Mercurial > sdl-ios-xcode
changeset 3818:49eadd6e8962 SDL-ryan-multiple-audio-device
Mangled ALSA dynamic loading...static loading will still work if you have the
right libraries, but this is expected to break in general cases as we start
dealing with different symbol versions, etc (but may work with, say,
distro-specific packages, etc).
| author | Ryan C. Gordon <icculus@icculus.org> |
|---|---|
| date | Fri, 06 Oct 2006 19:45:11 +0000 |
| parents | 103bbe13f5eb |
| children | b225d9820ee3 |
| files | src/audio/alsa/SDL_alsa_audio.c |
| diffstat | 1 files changed, 145 insertions(+), 213 deletions(-) [+] |
line wrap: on
line diff
--- a/src/audio/alsa/SDL_alsa_audio.c Fri Oct 06 04:49:48 2006 +0000 +++ b/src/audio/alsa/SDL_alsa_audio.c Fri Oct 06 19:45:11 2006 +0000 @@ -25,6 +25,9 @@ #include <sys/types.h> #include <signal.h> /* For kill() */ +#include <dlfcn.h> +#include <errno.h> +#include <string.h> #include "SDL_timer.h" #include "SDL_audio.h" @@ -32,14 +35,6 @@ #include "../SDL_audio_c.h" #include "SDL_alsa_audio.h" -#ifdef SDL_AUDIO_DRIVER_ALSA_DYNAMIC -#include <dlfcn.h> -#include "SDL_name.h" -#include "SDL_loadso.h" -#else -#define SDL_NAME(X) X -#endif - /* The tag name used by ALSA audio */ #define DRIVER_NAME "alsa" @@ -54,149 +49,111 @@ static Uint8 *ALSA_GetAudioBuf(_THIS); static void ALSA_CloseAudio(_THIS); +static int (*ALSA_snd_pcm_open) + (snd_pcm_t **, const char *, snd_pcm_stream_t, int); +static int (*ALSA_snd_pcm_close)(snd_pcm_t * pcm); +static snd_pcm_sframes_t(*ALSA_snd_pcm_writei) + (snd_pcm_t *,const void *, snd_pcm_uframes_t); +static int (*ALSA_snd_pcm_resume)(snd_pcm_t *); +static int (*ALSA_snd_pcm_prepare)(snd_pcm_t *); +static int (*ALSA_snd_pcm_drain)(snd_pcm_t *); +static const char *(*ALSA_snd_strerror)(int); +static size_t(*ALSA_snd_pcm_hw_params_sizeof)(void); +static size_t(*ALSA_snd_pcm_sw_params_sizeof)(void); +static int (*ALSA_snd_pcm_hw_params_any)(snd_pcm_t *, snd_pcm_hw_params_t *); +static int (*ALSA_snd_pcm_hw_params_set_access) + (snd_pcm_t *, snd_pcm_hw_params_t *, snd_pcm_access_t); +static int (*ALSA_snd_pcm_hw_params_set_format) + (snd_pcm_t *, snd_pcm_hw_params_t *, snd_pcm_format_t); +static int (*ALSA_snd_pcm_hw_params_set_channels) + (snd_pcm_t *, snd_pcm_hw_params_t *, unsigned int); +static int (*ALSA_snd_pcm_hw_params_get_channels)(const snd_pcm_hw_params_t *); +static unsigned int (*ALSA_snd_pcm_hw_params_set_rate_near) + (snd_pcm_t *, snd_pcm_hw_params_t *, unsigned int, int *); +static snd_pcm_uframes_t (*ALSA_snd_pcm_hw_params_set_period_size_near) + (snd_pcm_t *, snd_pcm_hw_params_t *, snd_pcm_uframes_t, int *); +static snd_pcm_sframes_t (*ALSA_snd_pcm_hw_params_get_period_size) + (const snd_pcm_hw_params_t *); +static unsigned int (*ALSA_snd_pcm_hw_params_set_periods_near) + (snd_pcm_t *,snd_pcm_hw_params_t *, unsigned int, int *); +static int (*ALSA_snd_pcm_hw_params_get_periods)(snd_pcm_hw_params_t *); +static int (*ALSA_snd_pcm_hw_params)(snd_pcm_t *, snd_pcm_hw_params_t *); +static int (*ALSA_snd_pcm_sw_params_current)(snd_pcm_t*, snd_pcm_sw_params_t*); +static