jack2/linux/alsa/alsa_driver.c

/* -*- mode: c; c-file-style: "linux"; -*- */
/*
    Copyright (C) 2001 Paul Davis

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/


#define __STDC_FORMAT_MACROS   // For inttypes.h to work in C++
#define _GNU_SOURCE            /* for strcasestr() from string.h */

#include <math.h>
#include <stdio.h>
#include <memory.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <stdarg.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/time.h>
#include <string.h>

#include "alsa_driver.h"
#include "hammerfall.h"
#include "hdsp.h"
#include "ice1712.h"
#include "usx2y.h"
#include "generic.h"
#include "memops.h"
#include "JackError.h"

#include "alsa_midi_impl.h"

extern void store_work_time (int);
extern void store_wait_time (int);
extern void show_wait_times ();
extern void show_work_times ();

#undef DEBUG_WAKEUP

char* strcasestr(const char* haystack, const char* needle);

/* Delay (in process calls) before jackd will report an xrun */
#define XRUN_REPORT_DELAY 0
/* Max re-try count for Alsa poll timeout handling */
#define MAX_RETRY_COUNT 5

void
jack_driver_init (jack_driver_t *driver)
{
    memset (driver, 0, sizeof (*driver));

    driver->attach = 0;
    driver->detach = 0;
    driver->write = 0;
    driver->read = 0;
    driver->null_cycle = 0;
    driver->bufsize = 0;
    driver->start = 0;
    driver->stop = 0;
}

void
jack_driver_nt_init (jack_driver_nt_t * driver)
{
    memset (driver, 0, sizeof (*driver));

    jack_driver_init ((jack_driver_t *) driver);

    driver->attach = 0;
    driver->detach = 0;
    driver->bufsize = 0;
    driver->stop = 0;
    driver->start = 0;

    driver->nt_bufsize = 0;
    driver->nt_start = 0;
    driver->nt_stop = 0;
    driver->nt_attach = 0;
    driver->nt_detach = 0;
    driver->nt_run_cycle = 0;
}

static void
alsa_driver_release_channel_dependent_memory (alsa_driver_t *driver)
{
	bitset_destroy (&driver->channels_done);
	bitset_destroy (&driver->channels_not_done);

	if (driver->playback_addr) {
		free (driver->playback_addr);
		driver->playback_addr = 0;
	}

	if (driver->capture_addr) {
		free (driver->capture_addr);
		driver->capture_addr = 0;
	}

	if (driver->playback_interleave_skip) {
		free (driver->playback_interleave_skip);
		driver->playback_interleave_skip = NULL;
	}

	if (driver->capture_interleave_skip) {
		free (driver->capture_interleave_skip);
		driver->capture_interleave_skip = NULL;
	}

	if (driver->silent) {
		free (driver->silent);
		driver->silent = 0;
	}

	if (driver->dither_state) {
		free (driver->dither_state);
		driver->dither_state = 0;
	}
}

static int
alsa_driver_check_capabilities (alsa_driver_t *driver)
{
	return 0;
}

char* get_control_device_name(const char * device_name);

static int
alsa_driver_check_card_type (alsa_driver_t *driver)
{
	int err;
	snd_ctl_card_info_t *card_info;
	char * ctl_name;

	snd_ctl_card_info_alloca (&card_info);

	ctl_name = get_control_device_name(driver->alsa_name_playback);

	// XXX: I don't know the "right" way to do this. Which to use
	// driver->alsa_name_playback or driver->alsa_name_capture.
	if ((err = snd_ctl_open (&driver->ctl_handle, ctl_name, 0)) < 0) {
		jack_error ("control open \"%s\" (%s)", ctl_name,
			    snd_strerror(err));
	} else if ((err = snd_ctl_card_info(driver->ctl_handle, card_info)) < 0) {
		jack_error ("control hardware info \"%s\" (%s)",
			    driver->alsa_name_playback, snd_strerror (err));
		snd_ctl_close (driver->ctl_handle);
	}

	driver->alsa_driver = strdup(snd_ctl_card_info_get_driver (card_info));

	free(ctl_name);

	return alsa_driver_check_capabilities (driver);
}

static int
alsa_driver_hammerfall_hardware (alsa_driver_t *driver)
{
	driver->hw = jack_alsa_hammerfall_hw_new (driver);
	return 0;
}

static int
alsa_driver_hdsp_hardware (alsa_driver_t *driver)
{
	driver->hw = jack_alsa_hdsp_hw_new (driver);
	return 0;
}

static int
alsa_driver_ice1712_hardware (alsa_driver_t *driver)
{
        driver->hw = jack_alsa_ice1712_hw_new (driver);
        return 0;
}

// JACK2
/*
static int
alsa_driver_usx2y_hardware (alsa_driver_t *driver)
{
    driver->hw = jack_alsa_usx2y_hw_new (driver);
    return 0;
}
*/

static int
alsa_driver_generic_hardware (alsa_driver_t *driver)
{
	driver->hw = jack_alsa_generic_hw_new (driver);
	return 0;
}

static int
alsa_driver_hw_specific (alsa_driver_t *driver, int hw_monitoring,
			 int hw_metering)
{
	int err;

	if (!strcmp(driver->alsa_driver, "RME9652")) {
		if ((err = alsa_driver_hammerfall_hardware (driver)) != 0) {
			return err;
		}
	} else if (!strcmp(driver->alsa_driver, "H-DSP")) {
                if ((err = alsa_driver_hdsp_hardware (driver)) !=0) {
                        return err;
                }
	} else if (!strcmp(driver->alsa_driver, "ICE1712")) {
                if ((err = alsa_driver_ice1712_hardware (driver)) !=0) {
                        return err;
                }
	}
    // JACK2
    /*
        else if (!strcmp(driver->alsa_driver, "USB US-X2Y")) {
		if ((err = alsa_driver_usx2y_hardware (driver)) !=0) {
				return err;
		}
	}
    */
       else {
	        if ((err = alsa_driver_generic_hardware (driver)) != 0) {
			return err;
		}
	}

	if (driver->hw->capabilities & Cap_HardwareMonitoring) {
		driver->has_hw_monitoring = TRUE;
		/* XXX need to ensure that this is really FALSE or
		 * TRUE or whatever*/
		driver->hw_monitoring = hw_monitoring;
	} else {
		driver->has_hw_monitoring = FALSE;
		driver->hw_monitoring = FALSE;
	}

	if (driver->hw->capabilities & Cap_ClockLockReporting) {
		driver->has_clock_sync_reporting = TRUE;
	} else {
		driver->has_clock_sync_reporting = FALSE;
	}

	if (driver->hw->capabilities & Cap_HardwareMetering) {
		driver->has_hw_metering = TRUE;
		driver->hw_metering = hw_metering;
	} else {
		driver->has_hw_metering = FALSE;
		driver->hw_metering = FALSE;
	}

	return 0;
}

static void
alsa_driver_setup_io_function_pointers (alsa_driver_t *driver)
{
	if (driver->playback_handle) {
		if (SND_PCM_FORMAT_FLOAT_LE == driver->playback_sample_format) {
			driver->write_via_copy = sample_move_dS_floatLE;
		} else {
			switch (driver->playback_sample_bytes) {
			case 2:
				switch (driver->dither) {
				case Rectangular:
					jack_info("Rectangular dithering at 16 bits");
					driver->write_via_copy = driver->quirk_bswap?
						sample_move_dither_rect_d16_sSs:
						sample_move_dither_rect_d16_sS;
					break;

				case Triangular:
					jack_info("Triangular dithering at 16 bits");
					driver->write_via_copy = driver->quirk_bswap?
						sample_move_dither_tri_d16_sSs:
						sample_move_dither_tri_d16_sS;
					break;

				case Shaped:
					jack_info("Noise-shaped dithering at 16 bits");
					driver->write_via_copy = driver->quirk_bswap?
						sample_move_dither_shaped_d16_sSs:
						sample_move_dither_shaped_d16_sS;
					break;

				default:
					driver->write_via_copy = driver->quirk_bswap?
						sample_move_d16_sSs :
						sample_move_d16_sS;
					break;
				}
				break;

			case 3: /* NO DITHER */
				driver->write_via_copy = driver->quirk_bswap?
					sample_move_d24_sSs:
					sample_move_d24_sS;

				break;

			case 4: /* NO DITHER */
				switch (driver->playback_sample_format)
				{
					case SND_PCM_FORMAT_S24_LE:
					case SND_PCM_FORMAT_S24_BE:
				driver->write_via_copy = driver->quirk_bswap?
					sample_move_d32l24_sSs:
					sample_move_d32l24_sS;
				break;
					case SND_PCM_FORMAT_S32_LE:
					case SND_PCM_FORMAT_S32_BE:
					{
						int bits = snd_pcm_hw_params_get_sbits(driver->playback_hw_params);
						if (bits == 32)
						{
							driver->write_via_copy = driver->quirk_bswap?
								sample_move_d32_sSs:
								sample_move_d32_sS;
						}
						else if (bits == 24)
						{
							jack_log("sample format is SND_PCM_FORMAT_S32 but only 24 bits available");
							driver->write_via_copy = driver->quirk_bswap?
								sample_move_d32u24_sSs:
								sample_move_d32u24_sS;
						}
						else
						{
							jack_error("unsupported sample format for playback: "
									   "SND_PCM_FORMAT_S32 with %d bits",
									   bits);
							exit (1);
						}
						break;
					}
					default:
					jack_error("unsupported 4 byte sample_format");
					exit (1);
				}
				break;

