path: root/pd/portaudio/pa_sgi/pthread-pa_sgi.c

/*
 * PortAudio Portable Real-Time Audio Library
 * Latest Version at: http://www.portaudio.com
 * SGI IRIX implementation by Pieter Suurmond, september 22, 2001 (#0.18).
 *
 * Copyright (c) 1999-2001 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.
 */
/*
Modfication History:
  8/12/2001 - Pieter Suurmond - took the v15 pa_linux_oss.c file and started to adapt for IRIX 6.2.
  8/17/2001 - alpha release with IRIX sproc()-method, may sometimes let IRIX6.2 crash at closing audiostream.
  9/22/2001 - #0.18 pthread starts to work a bit:
              BUT UNDER IRIX6.2, I DON'T GET IT TO WORK REALLY CORRECTLY,
                                 this POSIX-attempt,
              DON'T USE THIS FILE FOR RELIABLE OPERATION, IT IS HERE JUST 
              FOR DOCUMENTATION/ARCHIVE... OR FOR ANYONE WHO WANTS TO FIX......
TODO:
  - Test under IRIX 6.5.
  - Dynamically switch to 32 bit float as native format when appropriate (let SGI do the conversion), 
    and maybe also the other natively supported formats? (might increase performance)
  - Not sure whether CPU UTILIZATION MEASUREMENT (from OSS/linux) really works. Changed nothing yet,
    seems ok, but I've not yet tested it thoroughly. (maybe utilization-code may be made _unix_common_ then?)
  - The minimal number of buffers setting... I do not yet fully understand it.. I now just take *4.
REFERENCES:
  - IRIX 6.2 man pages regarding SGI AL library.
  - IRIS Digital MediaProgramming Guide (online books as well as man-pages come with IRIX 6.2 and 
    may not be publically available on the internet).
*/

#include <stdio.h>              /* Standard libraries. */
#include <stdlib.h>

#include "../pa_common/portaudio.h"     /* Portaudio headers. */
#include "../pa_common/pa_host.h"
#include "../pa_common/pa_trace.h"

/*
#include <malloc.h>
#include <memory.h>
#include <sys/prctl.h>          Not needed
#include <sys/types.h>
#include <sys/schedctl.h>
#include <signal.h>
#include <sys/ioctl.h>           Needed? 
#include <sys/time.h>
#include <sched.h>               sched_param struct and related functions  
                                 used in setting thread priorities.        
#include <limits.h>              Some POSIX constants such as _POSIX_THREAD_THREADS_MAX
*/

#include <pthread.h>            /* Pthreads are supported by IRIX 6.2 after       */
                                /* patches 1361, 1367, and 1429 are applied.      */
                                
#include <fcntl.h>              /* fcntl.h needed for "O_RDONLY". */
#include <unistd.h>             /* For usleep() and constants used when calling sysconf() */
                                /* to query POSIX limits (see the sysconf(3) ref. page.   */

#include <dmedia/audio.h>       /* SGI-specific audio library.    */


/*--------------------------------------------*/
#define PRINT(x)   { printf x; fflush(stdout); }
#define ERR_RPT(x) PRINT(x)
#define DBUG(x)    PRINT(x)
#define DBUGX(x)   /* PRINT(x) */

#define MAX_CHARS_DEVNAME           (16)        /* Was 32 in OSS (20 for AL but "in"/"out" is concat. */
#define MAX_SAMPLE_RATES            (8)         /* Known from SGI AL there are 7 (was 10 in OSS v15). */

typedef struct                    internalPortAudioDevice                 /* IRIX specific device info:      */
{
  PaDeviceID           /* NEW: */ pad_DeviceID;                           /* THIS "ID" IS NEW HERE (Pieter)! */
  long                            pad_ALdevice;                           /* SGI-number!                     */
  double                          pad_SampleRates[MAX_SAMPLE_RATES];      /* for pointing to from pad_Info   */
  char                            pad_DeviceName[MAX_CHARS_DEVNAME+1];    /* +1 for \0, one more than OSS.   */
  PaDeviceInfo                    pad_Info;                               /* pad_Info (v15) contains:        */
   	                              /* int            structVersion;                                           */
	                              /* const char*    name;                                                    */
	                              /* int            maxInputChannels, maxOutputChannels;                     */
	                              /* int            numSampleRates;       Num rates, or -1 if range supprtd. */
                                  /* const double*  sampleRates;          Array of supported sample rates,   */
	                              /* PaSampleFormat nativeSampleFormats;  or {min,max} if range supported.   */
  struct internalPortAudioDevice* pad_Next;                               /* Singly linked list, (NULL=end). */
} internalPortAudioDevice;

typedef struct      PaHostSoundControl              /* Structure to contain all SGI IRIX specific data. */
{
  ALport            pahsc_ALportIN,                 /* IRIX-audio-library-datatype. ALports can only be */
                    pahsc_ALportOUT;                /* unidirectional, so we sometimes need 2 of them.  */
  pthread_t         pahsc_ThreadPID;
  short             *pahsc_NativeInputBuffer,       /* Allocated here, in this file, if necessary.      */
                    *pahsc_NativeOutputBuffer;
  unsigned int      pahsc_BytesPerInputBuffer,      /* Native buffer sizes in bytes, really needed here */
                    pahsc_BytesPerOutputBuffer;     /* to free FAST memory, if buffs were alloctd FAST. */
  unsigned int      pahsc_SamplesPerInputBuffer,    /* These amounts are needed again and again in the  */
                    pahsc_SamplesPerOutputBuffer;   /* audio-thread (don't need to be kept globally).   */
  struct itimerval  pahsc_EntryTime,                /* For measuring CPU utilization (same as linux).   */
                    pahsc_LastExitTime;
  long              pahsc_InsideCountSum,
                    pahsc_TotalCountSum;
} PaHostSoundControl;

