This commit was generated by cvs2svn to compensate for changes in r1301,

which included commits to RCS files with non-trunk default branches.

svn path=/trunk/; revision=1302

1 files changed, 1122 insertions, 0 deletions

diff --git a/pd/portaudio_v18/pa_unix_oss/pa_unix.c b/pd/portaudio_v18/pa_unix_oss/pa_unix.c
new file mode 100644
index 00000000..8d652b73
--- /dev/null
+++ b/pd/portaudio_v18/pa_unix_oss/pa_unix.c
@@ -0,0 +1,1122 @@
+/*
+ * PortAudio Portable Real-Time Audio Library
+ * Latest Version at: http://www.portaudio.com
+ * Linux OSS Implementation by douglas repetto and Phil Burk
+ *
+ * Copyright (c) 1999-2000 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.
+ *
+ */
+
+/*
+Modification History
+  1/2001 - Phil Burk - initial hack for Linux
+  2/2001 - Douglas Repetto - many improvements, initial query support
+  4/2/2001 - Phil - stop/abort thread control, separate in/out native buffers
+  5/28/2001 - Phil - use pthread_create() instead of clone(). Thanks Stephen Brandon!
+       use pthread_join() after thread shutdown.
+  5/29/2001 - Phil - query for multiple devices, multiple formats,
+                     input mode and input+output mode working,
+       Pa_GetCPULoad() implemented.
+  PLB20010817 - Phil & Janos Haber - don't halt if test of sample rate fails.
+  SB20010904 - Stephen Brandon - mods needed for GNUSTEP and SndKit
+  JH20010905 - Janos Haber - FreeBSD mods
+  2001-09-22 - Heiko - (i.e. Heiko Purnhagen <purnhage@tnt.uni-hannover.de> ;-)
+                       added 24k and 16k to ratesToTry[]
+         fixed Pa_GetInternalDevice()
+         changed DEVICE_NAME_BASE from /dev/audio to /dev/dsp
+         handled SNDCTL_DSP_SPEED in Pq_QueryDevice() more graceful
+         fixed Pa_StreamTime() for paqa_errs.c
+         fixed numCannel=2 oddity and error handling in Pa_SetupDeviceFormat()
+         grep also for HP20010922 ...
+  PLB20010924 - Phil - merged Heiko's changes
+                       removed sNumDevices and potential related bugs,
+         use getenv("PA_MIN_LATENCY_MSEC") to set desired latency,
+         simplify CPU Load calculation by comparing real-time to framesPerBuffer,
+         always close device when querying even if error occurs,
+  PLB20010927 - Phil - Improved negotiation for numChannels.
+  SG20011005 - Stewart Greenhill - set numChannels back to reasonable value after query.
+  DH20010115 - David Herring - fixed uninitialized handle.
+
+  DM20020218 - Dominic Mazzoni - Try to open in nonblocking mode first, in case
+                                 the device is already open.  New implementation of
+                                 Pa_StreamTime that uses SNDCTL_DSP_GETOPTR but
+                                 uses our own counter to avoid wraparound.
+  PLB20020222 - Phil Burk - Added WatchDog proc if audio running at high priority.
+                      Check error return from read() and write().
+                      Check CPU endianness instead of assuming Little Endian.
+  20020621 - pa_unix_oss.c split into pa_unix.c, pa_unix.h, pa_unix_oss.c by
+         Augustus Saunders. Return values from usleep() ignored by Sam Bayer
+         because not cross-platform compatible (at least until we get configure
+         going). Pa_SetupDeviceFormat split into input and output sides to
+         reflect capabilities of Solaris.
+
+  20030206 - Martin Rohrbach - various mods for Solaris
+  
+  20030410 - Bjorn Dittmer-Roche - fixed numerous problems associated with pthread_t
+  
+  20030630 - Thomas Richter - eliminated unused variable warnings.
+
+TODO
+O- put semaphore lock around shared data?
+O- handle native formats better
+O- handle stereo-only device better ???
+O- what if input and output of a device capabilities differ (e.g. es1371) ???
+*/
+
+
+#include "pa_unix.h"
+
+typedef void *(*pthread_function_t)(void *);
+
+/************************************************* Shared Data ********/
+/* FIXME - put Mutex around this shared data. */
+static internalPortAudioDevice *sDeviceList = NULL;
+static int sDefaultInputDeviceID = paNoDevice;
+static int sDefaultOutputDeviceID = paNoDevice;
+static int sPaHostError = 0;
+
+/********************************* BEGIN CPU UTILIZATION MEASUREMENT ****/
+static void Pa_StartUsageCalculation( internalPortAudioStream   *past )
+{
+    PaHostSoundControl *pahsc = (PaHostSoundControl *) past->past_DeviceData;
+    if( pahsc == NULL ) return;
+    /* Query system timer for usage analysis and to prevent overuse of CPU. */
+    gettimeofday( &pahsc->pahsc_EntryTime, NULL );
+}
+
+static long SubtractTime_AminusB( struct timeval *timeA, struct timeval *timeB )
+{
+    long secs = timeA->tv_sec - timeB->tv_sec;
+    long usecs = secs * 1000000;
+    usecs += (timeA->tv_usec - timeB->tv_usec);
+    return usecs;
+}
+
+/******************************************************************************
+** Measure fractional CPU load based on real-time it took to calculate
+** buffers worth of output.