			default:
				jack_error ("impossible sample width (%d) discovered!",
						driver->playback_sample_bytes);
				exit (1);
			}
		}
	}

	if (driver->capture_handle) {
		if (SND_PCM_FORMAT_FLOAT_LE == driver->capture_sample_format) {
			driver->read_via_copy = sample_move_floatLE_sSs;
		} else {
			switch (driver->capture_sample_bytes) {
			case 2:
				driver->read_via_copy = driver->quirk_bswap?
					sample_move_dS_s16s:
					sample_move_dS_s16;
				break;
			case 3:
				driver->read_via_copy = driver->quirk_bswap?
					sample_move_dS_s24s:
					sample_move_dS_s24;
				break;
			case 4:
				switch (driver->capture_sample_format)
				{
					case SND_PCM_FORMAT_S24_LE:
					case SND_PCM_FORMAT_S24_BE:
				driver->read_via_copy = driver->quirk_bswap?
					sample_move_dS_s32l24s:
					sample_move_dS_s32l24;
				break;
					case SND_PCM_FORMAT_S32_LE:
					case SND_PCM_FORMAT_S32_BE:
					{
						int bits = snd_pcm_hw_params_get_sbits(driver->capture_hw_params);
						if (bits == 32)
						{
							driver->read_via_copy = driver->quirk_bswap?
								sample_move_dS_s32s:
								sample_move_dS_s32;
						}
						else if(bits == 24)
						{
							jack_log("sample format is SND_PCM_FORMAT_S32 but only 24 bits available");
							driver->read_via_copy = driver->quirk_bswap?
								sample_move_dS_s32u24s:
								sample_move_dS_s32u24;
						}
						else
						{
							jack_error("unsupported sample format for capture: "
									   "SND_PCM_FORMAT_S32 with %d bits",
									   bits);
							exit (1);
						}
						break;
					}
					default:
                        jack_error("unsupported 4 byte sample_format");
                        exit (1);
                }
				break;
			}
		}
	}
}

static int
alsa_driver_configure_stream (alsa_driver_t *driver, char *device_name,
			      const char *stream_name,
			      snd_pcm_t *handle,
			      snd_pcm_hw_params_t *hw_params,
			      snd_pcm_sw_params_t *sw_params,
			      unsigned int *nperiodsp,
			      channel_t *nchns,
			      unsigned long sample_width)
{
	int err, format;
	unsigned int frame_rate;
	snd_pcm_uframes_t stop_th;
	static struct {
		char Name[40];
		snd_pcm_format_t format;
		int swapped;
	} formats[] = {
		{"32bit float little-endian", SND_PCM_FORMAT_FLOAT_LE, IS_LE},
		{"32bit integer little-endian", SND_PCM_FORMAT_S32_LE, IS_LE},
		{"32bit integer big-endian", SND_PCM_FORMAT_S32_BE, IS_BE},
		{"24bit little-endian in 3bytes format", SND_PCM_FORMAT_S24_3LE, IS_LE},
		{"24bit big-endian in 3bytes format", SND_PCM_FORMAT_S24_3BE, IS_BE},
		{"24bit little-endian", SND_PCM_FORMAT_S24_LE, IS_LE},
		{"24bit big-endian", SND_PCM_FORMAT_S24_BE, IS_BE},
		{"16bit little-endian", SND_PCM_FORMAT_S16_LE, IS_LE},
		{"16bit big-endian", SND_PCM_FORMAT_S16_BE, IS_BE},
	};
#define NUMFORMATS (sizeof(formats)/sizeof(formats[0]))
#define FIRST_16BIT_FORMAT 5

	if ((err = snd_pcm_hw_params_any (handle, hw_params)) < 0)  {
		jack_error ("ALSA: no playback configurations available (%s)",
			    snd_strerror (err));
		return -1;
	}

	if ((err = snd_pcm_hw_params_set_periods_integer (handle, hw_params))
	    < 0) {
		jack_error ("ALSA: cannot restrict period size to integral"
			    " value.");
		return -1;
	}

	if ((err = snd_pcm_hw_params_set_access (handle, hw_params, SND_PCM_ACCESS_MMAP_NONINTERLEAVED)) < 0) {
		if ((err = snd_pcm_hw_params_set_access (handle, hw_params, SND_PCM_ACCESS_MMAP_INTERLEAVED)) < 0) {
			if ((err = snd_pcm_hw_params_set_access (
				     handle, hw_params,
				     SND_PCM_ACCESS_MMAP_COMPLEX)) < 0) {
				jack_error ("ALSA: mmap-based access is not possible"
					    " for the %s "
					    "stream of this audio interface",
					    stream_name);
				return -1;
			}
		}
	}

	format = (sample_width == 4) ? 0 : NUMFORMATS - 1;

	while (1) {
		if ((err = snd_pcm_hw_params_set_format (
			     handle, hw_params, formats[format].format)) < 0) {

			if ((sample_width == 4
			     ? format++ >= NUMFORMATS - 1
			     : format-- <= 0)) {
				jack_error ("Sorry. The audio interface \"%s\""
					    " doesn't support any of the"
					    " hardware sample formats that"
					    " JACK's alsa-driver can use.",
					    device_name);
				return -1;
			}
		} else {
			if (formats[format].swapped) {
				driver->quirk_bswap = 1;
			} else {
				driver->quirk_bswap = 0;
			}
			jack_info ("ALSA: final selected sample format for %s: %s", stream_name, formats[format].Name);
			break;
		}
	}

	frame_rate = driver->frame_rate ;
	err = snd_pcm_hw_params_set_rate_near (handle, hw_params,
					       &frame_rate, NULL) ;
	driver->frame_rate = frame_rate ;
	if (err < 0) {
		jack_error ("ALSA: cannot set sample/frame rate to %"
			    PRIu32 " for %s", driver->frame_rate,
			    stream_name);
		return -1;
	}
	if (!*nchns) {
		/*if not user-specified, try to find the maximum
		 * number of channels */
		unsigned int channels_max ;
		err = snd_pcm_hw_params_get_channels_max (hw_params,
							  &channels_max);
		*nchns = channels_max ;

		if (*nchns > 1024) {

			/* the hapless user is an unwitting victim of
			   the "default" ALSA PCM device, which can
			   support up to 16 million channels. since
			   they can't be bothered to set up a proper
			   default device, limit the number of
			   channels for them to a sane default.
			*/

			jack_error (
"You appear to be using the ALSA software \"plug\" layer, probably\n"
"a result of using the \"default\" ALSA device. This is less\n"
"efficient than it could be. Consider using a hardware device\n"
"instead rather than using the plug layer. Usually the name of the\n"
"hardware device that corresponds to the first sound card is hw:0\n"
				);
			*nchns = 2;
		}
	}

	if ((err = snd_pcm_hw_params_set_channels (handle, hw_params,
						   *nchns)) < 0) {
		jack_error ("ALSA: cannot set channel count to %u for %s",
			    *nchns, stream_name);
		return -1;
	}

	if ((err = snd_pcm_hw_params_set_period_size (handle, hw_params,
						      driver->frames_per_cycle,
						      0))
	    < 0) {
		jack_error ("ALSA: cannot set period size to %" PRIu32
			    " frames for %s", driver->frames_per_cycle,
			    stream_name);
		return -1;
	}

	*nperiodsp = driver->user_nperiods;
	snd_pcm_hw_params_set_periods_min (handle, hw_params, nperiodsp, NULL);
	if (*nperiodsp < driver->user_nperiods)
		*nperiodsp = driver->user_nperiods;
	if (snd_pcm_hw_params_set_periods_near (handle, hw_params,
						nperiodsp, NULL) < 0) {
		jack_error ("ALSA: cannot set number of periods to %u for %s",
			    *nperiodsp, stream_name);
		return -1;
	}

	if (*nperiodsp < driver->user_nperiods) {
		jack_error ("ALSA: got smaller periods %u than %u for %s",
			    *nperiodsp, (unsigned int) driver->user_nperiods,
			    stream_name);
		return -1;
	}
	jack_info ("ALSA: use %d periods for %s", *nperiodsp, stream_name);
#if 0
	if (!jack_power_of_two(driver->frames_per_cycle)) {
		jack_error("JACK: frames must be a power of two "
			   "(64, 512, 1024, ...)\n");
		return -1;
	}
#endif

	if ((err = snd_pcm_hw_params_set_buffer_size (handle, hw_params,
						      *nperiodsp *
						      driver->frames_per_cycle))
	    < 0) {
		jack_error ("ALSA: cannot set buffer length to %" PRIu32
			    " for %s",
			    *nperiodsp * driver->frames_per_cycle,
			    stream_name);
		return -1;
	}

	if ((err = snd_pcm_hw_params (handle, hw_params)) < 0) {
		jack_error ("ALSA: cannot set hardware parameters for %s",
			    stream_name);
		return -1;
	}

	snd_pcm_sw_params_current (handle, sw_params);

	if ((err = snd_pcm_sw_params_set_start_threshold (handle, sw_params,
							  0U)) < 0) {
		jack_error ("ALSA: cannot set start mode for %s", stream_name);
		return -1;
	}

	stop_th = *nperiodsp * driver->frames_per_cycle;
	if (driver->soft_mode) {
		stop_th = (snd_pcm_uframes_t)-1;
	}

	if ((err = snd_pcm_sw_params_set_stop_threshold (
		     handle, sw_params, stop_th)) < 0) {
		jack_error ("ALSA: cannot set stop mode for %s",
			    stream_name);
		return -1;
	}

	if ((err = snd_pcm_sw_params_set_silence_threshold (
		     handle, sw_params, 0)) < 0) {
		jack_error ("ALSA: cannot set silence threshold for %s",
			    stream_name);
		return -1;
	}