/*----------------------------- Shared Data ------------------------------------------------------*/
static internalPortAudioDevice* sDeviceList = NULL; /* FIXME - put Mutex around this shared data. */
static int                      sPaHostError = 0;   /* Maybe more than one process writing errs!? */

long Pa_GetHostError(void)
{
    return (long)sPaHostError;
}

/*----------------------------- BEGIN CPU UTILIZATION MEASUREMENT -----------------*/
/*                              (copied from source pa_linux_oss/pa_linux_oss.c)   */
static void Pa_StartUsageCalculation( internalPortAudioStream   *past )
{
	struct itimerval itimer;
	PaHostSoundControl *pahsc = (PaHostSoundControl *) past->past_DeviceData;
	if( pahsc == NULL ) return;
/* Query system timer for usage analysis and to prevent overuse of CPU. */
	getitimer( ITIMER_REAL, &pahsc->pahsc_EntryTime );
}

static long SubtractTime_AminusB( struct itimerval *timeA, struct itimerval *timeB )
{
	long secs = timeA->it_value.tv_sec - timeB->it_value.tv_sec;
	long usecs = secs * 1000000;
	usecs += (timeA->it_value.tv_usec - timeB->it_value.tv_usec);
	return usecs;
}

static void Pa_EndUsageCalculation( internalPortAudioStream   *past )
{
	struct  itimerval currentTime;
	long    insideCount;
	long    totalCount;       /* Measure CPU utilization during this callback. */

#define LOWPASS_COEFFICIENT_0   (0.95)
#define LOWPASS_COEFFICIENT_1   (0.99999 - LOWPASS_COEFFICIENT_0)

	PaHostSoundControl *pahsc = (PaHostSoundControl *) past->past_DeviceData;
	if (pahsc == NULL)
        return;
	if (getitimer( ITIMER_REAL, &currentTime ) == 0 )
	    {
		if (past->past_IfLastExitValid)
		    {
			insideCount = SubtractTime_AminusB( &pahsc->pahsc_EntryTime, &currentTime );
			pahsc->pahsc_InsideCountSum += insideCount;
			totalCount =  SubtractTime_AminusB( &pahsc->pahsc_LastExitTime, &currentTime );
			pahsc->pahsc_TotalCountSum += totalCount;
		/*  DBUG(("insideCount = %d, totalCount = %d\n", insideCount, totalCount )); */
            /* Low pass filter the result because sometimes we get called several times in a row. */
            /* That can cause the TotalCount to be very low which can cause the usage to appear   */
            /* unnaturally high. So we must filter numerator and denominator separately!!!        */
 			if (pahsc->pahsc_InsideCountSum > 0)
			    {
				past->past_AverageInsideCount = ((LOWPASS_COEFFICIENT_0 * past->past_AverageInsideCount) +
					                             (LOWPASS_COEFFICIENT_1 * pahsc->pahsc_InsideCountSum));
				past->past_AverageTotalCount  = ((LOWPASS_COEFFICIENT_0 * past->past_AverageTotalCount) +
					                             (LOWPASS_COEFFICIENT_1 * pahsc->pahsc_TotalCountSum));
				past->past_Usage = past->past_AverageInsideCount / past->past_AverageTotalCount;
				pahsc->pahsc_InsideCountSum = 0;
				pahsc->pahsc_TotalCountSum = 0;
			    }
		    }
		past->past_IfLastExitValid = 1;
	    }
	pahsc->pahsc_LastExitTime.it_value.tv_sec = 100;
	pahsc->pahsc_LastExitTime.it_value.tv_usec = 0;
	setitimer( ITIMER_REAL, &pahsc->pahsc_LastExitTime, NULL );
	past->past_IfLastExitValid = 1;
}   /*----------- END OF CPU UTILIZATION CODE (from pa_linux_oss/pa_linux_oss.c v15)--------------------*/


/*--------------------------------------------------------------------------------------*/
PaError translateSGIerror(void) /* Calls oserror(), may be used after an SGI AL-library */
{                               /* call to report via ERR_RPT(), yields a PaError-num.  */
    const char* a = "SGI AL ";  /* (Not absolutely sure errno came from THIS thread!    */
    switch(oserror())           /* Read IRIX man-pages about the _SGI_MP_SOURCE macro.) */
        {
        case AL_BAD_OUT_OF_MEM:
             ERR_RPT(("%sout of memory.\n", a)); 
             return paInsufficientMemory;                   /* Known PaError.   */
        case AL_BAD_CONFIG:
             ERR_RPT(("%sconfiguration invalid or NULL.\n", a));
             return paHostError;                            /* Generic PaError. */
        case AL_BAD_CHANNELS:
             ERR_RPT(("%schannels not 1,2 or 4.\n", a));
             return paHostError;                            /* Generic PaError. */
        case AL_BAD_NO_PORTS:
             ERR_RPT(("%sout of audio ports.\n", a));
             return paHostError;                            /* Generic PaError. */
        case AL_BAD_DEVICE:
             ERR_RPT(("%swrong device number.\n", a));
             return paHostError;                            /* Generic PaError. */
        case AL_BAD_DEVICE_ACCESS:
             ERR_RPT(("%swrong device access.\n", a));
             return paHostError;                            /* Generic PaError. */
        case AL_BAD_DIRECTION:
             ERR_RPT(("%sinvalid direction.\n", a));
             return paHostError;                            /* Generic PaError. */
        case AL_BAD_SAMPFMT:
             ERR_RPT(("%sdoesn't accept sampleformat.\n", a));
             return paHostError;                            /* Generic PaError. */
        case AL_BAD_FLOATMAX:
             ERR_RPT(("%smax float value is zero.\n", a));
             return paHostError;                            /* Generic PaError. */
        case AL_BAD_WIDTH:
             ERR_RPT(("%sunsupported samplewidth.\n", a));
             return paHostError;                            /* Generic PaError. */
        case AL_BAD_QSIZE:
             ERR_RPT(("%sinvalid queue size.\n", a));
             return paHostError;                            /* Generic PaError. */
        case AL_BAD_PVBUFFER:
             ERR_RPT(("%sPVbuffer null.\n", a));
             return paHostError;                            /* Generic PaError. */
        case AL_BAD_BUFFERLENGTH_NEG:
             ERR_RPT(("%snegative bufferlength.\n", a));
             return paHostError;                            /* Generic PaError. */
        case AL_BAD_BUFFERLENGTH_ODD:
             ERR_RPT(("%sodd bufferlength.\n", a));
             return paHostError;                            /* Generic PaError. */
        case AL_BAD_PARAM:
             ERR_RPT(("%sparameter not valid for device.\n", a));
             return paHostError;                            /* Generic PaError. */
        default:
             ERR_RPT(("%sunknown error.\n", a));
             return paHostError;                            /* Generic PaError. */
        }
}