+*/
+static void Pa_EndUsageCalculation( internalPortAudioStream   *past )
+{
+    struct timeval currentTime;
+    long  usecsElapsed;
+    double newUsage;
+
+#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( gettimeofday( &currentTime, NULL ) == 0 )
+    {
+        usecsElapsed = SubtractTime_AminusB( &currentTime, &pahsc->pahsc_EntryTime );
+        /* Use inverse because it is faster than the divide. */
+        newUsage =  usecsElapsed * pahsc->pahsc_InverseMicrosPerBuffer;
+
+        past->past_Usage = (LOWPASS_COEFFICIENT_0 * past->past_Usage) +
+                           (LOWPASS_COEFFICIENT_1 * newUsage);
+
+    }
+}
+/****************************************** END CPU UTILIZATION *******/
+
+/*********************************************************************
+ * Determines the number of available devices by trying to open
+ * each "/dev/dsp#" or "/dsp/audio#" in order until it fails.
+ * Add each working device to a singly linked list of devices.
+ */
+PaError Pa_QueryDevices( void )
+{
+    internalPortAudioDevice *pad, *lastPad;
+    int      go = 1;
+    int      numDevices = 0;
+    PaError  testResult;
+    PaError  result = paNoError;
+    char     *envdev;
+
+    sDefaultInputDeviceID = paNoDevice;
+    sDefaultOutputDeviceID = paNoDevice;
+
+    lastPad = NULL;
+
+    while( go )
+    {
+        /* Allocate structure to hold device info. */
+        pad = (internalPortAudioDevice *)
+              PaHost_AllocateFastMemory( sizeof(internalPortAudioDevice) );
+        if( pad == NULL ) return paInsufficientMemory;
+        memset( pad, 0, sizeof(internalPortAudioDevice) );
+
+        /* Build name for device. */
+        if( numDevices == 0 )
+        {
+            sprintf( pad->pad_DeviceName, DEVICE_NAME_BASE);
+        }
+        else
+        {
+            sprintf( pad->pad_DeviceName, DEVICE_NAME_BASE "%d", numDevices );
+        }
+
+        DBUG(("Try device %s\n", pad->pad_DeviceName ));
+        testResult = Pa_QueryDevice( pad->pad_DeviceName, pad );
+        DBUG(("Pa_QueryDevice returned %d\n", testResult ));
+        if( testResult != paNoError )
+        {
+            if( lastPad == NULL )
+            {
+                result = testResult; /* No good devices! */
+            }
+            go = 0;
+            PaHost_FreeFastMemory( pad, sizeof(internalPortAudioDevice) );
+        }
+        else
+        {
+            numDevices += 1;
+            /* Add to linked list of devices. */
+            if( lastPad )
+            {
+                lastPad->pad_Next = pad;
+            }
+            else
+            {
+                sDeviceList = pad; /* First element in linked list. */
+            }
+            lastPad = pad;
+        }
+    }
+
+    /* I'm sitting at a SunRay1 and I neither have /dev/audio# nor /dev/dsp#.
+       Instead, the correct audio device is stored in the environment variable
+       AUDIODEV and/or UTAUDIODEV, so check these devices as well if we haven't
+       checked them yet above  - MR */
+
+    DBUG(("Checking for AUDIODEV and UTAUDIODEV\n"));
+    envdev = getenv("AUDIODEV");
+    if (envdev != NULL && !strstr(envdev, DEVICE_NAME_BASE)) {
+        result = paNoError;
+
+        /* Allocate structure to hold device info. */
+        pad = (internalPortAudioDevice *)
+              PaHost_AllocateFastMemory( sizeof(internalPortAudioDevice) );
+        if( pad == NULL ) return paInsufficientMemory;
+        memset( pad, 0, sizeof(internalPortAudioDevice) );
+
+        /* Build name for device. */
+        strcpy(pad->pad_DeviceName, envdev);
+
+        DBUG(("Try device %s\n", pad->pad_DeviceName ));
+        testResult = Pa_QueryDevice( pad->pad_DeviceName, pad );
+        DBUG(("Pa_QueryDevice returned %d\n", testResult ));
+        if( testResult != paNoError )
+        {
+            if( lastPad == NULL )
+            {
+                result = testResult; /* No good devices! */
+            }
+            PaHost_FreeFastMemory( pad, sizeof(internalPortAudioDevice) );
+        }
+        else
+        {
+            numDevices += 1;
+            /* Add to linked list of devices. */
+            if( lastPad )
+            {
+                lastPad->pad_Next = pad;
+            }
+            else
+            {
+                sDeviceList = pad; /* First element in linked list. */
