
 
 
209
static int
 
210
jack_driver_nt_bufsize (jack_driver_nt_t * driver, jack_nframes_t nframes)
 
211
{
 
212
        int err;
 
213
        int ret;
 
214
 
 
215
        err = jack_driver_nt_do_stop (driver, DRIVER_NT_PAUSE);
 
216
        if (err) {
 
217
                jack_error ("DRIVER NT: could not stop driver to change buffer size");
 
218
                driver->engine->driver_exit (driver->engine);
 
219
                return err;
 
220
        }
 
221
 
 
222
        ret = driver->nt_bufsize (driver, nframes);
 
223
 
 
224
        err = jack_driver_nt_start (driver);
 
225
        if (err) {
 
226
                jack_error ("DRIVER NT: could not restart driver during buffer size change");
 
227
                driver->engine->driver_exit (driver->engine);
 
228
                return err;
 
229
        }
 
230
 
 
231
        return ret;
 
232
}
 
233
 
 
234
void
 
235
jack_driver_nt_init (jack_driver_nt_t * driver)
 
236
{
 
237
        memset (driver, 0, sizeof (*driver));
 
238
 
 
239
        jack_driver_init ((jack_driver_t *) driver);
 
240
 
 
241
        driver->attach       = (JackDriverAttachFunction)    jack_driver_nt_attach;
 
242
        driver->detach       = (JackDriverDetachFunction)    jack_driver_nt_detach;
 
243
        driver->bufsize      = (JackDriverBufSizeFunction)   jack_driver_nt_bufsize;
 
244
        driver->stop         = (JackDriverStopFunction)      jack_driver_nt_stop;
 
245
        driver->start        = (JackDriverStartFunction)     jack_driver_nt_start;
 
246
 
 
247
        driver->nt_bufsize   = (JackDriverNTBufSizeFunction) dummy_bufsize;
 
248
        driver->nt_start     = (JackDriverNTStartFunction)   dummy_start;
 
249
        driver->nt_stop      = (JackDriverNTStopFunction)    dummy_stop;
 
250
        driver->nt_attach    =                               dummy_nt_attach;
 
251
        driver->nt_detach    =                               dummy_nt_detach;
 
252
        driver->nt_run_cycle =                               dummy_nt_run_cycle;
 
253
 
 
254
 
 
255
        pthread_mutex_init (&driver->nt_run_lock, NULL);
 
256
}
 
257
 
 
258
void
 
259
jack_driver_nt_finish     (jack_driver_nt_t * driver)
 
260
{
 
261
        pthread_mutex_destroy (&driver->nt_run_lock);
 
262
}