Jack2  1.9.8
JackMessageBuffer.cpp
00001 /*
00002  *  Copyright (C) 2004 Rui Nuno Capela, Steve Harris
00003  *  Copyright (C) 2008 Nedko Arnaudov
00004  *  Copyright (C) 2008 Grame
00005  *
00006  *  This program is free software; you can redistribute it and/or modify
00007  *  it under the terms of the GNU Lesser General Public License as published by
00008  *  the Free Software Foundation; either version 2.1 of the License, or
00009  *  (at your option) any later version.
00010  *
00011  *  This program is distributed in the hope that it will be useful,
00012  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014  *  GNU Lesser General Public License for more details.
00015  *
00016  *  You should have received a copy of the GNU Lesser General Public License
00017  *  along with this program; if not, write to the Free Software
00018  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
00019  *
00020  */
00021 
00022 #include "JackMessageBuffer.h"
00023 #include "JackGlobals.h"
00024 #include "JackError.h"
00025 
00026 namespace Jack
00027 {
00028 
00029 JackMessageBuffer* JackMessageBuffer::fInstance = NULL;
00030 
00031 JackMessageBuffer::JackMessageBuffer()
00032     :fInit(NULL),fInitArg(NULL),fThread(this),fInBuffer(0),fOutBuffer(0),fOverruns(0),fRunning(false)
00033 {}
00034 
00035 JackMessageBuffer::~JackMessageBuffer()
00036 {}
00037 
00038 void JackMessageBuffer::Start()
00039 {
00040     fRunning = true;
00041     fThread.StartSync();
00042 }
00043 
00044 void JackMessageBuffer::Stop()
00045 {
00046     if (fOverruns > 0) {
00047         jack_error("WARNING: %d message buffer overruns!", fOverruns);
00048     } else {
00049         jack_log("no message buffer overruns");
00050     }
00051 
00052     if (fGuard.Lock()) {
00053         fRunning = false;
00054         fGuard.Signal();
00055         fGuard.Unlock();
00056         fThread.Stop();
00057     } else {
00058         fThread.Kill();
00059     }
00060 
00061     Flush();
00062 }
00063 
00064 void JackMessageBuffer::Flush()
00065 {
00066     while (fOutBuffer != fInBuffer) {
00067         jack_log_function(fBuffers[fOutBuffer].level, fBuffers[fOutBuffer].message);
00068         fOutBuffer = MB_NEXT(fOutBuffer);
00069     }
00070 }
00071 
00072 void JackMessageBuffer::AddMessage(int level, const char *message)
00073 {
00074     if (fGuard.Trylock()) {
00075         fBuffers[fInBuffer].level = level;
00076         strncpy(fBuffers[fInBuffer].message, message, MB_BUFFERSIZE);
00077         fInBuffer = MB_NEXT(fInBuffer);
00078         fGuard.Signal();
00079         fGuard.Unlock();
00080     } else {            /* lock collision */
00081         INC_ATOMIC(&fOverruns);
00082     }
00083 }
00084 
00085 bool JackMessageBuffer::Execute()
00086 {
00087     if (fGuard.Lock()) {
00088         while (fRunning) {
00089             fGuard.Wait();
00090             /* the client asked for all threads to run a thread
00091             initialization callback, which includes us.
00092             */
00093             if (fInit) {
00094                 fInit(fInitArg);
00095                 fInit = NULL;
00096                 /* and we're done */
00097                 fGuard.Signal();
00098             }
00099 
00100             /* releasing the mutex reduces contention */
00101             fGuard.Unlock();
00102             Flush();
00103             fGuard.Lock();
00104         }
00105         fGuard.Unlock();
00106     } else {
00107         jack_error("JackMessageBuffer::Execute lock cannot be taken");
00108     }
00109 
00110     return false;
00111 }
00112 
00113 void JackMessageBuffer::Create()
00114 {
00115     if (fInstance == NULL) {
00116         fInstance = new JackMessageBuffer();
00117         fInstance->Start();
00118     }
00119 }
00120 
00121 void JackMessageBuffer::Destroy()
00122 {
00123     if (fInstance != NULL) {
00124         fInstance->Stop();
00125         delete fInstance;
00126         fInstance = NULL;
00127     }
00128 }
00129 
00130 void JackMessageBufferAdd(int level, const char *message)
00131 {
00132     if (Jack::JackMessageBuffer::fInstance == NULL) {
00133         /* Unable to print message with realtime safety. Complain and print it anyway. */
00134         jack_log_function(LOG_LEVEL_ERROR, "messagebuffer not initialized, skip message");
00135     } else {
00136         Jack::JackMessageBuffer::fInstance->AddMessage(level, message);
00137     }
00138 }
00139 
00140 void JackMessageBuffer::SetInitCallback(JackThreadInitCallback callback, void *arg)
00141 {
00142     if (fGuard.Lock()) {
00143         /* set up the callback */
00144         fInitArg = arg;
00145         fInit = callback;
00146         /* wake msg buffer thread */
00147         fGuard.Signal();
00148         /* wait for it to be done */
00149         fGuard.Wait();
00150         /* and we're done */
00151         fGuard.Unlock();
00152     } else {
00153         jack_error("JackMessageBuffer::SetInitCallback lock cannot be taken");
00154     }
00155 }
00156 
00157 };
00158