#if 0
	jack_info ("set silence size to %lu * %lu = %lu",
		 driver->frames_per_cycle, *nperiodsp,
		 driver->frames_per_cycle * *nperiodsp);

	if ((err = snd_pcm_sw_params_set_silence_size (
		     handle, sw_params,
		     driver->frames_per_cycle * *nperiodsp)) < 0) {
		jack_error ("ALSA: cannot set silence size for %s",
			    stream_name);
		return -1;
	}
#endif

	if (handle == driver->playback_handle)
		err = snd_pcm_sw_params_set_avail_min (
			handle, sw_params,
			driver->frames_per_cycle
			* (*nperiodsp - driver->user_nperiods + 1));
	else
		err = snd_pcm_sw_params_set_avail_min (
			handle, sw_params, driver->frames_per_cycle);

	if (err < 0) {
		jack_error ("ALSA: cannot set avail min for %s", stream_name);
		return -1;
	}

	err = snd_pcm_sw_params_set_tstamp_mode(handle, sw_params, SND_PCM_TSTAMP_ENABLE);
	if (err < 0) {
		jack_info("Could not enable ALSA time stamp mode for %s (err %d)",
			  stream_name, err);
	}

#if SND_LIB_MAJOR >= 1 && SND_LIB_MINOR >= 1
	err = snd_pcm_sw_params_set_tstamp_type(handle, sw_params, SND_PCM_TSTAMP_TYPE_MONOTONIC);
	if (err < 0) {
		jack_info("Could not use monotonic ALSA time stamps for %s (err %d)",
			  stream_name, err);
	}
#endif

	if ((err = snd_pcm_sw_params (handle, sw_params)) < 0) {
		jack_error ("ALSA: cannot set software parameters for %s\n",
			    stream_name);
		return -1;
	}

	return 0;
}

static int
alsa_driver_set_parameters (alsa_driver_t *driver,
			    jack_nframes_t frames_per_cycle,
			    jack_nframes_t user_nperiods,
			    jack_nframes_t rate)
{
	int dir;
	snd_pcm_uframes_t p_period_size = 0;
	snd_pcm_uframes_t c_period_size = 0;
	channel_t chn;
	unsigned int pr = 0;
	unsigned int cr = 0;
	int err;

	driver->frame_rate = rate;
	driver->frames_per_cycle = frames_per_cycle;
	driver->user_nperiods = user_nperiods;

	jack_info ("configuring for %" PRIu32 "Hz, period = %"
		 PRIu32 " frames (%.1f ms), buffer = %" PRIu32 " periods",
		 rate, frames_per_cycle, (((float)frames_per_cycle / (float) rate) * 1000.0f), user_nperiods);

	if (driver->capture_handle) {
		if (alsa_driver_configure_stream (
			    driver,
			    driver->alsa_name_capture,
			    "capture",
			    driver->capture_handle,
			    driver->capture_hw_params,
			    driver->capture_sw_params,
			    &driver->capture_nperiods,
			    &driver->capture_nchannels,
			    driver->capture_sample_bytes)) {
			jack_error ("ALSA: cannot configure capture channel");
			return -1;
		}
	}

	if (driver->playback_handle) {
		if (alsa_driver_configure_stream (
			    driver,
			    driver->alsa_name_playback,
			    "playback",
			    driver->playback_handle,
			    driver->playback_hw_params,
			    driver->playback_sw_params,
			    &driver->playback_nperiods,
			    &driver->playback_nchannels,
			    driver->playback_sample_bytes)) {
			jack_error ("ALSA: cannot configure playback channel");
			return -1;
		}
	}

	/* check the rate, since that's rather important */

	if (driver->playback_handle) {
		snd_pcm_hw_params_get_rate (driver->playback_hw_params,
					    &pr, &dir);
	}

	if (driver->capture_handle) {
		snd_pcm_hw_params_get_rate (driver->capture_hw_params,
					    &cr, &dir);
	}

	if (driver->capture_handle && driver->playback_handle) {
		if (cr != pr) {
			jack_error ("playback and capture sample rates do "
				    "not match (%d vs. %d)", pr, cr);
		}

		/* only change if *both* capture and playback rates
		 * don't match requested certain hardware actually
		 * still works properly in full-duplex with slightly
		 * different rate values between adc and dac
		 */
		if (cr != driver->frame_rate && pr != driver->frame_rate) {
			jack_error ("sample rate in use (%d Hz) does not "
				    "match requested rate (%d Hz)",
				    cr, driver->frame_rate);
			driver->frame_rate = cr;
		}

	}
	else if (driver->capture_handle && cr != driver->frame_rate) {
		jack_error ("capture sample rate in use (%d Hz) does not "
			    "match requested rate (%d Hz)",
			    cr, driver->frame_rate);
		driver->frame_rate = cr;
	}
	else if (driver->playback_handle && pr != driver->frame_rate) {
		jack_error ("playback sample rate in use (%d Hz) does not "
			    "match requested rate (%d Hz)",
			    pr, driver->frame_rate);
		driver->frame_rate = pr;
	}


	/* check the fragment size, since that's non-negotiable */

	if (driver->playback_handle) {
 		snd_pcm_access_t access;

 		err = snd_pcm_hw_params_get_period_size (
 			driver->playback_hw_params, &p_period_size, &dir);
 		err = snd_pcm_hw_params_get_format (
 			driver->playback_hw_params,
			&(driver->playback_sample_format));
 		err = snd_pcm_hw_params_get_access (driver->playback_hw_params,
						    &access);
 		driver->playback_interleaved =
			(access == SND_PCM_ACCESS_MMAP_INTERLEAVED)
			|| (access == SND_PCM_ACCESS_MMAP_COMPLEX);

		if (p_period_size != driver->frames_per_cycle) {
			jack_error ("alsa_pcm: requested an interrupt every %"
				    PRIu32
				    " frames but got %u frames for playback",
				    driver->frames_per_cycle, p_period_size);
			return -1;
		}
	}

	if (driver->capture_handle) {
 		snd_pcm_access_t access;

 		err = snd_pcm_hw_params_get_period_size (
 			driver->capture_hw_params, &c_period_size, &dir);
 		err = snd_pcm_hw_params_get_format (
 			driver->capture_hw_params,
			&(driver->capture_sample_format));
 		err = snd_pcm_hw_params_get_access (driver->capture_hw_params,
						    &access);
 		driver->capture_interleaved =
			(access == SND_PCM_ACCESS_MMAP_INTERLEAVED)
			|| (access == SND_PCM_ACCESS_MMAP_COMPLEX);

		if (c_period_size != driver->frames_per_cycle) {
			jack_error ("alsa_pcm: requested an interrupt every %"
				    PRIu32
				    " frames but got %u frames for capture",
				    driver->frames_per_cycle, c_period_size);
			return -1;
		}
	}

	driver->playback_sample_bytes =
		snd_pcm_format_physical_width (driver->playback_sample_format)
		/ 8;
	driver->capture_sample_bytes =
		snd_pcm_format_physical_width (driver->capture_sample_format)
		/ 8;

	if (driver->playback_handle) {
		switch (driver->playback_sample_format) {
        case SND_PCM_FORMAT_FLOAT_LE:
		case SND_PCM_FORMAT_S32_LE:
		case SND_PCM_FORMAT_S24_3LE:
		case SND_PCM_FORMAT_S24_3BE:
		case SND_PCM_FORMAT_S24_LE:
		case SND_PCM_FORMAT_S24_BE:
		case SND_PCM_FORMAT_S16_LE:
		case SND_PCM_FORMAT_S32_BE:
		case SND_PCM_FORMAT_S16_BE:
			break;

		default:
			jack_error ("programming error: unhandled format "
				    "type for playback");
			exit (1);
		}
	}

	if (driver->capture_handle) {
		switch (driver->capture_sample_format) {
        case SND_PCM_FORMAT_FLOAT_LE:
		case SND_PCM_FORMAT_S32_LE:
		case SND_PCM_FORMAT_S24_3LE:
		case SND_PCM_FORMAT_S24_3BE:
		case SND_PCM_FORMAT_S24_LE:
		case SND_PCM_FORMAT_S24_BE:
		case SND_PCM_FORMAT_S16_LE:
		case SND_PCM_FORMAT_S32_BE:
		case SND_PCM_FORMAT_S16_BE:
			break;