/*------------------------------------------------------------------------------------------*/
/* Tries to set various rates and formats and fill in the device info structure.            */
static PaError Pa_sgiQueryDevice(long                     ALdev,  /* (AL_DEFAULT_DEVICE)    */
                                 PaDeviceID               id,     /* (DefaultI|ODeviceID()) */
                                 char*                    name,   /* (for example "SGI AL") */
                                 internalPortAudioDevice* pad)    /* Result written to pad. */
{
	int     format;
    long    min, max;                           /* To catch hardware characteristics.       */
    ALseterrorhandler(0);                       /* 0 = turn off the default error handler.  */
    /*--------------------------------------------------------------------------------------*/
    pad->pad_ALdevice = ALdev;                              /* Set the AL device number.    */
    pad->pad_DeviceID = id;                                 /* Set the PA device number.    */
    if (strlen(name) > MAX_CHARS_DEVNAME)                   /* MAX_CHARS defined above.     */
        {
        ERR_RPT(("Pa_QueryDevice(): name too long (%s).\n", name));
        return paHostError;
        }
    strcpy(pad->pad_DeviceName, name);                      /* Write name-string.           */
	pad->pad_Info.name = pad->pad_DeviceName;               /* Set pointer,..hmmm.          */
    /*--------------------------------- natively supported sample formats: -----------------*/
    pad->pad_Info.nativeSampleFormats = paInt16; /* Later also include paFloat32 | ..| etc. */
                                                 /* Then also choose other CallConvertXX()! */
    /*--------------------------------- number of available i/o channels: ------------------*/
    if (ALgetminmax(ALdev, AL_INPUT_COUNT, &min, &max))
        return translateSGIerror();
	pad->pad_Info.maxInputChannels = max;
	DBUG(("Pa_QueryDevice: maxInputChannels = %d\n", pad->pad_Info.maxInputChannels))
    if (ALgetminmax(ALdev, AL_OUTPUT_COUNT, &min, &max))
        return translateSGIerror();
	pad->pad_Info.maxOutputChannels = max;
	DBUG(("Pa_QueryDevice: maxOutputChannels = %d\n", pad->pad_Info.maxOutputChannels))
    /*--------------------------------- supported samplerates: ----------------------*/ 
	pad->pad_Info.numSampleRates = 7;   
	pad->pad_Info.sampleRates = pad->pad_SampleRates;
    pad->pad_SampleRates[0] = (double)AL_RATE_8000;     /* long -> double. */
    pad->pad_SampleRates[1] = (double)AL_RATE_11025;
    pad->pad_SampleRates[2] = (double)AL_RATE_16000;
    pad->pad_SampleRates[3] = (double)AL_RATE_22050;
    pad->pad_SampleRates[4] = (double)AL_RATE_32000;
    pad->pad_SampleRates[5] = (double)AL_RATE_44100;
    pad->pad_SampleRates[6] = (double)AL_RATE_48000;
    if (ALgetminmax(ALdev, AL_INPUT_RATE, &min, &max))  /* Ask INPUT rate-max.       */
        return translateSGIerror();                     /* double -> long.           */
    if (max != (long)(0.5 + pad->pad_SampleRates[6]))   /* FP-compare not recommndd. */
        goto weird;
    if (ALgetminmax(ALdev, AL_OUTPUT_RATE, &min, &max)) /* Ask OUTPUT rate-max.      */
        return translateSGIerror();
    if (max != (long)(0.5 + pad->pad_SampleRates[6]))
        {
weird:  ERR_RPT(("Pa_sgiQueryDevice() did not confirm max samplerate (%ld)\n",max));
        return paHostError;             /* Or make it a warning and just carry on... */
        }
    /*-------------------------------------------------------------------------------*/ 
	return paNoError;
}


/*--------------------------------------------------------------------------------*/
int Pa_CountDevices()       /* Name of this function suggests it only counts and  */
{                           /* is NOT destructive, it however resets whole PA !   */   
    int                        numDevices = 0;        /* Let 's not do that here. */
    internalPortAudioDevice*   currentDevice = sDeviceList;   /* COPY GLOBAL VAR. */
#if 0                       /* Remains from linux_oss v15: Pa_Initialize(), on    */
    if (!currentDevice)     /* its turn, calls PaHost_Init() via file pa_lib.c.   */
        Pa_Initialize();    /* Isn't that a bit too 'rude'?        Don't be too   */
#endif                      /* friendly to clients that forgot to initialize PA.  */
    while (currentDevice)   /* Slower but more elegant than the sNumDevices-way:  */
        {
        numDevices++;
        currentDevice = currentDevice->pad_Next;
        }
	return numDevices;
}

