common/JackMessageBuffer.h

   1 /*
   2  * messagebuffer.h -- realtime-safe message interface for jackd.
   3  *
   4  *  This function is included in libjack so backend drivers can use
   5  *  it, *not* for external client processes.  The VERBOSE() and
   6  *  MESSAGE() macros are realtime-safe.
   7  */
   8
   9 /*
  10  *  Copyright (C) 2004 Rui Nuno Capela, Steve Harris
  11  *  Copyright (C) 2008 Nedko Arnaudov
  12  *  Copyright (C) 2008 Grame
  13  *
  14  *  This program is free software; you can redistribute it and/or modify
  15  *  it under the terms of the GNU Lesser General Public License as published by
  16  *  the Free Software Foundation; either version 2.1 of the License, or
  17  *  (at your option) any later version.
  18  *
  19  *  This program is distributed in the hope that it will be useful,
  20  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  *  GNU Lesser General Public License for more details.
  23  *
  24  *  You should have received a copy of the GNU Lesser General Public License
  25  *  along with this program; if not, write to the Free Software
  26  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  *
  28  */
  29
  30 #ifndef __JackMessageBuffer__
  31 #define __JackMessageBuffer__
  32
  33 #include "JackPlatformPlug.h"
  34 #include "JackMutex.h"
  35 #include "JackAtomic.h"
  36
  37 namespace Jack
  38 {
  39
  40 /* MB_NEXT() relies on the fact that MB_BUFFERS is a power of two */
  41 #define MB_BUFFERS  128
  42 #define MB_NEXT(index) ((index+1) & (MB_BUFFERS-1))
  43 #define MB_BUFFERSIZE   256     /* message length limit */
  44
  45 struct JackMessage
  46 {
  47     int level;
  48     char message[MB_BUFFERSIZE];
  49 };
  50
  51 /*!
  52 \brief Message buffer to be used from RT threads.
  53 */
  54
  55 class JackMessageBuffer : public JackRunnableInterface
  56 {
  57
  58     private:
  59
  60         volatile JackThreadInitCallback fInit;
  61         void* fInitArg;
  62         JackMessage fBuffers[MB_BUFFERS];
  63         JackThread fThread;
  64         JackProcessSync fGuard;
  65         volatile unsigned int fInBuffer;
  66         volatile unsigned int fOutBuffer;
  67         SInt32 fOverruns;
  68         bool fRunning;
  69
  70         void Flush();
  71
  72         bool Start();
  73         bool Stop();
  74
  75     public:
  76
  77         JackMessageBuffer();
  78         ~JackMessageBuffer();
  79
  80         // JackRunnableInterface interface
  81         bool Execute();
  82
  83             bool static Create();
  84             bool static Destroy();
  85
  86         void AddMessage(int level, const char *message);
  87         int SetInitCallback(JackThreadInitCallback callback, void *arg);
  88
  89             static JackMessageBuffer* fInstance;
  90 };
  91
  92 #ifdef __cplusplus
  93 extern "C"
  94 {
  95 #endif
  96
  97 void JackMessageBufferAdd(int level, const char *message);
  98
  99 #ifdef __cplusplus
 100 }
 101 #endif
 102
 103 };
 104
 105 #endif