Jack2  1.9.9
JackTimedDriver.cpp
1 /*
2 Copyright (C) 2001 Paul Davis
3 Copyright (C) 2004-2008 Grame
4 
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 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 General Public License for more details.
14 
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18 
19 */
20 
21 #include "JackTimedDriver.h"
22 #include "JackEngineControl.h"
23 #include "JackTime.h"
24 #include "JackCompilerDeps.h"
25 #include <iostream>
26 #include <unistd.h>
27 #include <math.h>
28 
29 namespace Jack
30 {
31 
32 int JackTimedDriver::FirstCycle(jack_time_t cur_time_usec)
33 {
34  fAnchorTimeUsec = cur_time_usec;
35  return int((double(fEngineControl->fBufferSize) * 1000000) / double(fEngineControl->fSampleRate));
36 }
37 
38 int JackTimedDriver::CurrentCycle(jack_time_t cur_time_usec)
39 {
40  return int(((double(fCycleCount) * double(fEngineControl->fBufferSize) * 1000000.) / double(fEngineControl->fSampleRate)) - (cur_time_usec - fAnchorTimeUsec));
41 }
42 
43 int JackTimedDriver::Start()
44 {
45  fCycleCount = 0;
46  return JackAudioDriver::Start();
47 }
48 
49 void JackTimedDriver::ProcessWait()
50 {
51  jack_time_t cur_time_usec = GetMicroSeconds();
52  int wait_time_usec;
53 
54  if (fCycleCount++ == 0) {
55  wait_time_usec = FirstCycle(cur_time_usec);
56  } else {
57  wait_time_usec = CurrentCycle(cur_time_usec);
58  }
59 
60  if (wait_time_usec < 0) {
61  NotifyXRun(cur_time_usec, float(cur_time_usec - fBeginDateUst));
62  fCycleCount = 0;
63  wait_time_usec = 0;
64  jack_error("JackTimedDriver::Process XRun = %ld usec", (cur_time_usec - fBeginDateUst));
65  }
66 
67  //jack_log("JackTimedDriver::Process wait_time = %d", wait_time_usec);
68  JackSleep(wait_time_usec);
69 }
70 
71 int JackWaiterDriver::ProcessNull()
72 {
73  JackDriver::CycleTakeBeginTime();
74 
75  // Graph processing without Read/Write
76  if (fEngineControl->fSyncMode) {
77  ProcessGraphSync();
78  } else {
79  ProcessGraphAsync();
80  }
81 
82  // Keep end cycle time
83  JackDriver::CycleTakeEndTime();
84 
85  ProcessWait();
86  return 0;
87 }
88 
89 } // end of namespace
SERVER_EXPORT void jack_error(const char *fmt,...)
Definition: JackError.cpp:91