/*-------------------------------------------------------------------------------*/
static internalPortAudioDevice *Pa_GetInternalDevice(PaDeviceID id)
{
    int                         numDevices = 0;
    internalPortAudioDevice     *res = (internalPortAudioDevice*)NULL;
	internalPortAudioDevice     *pad = sDeviceList;         /* COPY GLOBAL VAR.  */
    while (pad)                         /* pad may be NULL, that's ok, return 0. */
        {  /* (Added ->pad_DeviceID field to the pad-struct, Pieter, 2001.)      */
        if (pad->pad_DeviceID == id)    /* This the device we were looking for?  */
            res = pad;                  /* But keep on(!) counting so we don't   */
        numDevices++;                   /* have to call Pa_CountDevices() later. */
        pad = pad->pad_Next;            /* Advance to the next device or NULL.   */
        }                               /* No assumptions about order of ID's in */
    if (!res)                           /* the list.                             */
        ERR_RPT(("Pa_GetInternalDevice() could not find specified ID (%d).\n",id));
    if ((id < 0) || (id >= numDevices))
        {
        ERR_RPT(("Pa_GetInternalDevice() supplied with an illegal ID (%d).\n",id));
#if 1                                             /* Be strict, even when found, */
        res = (internalPortAudioDevice*)NULL;     /* do not accept illegal ID's. */
#endif
        }
	return res;
}

/*----------------------------------------------------------------------*/
const PaDeviceInfo* Pa_GetDeviceInfo(PaDeviceID id)
{
    PaDeviceInfo*             res = (PaDeviceInfo*)NULL;
	internalPortAudioDevice*  pad = Pa_GetInternalDevice(id);  /* Call. */
    if (pad)
	    res = &pad->pad_Info;   /* Not finding the specified ID is not  */
    if (!res)                   /* the same as &pad->pad_Info == NULL.  */
        ERR_RPT(("Pa_GetDeviceInfo() could not find it (ID=%d).\n", id));
    return res;                 /* So (maybe) a second/third ERR_RPT(). */
}

/*------------------------------------------------*/
PaDeviceID Pa_GetDefaultInputDeviceID(void)
{
	return 0;	/* 0 is the default device ID. */
}
/*------------------------------------------------*/
PaDeviceID Pa_GetDefaultOutputDeviceID(void)
{
	return 0;
}

/*-------------------------------------------------------------------------------------------------*/
/* Build linked a list with all the available audio devices on this SGI machine (only 1 for now).  */
PaError PaHost_Init(void)                              /* Called by Pa_Initialize() from pa_lib.c. */
{
    internalPortAudioDevice*    pad;
	PaError                     r = paNoError;
    int                         audioLibFileID;             /* To test for the presence of audio.  */

    if (sDeviceList)                                        /* Allow re-init, only warn, no error. */
        {
        ERR_RPT(("Warning: PaHost_Init() did not really re-init PA.\n"));
        return r;
        }
    /*------------- ADD THE SGI DEFAULT DEVICE TO THE LIST: ---------------------------------------*/
    audioLibFileID = open("/dev/hdsp/hdsp0master", O_RDONLY);   /* Try to open Indigo style audio  */
    if (audioLibFileID < 0)                                     /* IO port. On failure, machine    */
        {                                                       /* has no audio ability.           */
        ERR_RPT(("PaHost_Init(): This machine has no (Indigo-style) audio abilities.\n"));
        return paHostError;
        }
    close(audioLibFileID);                              /* Allocate fast mem to hold device info.  */
	pad = PaHost_AllocateFastMemory(sizeof(internalPortAudioDevice));
	if (pad == NULL)
        return paInsufficientMemory;
    memset(pad, 0, sizeof(internalPortAudioDevice));    /* "pad->pad_Next = NULL" is more elegant. */
	r = Pa_sgiQueryDevice(AL_DEFAULT_DEVICE,            /* Set AL device num (AL_DEFAULT_DEVICE).  */
                          Pa_GetDefaultOutputDeviceID(),/* Set PA device num (or InputDeviceID()). */
                          "AL default",                 /* A suitable name.                        */
                          pad);                         /* Write args and queried info into pad.   */
	if (r != paNoError)
		{
        ERR_RPT(("Pa_QueryDevice for '%s' returned: %d\n", pad->pad_DeviceName, r));
		PaHost_FreeFastMemory(pad, sizeof(internalPortAudioDevice));   /* sDeviceList still NULL ! */
		}
    else
        sDeviceList = pad;            /* First element in linked list. pad->pad_Next already NULL. */
    /*------------- QUERY AND ADD MORE POSSIBLE SGI DEVICES TO THE LINKED LIST: -------------------*/
    /*---------------------------------------------------------------------------------------------*/
	return r;
}

/*---------------------------------------------------------------------------------------------------*/
static PaError Pa_SgiAudioProcess(internalPortAudioStream *past) /* Spawned by PaHost_StartEngine(). */
{
    PaError                 result = paNoError;
    PaHostSoundControl      *pahsc;
    
    if (!past)
        return paBadStreamPtr;
    pahsc = (PaHostSoundControl*)past->past_DeviceData;
	if (!pahsc)
        return paInternalError;
	past->past_IsActive = 1;            /* Wasn't this already done by the calling parent?!   */
    DBUG(("entering thread.\n"));