+            }
+            lastPad = pad;
+        }
+    }
+
+    envdev = getenv("UTAUDIODEV");
+    if (envdev != NULL && !strstr(envdev, DEVICE_NAME_BASE) && getenv("AUDIODEV") != NULL && strcmp(envdev, getenv("AUDIODEV"))) {
+        result = paNoError;
+
+        /* Allocate structure to hold device info. */
+        pad = (internalPortAudioDevice *)
+              PaHost_AllocateFastMemory( sizeof(internalPortAudioDevice) );
+        if( pad == NULL ) return paInsufficientMemory;
+        memset( pad, 0, sizeof(internalPortAudioDevice) );
+
+        /* Build name for device. */
+        strcpy(pad->pad_DeviceName, envdev);
+
+        DBUG(("Try device %s\n", pad->pad_DeviceName ));
+        testResult = Pa_QueryDevice( pad->pad_DeviceName, pad );
+        DBUG(("Pa_QueryDevice returned %d\n", testResult ));
+        if( testResult != paNoError )
+        {
+            if( lastPad == NULL )
+            {
+                result = testResult; /* No good devices! */
+            }
+            PaHost_FreeFastMemory( pad, sizeof(internalPortAudioDevice) );
+        }
+        else
+        {
+            numDevices += 1;
+            /* Add to linked list of devices. */
+            if( lastPad )
+            {
+                lastPad->pad_Next = pad;
+            }
+            else
+            {
+                sDeviceList = pad; /* First element in linked list. */
+            }
+            lastPad = pad;
+        }
+    }
+
+    return result;
+}
+
+/*************************************************************************/
+int Pa_CountDevices()
+{
+    int numDevices = 0;
+    internalPortAudioDevice *pad;
+
+    if( sDeviceList == NULL ) Pa_Initialize();
+    /* Count devices in list. */
+    pad = sDeviceList;
+    while( pad != NULL )
+    {
+        pad = pad->pad_Next;
+        numDevices++;
+    }
+
+    return numDevices;
+}
+
+/*************************************************************************/
+internalPortAudioDevice *Pa_GetInternalDevice( PaDeviceID id )
+{
+    internalPortAudioDevice *pad;
+    if( (id < 0) || ( id >= Pa_CountDevices()) ) return NULL;
+    pad = sDeviceList;
+    while( id > 0 )
+    {
+        pad = pad->pad_Next;
+        id--;
+    }
+    return pad;
+}
+
+/*************************************************************************/
+const PaDeviceInfo* Pa_GetDeviceInfo( PaDeviceID id )
+{
+    internalPortAudioDevice *pad;
+    if( (id < 0) || ( id >= Pa_CountDevices()) ) return NULL;
+    pad = Pa_GetInternalDevice( id );
+    return  &pad->pad_Info ;
+}
+
+static PaError Pa_MaybeQueryDevices( void )
+{
+    if( sDeviceList == NULL )
+    {
+        return Pa_QueryDevices();
+    }
+    return 0;
+}
+
+PaDeviceID Pa_GetDefaultInputDeviceID( void )
+{
+    /* return paNoDevice; */
+    return 0;
+}
+
+PaDeviceID Pa_GetDefaultOutputDeviceID( void )
+{
+    return 0;
+}
+
+/**********************************************************************
+** Make sure that we have queried the device capabilities.
+*/
+
+PaError PaHost_Init( void )
+{
+    return Pa_MaybeQueryDevices();
+}
+
+/*******************************************************************************************
+ * The ol' Canary in a Coal Mine trick.
+ * Just update the time periodically.
+ * Runs at low priority so if audio thread runs wild, this thread will get starved
+ * and the watchdog will detect it.
+ */
+
+#define SCHEDULER_POLICY         SCHED_RR
+#define WATCHDOG_MAX_SECONDS    (3)
+#define WATCHDOG_INTERVAL_USEC  (1000000)
+
+static int PaHost_CanaryProc( PaHostSoundControl   *pahsc )
+{
+    int   result = 0;
+
+#ifdef GNUSTEP
+    GSRegisterCurrentThread(); /* SB20010904 */
+#endif
+
+    while( pahsc->pahsc_CanaryRun) {
+      usleep( WATCHDOG_INTERVAL_USEC );
+      gettimeofday( &pahsc->pahsc_CanaryTime, NULL );
+    }
+
+    DBUG(("PaHost_CanaryProc: exiting.\n"));
+
+#ifdef GNUSTEP
+    GSUnregisterCurrentThread();  /* SB20010904 */
+#endif
+
+    return result;
+}
+
+/*******************************************************************************************
+ * Monitor audio thread and lower its it if it hogs the CPU.
+ * To prevent getting killed, the audio thread must update a
+ * variable with a timer value.
+ * If the value is not recent enough, then the
+ * thread will get killed.