		default:
			jack_error ("programming error: unhandled format "
				    "type for capture");
			exit (1);
		}
	}

	if (driver->playback_interleaved) {
		const snd_pcm_channel_area_t *my_areas;
		snd_pcm_uframes_t offset, frames;
		if (snd_pcm_mmap_begin(driver->playback_handle,
				       &my_areas, &offset, &frames) < 0) {
			jack_error ("ALSA: %s: mmap areas info error",
				    driver->alsa_name_playback);
			return -1;
		}
		driver->interleave_unit =
			snd_pcm_format_physical_width (
				driver->playback_sample_format) / 8;
	} else {
		driver->interleave_unit = 0;  /* NOT USED */
	}

	if (driver->capture_interleaved) {
		const snd_pcm_channel_area_t *my_areas;
		snd_pcm_uframes_t offset, frames;
		if (snd_pcm_mmap_begin(driver->capture_handle,
				       &my_areas, &offset, &frames) < 0) {
			jack_error ("ALSA: %s: mmap areas info error",
				    driver->alsa_name_capture);
			return -1;
		}
	}

	if (driver->playback_nchannels > driver->capture_nchannels) {
		driver->max_nchannels = driver->playback_nchannels;
	} else {
		driver->max_nchannels = driver->capture_nchannels;
	}

	alsa_driver_setup_io_function_pointers (driver);

	/* Allocate and initialize structures that rely on the
	   channels counts.

	   Set up the bit pattern that is used to record which
	   channels require action on every cycle. any bits that are
	   not set after the engine's process() call indicate channels
	   that potentially need to be silenced.
	*/

	bitset_create (&driver->channels_done, driver->max_nchannels);
	bitset_create (&driver->channels_not_done, driver->max_nchannels);

	if (driver->playback_handle) {
		driver->playback_addr = (char **)
			malloc (sizeof (char *) * driver->playback_nchannels);
		memset (driver->playback_addr, 0,
			sizeof (char *) * driver->playback_nchannels);
		driver->playback_interleave_skip = (unsigned long *)
			malloc (sizeof (unsigned long *) * driver->playback_nchannels);
		memset (driver->playback_interleave_skip, 0,
			sizeof (unsigned long *) * driver->playback_nchannels);
		driver->silent = (unsigned long *)
			malloc (sizeof (unsigned long)
				* driver->playback_nchannels);

		for (chn = 0; chn < driver->playback_nchannels; chn++) {
			driver->silent[chn] = 0;
		}

		for (chn = 0; chn < driver->playback_nchannels; chn++) {
			bitset_add (driver->channels_done, chn);
		}

		driver->dither_state = (dither_state_t *)
			calloc ( driver->playback_nchannels,
				 sizeof (dither_state_t));
	}

	if (driver->capture_handle) {
		driver->capture_addr = (char **)
			malloc (sizeof (char *) * driver->capture_nchannels);
		memset (driver->capture_addr, 0,
			sizeof (char *) * driver->capture_nchannels);
		driver->capture_interleave_skip = (unsigned long *)
			malloc (sizeof (unsigned long *) * driver->capture_nchannels);
		memset (driver->capture_interleave_skip, 0,
			sizeof (unsigned long *) * driver->capture_nchannels);
	}

	driver->clock_sync_data = (ClockSyncStatus *)
		malloc (sizeof (ClockSyncStatus) * driver->max_nchannels);

	driver->period_usecs =
		(jack_time_t) floor ((((float) driver->frames_per_cycle) /
				      driver->frame_rate) * 1000000.0f);
	driver->poll_timeout = (int) floor (1.5f * driver->period_usecs);

// JACK2
/*
	if (driver->engine) {
		if (driver->engine->set_buffer_size (driver->engine,
						     driver->frames_per_cycle)) {
			jack_error ("ALSA: Cannot set engine buffer size to %d (check MIDI)", driver->frames_per_cycle);
			return -1;
		}
	}
*/

	return 0;

	// may be unused
	(void)err;
}

int
alsa_driver_reset_parameters (alsa_driver_t *driver,
			      jack_nframes_t frames_per_cycle,
			      jack_nframes_t user_nperiods,
			      jack_nframes_t rate)
{
	/* XXX unregister old ports ? */
	alsa_driver_release_channel_dependent_memory (driver);
	return alsa_driver_set_parameters (driver,
					   frames_per_cycle,
					   user_nperiods, rate);
}

static int
alsa_driver_get_channel_addresses (alsa_driver_t *driver,
				   snd_pcm_uframes_t *capture_avail,
				   snd_pcm_uframes_t *playback_avail,
				   snd_pcm_uframes_t *capture_offset,
				   snd_pcm_uframes_t *playback_offset)
{
	int err;
	channel_t chn;

	if (capture_avail) {
		if ((err = snd_pcm_mmap_begin (
			     driver->capture_handle, &driver->capture_areas,
			     (snd_pcm_uframes_t *) capture_offset,
			     (snd_pcm_uframes_t *) capture_avail)) < 0) {
			jack_error ("ALSA: %s: mmap areas info error",
				    driver->alsa_name_capture);
			return -1;
		}

		for (chn = 0; chn < driver->capture_nchannels; chn++) {
			const snd_pcm_channel_area_t *a =
				&driver->capture_areas[chn];
			driver->capture_addr[chn] = (char *) a->addr
				+ ((a->first + a->step * *capture_offset) / 8);
			driver->capture_interleave_skip[chn] = (unsigned long ) (a->step / 8);
		}
	}

	if (playback_avail) {
		if ((err = snd_pcm_mmap_begin (
			     driver->playback_handle, &driver->playback_areas,
			     (snd_pcm_uframes_t *) playback_offset,
			     (snd_pcm_uframes_t *) playback_avail)) < 0) {
			jack_error ("ALSA: %s: mmap areas info error ",
				    driver->alsa_name_playback);
			return -1;
		}

		for (chn = 0; chn < driver->playback_nchannels; chn++) {
			const snd_pcm_channel_area_t *a =
				&driver->playback_areas[chn];
			driver->playback_addr[chn] = (char *) a->addr
				+ ((a->first + a->step * *playback_offset) / 8);
			driver->playback_interleave_skip[chn] = (unsigned long ) (a->step / 8);
		}
	}

	return 0;
}

int
alsa_driver_start (alsa_driver_t *driver)
{
	int err;
	snd_pcm_uframes_t poffset, pavail;
	channel_t chn;

	driver->poll_last = 0;
	driver->poll_next = 0;

	if (driver->playback_handle) {
		if ((err = snd_pcm_prepare (driver->playback_handle)) < 0) {
			jack_error ("ALSA: prepare error for playback on "
				    "\"%s\" (%s)", driver->alsa_name_playback,
				    snd_strerror(err));
			return -1;
		}
	}

	if ((driver->capture_handle && driver->capture_and_playback_not_synced)
	    || !driver->playback_handle) {
		if ((err = snd_pcm_prepare (driver->capture_handle)) < 0) {
			jack_error ("ALSA: prepare error for capture on \"%s\""
				    " (%s)", driver->alsa_name_capture,
				    snd_strerror(err));
			return -1;
		}
	}

	if (driver->hw_monitoring) {
		if (driver->input_monitor_mask || driver->all_monitor_in) {
			if (driver->all_monitor_in) {
				driver->hw->set_input_monitor_mask (driver->hw, ~0U);
			} else {
				driver->hw->set_input_monitor_mask (
					driver->hw, driver->input_monitor_mask);
			}
		} else {
			driver->hw->set_input_monitor_mask (driver->hw,
							    driver->input_monitor_mask);
		}
	}

	if (driver->playback_handle) {
		driver->playback_nfds =
			snd_pcm_poll_descriptors_count (driver->playback_handle);
	} else {
		driver->playback_nfds = 0;
	}

	if (driver->capture_handle) {
		driver->capture_nfds =
			snd_pcm_poll_descriptors_count (driver->capture_handle);
	} else {
		driver->capture_nfds = 0;
	}

	if (driver->pfd) {
		free (driver->pfd);
	}

	driver->pfd = (struct pollfd *)
		malloc (sizeof (struct pollfd) *
			(driver->playback_nfds + driver->capture_nfds + 2));

	if (driver->midi && !driver->xrun_recovery)
		(driver->midi->start)(driver->midi);

	if (driver->playback_handle) {
		/* fill playback buffer with zeroes, and mark
		   all fragments as having data.
		*/

		pavail = snd_pcm_avail_update (driver->playback_handle);

		if (pavail !=
		    driver->frames_per_cycle * driver->playback_nperiods) {
			jack_error ("ALSA: full buffer not available at start");
			return -1;
		}

		if (alsa_driver_get_channel_addresses (driver,
					0, &pavail, 0, &poffset)) {
			return -1;
		}