    while (!past->past_StopSoon)        /* OR-ing StopSoon and StopNow here gives problems! */
        {
        /*---------------------------------------- INPUT: ------------------------------------*/
        if (pahsc->pahsc_NativeInputBuffer)     /* Then pahsc_ALportIN should also be there!  */
            {
            while (ALgetfilled(pahsc->pahsc_ALportIN) < pahsc->pahsc_SamplesPerInputBuffer)
                {
                /* Trying sginap(1); and usleep(); here... things get blocked under IRIX6.2. */
                if (past->past_StopNow)    /* Don't let ALreadsamps() block */
                    goto done;
                }
            if (ALreadsamps(pahsc->pahsc_ALportIN, (void*)pahsc->pahsc_NativeInputBuffer,
                            pahsc->pahsc_SamplesPerInputBuffer))    /* Number of samples instead  */
                {                                                   /* of number of frames.       */
                ERR_RPT(("ALreadsamps() failed.\n"));
                result =  paInternalError;
                goto done;
                }
            }
        /*---------------------------------------------------- USER CALLBACK ROUTINE: ----------*/
        /* DBUG(("Calling Pa_CallConvertInt16()...\n")); */
        Pa_StartUsageCalculation(past);                     /* Convert 16 bit native data to    */
	    result = Pa_CallConvertInt16(past,                  /* user data and call user routine. */
				                 pahsc->pahsc_NativeInputBuffer, pahsc->pahsc_NativeOutputBuffer);
	    Pa_EndUsageCalculation(past);
	    if (result) 
		    {
			DBUG(("Pa_CallConvertInt16() returned %d, stopping...\n", result));
            goto done;                      /* This is apparently NOT an error!       */
		    }                               /* Just letting the userCallBack stop us. */
        /*---------------------------------------- OUTPUT: ------------------------------------*/
        if (pahsc->pahsc_NativeOutputBuffer)    /* Then pahsc_ALportOUT should also be there!  */
            {
            while (ALgetfillable(pahsc->pahsc_ALportOUT) < pahsc->pahsc_SamplesPerOutputBuffer)
                {
                /* Trying sginap(1); and usleep(); here... things get blocked under IRIX6.2. */
                if (past->past_StopNow)    /* Don't let ALwritesamps() block */
                    goto done;
                }
            if (ALwritesamps(pahsc->pahsc_ALportOUT, (void*)pahsc->pahsc_NativeOutputBuffer,
                             pahsc->pahsc_SamplesPerOutputBuffer))
                {
                ERR_RPT(("ALwritesamps() failed.\n"));
                result = paInternalError;
                goto done;
                }
            }
        /*-------------------------------------------------------------------------------------*/
        }
done:
    /* pahsc->pahsc_ThreadPID = -1;   Hu? doesn't help!! (added by Pieter) */
    past->past_IsActive = 0;
    DBUG(("leaving thread.\n"));
    return result;
}