+ */
+
+static PaError PaHost_WatchDogProc( PaHostSoundControl   *pahsc )
+{
+    struct sched_param    schp = { 0 };
+    int                   maxPri;
+
+#ifdef GNUSTEP
+    GSRegisterCurrentThread(); /* SB20010904 */
+#endif
+
+/* Run at a priority level above audio thread so we can still run if it hangs. */
+/* Rise more than 1 because of rumored off-by-one scheduler bugs. */
+    schp.sched_priority = pahsc->pahsc_AudioPriority + 4;
+    maxPri = sched_get_priority_max(SCHEDULER_POLICY);
+    if( schp.sched_priority > maxPri ) schp.sched_priority = maxPri;
+
+    if (sched_setscheduler(0, SCHEDULER_POLICY, &schp) != 0)
+    {
+        ERR_RPT(("PaHost_WatchDogProc: cannot set watch dog priority!\n"));
+        goto killAudio;
+    }
+
+    /* Compare watchdog time with audio and canary thread times. */
+    /* Sleep for a while or until thread cancelled. */
+    while( pahsc->pahsc_WatchDogRun )
+    {
+
+        int              delta;
+        struct timeval   currentTime;
+
+        usleep( WATCHDOG_INTERVAL_USEC );
+        gettimeofday( &currentTime, NULL );
+
+        /* If audio thread is not advancing, then it must be hung so kill it. */
+        delta = currentTime.tv_sec - pahsc->pahsc_EntryTime.tv_sec;
+        DBUG(("PaHost_WatchDogProc: audio delta = %d\n", delta ));
+        if( delta > WATCHDOG_MAX_SECONDS )
+        {
+            goto killAudio;
+        }
+
+        /* If canary died, then lower audio priority and halt canary. */
+        delta = currentTime.tv_sec - pahsc->pahsc_CanaryTime.tv_sec;
+        if( delta > WATCHDOG_MAX_SECONDS )
+        {
+            ERR_RPT(("PaHost_WatchDogProc: canary died!\n"));
+            goto lowerAudio;
+        }
+    }
+
+    DBUG(("PaHost_WatchDogProc: exiting.\n"));
+#ifdef GNUSTEP
+    GSUnregisterCurrentThread();  /* SB20010904 */
+#endif
+    return 0;
+
+lowerAudio:
+    {
+        struct sched_param    schat = { 0 };
+        if( sched_setscheduler(pahsc->pahsc_AudioThreadPID, SCHED_OTHER, &schat) != 0)
+        {
+            ERR_RPT(("PaHost_WatchDogProc: failed to lower audio priority. errno = %d\n", errno ));
+            /* Fall through into killing audio thread. */
+        }
+        else
+        {
+            ERR_RPT(("PaHost_WatchDogProc: lowered audio priority to prevent hogging of CPU.\n"));
+            goto cleanup;
+        }
+    }
+
+killAudio:
+    ERR_RPT(("PaHost_WatchDogProc: killing hung audio thread!\n"));
+    pthread_kill( pahsc->pahsc_AudioThread, SIGKILL );
+
+cleanup:
+    pahsc->pahsc_CanaryRun = 0;
+    DBUG(("PaHost_WatchDogProc: cancel Canary\n"));
+    pthread_cancel( pahsc->pahsc_CanaryThread );
+    DBUG(("PaHost_WatchDogProc: join Canary\n"));
+    pthread_join( pahsc->pahsc_CanaryThread, NULL );
+    DBUG(("PaHost_WatchDogProc: forget Canary\n"));
+    pahsc->pahsc_IsCanaryThreadValid = 0;
+
+#ifdef GNUSTEP
+    GSUnregisterCurrentThread();  /* SB20010904 */
+#endif
+    return 0;
+}
+
+/*******************************************************************************************/
+static void PaHost_StopWatchDog( PaHostSoundControl   *pahsc )
+{
+/* Cancel WatchDog thread if there is one. */
+    if( pahsc->pahsc_IsWatchDogThreadValid )
+    {
+        pahsc->pahsc_WatchDogRun = 0;
+        DBUG(("PaHost_StopWatchDog: cancel WatchDog\n"));
+        pthread_cancel( pahsc->pahsc_WatchDogThread );
+        pthread_join( pahsc->pahsc_WatchDogThread, NULL );
+        pahsc->pahsc_IsWatchDogThreadValid = 0;
+    }
+/* Cancel Canary thread if there is one. */
+    if( pahsc->pahsc_IsCanaryThreadValid )
+    {
+        pahsc->pahsc_CanaryRun = 0;
+        DBUG(("PaHost_StopWatchDog: cancel Canary\n"));
+        pthread_cancel( pahsc->pahsc_CanaryThread );
+        DBUG(("PaHost_StopWatchDog: join Canary\n"));
+        pthread_join( pahsc->pahsc_CanaryThread, NULL );
+        pahsc->pahsc_IsCanaryThreadValid = 0;
+    }
+}
+
+/*******************************************************************************************/
+static PaError PaHost_StartWatchDog( PaHostSoundControl   *pahsc )
+{
+    int      hres;
+    PaError  result = 0;
+
+    /* The watch dog watches for these timer updates */
+    gettimeofday( &pahsc->pahsc_EntryTime, NULL );
+    gettimeofday( &pahsc->pahsc_CanaryTime, NULL );
+
+    /* Launch a canary thread to detect priority abuse. */
+    pahsc->pahsc_CanaryRun = 1;
+    hres = pthread_create(&(pahsc->pahsc_CanaryThread),
+                      NULL /*pthread_attr_t * attr*/,
+                      (pthread_function_t)PaHost_CanaryProc, pahsc);
+    if( hres != 0 )
+    {
+        pahsc->pahsc_IsCanaryThreadValid = 0;
+        result = paHostError;
+        sPaHostError = hres;
+        goto error;
+    }
+    pahsc->pahsc_IsCanaryThreadValid = 1;
+
+    /* Launch a watchdog thread to prevent runaway audio thread. */
+    pahsc->pahsc_WatchDogRun = 1;
+    hres = pthread_create(&(pahsc->pahsc_WatchDogThread),
+                      NULL /*pthread_attr_t * attr*/,
+                      (pthread_function_t)PaHost_WatchDogProc, pahsc);
+    if( hres != 0 )
+    {
+        pahsc->pahsc_IsWatchDogThreadValid = 0;
+        result = paHostError;
+        sPaHostError = hres;
+        goto error;
+    }
+    pahsc->pahsc_IsWatchDogThreadValid = 1;
+    return result;
+
+error:
+    PaHost_StopWatchDog( pahsc );
+    return result;
+}
+
+/*******************************************************************************************
+ * Bump priority of audio thread if running with superuser priveledges.