int (*ALSA_snd_pcm_sw_params_set_start_threshold) + (snd_pcm_t *, snd_pcm_sw_params_t *, snd_pcm_uframes_t); +static int (*ALSA_snd_pcm_sw_params_set_avail_min) + (snd_pcm_t *, snd_pcm_sw_params_t *, snd_pcm_uframes_t); +static int (*ALSA_snd_pcm_sw_params)(snd_pcm_t *, snd_pcm_sw_params_t *); +static int (*ALSA_snd_pcm_nonblock)(snd_pcm_t *, int); +#define snd_pcm_hw_params_sizeof ALSA_snd_pcm_hw_params_sizeof +#define snd_pcm_sw_params_sizeof ALSA_snd_pcm_sw_params_sizeof + + #ifdef SDL_AUDIO_DRIVER_ALSA_DYNAMIC static const char *alsa_library = SDL_AUDIO_DRIVER_ALSA_DYNAMIC; static void *alsa_handle = NULL; -static int alsa_loaded = 0; -static int (*SDL_snd_pcm_open) (snd_pcm_t ** pcm, const char *name, - snd_pcm_stream_t stream, int mode); -static int (*SDL_NAME(snd_pcm_open)) (snd_pcm_t ** pcm, const char *name, - snd_pcm_stream_t stream, int mode); -static int (*SDL_NAME(snd_pcm_close)) (snd_pcm_t * pcm); -static snd_pcm_sframes_t(*SDL_NAME(snd_pcm_writei)) (snd_pcm_t * pcm, - const void *buffer, - snd_pcm_uframes_t size); -static int (*SDL_NAME(snd_pcm_resume)) (snd_pcm_t * pcm); -static int (*SDL_NAME(snd_pcm_prepare)) (snd_pcm_t * pcm); -static int (*SDL_NAME(snd_pcm_drain)) (snd_pcm_t * pcm); -static const char *(*SDL_NAME(snd_strerror)) (int errnum); -static size_t(*SDL_NAME(snd_pcm_hw_params_sizeof)) (void); -static size_t(*SDL_NAME(snd_pcm_sw_params_sizeof)) (void); -static int (*SDL_NAME(snd_pcm_hw_params_any)) (snd_pcm_t * pcm, - snd_pcm_hw_params_t * params); -static int (*SDL_NAME(snd_pcm_hw_params_set_access)) (snd_pcm_t * pcm, - snd_pcm_hw_params_t * - params, - snd_pcm_access_t - access); -static int (*SDL_NAME(snd_pcm_hw_params_set_format)) (snd_pcm_t * pcm, - snd_pcm_hw_params_t * - params, - snd_pcm_format_t val); -static int (*SDL_NAME(snd_pcm_hw_params_set_channels)) (snd_pcm_t * pcm, - snd_pcm_hw_params_t * - params, - unsigned int val); -static int (*SDL_NAME(snd_pcm_hw_params_get_channels)) (const - snd_pcm_hw_params_t * - params); -static unsigned int - (*SDL_NAME(snd_pcm_hw_params_set_rate_near)) (snd_pcm_t * - pcm, - snd_pcm_hw_params_t - * params, - unsigned int val, int *dir); -static snd_pcm_uframes_t - (*SDL_NAME(snd_pcm_hw_params_set_period_size_near)) (snd_pcm_t * pcm, - snd_pcm_hw_params_t - * params, - snd_pcm_uframes_t - val, int *dir); -static snd_pcm_sframes_t - (*SDL_NAME(snd_pcm_hw_params_get_period_size)) (const - snd_pcm_hw_params_t - * params); -static unsigned int - (*SDL_NAME(snd_pcm_hw_params_set_periods_near)) (snd_pcm_t * pcm, - snd_pcm_hw_params_t - * params, - unsigned int val, - int *dir); -static int (*SDL_NAME(snd_pcm_hw_params_get_periods)) (snd_pcm_hw_params_t * - params); -static int (*SDL_NAME(snd_pcm_hw_params)) (snd_pcm_t * pcm, - snd_pcm_hw_params_t * params); -/* -*/ -static int (*SDL_NAME(snd_pcm_sw_params_current)) (snd_pcm_t * pcm, - snd_pcm_sw_params_t * - swparams); -static int (*SDL_NAME(snd_pcm_sw_params_set_start_threshold)) (snd_pcm_t * - pcm, - snd_pcm_sw_params_t - * params, - snd_pcm_uframes_t - val); -static