/*--------------------------------------------------------------------------------------*/
PaError PaHost_OpenStream(internalPortAudioStream *past)
{
	PaError                 result = paNoError;
	PaHostSoundControl      *pahsc;
	unsigned int            minNumBuffers;
	internalPortAudioDevice *padIN, *padOUT;        /* For looking up native AL-numbers. */
    ALconfig                sgiALconfig = NULL;     /* IRIX-datatype.   */
    long                    pvbuf[8];               /* To get/set hardware configs.      */
    long                    sr, ALqsize;
    DBUG(("PaHost_OpenStream() called.\n"));        /* Alloc FASTMEM and init host data. */
    if (!past)
        {
        ERR_RPT(("Streampointer NULL!\n"));
        result = paBadStreamPtr;        goto done;
        }
	pahsc = (PaHostSoundControl*)PaHost_AllocateFastMemory(sizeof(PaHostSoundControl));
	if (pahsc == NULL)
	    {
        ERR_RPT(("FAST Memory allocation failed.\n"));  /* Pass trough some ERR_RPT-exit-  */
        result = paInsufficientMemory;  goto done;      /* code (nothing will be freed).   */
	    }
	memset(pahsc, 0, sizeof(PaHostSoundControl));
/*  pahsc->pahsc_threadPID = -1;                       Should pahsc_threadPID be inited to */
	past->past_DeviceData = (void*)pahsc;           /* -1 instead of 0 ??                  */
    /*--------------------------------------------------- Allocate native buffers: --------*/
    pahsc->pahsc_SamplesPerInputBuffer = past->past_FramesPerUserBuffer * /* Needed by the */
                                         past->past_NumInputChannels;     /* audio-thread. */
	pahsc->pahsc_BytesPerInputBuffer   = pahsc->pahsc_SamplesPerInputBuffer * sizeof(short);
	if (past->past_NumInputChannels > 0)                       /* Assumes short = 16 bits! */
	    {
		pahsc->pahsc_NativeInputBuffer = (short*)PaHost_AllocateFastMemory(pahsc->pahsc_BytesPerInputBuffer);        
		if( pahsc->pahsc_NativeInputBuffer == NULL )
		    {
            ERR_RPT(("Fast memory allocation for input-buffer failed.\n"));
			result = paInsufficientMemory;  goto done;
		    }
	    }
    pahsc->pahsc_SamplesPerOutputBuffer = past->past_FramesPerUserBuffer * /* Needed by the */
                                          past->past_NumOutputChannels;    /* audio-thread. */
	pahsc->pahsc_BytesPerOutputBuffer   = pahsc->pahsc_SamplesPerOutputBuffer * sizeof(short);
	if (past->past_NumOutputChannels > 0)                       /* Assumes short = 16 bits! */
	    {
		pahsc->pahsc_NativeOutputBuffer = (short*)PaHost_AllocateFastMemory(pahsc->pahsc_BytesPerOutputBuffer);
		if (pahsc->pahsc_NativeOutputBuffer == NULL)
		    {
            ERR_RPT(("Fast memory allocation for output-buffer failed.\n"));
			result = paInsufficientMemory;  goto done;
		    }
	    }
    /*------------------------------------------ Manipulate hardware if necessary and allowed: --*/
    ALseterrorhandler(0);                           /* 0 = turn off the default error handler.   */
    pvbuf[0] = AL_INPUT_RATE;
    pvbuf[2] = AL_INPUT_COUNT;
    pvbuf[4] = AL_OUTPUT_RATE;              /* TO FIX: rates may be logically, not always in Hz! */
    pvbuf[6] = AL_OUTPUT_COUNT;
    sr = (long)(past->past_SampleRate + 0.5);   /* Common for input and output :-)               */
    if (past->past_NumInputChannels > 0)                        /* We need to lookup the corre-  */
        {                                                       /* sponding native AL-number(s). */
        padIN = Pa_GetInternalDevice(past->past_InputDeviceID);
        if (!padIN)
            {
            ERR_RPT(("Pa_GetInternalDevice() for input failed.\n"));
	        result = paHostError;  goto done;
            }
        if (ALgetparams(padIN->pad_ALdevice, &pvbuf[0], 4)) /* Although input and output will both be on */
            goto sgiError;                                  /* the same AL-device, the AL-library might  */
        if (pvbuf[1] != sr)                                 /* contain more than AL_DEFAULT_DEVICE in    */
            {  /* Rate different from current harware-rate?    the future. Therefore 2 seperate queries. */
            if (pvbuf[3] > 0)     /* Means, there's other clients using AL-input-ports */
                {
                ERR_RPT(("Sorry, not allowed to switch input-hardware to %ld Hz because \
another process is currently using input at %ld kHz.\n", sr, pvbuf[1]));
                result = paHostError;   goto done;
                }
            pvbuf[1] = sr;                  /* Then set input-rate. */
            if (ALsetparams(padIN->pad_ALdevice, &pvbuf[0], 2))
                goto sgiError;      /* WHETHER THIS SAMPLERATE WAS REALLY PRESENT IN OUR ARRAY OF RATES, */
            }                       /* IS NOT CHECKED, AT LEAST NOT BY ME, WITHIN THIS FILE! Does PA do? */
        }
    if (past->past_NumOutputChannels > 0)           /* CARE: padOUT/IN may NOT be NULL if Channels <= 0! */
        {                                           /* We use padOUT/IN later on, or at least 1 of both. */
        padOUT = Pa_GetInternalDevice(past->past_OutputDeviceID);
        if (!padOUT)
            {
            ERR_RPT(("Pa_GetInternalDevice() for output failed.\n"));
	        result = paHostError;  goto done;
            }
        if (ALgetparams(padOUT->pad_ALdevice,&pvbuf[4], 4))
            goto sgiError;
        if ((past->past_NumOutputChannels > 0) && (pvbuf[5] != sr))
            {   /* Output needed and rate different from current harware-rate. */
            if (pvbuf[7] > 0)     /* Means, there's other clients using AL-output-ports */
                {
                ERR_RPT(("Sorry, not allowed to switch output-hardware to %ld Hz because \
another process is currently using output at %ld kHz.\n", sr, pvbuf[5]));            
                result = paHostError;   goto done;      /* Will free again the inputbuffer */
                }                                       /* that was just created above.    */
            pvbuf[5] = sr;                  /* Then set output-rate. */
            if (ALsetparams(padOUT->pad_ALdevice, &pvbuf[4], 2))
                goto sgiError;
            }
        }
    /*------------------------------------------ Construct an audio-port-configuration ----------*/
    sgiALconfig = ALnewconfig();                    /* Change the SGI-AL-default-settings.       */
    if (sgiALconfig == (ALconfig)0)                 /* sgiALconfig is released here after use!   */
        goto sgiError;                              /* See that sgiALconfig is NOT released!     */
    if (ALsetsampfmt(sgiALconfig, AL_SAMPFMT_TWOSCOMP))  /* Choose paInt16 as native i/o-format. */
        goto sgiError;
    if (ALsetwidth (sgiALconfig, AL_SAMPLE_16))     /* Only meaningful when sample format for    */
        goto sgiError;                              /* config is set to two's complement format. */
    /************************ Future versions might (dynamically) switch to 32-bit floats? *******
    if (ALsetsampfmt(sgiALconfig, AL_SAMPFMT_FLOAT))    (Then also call another CallConvert-func.)
        goto sgiError;
    if (ALsetfloatmax (sgiALconfig, 1.0))       Only meaningful when sample format for config 
        goto sgiError;                          is set to AL_SAMPFMT_FLOAT or AL_SAMPFMT_DOUBLE. */
    /*---------- ?? --------------------*/
	/* DBUG(("PaHost_OpenStream: pahsc_MinFramesPerHostBuffer = %d\n", pahsc->pahsc_MinFramesPerHostBuffer )); */
    minNumBuffers = Pa_GetMinNumBuffers(past->past_FramesPerUserBuffer, past->past_SampleRate);
	past->past_NumUserBuffers = (minNumBuffers > past->past_NumUserBuffers) ? 
                                 minNumBuffers : past->past_NumUserBuffers;
    /*------------------------------------------------ Set internal AL queuesize (in samples) ----*/
    if (pahsc->pahsc_SamplesPerInputBuffer >= pahsc->pahsc_SamplesPerOutputBuffer)
        ALqsize = (long)pahsc->pahsc_SamplesPerInputBuffer;
    else                                            /* Take the largest of the two amounts.       */
        ALqsize = (long)pahsc->pahsc_SamplesPerOutputBuffer;
    ALqsize *= 4;                                   /* 4 times as large as amount per transfer!   */    
    if (ALsetqueuesize(sgiALconfig, ALqsize))       /* Or should we use past_NumUserBuffers here? */
        goto sgiError;                              /* Using 2 times may give glitches... */
    /* Have to work on ALsetqueuesize() above. */