		/* XXX this is cheating. ALSA offers no guarantee that
		   we can access the entire buffer at any one time. It
		   works on most hardware tested so far, however, buts
		   its a liability in the long run. I think that
		   alsa-lib may have a better function for doing this
		   here, where the goal is to silence the entire
		   buffer.
		*/

		for (chn = 0; chn < driver->playback_nchannels; chn++) {
			alsa_driver_silence_on_channel (
				driver, chn,
				driver->user_nperiods
				* driver->frames_per_cycle);
		}

		snd_pcm_mmap_commit (driver->playback_handle, poffset,
				     driver->user_nperiods
				     * driver->frames_per_cycle);

		if ((err = snd_pcm_start (driver->playback_handle)) < 0) {
			jack_error ("ALSA: could not start playback (%s)",
				    snd_strerror (err));
			return -1;
		}
	}

	if ((driver->capture_handle && driver->capture_and_playback_not_synced)
	    || !driver->playback_handle) {
		if ((err = snd_pcm_start (driver->capture_handle)) < 0) {
			jack_error ("ALSA: could not start capture (%s)",
				    snd_strerror (err));
			return -1;
		}
	}

	return 0;
}

int
alsa_driver_stop (alsa_driver_t *driver)
{
	int err;
//	JSList* node;
//	int chn;

	/* silence all capture port buffers, because we might
	   be entering offline mode.
	*/

// JACK2
/*
	for (chn = 0, node = driver->capture_ports; node;
	     node = jack_slist_next (node), chn++) {

		jack_port_t* port;
		char* buf;
		jack_nframes_t nframes = driver->engine->control->buffer_size;

		port = (jack_port_t *) node->data;
		buf = jack_port_get_buffer (port, nframes);
		memset (buf, 0, sizeof (jack_default_audio_sample_t) * nframes);
	}
*/

// JACK2
    ClearOutput();

	if (driver->playback_handle) {
		if ((err = snd_pcm_drop (driver->playback_handle)) < 0) {
			jack_error ("ALSA: channel flush for playback "
				    "failed (%s)", snd_strerror (err));
			return -1;
		}
	}

	if (!driver->playback_handle
	    || driver->capture_and_playback_not_synced) {
		if (driver->capture_handle) {
			if ((err = snd_pcm_drop (driver->capture_handle)) < 0) {
				jack_error ("ALSA: channel flush for "
					    "capture failed (%s)",
					    snd_strerror (err));
				return -1;
			}
		}
	}

	if (driver->hw_monitoring) {
		driver->hw->set_input_monitor_mask (driver->hw, 0);
	}

	if (driver->midi && !driver->xrun_recovery)
		(driver->midi->stop)(driver->midi);

	return 0;
}

static int
alsa_driver_restart (alsa_driver_t *driver)
{
	int res;

	driver->xrun_recovery = 1;
    // JACK2
    /*
 	if ((res = driver->nt_stop((struct _jack_driver_nt *) driver))==0)
		res = driver->nt_start((struct _jack_driver_nt *) driver);
    */
    res = Restart();
	driver->xrun_recovery = 0;

	if (res && driver->midi)
		(driver->midi->stop)(driver->midi);

	return res;
}

static int
alsa_driver_xrun_recovery (alsa_driver_t *driver, float *delayed_usecs)
{
	snd_pcm_status_t *status;
	int res;

	snd_pcm_status_alloca(&status);

	if (driver->capture_handle) {
		if ((res = snd_pcm_status(driver->capture_handle, status))
		    < 0) {
			jack_error("status error: %s", snd_strerror(res));
		}
	} else {
		if ((res = snd_pcm_status(driver->playback_handle, status))
		    < 0) {
			jack_error("status error: %s", snd_strerror(res));
		}
	}

	if (snd_pcm_status_get_state(status) == SND_PCM_STATE_SUSPENDED)
	{
		jack_log("**** alsa_pcm: pcm in suspended state, resuming it" );
		if (driver->capture_handle) {
			if ((res = snd_pcm_prepare(driver->capture_handle))
			    < 0) {
				jack_error("error preparing after suspend: %s", snd_strerror(res));
			}
		} 
		if (driver->playback_handle) {
			if ((res = snd_pcm_prepare(driver->playback_handle))
			    < 0) {
				jack_error("error preparing after suspend: %s", snd_strerror(res));
			}
		}
	}

	if (snd_pcm_status_get_state(status) == SND_PCM_STATE_XRUN
	    && driver->process_count > XRUN_REPORT_DELAY) {
		struct timeval now, diff, tstamp;
		driver->xrun_count++;
		snd_pcm_status_get_tstamp(status,&now);
		snd_pcm_status_get_trigger_tstamp(status, &tstamp);
		timersub(&now, &tstamp, &diff);
		*delayed_usecs = diff.tv_sec * 1000000.0 + diff.tv_usec;
		jack_log("**** alsa_pcm: xrun of at least %.3f msecs",*delayed_usecs / 1000.0);
		if (driver->capture_handle) {
			jack_log("Repreparing capture");
			if ((res = snd_pcm_prepare(driver->capture_handle)) < 0) {
				jack_error("error preparing after xrun: %s", snd_strerror(res));
			}
		}
		if (driver->playback_handle) {
			jack_log("Repreparing playback");
			if ((res = snd_pcm_prepare(driver->playback_handle)) < 0) {
				jack_error("error preparing after xrun: %s", snd_strerror(res));
			}
		}
	}

	if (alsa_driver_restart (driver)) {
		return -1;
	}
	return 0;
}

void
alsa_driver_silence_untouched_channels (alsa_driver_t *driver,
					jack_nframes_t nframes)
{
	channel_t chn;
	jack_nframes_t buffer_frames =
		driver->frames_per_cycle * driver->playback_nperiods;

	for (chn = 0; chn < driver->playback_nchannels; chn++) {
		if (bitset_contains (driver->channels_not_done, chn)) {
			if (driver->silent[chn] < buffer_frames) {
				alsa_driver_silence_on_channel_no_mark (
					driver, chn, nframes);
				driver->silent[chn] += nframes;
			}
		}
	}
}

void
alsa_driver_set_clock_sync_status (alsa_driver_t *driver, channel_t chn,
				   ClockSyncStatus status)
{
	driver->clock_sync_data[chn] = status;
	alsa_driver_clock_sync_notify (driver, chn, status);
}

static int under_gdb = FALSE;

jack_nframes_t
alsa_driver_wait (alsa_driver_t *driver, int extra_fd, int *status, float
		  *delayed_usecs)
{
	snd_pcm_sframes_t avail = 0;
	snd_pcm_sframes_t capture_avail = 0;
	snd_pcm_sframes_t playback_avail = 0;
	int xrun_detected = FALSE;
	int need_capture;
	int need_playback;
	int retry_cnt = 0;
	unsigned int i;
	jack_time_t poll_enter;
	jack_time_t poll_ret = 0;

	*status = -1;
	*delayed_usecs = 0;

	need_capture = driver->capture_handle ? 1 : 0;

	if (extra_fd >= 0) {
		need_playback = 0;
	} else {
		need_playback = driver->playback_handle ? 1 : 0;
	}

  again:

	while ((need_playback || need_capture) && !xrun_detected) {

		int poll_result;
		unsigned int ci = 0;
		unsigned int nfds;
		unsigned short revents;

		nfds = 0;

		if (need_playback) {
			snd_pcm_poll_descriptors (driver->playback_handle,
						  &driver->pfd[0],
						  driver->playback_nfds);
			nfds += driver->playback_nfds;
		}

		if (need_capture) {
			snd_pcm_poll_descriptors (driver->capture_handle,
						  &driver->pfd[nfds],
						  driver->capture_nfds);
			ci = nfds;
			nfds += driver->capture_nfds;
		}

		/* ALSA doesn't set POLLERR in some versions of 0.9.X */

		for (i = 0; i < nfds; i++) {
			driver->pfd[i].events |= POLLERR;
		}

		if (extra_fd >= 0) {
			driver->pfd[nfds].fd = extra_fd;
			driver->pfd[nfds].events =
				POLLIN|POLLERR|POLLHUP|POLLNVAL;
			nfds++;
		}

		poll_enter = jack_get_microseconds ();

		if (poll_enter > driver->poll_next) {
			/*
			 * This processing cycle was delayed past the
			 * next due interrupt!  Do not account this as
			 * a wakeup delay:
			 */
			driver->poll_next = 0;
			driver->poll_late++;
		}

#ifdef __ANDROID__
		poll_result = poll (driver->pfd, nfds, -1);  //fix for sleep issue
#else
		poll_result = poll (driver->pfd, nfds, driver->poll_timeout);
#endif
		if (poll_result < 0) {

			if (errno == EINTR) {
				const char poll_log[] = "ALSA: poll interrupt";
				// this happens mostly when run
				// under gdb, or when exiting due to a signal
				if (under_gdb) {
					jack_info(poll_log);
					goto again;
				}
				jack_error(poll_log);
				*status = -2;
				return 0;
			}

			jack_error ("ALSA: poll call failed (%s)",
				    strerror (errno));
			*status = -3;
			return 0;