int (*SDL_NAME(snd_pcm_sw_params_set_avail_min)) (snd_pcm_t * pcm, - snd_pcm_sw_params_t - * params, - snd_pcm_uframes_t - val); -static int (*SDL_NAME(snd_pcm_sw_params)) (snd_pcm_t * pcm, - snd_pcm_sw_params_t * params); -static int (*SDL_NAME(snd_pcm_nonblock)) (snd_pcm_t * pcm, int nonblock); -#define snd_pcm_hw_params_sizeof SDL_NAME(snd_pcm_hw_params_sizeof) -#define snd_pcm_sw_params_sizeof SDL_NAME(snd_pcm_sw_params_sizeof) +static int +load_alsa_sym(const char *fn, void **addr) +{ +#if HAVE_DLVSYM + *addr = dlvsym(alsa_handle, fn, "ALSA_0.9"); + if (*addr == NULL) +#endif + { + *addr = dlsym(alsa_handle, fn); + if (*addr == NULL) { + return 0; + } + } + + return 1; +} /* cast funcs to char* first, to please GCC's strict aliasing rules. */ -static struct +#define SDL_ALSA_SYM(x) \ + if (!load_alsa_sym(#x, (void **) (char *) &ALSA_##x)) return -1 +#else +#define SDL_ALSA_SYM(x) ALSA_##x = x +#endif + +static int load_alsa_syms(void) { - const char *name; - void **func; -} alsa_functions[] = { - { - "snd_pcm_open", (void **) (char *) &SDL_NAME(snd_pcm_open)}, { - "snd_pcm_close", (void **) (char *) &SDL_NAME(snd_pcm_close)}, { - "snd_pcm_writei", (void **) (char *) &SDL_NAME(snd_pcm_writei)}, { - "snd_pcm_resume", (void **) (char *) &SDL_NAME(snd_pcm_resume)}, { - "snd_pcm_prepare", (void **) (char *) &SDL_NAME(snd_pcm_prepare)}, { - "snd_pcm_drain", (void **) (char *) &SDL_NAME(snd_pcm_drain)}, { - "snd_strerror", (void **) (char *) &SDL_NAME(snd_strerror)}, { - "snd_pcm_hw_params_sizeof", - (void **) (char *) &SDL_NAME(snd_pcm_hw_params_sizeof)}, { - "snd_pcm_sw_params_sizeof", - (void **) (char *) &SDL_NAME(snd_pcm_sw_params_sizeof)}, { - "snd_pcm_hw_params_any", - (void **) (char *) &SDL_NAME(snd_pcm_hw_params_any)}, { - "snd_pcm_hw_params_set_access", - (void **) (char *) &SDL_NAME(snd_pcm_hw_params_set_access)}, { - "snd_pcm_hw_params_set_format", - (void **) (char *) &SDL_NAME(snd_pcm_hw_params_set_format)}, { - "snd_pcm_hw_params_set_channels", - (void **) (char *) &SDL_NAME(snd_pcm_hw_params_set_channels)}, { - "snd_pcm_hw_params_get_channels", - (void **) (char *) &SDL_NAME(snd_pcm_hw_params_get_channels)}, { - "snd_pcm_hw_params_set_rate_near", - (void **) (char *) &SDL_NAME(snd_pcm_hw_params_set_rate_near)}, { - "snd_pcm_hw_params_set_period_size_near", (void **) (char *) - &SDL_NAME(snd_pcm_hw_params_set_period_size_near)}, { - "snd_pcm_hw_params_get_period_size", - (void **) (char *) &SDL_NAME(snd_pcm_hw_params_get_period_size)}, - { - "snd_pcm_hw_params_set_periods_near", (void **) (char *) - &SDL_NAME(snd_pcm_hw_params_set_periods_near)}, { - "snd_pcm_hw_params_get_periods", - (void **) (char *) &SDL_NAME(snd_pcm_hw_params_get_periods)}, { - "snd_pcm_hw_params", (void **) (char *) &SDL_NAME(snd_pcm_hw_params)}, { - "snd_pcm_sw_params_current", - (void **) (char *) &SDL_NAME(snd_pcm_sw_params_current)}, { - "snd_pcm_sw_params_set_start_threshold", (void **) (char *) - &SDL_NAME(snd_pcm_sw_params_set_start_threshold)}, { - "snd_pcm_sw_params_set_avail_min", - (void **) (char *) &SDL_NAME(snd_pcm_sw_params_set_avail_min)}, { - "snd_pcm_sw_params", (void **) (char *) &SDL_NAME(snd_pcm_sw_params)}, { -"snd_pcm_nonblock", (void **) (char *) &SDL_NAME(snd_pcm_nonblock)},}; + SDL_ALSA_SYM(snd_pcm_open); + SDL_ALSA_SYM(snd_pcm_close); + SDL_ALSA_SYM(snd_pcm_writei); + SDL_ALSA_SYM(snd_pcm_resume); + SDL_ALSA_SYM(snd_pcm_prepare); + SDL_ALSA_SYM(snd_pcm_drain); + SDL_ALSA_SYM(snd_strerror); + SDL_ALSA_SYM(snd_pcm_hw_params_sizeof); + SDL_ALSA_SYM(snd_pcm_sw_params_sizeof); + SDL_ALSA_SYM(snd_pcm_hw_params_any); + SDL_ALSA_SYM(snd_pcm_hw_params_set_access); + SDL_ALSA_SYM(snd_pcm_hw_params_set_format); + SDL_ALSA_SYM(snd_pcm_hw_params_set_channels); + SDL_ALSA_SYM(snd_pcm_hw_params_get_channels); + SDL_ALSA_SYM(snd_pcm_hw_params_set_rate_near); + SDL_ALSA_SYM(snd_pcm_hw_params_set_period_size_near); + SDL_ALSA_SYM(snd_pcm_hw_params_get_period_size); + SDL_ALSA_SYM(snd_pcm_hw_params_set_periods_near); + SDL_ALSA_SYM(snd_pcm_hw_params_get_periods); + SDL_ALSA_SYM(snd_pcm_hw_params); + SDL_ALSA_SYM(snd_pcm_sw_params_current); + SDL_ALSA_SYM(snd_pcm_sw_params_set_start_threshold); + SDL_ALSA_SYM(snd_pcm_sw_params_set_avail_min); + SDL_ALSA_SYM(snd_pcm_sw_params); + SDL_ALSA_SYM(snd_pcm_nonblock); + return 0; +} static void UnloadALSALibrary(void) { - if (alsa_loaded) { -/* SDL_UnloadObject(alsa_handle);*/ + if (alsa_handle != NULL) { dlclose(alsa_handle); alsa_handle = NULL; - alsa_loaded = 0; } } @@ -205,25 +162,14 @@ { int i, retval = -1; -/* alsa_handle = SDL_LoadObject(alsa_library);*/ alsa_handle = dlopen(alsa_library, RTLD_NOW); - if (alsa_handle) { - alsa_loaded = 1; - retval = 0; - for (i = 0; i < SDL_arraysize(alsa_functions); i++) { -/* *alsa_functions[i].func = SDL_LoadFunction(alsa_handle,alsa_functions[i].name);*/ -#if HAVE_DLVSYM - *alsa_functions[i].func = - dlvsym(alsa_handle, alsa_functions[i].name, "ALSA_0.9"); - if (!*alsa_functions[i].func) -#endif - *alsa_functions[i].func = - dlsym(alsa_handle, alsa_functions[i].name); - if (!*alsa_functions[i].func) { - retval = -1; - UnloadALSALibrary(); - break; - } + if (alsa_handle == NULL) { + SDL_SetError("ALSA: dlopen('%s') failed: %s\n", + alsa_library, strerror(errno)); + } else { + retval = load_alsa_syms(); + if (retval < 0) { + UnloadALSALibrary(); } } return retval; @@ -240,6 +186,7 @@ static int LoadALSALibrary(void) { + load_alsa_syms(); return 0; } @@ -275,12 +222,11 @@ if (LoadALSALibrary() < 0) { return available; } - status = - SDL_NAME(snd_pcm_open) (&handle, get_audio_device(2), - SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK); + status = ALSA_snd_pcm_open(&handle, get_audio_device(2), + SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK); if (status >= 0) { available = 1; - SDL_NAME(snd_pcm_close) (handle); + ALSA_snd_pcm_close(handle); } UnloadALSALibrary(); return (available); @@ -427,8 +373,7 @@ sample_buf = (signed short *) mixbuf; while (sample_len > 0) { - status = - SDL_NAME(snd_pcm_writei) (pcm_handle, sample_buf, sample_len); + status = ALSA_snd_pcm_writei(pcm_handle, sample_buf, sample_len); if (status < 0) { if (status == -EAGAIN) { SDL_Delay(1); @@ -437,11 +382,11 @@ if (status == -ESTRPIPE) { do { SDL_Delay(1); - status = SDL_NAME(snd_pcm_resume) (pcm_handle); + status = ALSA_snd_pcm_resume(pcm_handle); } while (status == -EAGAIN); } if (status < 0) { - status = SDL_NAME(snd_pcm_prepare) (pcm_handle); + status = ALSA_snd_pcm_prepare(pcm_handle); } if (status < 0) { /* Hmm, not much we can do - abort */ @@ -469,8 +414,8 @@ mixbuf = NULL; } if (pcm_handle) { - SDL_NAME(snd_pcm_drain) (pcm_handle); - SDL_NAME(snd_pcm_close) (pcm_handle); + ALSA_snd_pcm_drain(pcm_handle); + ALSA_snd_pcm_close(pcm_handle); pcm_handle = NULL; } } @@ -487,34 +432,32 @@ /* Open the audio device */ /* Name of device should depend on # channels in spec */ - status = - SDL_NAME(snd_pcm_open) (&pcm_handle, - get_audio_device(spec->channels), - SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK); + status = ALSA_snd_pcm_open(&pcm_handle, + get_audio_device(spec->channels), + SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK); if (status < 0) { SDL_SetError("Couldn't open audio device: %s", - SDL_NAME(snd_strerror) (status)); + ALSA_snd_strerror(status)); return (-1); } /* Figure out what the hardware is capable of */ snd_pcm_hw_params_alloca(&hwparams); - status = SDL_NAME(snd_pcm_hw_params_any) (pcm_handle, hwparams); + status = ALSA_snd_pcm_hw_params_any(pcm_handle, hwparams); if (status < 0) { SDL_SetError("Couldn't get hardware config: %s", - SDL_NAME(snd_strerror) (status)); + ALSA_snd_strerror(status)); ALSA_CloseAudio(this); return (-1); } /* SDL only uses interleaved sample output */ - status = - SDL_NAME(snd_pcm_hw_params_set_access) (pcm_handle, hwparams, - SND_PCM_ACCESS_RW_INTERLEAVED); + status = ALSA_snd_pcm_hw_params_set_access(pcm_handle, hwparams, + SND_PCM_ACCESS_RW_INTERLEAVED); if (status < 0) { SDL_SetError("Couldn't set interleaved access: %s", - SDL_NAME(snd_strerror) (status)); + ALSA_snd_strerror(status)); ALSA_CloseAudio(this); return (-1); } @@ -560,9 +503,8 @@ break; } if (status >= 0) { - status = - SDL_NAME(snd_pcm_hw_params_set_format) (pcm_handle, - hwparams, format); + status = ALSA_snd_pcm_hw_params_set_format(pcm_handle, + hwparams, format); } if (status < 0) { test_format = SDL_NextAudioFormat(); @@ -576,11 +518,10 @@ spec->format = test_format; /* Set the number of channels */ - status = - SDL_NAME(snd_pcm_hw_params_set_channels) (pcm_handle, hwparams, - spec->channels); + status = ALSA_snd_pcm_hw_params_set_channels(pcm_handle, hwparams, + spec->channels); if (status < 0) { - status = SDL_NAME(snd_pcm_hw_params_get_channels) (hwparams); + status = ALSA_snd_pcm_hw_params_get_channels(hwparams); if ((status <= 0) || (status > 2)) { SDL_SetError("Couldn't set audio channels"); ALSA_CloseAudio(this); @@ -590,41 +531,37 @@ } /* Set the audio rate */ - status = - SDL_NAME(snd_pcm_hw_params_set_rate_near) (pcm_handle, hwparams, - spec->freq, NULL); + status = ALSA_snd_pcm_hw_params_set_rate_near(pcm_handle, hwparams, + spec->freq, NULL); if (status < 