    /* Do ALsetchannels() later, apart per input and/or output. */
    /*----------------------------------------------- OPEN 1 OR 2 AL-DEVICES: --------------------*/
	if (past->past_OutputDeviceID == past->past_InputDeviceID)  /* Who SETS these devive-numbers? */
	    {
		if ((past->past_NumOutputChannels > 0) && (past->past_NumInputChannels > 0))
		    {
            DBUG(("PaHost_OpenStream: opening both input and output channels.\n"));
            /*------------------------- open output port: ----------------------------------*/
            if (ALsetchannels (sgiALconfig, (long)(past->past_NumOutputChannels)))
                goto sgiError;                      /* Returns 0 on success, -1 on failure. */
            pahsc->pahsc_ALportOUT = ALopenport("PA sgi out", "w", sgiALconfig);
            if (pahsc->pahsc_ALportOUT == (ALport)0)
                goto sgiError;
            /*------------------------- open input port: -----------------------------------*/
            if (ALsetchannels (sgiALconfig, (long)(past->past_NumInputChannels)))
                goto sgiError;                      /* Returns 0 on success, -1 on failure. */
            pahsc->pahsc_ALportIN = ALopenport("PA sgi in", "r", sgiALconfig);
            if (pahsc->pahsc_ALportIN == (ALport)0)
                goto sgiError;          /* For some reason the "patest_wire.c"-test crashes! */
		    }                           /* Probably due to too small buffersizes?....        */
        else
            {
            ERR_RPT(("Cannot setup bidirectional stream between different devices.\n"));
            result = paHostError;
            goto done;
            }
	    }
	else /* (OutputDeviceID != InputDeviceID) */
	    {
		if (past->past_NumOutputChannels > 0)   /* WRITE-ONLY: */
		    {	    
            /*------------------------- open output port: ----------------------------------*/
            DBUG(("PaHost_OpenStream: opening %d output channel(s) on %s.\n",
                 past->past_NumOutputChannels, padOUT->pad_DeviceName));
            if (ALsetchannels (sgiALconfig, (long)(past->past_NumOutputChannels)))
                goto sgiError;                      /* Returns 0 on success, -1 on failure. */
            pahsc->pahsc_ALportOUT = ALopenport("PA sgi out", "w", sgiALconfig);
            if (pahsc->pahsc_ALportOUT == (ALport)0)
                goto sgiError;
		    }
		if (past->past_NumInputChannels > 0)   /* READ-ONLY: */
		    {	    
            /*------------------------- open input port: -----------------------------------*/
            DBUG(("PaHost_OpenStream: opening %d input channel(s) on %s.\n",
                 past->past_NumInputChannels, padIN->pad_DeviceName));
            if (ALsetchannels (sgiALconfig, (long)(past->past_NumInputChannels)))
                goto sgiError;                      /* Returns 0 on success, -1 on failure. */
            pahsc->pahsc_ALportIN = ALopenport("PA sgi in", "r", sgiALconfig);
            if (pahsc->pahsc_ALportIN == (ALport)0)
                goto sgiError;
		    }
	    }
	DBUG(("PaHost_OpenStream() succeeded.\n"));
    goto done;  /* (no errors occured) */
sgiError:   
    result = translateSGIerror();   /* Translates SGI AL-code to PA-code and ERR_RPTs string. */
done:
    if (sgiALconfig)
        ALfreeconfig(sgiALconfig);              /* We don't need that struct anymore. */
    if (result != paNoError)
        PaHost_CloseStream(past);               /* Frees memory (only if really allocated!).  */
    return result;
}

/*-----------------------------------------------------*/
PaError PaHost_StartOutput(internalPortAudioStream *past)
{
	return paNoError;   /* Hmm, not implemented yet? */
}
PaError PaHost_StartInput(internalPortAudioStream *past)
{
	return paNoError;
}

/*------------------------------------------------------------------------------*/
PaError PaHost_StartEngine(internalPortAudioStream *past)
{
	PaHostSoundControl  *pahsc;
    int                 hres;
    PaError             result = paNoError;

    if (!past)          /* Test argument. */
        {
        ERR_RPT(("PaHost_StartEngine(NULL)!\n"));
        return paBadStreamPtr;
        }
    pahsc = (PaHostSoundControl*)past->past_DeviceData;
    if (!pahsc)
        {
        ERR_RPT(("PaHost_StartEngine(arg): arg->past_DeviceData == NULL!\n"));
        return paHostError;
        }
	past->past_StopSoon = 0;            /* Assume SGI ALport is already opened! */
	past->past_StopNow  = 0;
    past->past_IsActive = 1;
    DBUG(("PaHost_StartEngine() called.\n"));
    /* Use pthread_create() instead of __clone() because:                         */
    /* - pthread_create also works for other UNIX systems like Solaris,           */
    /* - Java HotSpot VM crashes in pthread_setcanceltype() when using __clone(). */
	hres = pthread_create(&(pahsc->pahsc_ThreadPID),    /* SPAWN AUDIO-CHILD.     */
		                  NULL,                         /* pthread_attr_t * attr  */
		                  (void*)Pa_SgiAudioProcess,
                          past);
	if (hres)
	    {
		result = paHostError;
		sPaHostError = hres;
        ERR_RPT(("PaHost_StartEngine() failed to spawn audio-thread.\n"));
	    }
    return result;
}

/*------------------------------------------------------------------------------*/
PaError PaHost_StopEngine(internalPortAudioStream *past, int abort)
{
	int                 hres;
	PaError             result = paNoError;
	PaHostSoundControl  *pahsc;
    
    DBUG(("PaHost_StopEngine() called.\n"));
    if (!past)
        return paBadStreamPtr;
    pahsc = (PaHostSoundControl*)past->past_DeviceData;
	if (pahsc == NULL)
        return result;                  /* paNoError (already stopped, no err?).       */
    past->past_StopSoon = 1;            /* Tell background thread to stop generating   */
    if (abort)                          /* more and to let current data play out. If   */
        past->past_StopNow = 1;         /* aborting, tell backgrnd thread to stop NOW! */
	if (pahsc->pahsc_ThreadPID != -1)   /* Join thread to recover memory resources.    */
	    {
        DBUG(("pthread_join() called.\n"));
		hres = pthread_join(pahsc->pahsc_ThreadPID, NULL);
		if (hres)
		    {
			result = paHostError;
			sPaHostError = hres;
            ERR_RPT(("PaHost_StopEngine() failed pthread_join().\n"));
		    }
		pahsc->pahsc_ThreadPID = -1;
	    }
    past->past_IsActive = 0;
	return result;
}