		}

		poll_ret = jack_get_microseconds ();

		if (poll_result == 0) {
			retry_cnt++;
			if(retry_cnt > MAX_RETRY_COUNT) {
				jack_error ("ALSA: poll time out, polled for %" PRIu64
					    " usecs, Reached max retry cnt = %d, Exiting",
					    poll_ret - poll_enter, MAX_RETRY_COUNT);
				*status = -5;
				return 0;
			}
			jack_error ("ALSA: poll time out, polled for %" PRIu64
				    " usecs, Retrying with a recovery, retry cnt = %d",
				    poll_ret - poll_enter, retry_cnt);
			*status = alsa_driver_xrun_recovery (driver, delayed_usecs);
			if(*status != 0) {
				jack_error ("ALSA: poll time out, recovery failed with status = %d", *status);
				return 0;
			}
		}

        // JACK2
        SetTime(poll_ret);

		if (extra_fd < 0) {
			if (driver->poll_next && poll_ret > driver->poll_next) {
				*delayed_usecs = poll_ret - driver->poll_next;
			}
			driver->poll_last = poll_ret;
			driver->poll_next = poll_ret + driver->period_usecs;
// JACK2
/*
			driver->engine->transport_cycle_start (driver->engine,
							       poll_ret);
*/
		}

#ifdef DEBUG_WAKEUP
		fprintf (stderr, "%" PRIu64 ": checked %d fds, started at %" PRIu64 " %" PRIu64 "  usecs since poll entered\n",
			 poll_ret, nfds, poll_enter, poll_ret - poll_enter);
#endif

		/* check to see if it was the extra FD that caused us
		 * to return from poll */

		if (extra_fd >= 0) {

			if (driver->pfd[nfds-1].revents == 0) {
				/* we timed out on the extra fd */

				*status = -4;
				return -1;
			}

			/* if POLLIN was the only bit set, we're OK */

			*status = 0;
			return (driver->pfd[nfds-1].revents == POLLIN) ? 0 : -1;
		}

		if (need_playback) {
			if (snd_pcm_poll_descriptors_revents
			    (driver->playback_handle, &driver->pfd[0],
			     driver->playback_nfds, &revents) < 0) {
				jack_error ("ALSA: playback revents failed");
				*status = -6;
				return 0;
			}

			if (revents & POLLNVAL) {
				jack_error ("ALSA: playback device disconnected");
				*status = -7;
				return 0;
			}

			if (revents & POLLERR) {
				xrun_detected = TRUE;
			}

			if (revents & POLLOUT) {
				need_playback = 0;
#ifdef DEBUG_WAKEUP
				fprintf (stderr, "%" PRIu64
					 " playback stream ready\n",
					 poll_ret);
#endif
			}
		}

		if (need_capture) {
			if (snd_pcm_poll_descriptors_revents
			    (driver->capture_handle, &driver->pfd[ci],
			     driver->capture_nfds, &revents) < 0) {
				jack_error ("ALSA: capture revents failed");
				*status = -6;
				return 0;
			}

			if (revents & POLLNVAL) {
				jack_error ("ALSA: capture device disconnected");
				*status = -7;
				return 0;
			}

			if (revents & POLLERR) {
				xrun_detected = TRUE;
			}

			if (revents & POLLIN) {
				need_capture = 0;
#ifdef DEBUG_WAKEUP
				fprintf (stderr, "%" PRIu64
					 " capture stream ready\n",
					 poll_ret);
#endif
			}
		}
	}

	if (driver->capture_handle) {
		if ((capture_avail = snd_pcm_avail_update (
			     driver->capture_handle)) < 0) {
			if (capture_avail == -EPIPE) {
				xrun_detected = TRUE;
			} else {
				jack_error ("unknown ALSA avail_update return"
					    " value (%u)", capture_avail);
			}
		}
	} else {
		/* odd, but see min() computation below */
		capture_avail = INT_MAX;
	}

	if (driver->playback_handle) {
		if ((playback_avail = snd_pcm_avail_update (
			     driver->playback_handle)) < 0) {
			if (playback_avail == -EPIPE) {
				xrun_detected = TRUE;
			} else {
				jack_error ("unknown ALSA avail_update return"
					    " value (%u)", playback_avail);
			}
		}
	} else {
		/* odd, but see min() computation below */
		playback_avail = INT_MAX;
	}

	if (xrun_detected) {
		*status = alsa_driver_xrun_recovery (driver, delayed_usecs);
		return 0;
	}

	*status = 0;
	driver->last_wait_ust = poll_ret;

	avail = capture_avail < playback_avail ? capture_avail : playback_avail;

#ifdef DEBUG_WAKEUP
	fprintf (stderr, "wakeup complete, avail = %lu, pavail = %lu "
		 "cavail = %lu\n",
		 avail, playback_avail, capture_avail);
#endif

	/* mark all channels not done for now. read/write will change this */

	bitset_copy (driver->channels_not_done, driver->channels_done);

	/* constrain the available count to the nearest (round down) number of
	   periods.
	*/

	return avail - (avail % driver->frames_per_cycle);
}


int
alsa_driver_read (alsa_driver_t *driver, jack_nframes_t nframes)
{
	snd_pcm_sframes_t contiguous;
	snd_pcm_sframes_t nread;
	snd_pcm_uframes_t offset;
	jack_nframes_t  orig_nframes;
//	jack_default_audio_sample_t* buf;
//	channel_t chn;
//	JSList *node;
//	jack_port_t* port;
	int err;

	if (nframes > driver->frames_per_cycle) {
		return -1;
	}

// JACK2
/*
	if (driver->engine->freewheeling) {
		return 0;
	}
*/
	if (driver->midi)
		(driver->midi->read)(driver->midi, nframes);

	if (!driver->capture_handle) {
		return 0;
	}

	nread = 0;
	contiguous = 0;
	orig_nframes = nframes;

	while (nframes) {

		contiguous = nframes;

		if (alsa_driver_get_channel_addresses (
			    driver,
			    (snd_pcm_uframes_t *) &contiguous,
			    (snd_pcm_uframes_t *) 0,
			    &offset, 0) < 0) {
			return -1;
		}
// JACK2
/*
		for (chn = 0, node = driver->capture_ports; node;
		     node = jack_slist_next (node), chn++) {

			port = (jack_port_t *) node->data;

			if (!jack_port_connected (port)) {
				// no-copy optimization
				continue;
			}
			buf = jack_port_get_buffer (port, orig_nframes);
			alsa_driver_read_from_channel (driver, chn,
				buf + nread, contiguous);
		}
*/
        ReadInput(orig_nframes, contiguous, nread);

		if ((err = snd_pcm_mmap_commit (driver->capture_handle,
				offset, contiguous)) < 0) {
			jack_error ("ALSA: could not complete read of %"
				PRIu32 " frames: error = %d", contiguous, err);
			return -1;
		}

		nframes -= contiguous;
		nread += contiguous;
	}

	return 0;
}

int
alsa_driver_write (alsa_driver_t* driver, jack_nframes_t nframes)
{
//	channel_t chn;
//	JSList *node;
//	JSList *mon_node;
//	jack_default_audio_sample_t* buf;
//	jack_default_audio_sample_t* monbuf;
	jack_nframes_t orig_nframes;
	snd_pcm_sframes_t nwritten;
	snd_pcm_sframes_t contiguous;
	snd_pcm_uframes_t offset;
//	jack_port_t *port;
	int err;

	driver->process_count++;

// JACK2
/*
	if (!driver->playback_handle || driver->engine->freewheeling) {
		return 0;
	}
*/
	if (!driver->playback_handle) {
		return 0;
	}

	if (nframes > driver->frames_per_cycle) {
		return -1;
	}

	if (driver->midi)
		(driver->midi->write)(driver->midi, nframes);

	nwritten = 0;
	contiguous = 0;
	orig_nframes = nframes;

	/* check current input monitor request status */

	driver->input_monitor_mask = 0;

// JACK2
/*
	for (chn = 0, node = driver->capture_ports; node;
	     node = jack_slist_next (node), chn++) {
		if (((jack_port_t *) node->data)->shared->monitor_requests) {
			driver->input_monitor_mask |= (1<<chn);
		}
	}
*/
    MonitorInput();

	if (driver->hw_monitoring) {
		if ((driver->hw->input_monitor_mask
		     != driver->input_monitor_mask)
		    && !driver->all_monitor_in) {
			driver->hw->set_input_monitor_mask (
				driver->hw, driver->input_monitor_mask);
		}
	}

	while (nframes) {

		contiguous = nframes;

		if (alsa_driver_get_channel_addresses (
			    driver,
			    (snd_pcm_uframes_t *) 0,
			    (snd_pcm_uframes_t *) &contiguous,
			    0, &offset) < 0) {
			return -1;
		}

// JACK2
/*
		for (chn = 0, node = driver->playback_ports, mon_node=driver->monitor_ports;
		     node;
		     node = jack_slist_next (node), chn++) {

			port = (jack_port_t *) node->data;

			if (!jack_port_connected (port)) {
				continue;
			}
			buf = jack_port_get_buffer (port, orig_nframes);
			alsa_driver_write_to_channel (driver, chn,
				buf + nwritten, contiguous);

			if (mon_node) {
				port = (jack_port_t *) mon_node->data;
				if (!jack_port_connected (port)) {
					continue;
				}
				monbuf = jack_port_get_buffer (port, orig_nframes);
				memcpy (monbuf + nwritten, buf + nwritten, contiguous * sizeof(jack_default_audio_sample_t));
				mon_node = jack_slist_next (mon_node);
			}
		}
*/