+ * if priority bumped then launch a watchdog.
+ */
+static PaError PaHost_BoostPriority( internalPortAudioStream *past )
+{
+    PaHostSoundControl  *pahsc;
+    PaError              result = paNoError;
+    struct sched_param   schp = { 0 };
+
+    pahsc = (PaHostSoundControl *) past->past_DeviceData;
+    if( pahsc == NULL ) return paInternalError;
+
+    pahsc->pahsc_AudioThreadPID = getpid();
+    DBUG(("PaHost_BoostPriority: audio PID = %d\n", pahsc->pahsc_AudioThreadPID ));
+
+    /* Choose a priority in the middle of the range. */
+    pahsc->pahsc_AudioPriority = (sched_get_priority_max(SCHEDULER_POLICY) -
+                                  sched_get_priority_min(SCHEDULER_POLICY)) / 2;
+    schp.sched_priority = pahsc->pahsc_AudioPriority;
+
+    if (sched_setscheduler(0, SCHEDULER_POLICY, &schp) != 0)
+    {
+        DBUG(("PortAudio: only superuser can use real-time priority.\n"));
+    }
+    else
+    {
+        DBUG(("PortAudio: audio callback priority set to level %d!\n", schp.sched_priority));
+        /* We are running at high priority so we should have a watchdog in case audio goes wild. */
+        result = PaHost_StartWatchDog( pahsc );
+    }
+
+    return result;
+}
+
+/*******************************************************************************************/
+static PaError Pa_AudioThreadProc( internalPortAudioStream   *past )
+{
+    PaError      result;
+    PaHostSoundControl             *pahsc;
+    ssize_t      bytes_read, bytes_written;
+
+    pahsc = (PaHostSoundControl *) past->past_DeviceData;
+    if( pahsc == NULL ) return paInternalError;
+
+#ifdef GNUSTEP
+    GSRegisterCurrentThread(); /* SB20010904 */
+#endif
+
+    result = PaHost_BoostPriority( past );
+    if( result < 0 ) goto error;
+
+    past->past_IsActive = 1;
+    DBUG(("entering thread.\n"));
+
+    while( (past->past_StopNow == 0) && (past->past_StopSoon == 0) )
+    {
+        /* Read data from device */
+        if(pahsc->pahsc_NativeInputBuffer)
+        {
+            unsigned int totalread = 0;
+            DBUG(("Pa_AudioThreadProc: attempt to read %d bytes\n", pahsc->pahsc_BytesPerInputBuffer));
+            do
+            {
+                bytes_read = read(pahsc->pahsc_InputHandle,
+                    (char *)pahsc->pahsc_NativeInputBuffer + totalread,
+                    pahsc->pahsc_BytesPerInputBuffer - totalread);
+
+                if (bytes_read < 0)
+                {
+                    ERR_RPT(("PortAudio: read interrupted!\n"));
+                    break;
+                }
+
+                totalread += bytes_read;
+            } while( totalread < pahsc->pahsc_BytesPerInputBuffer);
+        }
+
+        /* Convert 16 bit native data to user data and call user routine. */
+        DBUG(("converting...\n"));
+        Pa_StartUsageCalculation( past );
+        result = Pa_CallConvertInt16( past,
+                                      pahsc->pahsc_NativeInputBuffer,
+                                      pahsc->pahsc_NativeOutputBuffer );
+        Pa_EndUsageCalculation( past );
+        if( result != 0)
+        {
+            DBUG(("hmm, Pa_CallConvertInt16() says: %d. i'm bailing.\n",
+                  result));
+            break;
+        }
+
+        /* Write data to device. */
+        if( pahsc->pahsc_NativeOutputBuffer )
+        {
+            unsigned int totalwritten = 0;
+            do
+            {
+                bytes_written = write(pahsc->pahsc_OutputHandle,
+                    (void *)pahsc->pahsc_NativeOutputBuffer,
+                    pahsc->pahsc_BytesPerOutputBuffer);
+                if( bytes_written < 0 )
+                {
+                    ERR_RPT(("PortAudio: write interrupted!"));
+                    break;
+                }
+
+                totalwritten += bytes_written;
+            } while( totalwritten < pahsc->pahsc_BytesPerOutputBuffer);
+        }
+
+        Pa_UpdateStreamTime(pahsc);
+    }
+    DBUG(("Pa_AudioThreadProc: left audio loop.\n"));
+
+    past->past_IsActive = 0;
+    PaHost_StopWatchDog( pahsc );
+
+error:
+    DBUG(("leaving audio thread.\n"));
+#ifdef GNUSTEP
+    GSUnregisterCurrentThread();  /* SB20010904 */
+#endif
+    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 cshrc file.
