text: /*
   * $Id: patest_hang.c,v 1.1.4.1 2003/02/11 21:41:32 philburk Exp $
   * Play a sine then hang audio callback to test watchdog.
   *
   * Authors:
   *    Ross Bencina <rossb@audiomulch.com>
   *    Phil Burk <philburk@softsynth.com>
   *
   * This program uses the PortAudio Portable Audio Library.
   * For more information see: http://www.audiomulch.com/portaudio/
   * Copyright (c) 1999-2000 Ross Bencina and Phil Burk
   *
   * Permission is hereby granted, free of charge, to any person obtaining
   * a copy of this software and associated documentation files
   * (the "Software"), to deal in the Software without restriction,
   * including without limitation the rights to use, copy, modify, merge,
   * publish, distribute, sublicense, and/or sell copies of the Software,
   * and to permit persons to whom the Software is furnished to do so,
   * subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be
   * included in all copies or substantial portions of the Software.
   *
   * Any person wishing to distribute modifications to the Software is
   * requested to send the modifications to the original developer so that
   * they can be incorporated into the canonical version.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
   * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
   * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
   * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
   * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   *
   */
  #include <stdio.h>
  #include <math.h>
  #include "portaudio.h"
  
  
  #define SAMPLE_RATE   (44100)
  #define FRAMES_PER_BUFFER  (1024)
  #ifndef M_PI
  #define M_PI  (3.14159265)
  #endif
  #define TWOPI (M_PI * 2.0)
  
  typedef struct paTestData
  {
      int    sleepFor;
      double phase;
  }
  paTestData;
  
  /* This routine will be called by the PortAudio engine when audio is needed.
  ** It may called at interrupt level on some machines so don't do anything
  ** that could mess up the system like calling malloc() or free().
  */
  static int patestCallback(   void *inputBuffer, void *outputBuffer,
                               unsigned long framesPerBuffer,
                               PaTimestamp outTime, void *userData )
  {
      paTestData *data = (paTestData*)userData;
      float *out = (float*)outputBuffer;
      unsigned long i;
      int finished = 0;
      double phaseInc = 0.02;
      double phase = data->phase;
      
      (void) outTime; /* Prevent unused variable warnings. */
      (void) inputBuffer;
  
      for( i=0; i<framesPerBuffer; i++ )
      {
          phase += phaseInc;
          if( phase > TWOPI ) phase -= TWOPI;
          /* This is not a very efficient way to calc sines. */
          *out++ = (float) sin( phase ); /* mono */
      }
      
      if( data->sleepFor > 0 )
      {
          Pa_Sleep( data->sleepFor );
      }
      
      data->phase = phase;
      return finished;
  }
  
  /*******************************************************************/
  int main(void);
  int main(void)
  {
      PortAudioStream *stream;
      PaError          err;
      int              i;
      paTestData       data = {0};
      
      printf("PortAudio Test: output sine wave. SR = %d, BufSize = %d\n",
          SAMPLE_RATE, FRAMES_PER_BUFFER );
  
      err = Pa_Initialize();
      if( err != paNoError ) goto error;
      
      err = Pa_OpenStream(
                &stream,
                paNoDevice,/* default input device */
                0,              /* no input */
                paFloat32,  /* 32 bit floating point input */
                NULL,
                Pa_GetDefaultOutputDeviceID(), /* default output device */
                1,          /* mono output */
                paFloat32,      /* 32 bit floating point output */
                NULL,
                SAMPLE_RATE,
                FRAMES_PER_BUFFER,            /* frames per buffer */
                0,              /* number of buffers, if zero then use default minimum */
                paClipOff,      /* we won't output out of range samples so don't bother clipping them */
                patestCallback,
                &data );
      if( err != paNoError ) goto error;
      
      err = Pa_StartStream( stream );
      if( err != paNoError ) goto error;
  
  /* Gradually increase sleep time. */
      for( i=0; i<10000; i+= 1000 )
      {
          printf("Sleep for %d milliseconds in audio callback.\n", i );
          data.sleepFor = i;
          fflush(stdout);
          Pa_Sleep( ((i<1000) ? 1000 : i) );
      }
      
      printf("Suffer for 10 seconds.\n");
      fflush(stdout);
      Pa_Sleep( 10000 );
      
      err = Pa_StopStream( stream );
      if( err != paNoError ) goto error;
      err = Pa_CloseStream( stream );
      if( err != paNoError ) goto error;
      Pa_Terminate();
      printf("Test finished.\n");
      return err;
  error:
      Pa_Terminate();
      fprintf( stderr, "An error occured while using the portaudio stream\n" );
      fprintf( stderr, "Error number: %d\n", err );
      fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) );
      return err;
  }
  