/*---------------------------------------------------------------*/
PaError PaHost_StopOutput(internalPortAudioStream *past, int abort)
{
	return paNoError;                   /* Not implemented yet? */
}
PaError PaHost_StopInput(internalPortAudioStream *past, int abort )
{
	return paNoError;
}

/*******************************************************************/
PaError PaHost_CloseStream(internalPortAudioStream *past)
{
	PaHostSoundControl  *pahsc;
    PaError             result = paNoError;
    
    DBUG(("PaHost_CloseStream() called.\n"));
	if (past == NULL)
        return paBadStreamPtr;
	pahsc = (PaHostSoundControl *) past->past_DeviceData;
	if (pahsc == NULL)          /* If pahsc not NULL, past_DeviceData will be freed, and set to NULL. */
        return result;          /* This test prevents from freeing NULL-pointers. */

    if (pahsc->pahsc_ALportIN)
        {
        if (ALcloseport(pahsc->pahsc_ALportIN))
            result = translateSGIerror();   /* Translates SGI AL-code to PA-code and ERR_RPTs string. */
        else                                /* But go on anyway... to release other stuff... */
            pahsc->pahsc_ALportIN = (ALport)0;
        }
    if (pahsc->pahsc_ALportOUT)
        {
        if (ALcloseport(pahsc->pahsc_ALportOUT))
            result = translateSGIerror();
        else
            pahsc->pahsc_ALportOUT = (ALport)0;
        }
	if (pahsc->pahsc_NativeInputBuffer)
	    {
        PaHost_FreeFastMemory(pahsc->pahsc_NativeInputBuffer, pahsc->pahsc_BytesPerInputBuffer);        
		pahsc->pahsc_NativeInputBuffer = NULL;
	    }
	if (pahsc->pahsc_NativeOutputBuffer)
	    {
        PaHost_FreeFastMemory(pahsc->pahsc_NativeOutputBuffer, pahsc->pahsc_BytesPerOutputBuffer);
		pahsc->pahsc_NativeOutputBuffer = NULL;
	    }
	PaHost_FreeFastMemory(pahsc, sizeof(PaHostSoundControl));
    past->past_DeviceData = NULL;                       /* PaHost_OpenStream() allocated FAST. */
	return result;
}

/*************************************************************************
** Determine minimum number of buffers required for this host based
** on minimum latency. Latency can be optionally set by user by setting
** an environment variable. For example, to set latency to 200 msec, put:
**    set PA_MIN_LATENCY_MSEC=200
** in the AUTOEXEC.BAT file and reboot.
** If the environment variable is not set, then the latency will be 
** determined based on the OS. Windows NT has higher latency than Win95.
*/
#define PA_LATENCY_ENV_NAME  ("PA_MIN_LATENCY_MSEC")

int Pa_GetMinNumBuffers( int framesPerBuffer, double sampleRate )
{
	return 2;
}
/* Hmmm, the note above isn't appropriate for SGI I'm afraid... */
/* Do we HAVE to do it this way under IRIX???....               */
/*--------------------------------------------------------------*/


/*---------------------------------------------------------------------*/
PaError PaHost_Term(void)   /* Frees all of the linked audio-devices.  */
{                           /* Called by Pa_Terminate() from pa_lib.c. */
	internalPortAudioDevice *pad = sDeviceList,
                            *nxt;
	while (pad)
	    {
		DBUG(("PaHost_Term: freeing %s\n", pad->pad_DeviceName));
        nxt = pad->pad_Next;
		PaHost_FreeFastMemory(pad, sizeof(internalPortAudioDevice));
		pad = nxt;              /* PaHost_Init allocated this FAST MEM.*/
	    }
	sDeviceList = (internalPortAudioDevice*)NULL;
	return 0;                           /* Got rid of	sNumDevices=0; */
}

/***********************************************************************/
void Pa_Sleep( long msec )  /* Sleep requested number of milliseconds. */
{
#if 0
	struct timeval timeout;
	timeout.tv_sec = msec / 1000;
	timeout.tv_usec = (msec % 1000) * 1000;
	select(0, NULL, NULL, NULL, &timeout);
#else
	long usecs = msec * 1000;
	usleep( usecs );
#endif
}

/*---------------------------------------------------------------------------------------*/
/* Allocate memory that can be accessed in real-time. This may need to be held in physi- */
/* cal memory so that it is not paged to virtual memory. This call MUST be balanced with */
/* a call to PaHost_FreeFastMemory().                                                    */
void *PaHost_AllocateFastMemory(long numBytes)
{
	void *addr = malloc(numBytes);
	if (addr)
        memset(addr, 0, numBytes);
	return addr;
}

/*---------------------------------------------------------------------------------------*/
/* Free memory that could be accessed in real-time. This call MUST be balanced with a    */
/* call to PaHost_AllocateFastMemory().                                                  */
void PaHost_FreeFastMemory(void *addr, long numBytes)
{
	if (addr)
        free(addr);
}

/*----------------------------------------------------------*/
PaError PaHost_StreamActive (internalPortAudioStream *past)
{
	PaHostSoundControl *pahsc;
	if (past == NULL)
        return paBadStreamPtr;
	pahsc = (PaHostSoundControl *) past->past_DeviceData;
	if (pahsc == NULL)
        return paInternalError;
	return (PaError)(past->past_IsActive != 0);
}

/*-------------------------------------------------------------------*/
PaTimestamp Pa_StreamTime( PortAudioStream *stream )
{
	internalPortAudioStream *past = (internalPortAudioStream *) stream; 
/* FIXME - return actual frames played, not frames generated.
** Need to query the output device somehow.
*/
	return past->past_FrameCount;
}