root/trunk/libffado/src/libieee1394/IsoHandler.h

Revision 1038, 5.8 kB (checked in by ppalmers, 13 years ago)

reduce the amount of system time read kernel calls

Line 
1 /*
2  * Copyright (C) 2005-2008 by Pieter Palmers
3  *
4  * This file is part of FFADO
5  * FFADO = Free Firewire (pro-)audio drivers for linux
6  *
7  * FFADO is based upon FreeBoB.
8  *
9  * This program is free software: you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation, either version 2 of the License, or
12  * (at your option) version 3 of the License.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
21  *
22  */
23
24 #ifndef __FFADO_ISOHANDLER__
25 #define __FFADO_ISOHANDLER__
26
27 #include "debugmodule/debugmodule.h"
28
29 #include "libutil/Thread.h"
30
31 enum raw1394_iso_disposition;
32
33 class IsoHandlerManager;
34 namespace Streaming {
35     class StreamProcessor;
36 }
37
38 /*!
39 \brief The Base Class for ISO Handlers
40
41  These classes perform the actual ISO communication through libraw1394.
42  They are different from Streaming::StreamProcessors because one handler can provide multiple
43  streams with packets in case of ISO multichannel receive.
44
45 */
46
47 class IsoHandler
48 {
49 public:
50     enum EHandlerType {
51             eHT_Receive,
52             eHT_Transmit
53     };
54     IsoHandler(IsoHandlerManager& manager, enum EHandlerType t);
55     IsoHandler(IsoHandlerManager& manager, enum EHandlerType t,
56                unsigned int buf_packets, unsigned int max_packet_size, int irq);
57     IsoHandler(IsoHandlerManager& manager, enum EHandlerType t,
58                unsigned int buf_packets, unsigned int max_packet_size, int irq, enum raw1394_iso_speed speed);
59     ~IsoHandler();
60
61 private: // the ISO callback interface
62     static enum raw1394_iso_disposition
63     iso_receive_handler(raw1394handle_t handle, unsigned char *data,
64                         unsigned int length, unsigned char channel,
65                         unsigned char tag, unsigned char sy, unsigned int cycle,
66                         unsigned int dropped);
67
68     enum raw1394_iso_disposition
69             putPacket(unsigned char *data, unsigned int length,
70                         unsigned char channel, unsigned char tag, unsigned char sy,
71                         unsigned int cycle, unsigned int dropped, unsigned int skipped);
72
73     static enum raw1394_iso_disposition iso_transmit_handler(raw1394handle_t handle,
74                     unsigned char *data, unsigned int *length,
75                     unsigned char *tag, unsigned char *sy,
76                     int cycle, unsigned int dropped);
77     enum raw1394_iso_disposition
78             getPacket(unsigned char *data, unsigned int *length,
79                     unsigned char *tag, unsigned char *sy,
80                     int cycle, unsigned int dropped, unsigned int skipped);
81
82 public:
83     // runnable interface
84     bool iterate();
85
86     int getFileDescriptor() { return raw1394_get_fd(m_handle);};
87
88     bool init();
89     bool prepare();
90
91     void setVerboseLevel(int l);
92
93     bool enable() {return enable(-1);};
94     bool enable(int cycle);
95     bool disable();
96
97     void flush();
98     enum EHandlerType getType() {return m_type;};
99     const char *getTypeString() {return eHTToString(m_type); };
100
101     // pretty printing
102     const char *eHTToString(enum EHandlerType);
103
104     bool isEnabled()
105         {return m_State == E_Running;};
106
107     // no setter functions, because those would require a re-init
108     unsigned int getMaxPacketSize() { return m_max_packet_size;};
109     unsigned int getNbBuffers() { return m_buf_packets;};
110     int getPacketLatency() { return m_irq_interval;};
111
112     unsigned int getPreBuffers() {return m_prebuffers;};
113     void setPreBuffers(unsigned int n) {m_prebuffers=n;};
114
115     void dumpInfo();
116
117     bool inUse() {return (m_Client != 0) ;};
118     bool isStreamRegistered(Streaming::StreamProcessor *s) {return (m_Client == s);};
119
120     bool registerStream(Streaming::StreamProcessor *);
121     bool unregisterStream(Streaming::StreamProcessor *);
122
123     bool canIterateClient(); // FIXME: implement with functor
124
125     /**
126      * @brief request that the handler exits the packet processing loop ASAP
127      *
128      * The raw1394 lib doesn't provide a means to stop the packet iteration loop
129      * except when the iterate callback returns a DEFER value. Calling this function
130      * will make the callback return DEFER ASAP.
131      */
132     void requestIterateLoopExit() {m_dont_exit_iterate_loop = false;};
133     /**
134      * @brief allow the handler to stay in the packet processing loop
135      *
136      * This resets the state set by requestIterateLoopExit()
137      */
138     void allowIterateLoop() {m_dont_exit_iterate_loop = true;};
139
140
141     /**
142      * @brief get last cycle number seen by handler
143      * @return cycle number
144      */
145     int getLastCycle() {return m_last_cycle;};
146
147 private:
148     IsoHandlerManager& m_manager;
149     enum EHandlerType m_type;
150     raw1394handle_t m_handle;
151     unsigned int    m_buf_packets;
152     unsigned int    m_max_packet_size;
153     int             m_irq_interval;
154     int             m_last_cycle;
155     uint32_t        m_last_now;
156
157     Streaming::StreamProcessor *m_Client; // FIXME: implement with functors
158
159     int handleBusReset(unsigned int generation);
160
161     static int busreset_handler(raw1394handle_t handle, unsigned int generation);
162
163     enum raw1394_iso_speed m_speed;
164     unsigned int m_prebuffers;
165     bool m_dont_exit_iterate_loop;
166
167     // the state machine
168     enum EHandlerStates {
169         E_Created,
170         E_Initialized,
171         E_Prepared,
172         E_Running,
173         E_Error
174     };
175     enum EHandlerStates m_State;
176
177     #ifdef DEBUG
178     unsigned int    m_packets;
179     unsigned int    m_dropped;
180     int             m_min_ahead;
181     #endif
182
183     DECLARE_DEBUG_MODULE;
184 };
185
186 #endif /* __FFADO_ISOHANDLER__  */
187
188
189
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