+*/
+#define PA_LATENCY_ENV_NAME  ("PA_MIN_LATENCY_MSEC")
+
+int Pa_GetMinNumBuffers( int framesPerBuffer, double framesPerSecond )
+{
+    int minBuffers;
+    int minLatencyMsec = MIN_LATENCY_MSEC;
+    char *minLatencyText = getenv(PA_LATENCY_ENV_NAME);
+    if( minLatencyText != NULL )
+    {
+        PRINT(("PA_MIN_LATENCY_MSEC = %s\n", minLatencyText ));
+        minLatencyMsec = atoi( minLatencyText );
+        if( minLatencyMsec < 1 ) minLatencyMsec = 1;
+        else if( minLatencyMsec > 5000 ) minLatencyMsec = 5000;
+    }
+
+    minBuffers = (int) ((minLatencyMsec * framesPerSecond) / ( 1000.0 * framesPerBuffer ));
+    if( minBuffers < 2 ) minBuffers = 2;
+    return minBuffers;
+}
+
+/*******************************************************************/
+PaError PaHost_OpenStream( internalPortAudioStream   *past )
+{
+    PaError          result = paNoError;
+    PaHostSoundControl *pahsc;
+    unsigned int     minNumBuffers;
+    internalPortAudioDevice *pad;
+    DBUG(("PaHost_OpenStream() called.\n" ));
+
+    /* Allocate and initialize host data. */
+    pahsc = (PaHostSoundControl *) malloc(sizeof(PaHostSoundControl));
+    if( pahsc == NULL )
+    {
+        result = paInsufficientMemory;
+        goto error;
+    }
+    memset( pahsc, 0, sizeof(PaHostSoundControl) );
+    past->past_DeviceData = (void *) pahsc;
+
+    pahsc->pahsc_OutputHandle = BAD_DEVICE_ID; /* No device currently opened. */
+    pahsc->pahsc_InputHandle = BAD_DEVICE_ID;
+    pahsc->pahsc_IsAudioThreadValid = 0;
+    pahsc->pahsc_IsWatchDogThreadValid = 0;
+
+    /* Allocate native buffers. */
+    pahsc->pahsc_BytesPerInputBuffer = past->past_FramesPerUserBuffer *
+                                       past->past_NumInputChannels * sizeof(short);
+    if( past->past_NumInputChannels > 0)
+    {
+        pahsc->pahsc_NativeInputBuffer = (short *) malloc(pahsc->pahsc_BytesPerInputBuffer);
+        if( pahsc->pahsc_NativeInputBuffer == NULL )
+        {
+            result = paInsufficientMemory;
+            goto error;
+        }
+    }
+    pahsc->pahsc_BytesPerOutputBuffer = past->past_FramesPerUserBuffer *
+                                        past->past_NumOutputChannels * sizeof(short);
+    if( past->past_NumOutputChannels > 0)
+    {
+        pahsc->pahsc_NativeOutputBuffer = (short *) malloc(pahsc->pahsc_BytesPerOutputBuffer);
+        if( pahsc->pahsc_NativeOutputBuffer == NULL )
+        {
+            result = paInsufficientMemory;
+            goto error;
+        }
+    }
+
+    /* 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;
+
+    pahsc->pahsc_InverseMicrosPerBuffer = past->past_SampleRate / (1000000.0 * past->past_FramesPerUserBuffer);
+    DBUG(("past_SampleRate = %g\n", past->past_SampleRate ));
+    DBUG(("past_FramesPerUserBuffer = %d\n", past->past_FramesPerUserBuffer ));
+    DBUG(("pahsc_InverseMicrosPerBuffer = %g\n", pahsc->pahsc_InverseMicrosPerBuffer ));
+
+    /* ------------------------- OPEN DEVICE -----------------------*/
+
+    /* just output */
+    if (past->past_OutputDeviceID == past->past_InputDeviceID)
+    {
+
+        if ((past->past_NumOutputChannels > 0) && (past->past_NumInputChannels > 0) )
+        {
+            pad = Pa_GetInternalDevice( past->past_OutputDeviceID );
+            DBUG(("PaHost_OpenStream: attempt to open %s for O_RDWR\n", pad->pad_DeviceName ));
+
+            /* dmazzoni: test it first in nonblocking mode to
+               make sure the device is not busy */
+            pahsc->pahsc_InputHandle = open(pad->pad_DeviceName,O_RDWR|O_NONBLOCK);
+            if(pahsc->pahsc_InputHandle==-1)
+            {
+                ERR_RPT(("PaHost_OpenStream: could not open %s for O_RDWR\n", pad->pad_DeviceName ));
+                result = paHostError;
+                goto error;
+            }
+            close(pahsc->pahsc_InputHandle);
+
+            pahsc->pahsc_OutputHandle = pahsc->pahsc_InputHandle =
+                                            open(pad->pad_DeviceName,O_RDWR);
+            if(pahsc->pahsc_InputHandle==-1)
+            {
+                ERR_RPT(("PaHost_OpenStream: could not open %s for O_RDWR\n", pad->pad_DeviceName ));
+                result = paHostError;
+                goto error;
+            }
+            Pa_SetLatency( pahsc->pahsc_OutputHandle,
+                           past->past_NumUserBuffers, past->past_FramesPerUserBuffer,
+                           past->past_NumOutputChannels );
+            result = Pa_SetupDeviceFormat( pahsc->pahsc_OutputHandle,
+                                           past->past_NumOutputChannels, (int)past->past_SampleRate );
+        }
+    }
+    else
+    {