        // JACK2
        WriteOutput(orig_nframes, contiguous, nwritten);

		if (!bitset_empty (driver->channels_not_done)) {
			alsa_driver_silence_untouched_channels (driver,
								contiguous);
		}

		if ((err = snd_pcm_mmap_commit (driver->playback_handle,
				offset, contiguous)) < 0) {
			jack_error ("ALSA: could not complete playback of %"
				PRIu32 " frames: error = %d", contiguous, err);
			if (err != -EPIPE && err != -ESTRPIPE)
				return -1;
		}

		nframes -= contiguous;
		nwritten += contiguous;
	}

	return 0;
}

#if 0
static int  /* UNUSED */
alsa_driver_change_sample_clock (alsa_driver_t *driver, SampleClockMode mode)
{
	return driver->hw->change_sample_clock (driver->hw, mode);
}

static void  /* UNUSED */
alsa_driver_request_all_monitor_input (alsa_driver_t *driver, int yn)

{
	if (driver->hw_monitoring) {
		if (yn) {
			driver->hw->set_input_monitor_mask (driver->hw, ~0U);
		} else {
			driver->hw->set_input_monitor_mask (
				driver->hw, driver->input_monitor_mask);
		}
	}

	driver->all_monitor_in = yn;
}

static void  /* UNUSED */
alsa_driver_set_hw_monitoring (alsa_driver_t *driver, int yn)
{
	if (yn) {
		driver->hw_monitoring = TRUE;

		if (driver->all_monitor_in) {
			driver->hw->set_input_monitor_mask (driver->hw, ~0U);
		} else {
			driver->hw->set_input_monitor_mask (
				driver->hw, driver->input_monitor_mask);
		}
	} else {
		driver->hw_monitoring = FALSE;
		driver->hw->set_input_monitor_mask (driver->hw, 0);
	}
}

static ClockSyncStatus  /* UNUSED */
alsa_driver_clock_sync_status (channel_t chn)
{
	return Lock;
}
#endif

void
alsa_driver_delete (alsa_driver_t *driver)
{
	JSList *node;

	if (driver->midi)
		(driver->midi->destroy)(driver->midi);

	for (node = driver->clock_sync_listeners; node;
	     node = jack_slist_next (node)) {
		free (node->data);
	}
	jack_slist_free (driver->clock_sync_listeners);

	if (driver->ctl_handle) {
		snd_ctl_close (driver->ctl_handle);
		driver->ctl_handle = 0;
	}

	if (driver->capture_handle) {
		snd_pcm_close (driver->capture_handle);
		driver->capture_handle = 0;
	}

	if (driver->playback_handle) {
		snd_pcm_close (driver->playback_handle);
		driver->capture_handle = 0;
	}

	if (driver->capture_hw_params) {
		snd_pcm_hw_params_free (driver->capture_hw_params);
		driver->capture_hw_params = 0;
	}

	if (driver->playback_hw_params) {
		snd_pcm_hw_params_free (driver->playback_hw_params);
		driver->playback_hw_params = 0;
	}

	if (driver->capture_sw_params) {
		snd_pcm_sw_params_free (driver->capture_sw_params);
		driver->capture_sw_params = 0;
	}

	if (driver->playback_sw_params) {
		snd_pcm_sw_params_free (driver->playback_sw_params);
		driver->playback_sw_params = 0;
	}

	if (driver->pfd) {
		free (driver->pfd);
	}

	if (driver->hw) {
		driver->hw->release (driver->hw);
		driver->hw = 0;
	}
	free(driver->alsa_name_playback);
	free(driver->alsa_name_capture);
	free(driver->alsa_driver);

	alsa_driver_release_channel_dependent_memory (driver);
    //JACK2
    //jack_driver_nt_finish ((jack_driver_nt_t *) driver);
	free (driver);
}

static char*
discover_alsa_using_apps ()
{
        char found[2048];
        char command[5192];
        char* path = getenv ("PATH");
        char* dir;
        size_t flen = 0;
        int card;
        int device;
        size_t cmdlen = 0;

        if (!path) {
                return NULL;
        }

        /* look for lsof and give up if its not in PATH */

        path = strdup (path);
        dir = strtok (path, ":");
        while (dir) {
                char maybe[PATH_MAX+1];
                snprintf (maybe, sizeof(maybe), "%s/lsof", dir);
                if (access (maybe, X_OK) == 0) {
                        break;
                }
                dir = strtok (NULL, ":");
        }
        free (path);

        if (!dir) {
                return NULL;
        }

        snprintf (command, sizeof (command), "lsof -Fc0 ");
        cmdlen = strlen (command);

        for (card = 0; card < 8; ++card) {
                for (device = 0; device < 8; ++device)  {
                        char buf[32];

                        snprintf (buf, sizeof (buf), "/dev/snd/pcmC%dD%dp", card, device);
                        if (access (buf, F_OK) == 0) {
                                snprintf (command+cmdlen, sizeof(command)-cmdlen, "%s ", buf);
                        }
                        cmdlen = strlen (command);

                        snprintf (buf, sizeof (buf), "/dev/snd/pcmC%dD%dc", card, device);
                        if (access (buf, F_OK) == 0) {
                                snprintf (command+cmdlen, sizeof(command)-cmdlen, "%s ", buf);
                        }
                        cmdlen = strlen (command);
                }
        }

        FILE* f = popen (command, "r");

        if (!f) {
                return NULL;
        }

        while (!feof (f)) {
                char buf[1024]; /* lsof doesn't output much */

                if (!fgets (buf, sizeof (buf), f)) {
                        break;
                }

                if (*buf != 'p') {
                        return NULL;
                }

                /* buf contains NULL as a separator between the process field and the command field */
                char *pid = buf;
                ++pid; /* skip leading 'p' */
                char *cmd = pid;

                /* skip to NULL */
                while (*cmd) {
                        ++cmd;
                }
                ++cmd; /* skip to 'c' */
                ++cmd; /* skip to first character of command */

                snprintf (found+flen, sizeof (found)-flen, "%s (process ID %s)\n", cmd, pid);
                flen = strlen (found);

                if (flen >= sizeof (found)) {
                        break;
                }
        }

        pclose (f);

        if (flen) {
                return strdup (found);
        } else {
                return NULL;
        }
}

jack_driver_t *
alsa_driver_new (char *name, char *playback_alsa_device,
		 char *capture_alsa_device,
		 jack_client_t *client,
		 jack_nframes_t frames_per_cycle,
		 jack_nframes_t user_nperiods,
		 jack_nframes_t rate,
		 int hw_monitoring,
		 int hw_metering,
		 int capturing,
		 int playing,
		 DitherAlgorithm dither,
		 int soft_mode,
		 int monitor,
		 int user_capture_nchnls,
		 int user_playback_nchnls,
		 int shorts_first,
		 jack_nframes_t capture_latency,
		 jack_nframes_t playback_latency,
		 alsa_midi_t *midi_driver
		 )
{
	int err;
    char* current_apps;
	alsa_driver_t *driver;

	jack_info ("creating alsa driver ... %s|%s|%" PRIu32 "|%" PRIu32
		"|%" PRIu32"|%" PRIu32"|%" PRIu32 "|%s|%s|%s|%s",
		playing ? playback_alsa_device : "-",
		capturing ? capture_alsa_device : "-",
		frames_per_cycle, user_nperiods, rate,
		user_capture_nchnls,user_playback_nchnls,
		hw_monitoring ? "hwmon": "nomon",
		hw_metering ? "hwmeter":"swmeter",
		soft_mode ? "soft-mode":"-",
		shorts_first ? "16bit":"32bit");

	driver = (alsa_driver_t *) calloc (1, sizeof (alsa_driver_t));

	jack_driver_nt_init ((jack_driver_nt_t *) driver);