0) { + ALSA_CloseAudio(this); SDL_SetError("Couldn't set audio frequency: %s", - SDL_NAME(snd_strerror) (status)); - ALSA_CloseAudio(this); + ALSA_snd_strerror(status)); return (-1); } spec->freq = status; /* Set the buffer size, in samples */ frames = spec->samples; - frames = - SDL_NAME(snd_pcm_hw_params_set_period_size_near) (pcm_handle, - hwparams, frames, - NULL); + frames = ALSA_snd_pcm_hw_params_set_period_size_near(pcm_handle, hwparams, + frames, NULL); spec->samples = frames; - SDL_NAME(snd_pcm_hw_params_set_periods_near) (pcm_handle, hwparams, 2, - NULL); + ALSA_snd_pcm_hw_params_set_periods_near(pcm_handle, hwparams, 2, NULL); /* "set" the hardware with the desired parameters */ - status = SDL_NAME(snd_pcm_hw_params) (pcm_handle, hwparams); + status = ALSA_snd_pcm_hw_params(pcm_handle, hwparams); if (status < 0) { + ALSA_CloseAudio(this); SDL_SetError("Couldn't set hardware audio parameters: %s", - SDL_NAME(snd_strerror) (status)); - ALSA_CloseAudio(this); + ALSA_snd_strerror(status)); return (-1); } /* This is useful for debugging... */ /* { snd_pcm_sframes_t bufsize; int fragments; - bufsize = SDL_NAME(snd_pcm_hw_params_get_period_size)(hwparams); - fragments = SDL_NAME(snd_pcm_hw_params_get_periods)(hwparams); + bufsize = ALSA_snd_pcm_hw_params_get_period_size(hwparams); + fragments = ALSA_snd_pcm_hw_params_get_periods(hwparams); fprintf(stderr, "ALSA: bufsize = %ld, fragments = %d\n", bufsize, fragments); } @@ -632,35 +569,30 @@ /* Set the software parameters */ snd_pcm_sw_params_alloca(&swparams); - status = SDL_NAME(snd_pcm_sw_params_current) (pcm_handle, swparams); + status = ALSA_snd_pcm_sw_params_current(pcm_handle, swparams); if (status < 0) { SDL_SetError("Couldn't get software config: %s", - SDL_NAME(snd_strerror) (status)); + ALSA_snd_strerror(status)); ALSA_CloseAudio(this); return (-1); } - status = - SDL_NAME(snd_pcm_sw_params_set_start_threshold) (pcm_handle, - swparams, 0); + status = ALSA_snd_pcm_sw_params_set_start_threshold(pcm_handle,swparams,0); if (status < 0) { SDL_SetError("Couldn't set start threshold: %s", - SDL_NAME(snd_strerror) (status)); + ALSA_snd_strerror(status)); ALSA_CloseAudio(this); return (-1); } - status = - SDL_NAME(snd_pcm_sw_params_set_avail_min) (pcm_handle, swparams, - frames); + status = ALSA_snd_pcm_sw_params_set_avail_min(pcm_handle, swparams, frames); if (status < 0) { - SDL_SetError("Couldn't set avail min: %s", - SDL_NAME(snd_strerror) (status)); + SDL_SetError("Couldn't set avail min: %s", ALSA_snd_strerror(status)); ALSA_CloseAudio(this); return (-1); } - status = SDL_NAME(snd_pcm_sw_params) (pcm_handle, swparams); + status = ALSA_snd_pcm_sw_params(pcm_handle, swparams); if (status < 0) { SDL_SetError("Couldn't set software audio parameters: %s", - SDL_NAME(snd_strerror) (status)); + ALSA_snd_strerror(status)); ALSA_CloseAudio(this); return (-1); } @@ -681,7 +613,7 @@ parent = getpid(); /* Switch to blocking mode for playback */ - SDL_NAME(snd_pcm_nonblock) (pcm_handle, 0); + ALSA_snd_pcm_nonblock(pcm_handle, 0); /* We're ready to rock and roll. :-) */ return (0);