+        if (past->past_NumOutputChannels > 0)
+        {
+            pad = Pa_GetInternalDevice( past->past_OutputDeviceID );
+            DBUG(("PaHost_OpenStream: attempt to open %s for O_WRONLY\n", pad->pad_DeviceName ));
+            /* dmazzoni: test it first in nonblocking mode to
+               make sure the device is not busy */
+            pahsc->pahsc_OutputHandle = open(pad->pad_DeviceName,O_WRONLY|O_NONBLOCK);
+            if(pahsc->pahsc_OutputHandle==-1)
+            {
+                ERR_RPT(("PaHost_OpenStream: could not open %s for O_WRONLY\n", pad->pad_DeviceName ));
+                result = paHostError;
+                goto error;
+            }
+            close(pahsc->pahsc_OutputHandle);
+
+            pahsc->pahsc_OutputHandle = open(pad->pad_DeviceName,O_WRONLY);
+            if(pahsc->pahsc_OutputHandle==-1)
+            {
+                ERR_RPT(("PaHost_OpenStream: could not open %s for O_WRONLY\n", pad->pad_DeviceName ));
+                result = paHostError;
+                goto error;
+            }
+            Pa_SetLatency( pahsc->pahsc_OutputHandle,
+                           past->past_NumUserBuffers, past->past_FramesPerUserBuffer,
+                           past->past_NumOutputChannels );
+            result = Pa_SetupOutputDeviceFormat( pahsc->pahsc_OutputHandle,
+                                           past->past_NumOutputChannels, (int)past->past_SampleRate );
+        }
+
+        if (past->past_NumInputChannels > 0)
+        {
+            pad = Pa_GetInternalDevice( past->past_InputDeviceID );
+            DBUG(("PaHost_OpenStream: attempt to open %s for O_RDONLY\n", pad->pad_DeviceName ));
+            /* dmazzoni: test it first in nonblocking mode to
+               make sure the device is not busy */
+            pahsc->pahsc_InputHandle = open(pad->pad_DeviceName,O_RDONLY|O_NONBLOCK);
+            if(pahsc->pahsc_InputHandle==-1)
+            {
+                ERR_RPT(("PaHost_OpenStream: could not open %s for O_RDONLY\n", pad->pad_DeviceName ));
+                result = paHostError;
+                goto error;
+            }
+            close(pahsc->pahsc_InputHandle);
+
+            pahsc->pahsc_InputHandle = open(pad->pad_DeviceName,O_RDONLY);
+            if(pahsc->pahsc_InputHandle==-1)
+            {
+                ERR_RPT(("PaHost_OpenStream: could not open %s for O_RDONLY\n", pad->pad_DeviceName ));
+                result = paHostError;
+                goto error;
+            }
+            Pa_SetLatency( pahsc->pahsc_InputHandle, /* DH20010115 - was OutputHandle! */
+                           past->past_NumUserBuffers, past->past_FramesPerUserBuffer,
+                           past->past_NumInputChannels );
+            result = Pa_SetupInputDeviceFormat( pahsc->pahsc_InputHandle,
+                                           past->past_NumInputChannels, (int)past->past_SampleRate );
+        }
+    }
+
+
+    DBUG(("PaHost_OpenStream: SUCCESS - result = %d\n", result ));
+    return result;
+
+error:
+    ERR_RPT(("PaHost_OpenStream: ERROR - result = %d\n", result ));
+    PaHost_CloseStream( past );
+    return result;
+}
+
+/*************************************************************************/
+PaError PaHost_StartOutput( internalPortAudioStream *past )
+{
+    past = past; /* unused */
+    return paNoError;
+}
+
+/*************************************************************************/
+PaError PaHost_StartInput( internalPortAudioStream *past )
+{
+    past = past; /* unused */
+    return paNoError;
+}
+
+/*************************************************************************/
+PaError PaHost_StartEngine( internalPortAudioStream *past )
+{
+    PaHostSoundControl *pahsc;
+    PaError             result = paNoError;
+    int                 hres;
+
+    pahsc = (PaHostSoundControl *) past->past_DeviceData;
+
+    past->past_StopSoon = 0;
+    past->past_StopNow = 0;
+    past->past_IsActive = 1;
+
+    /* Use pthread_create() instead of __clone() because:
+     *   - pthread_create also works for other UNIX systems like Solaris,
+     *   - the Java HotSpot VM crashes in pthread_setcanceltype() when using __clone()
+     */
+    hres = pthread_create(&(pahsc->pahsc_AudioThread),
+                          NULL /*pthread_attr_t * attr*/,
+                          (pthread_function_t)Pa_AudioThreadProc, past);
+    if( hres != 0 )
+    {
+        result = paHostError;
+        sPaHostError = hres;
+        pahsc->pahsc_IsAudioThreadValid = 0;
+        goto error;
+    }
+    pahsc->pahsc_IsAudioThreadValid = 1;
+
+error:
+    return result;
+}
+
+/*************************************************************************/