    // JACK2
    /*
	driver->nt_attach = (JackDriverNTAttachFunction) alsa_driver_attach;
    driver->nt_detach = (JackDriverNTDetachFunction) alsa_driver_detach;
	driver->read = (JackDriverReadFunction) alsa_driver_read;
	driver->write = (JackDriverReadFunction) alsa_driver_write;
	driver->null_cycle = (JackDriverNullCycleFunction) alsa_driver_null_cycle;
	driver->nt_bufsize = (JackDriverNTBufSizeFunction) alsa_driver_bufsize;
	driver->nt_start = (JackDriverNTStartFunction) alsa_driver_start;
	driver->nt_stop = (JackDriverNTStopFunction) alsa_driver_stop;
	driver->nt_run_cycle = (JackDriverNTRunCycleFunction) alsa_driver_run_cycle;
    */

	driver->playback_handle = NULL;
	driver->capture_handle = NULL;
	driver->ctl_handle = 0;
	driver->hw = 0;
	driver->capture_and_playback_not_synced = FALSE;
	driver->max_nchannels = 0;
	driver->playback_nchannels = user_playback_nchnls;
	driver->capture_nchannels = user_capture_nchnls;
	driver->playback_sample_bytes = (shorts_first ? 2:4);
	driver->capture_sample_bytes = (shorts_first ? 2:4);
	driver->capture_frame_latency = capture_latency;
	driver->playback_frame_latency = playback_latency;

	driver->playback_addr = 0;
	driver->capture_addr = 0;
	driver->playback_interleave_skip = NULL;
	driver->capture_interleave_skip = NULL;


	driver->silent = 0;
	driver->all_monitor_in = FALSE;
	driver->with_monitor_ports = monitor;

	driver->clock_mode = ClockMaster; /* XXX is it? */
	driver->input_monitor_mask = 0;   /* XXX is it? */

	driver->capture_ports = 0;
	driver->playback_ports = 0;
	driver->monitor_ports = 0;

	driver->pfd = 0;
	driver->playback_nfds = 0;
	driver->capture_nfds = 0;

	driver->dither = dither;
	driver->soft_mode = soft_mode;

	driver->quirk_bswap = 0;

	pthread_mutex_init (&driver->clock_sync_lock, 0);
	driver->clock_sync_listeners = 0;

	driver->poll_late = 0;
	driver->xrun_count = 0;
	driver->process_count = 0;

	driver->alsa_name_playback = strdup (playback_alsa_device);
	driver->alsa_name_capture = strdup (capture_alsa_device);

	driver->midi = midi_driver;
	driver->xrun_recovery = 0;

	if (alsa_driver_check_card_type (driver)) {
		alsa_driver_delete (driver);
		return NULL;
	}

	alsa_driver_hw_specific (driver, hw_monitoring, hw_metering);

	if (playing) {
		if (snd_pcm_open (&driver->playback_handle,
				  playback_alsa_device,
				  SND_PCM_STREAM_PLAYBACK,
				  SND_PCM_NONBLOCK) < 0) {
			switch (errno) {
			case EBUSY:
#ifdef __ANDROID__
                jack_error ("\n\nATTENTION: The playback device \"%s\" is "
                            "already in use. Please stop the"
                            " application using it and "
                            "run JACK again",
                            playback_alsa_device);
#else
                current_apps = discover_alsa_using_apps ();
                if (current_apps) {
                        jack_error ("\n\nATTENTION: The playback device \"%s\" is "
                                    "already in use. The following applications "
                                    " are using your soundcard(s) so you should "
                                    " check them and stop them as necessary before "
                                    " trying to start JACK again:\n\n%s",
                                    playback_alsa_device,
                                    current_apps);
                        free (current_apps);
                } else {
                        jack_error ("\n\nATTENTION: The playback device \"%s\" is "
                                    "already in use. Please stop the"
                                    " application using it and "
                                    "run JACK again",
                                    playback_alsa_device);
                }
#endif
                alsa_driver_delete (driver);
				return NULL;

			case EPERM:
				jack_error ("you do not have permission to open "
					    "the audio device \"%s\" for playback",
					    playback_alsa_device);
				alsa_driver_delete (driver);
				return NULL;
				break;
			}

			driver->playback_handle = NULL;
		}

		if (driver->playback_handle) {
			snd_pcm_nonblock (driver->playback_handle, 0);
		}
	}

	if (capturing) {
		if (snd_pcm_open (&driver->capture_handle,
				  capture_alsa_device,
				  SND_PCM_STREAM_CAPTURE,
				  SND_PCM_NONBLOCK) < 0) {
			switch (errno) {
			case EBUSY:
#ifdef __ANDROID__
                jack_error ("\n\nATTENTION: The capture (recording) device \"%s\" is "
                            "already in use",
                            capture_alsa_device);
#else
                current_apps = discover_alsa_using_apps ();
                if (current_apps) {
                        jack_error ("\n\nATTENTION: The capture device \"%s\" is "
                                    "already in use. The following applications "
                                    " are using your soundcard(s) so you should "
                                    " check them and stop them as necessary before "
                                    " trying to start JACK again:\n\n%s",
                                    capture_alsa_device,
                                    current_apps);
                        free (current_apps);
                } else {
                        jack_error ("\n\nATTENTION: The capture (recording) device \"%s\" is "
                                    "already in use. Please stop the"
                                    " application using it and "
                                    "run JACK again",
                                    capture_alsa_device);
                }
				alsa_driver_delete (driver);
				return NULL;
#endif
				break;

			case EPERM:
				jack_error ("you do not have permission to open "
					    "the audio device \"%s\" for capture",
					    capture_alsa_device);
				alsa_driver_delete (driver);
				return NULL;
				break;
			}

			driver->capture_handle = NULL;
		}

		if (driver->capture_handle) {
			snd_pcm_nonblock (driver->capture_handle, 0);
		}
	}

	if (driver->playback_handle == NULL) {
		if (playing) {

			/* they asked for playback, but we can't do it */

			jack_error ("ALSA: Cannot open PCM device %s for "
				    "playback. Falling back to capture-only"
				    " mode", name);

			if (driver->capture_handle == NULL) {
				/* can't do anything */
				alsa_driver_delete (driver);
				return NULL;
			}

			playing = FALSE;
		}
	}

	if (driver->capture_handle == NULL) {
		if (capturing) {

			/* they asked for capture, but we can't do it */

			jack_error ("ALSA: Cannot open PCM device %s for "
				    "capture. Falling back to playback-only"
				    " mode", name);

			if (driver->playback_handle == NULL) {
				/* can't do anything */
				alsa_driver_delete (driver);
				return NULL;
			}

			capturing = FALSE;
		}
	}

	driver->playback_hw_params = 0;
	driver->capture_hw_params = 0;
	driver->playback_sw_params = 0;
	driver->capture_sw_params = 0;

	if (driver->playback_handle) {
		if ((err = snd_pcm_hw_params_malloc (
			     &driver->playback_hw_params)) < 0) {
			jack_error ("ALSA: could not allocate playback hw"
				    " params structure");
			alsa_driver_delete (driver);
			return NULL;
		}

		if ((err = snd_pcm_sw_params_malloc (
			     &driver->playback_sw_params)) < 0) {
			jack_error ("ALSA: could not allocate playback sw"
				    " params structure");
			alsa_driver_delete (driver);
			return NULL;
		}
	}

	if (driver->capture_handle) {
		if ((err = snd_pcm_hw_params_malloc (
			     &driver->capture_hw_params)) < 0) {
			jack_error ("ALSA: could not allocate capture hw"
				    " params structure");
			alsa_driver_delete (driver);
			return NULL;
		}

		if ((err = snd_pcm_sw_params_malloc (
			     &driver->capture_sw_params)) < 0) {
			jack_error ("ALSA: could not allocate capture sw"
				    " params structure");
			alsa_driver_delete (driver);
			return NULL;
		}
	}

	if (alsa_driver_set_parameters (driver, frames_per_cycle,
					user_nperiods, rate)) {
		alsa_driver_delete (driver);
		return NULL;
	}

	driver->capture_and_playback_not_synced = FALSE;

	if (driver->capture_handle && driver->playback_handle) {
		if (snd_pcm_link (driver->playback_handle,
				  driver->capture_handle) != 0) {
			driver->capture_and_playback_not_synced = TRUE;
		}
	}

	driver->client = client;

	return (jack_driver_t *) driver;
}

int
alsa_driver_listen_for_clock_sync_status (alsa_driver_t *driver,
					  ClockSyncListenerFunction func,
					  void *arg)
{
	ClockSyncListener *csl;

	csl = (ClockSyncListener *) malloc (sizeof (ClockSyncListener));
	csl->function = func;
	csl->arg = arg;
	csl->id = driver->next_clock_sync_listener_id++;

	pthread_mutex_lock (&driver->clock_sync_lock);
	driver->clock_sync_listeners =
		jack_slist_prepend (driver->clock_sync_listeners, csl);
	pthread_mutex_unlock (&driver->clock_sync_lock);
	return csl->id;
}

int
alsa_driver_stop_listening_to_clock_sync_status (alsa_driver_t *driver,
						 unsigned int which)

{
	JSList *node;
	int ret = -1;
	pthread_mutex_lock (&driver->clock_sync_lock);
	for (node = driver->clock_sync_listeners; node;
	     node = jack_slist_next (node)) {
		if (((ClockSyncListener *) node->data)->id == which) {
			driver->clock_sync_listeners =
				jack_slist_remove_link (
					driver->clock_sync_listeners, node);
			free (node->data);
			jack_slist_free_1 (node);
			ret = 0;
			break;
		}
	}
	pthread_mutex_unlock (&driver->clock_sync_lock);
	return ret;
}

void
alsa_driver_clock_sync_notify (alsa_driver_t *driver, channel_t chn,
			       ClockSyncStatus status)
{
	JSList *node;

	pthread_mutex_lock (&driver->clock_sync_lock);
	for (node = driver->clock_sync_listeners; node;
	     node = jack_slist_next (node)) {
		ClockSyncListener *csl = (ClockSyncListener *) node->data;
		csl->function (chn, status, csl->arg);
	}
	pthread_mutex_unlock (&driver->clock_sync_lock);

}

/* DRIVER "PLUGIN" INTERFACE */

const char driver_client_name[] = "alsa_pcm";

void
driver_finish (jack_driver_t *driver)
{
	alsa_driver_delete ((alsa_driver_t *) driver);
}