+PaError PaHost_StopEngine( internalPortAudioStream *past, int abort )
+{
+    int                 hres;
+    PaError             result = paNoError;
+    PaHostSoundControl *pahsc = (PaHostSoundControl *) past->past_DeviceData;
+
+    if( pahsc == NULL ) return paNoError;
+
+    /* Tell background thread to stop generating more data and to let current data play out. */
+    past->past_StopSoon = 1;
+    /* If aborting, tell background thread to stop NOW! */
+    if( abort ) past->past_StopNow = 1;
+
+    /* Join thread to recover memory resources. */
+    if( pahsc->pahsc_IsAudioThreadValid )
+    {
+        /* This check is needed for GNUSTEP - SB20010904 */
+        if ( !pthread_equal( pahsc->pahsc_AudioThread, pthread_self() ) )
+        {
+            hres = pthread_join( pahsc->pahsc_AudioThread, NULL );
+        }
+        else
+        {
+            DBUG(("Play thread was stopped from itself - can't do pthread_join()\n"));
+            hres = 0;
+        }
+
+        if( hres != 0 )
+        {
+            result = paHostError;
+            sPaHostError = hres;
+        }
+        pahsc->pahsc_IsAudioThreadValid = 0;
+    }
+
+    past->past_IsActive = 0;
+
+    return result;
+}
+
+/*************************************************************************/
+PaError PaHost_StopInput( internalPortAudioStream *past, int abort )
+{
+    past = past; /* unused */
+    abort = abort; /* unused */
+    return paNoError;
+}
+
+/*************************************************************************/
+PaError PaHost_StopOutput( internalPortAudioStream *past, int abort )
+{
+    past = past; /* unused */
+    abort = abort; /* unused */
+    return paNoError;
+}
+
+/*******************************************************************/
+PaError PaHost_CloseStream( internalPortAudioStream   *past )
+{
+    PaHostSoundControl *pahsc;
+
+    if( past == NULL ) return paBadStreamPtr;
+    pahsc = (PaHostSoundControl *) past->past_DeviceData;
+    if( pahsc == NULL ) return paNoError;
+
+    if( pahsc->pahsc_OutputHandle != BAD_DEVICE_ID )
+    {
+        int err = 0;
+        DBUG(("PaHost_CloseStream: attempt to close output device handle = %d\n",
+              pahsc->pahsc_OutputHandle ));
+
+        Pa_FlushStream(pahsc->pahsc_OutputHandle);
+
+        err = close(pahsc->pahsc_OutputHandle);
+        if( err < 0 )
+        {
+            ERR_RPT(("PaHost_CloseStream: warning, closing output device failed.\n"));
+        }
+    }
+
+    if( (pahsc->pahsc_InputHandle != BAD_DEVICE_ID) &&
+            (pahsc->pahsc_InputHandle != pahsc->pahsc_OutputHandle) )
+    {
+        int err = 0;
+        DBUG(("PaHost_CloseStream: attempt to close input device handle = %d\n",
+              pahsc->pahsc_InputHandle ));
+
+        Pa_FlushStream(pahsc->pahsc_InputHandle);
+
+        err = close(pahsc->pahsc_InputHandle);
+        if( err < 0 )
+        {
+            ERR_RPT(("PaHost_CloseStream: warning, closing input device failed.\n"));
+        }
+    }
+    pahsc->pahsc_OutputHandle = BAD_DEVICE_ID;
+    pahsc->pahsc_InputHandle = BAD_DEVICE_ID;
+
+    if( pahsc->pahsc_NativeInputBuffer )
+    {
+        free( pahsc->pahsc_NativeInputBuffer );
+        pahsc->pahsc_NativeInputBuffer = NULL;
+    }
+    if( pahsc->pahsc_NativeOutputBuffer )
+    {
+        free( pahsc->pahsc_NativeOutputBuffer );
+        pahsc->pahsc_NativeOutputBuffer = NULL;
+    }
+
+    free( pahsc );
+    past->past_DeviceData = NULL;
+    return paNoError;
+}
+
+/*************************************************************************/
+PaError PaHost_Term( void )
+{
+    /* Free all of the linked devices. */
+    internalPortAudioDevice *pad, *nextPad;
+    pad = sDeviceList;
+    while( pad != NULL )
+    {
+        nextPad = pad->pad_Next;
+        DBUG(("PaHost_Term: freeing %s\n", pad->pad_DeviceName ));
+        PaHost_FreeFastMemory( pad, sizeof(internalPortAudioDevice) );
+        pad = nextPad;
+    }
+    sDeviceList = NULL;
+    return 0;
+}
+
+/*************************************************************************
+ * Sleep for the requested number of milliseconds.
+ */
+void Pa_Sleep( long msec )
+{
+#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 physical 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 ); /* FIXME - do we need physical, wired, non-virtual memory? */
+    if( addr != NULL ) 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 )
+{
+    numBytes = numBytes; /* unused */
+    if( addr != NULL ) 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);
+}
+
+/***********************************************************************/
+long Pa_GetHostError( void )
+{
+    return (long) sPaHostError;
+}