ALSA project - the C library reference: Timer Interface

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Timer Interface

## Data Structures
struct | snd_timer_read_t
struct | snd_timer_tread_t

## Macros
#define | SND_TIMER_DLSYM_VERSION _dlsym_timer_001
#define | SND_TIMER_QUERY_DLSYM_VERSION _dlsym_timer_query_001
#define | SND_TIMER_GLOBAL_SYSTEM 0
#define | SND_TIMER_GLOBAL_RTC 1 /* Obsoleted, due to enough legacy. */
#define | SND_TIMER_GLOBAL_HPET 2
#define | SND_TIMER_GLOBAL_HRTIMER 3
#define | SND_TIMER_OPEN_NONBLOCK (1<<0)
#define | SND_TIMER_OPEN_TREAD (1<<1)
#define | snd_timer_id_alloca(ptr) __snd_alloca(ptr, snd_timer_id)
#define | snd_timer_ginfo_alloca(ptr) __snd_alloca(ptr, snd_timer_ginfo)
#define | snd_timer_info_alloca(ptr) __snd_alloca(ptr, snd_timer_info)
#define | snd_timer_params_alloca(ptr) __snd_alloca(ptr, snd_timer_params)
#define | snd_timer_status_alloca(ptr) __snd_alloca(ptr, snd_timer_status)

## Typedefs
typedef struct _snd_timer_id | snd_timer_id_t
typedef struct _snd_timer_ginfo | snd_timer_ginfo_t
typedef struct _snd_timer_gparams | snd_timer_gparams_t
typedef struct _snd_timer_gstatus | snd_timer_gstatus_t
typedef struct _snd_timer_info | snd_timer_info_t
typedef struct _snd_timer_params | snd_timer_params_t
typedef struct _snd_timer_status | snd_timer_status_t
typedef struct _snd_timer_query | snd_timer_query_t
typedef struct _snd_timer | snd_timer_t

## Enumerations
enum | snd_timer_class_t { SND_TIMER_CLASS_NONE = -1, SND_TIMER_CLASS_SLAVE = 0, SND_TIMER_CLASS_GLOBAL, SND_TIMER_CLASS_CARD, SND_TIMER_CLASS_PCM, SND_TIMER_CLASS_LAST = SND_TIMER_CLASS_PCM }
enum | snd_timer_slave_class_t { SND_TIMER_SCLASS_NONE = 0, SND_TIMER_SCLASS_APPLICATION, SND_TIMER_SCLASS_SEQUENCER, SND_TIMER_SCLASS_OSS_SEQUENCER, SND_TIMER_SCLASS_LAST = SND_TIMER_SCLASS_OSS_SEQUENCER }
enum | snd_timer_event_t { SND_TIMER_EVENT_RESOLUTION = 0, SND_TIMER_EVENT_TICK, SND_TIMER_EVENT_START, SND_TIMER_EVENT_STOP, SND_TIMER_EVENT_CONTINUE, SND_TIMER_EVENT_PAUSE, SND_TIMER_EVENT_EARLY, SND_TIMER_EVENT_SUSPEND, SND_TIMER_EVENT_RESUME, SND_TIMER_EVENT_MSTART = SND_TIMER_EVENT_START + 10, SND_TIMER_EVENT_MSTOP = SND_TIMER_EVENT_STOP + 10, SND_TIMER_EVENT_MCONTINUE = SND_TIMER_EVENT_CONTINUE + 10, SND_TIMER_EVENT_MPAUSE = SND_TIMER_EVENT_PAUSE + 10, SND_TIMER_EVENT_MSUSPEND = SND_TIMER_EVENT_SUSPEND + 10, SND_TIMER_EVENT_MRESUME = SND_TIMER_EVENT_RESUME + 10 }
enum | snd_timer_type_t { SND_TIMER_TYPE_HW = 0, SND_TIMER_TYPE_SHM, SND_TIMER_TYPE_INET }

## Functions
int | snd_timer_query_open (snd_timer_query_t **handle, const char *name, int mode)
| Opens a new connection to the timer query interface. More...
int | snd_timer_query_open_lconf (snd_timer_query_t **handle, const char *name, int mode, snd_config_t *lconf)
| Opens a new connection to the timer query interface using local configuration. More...
int | snd_timer_query_close (snd_timer_query_t *handle)
| close timer query handle More...
int | snd_timer_query_next_device (snd_timer_query_t *handle, snd_timer_id_t *tid)
| obtain the next timer identification More...
int | snd_timer_query_info (snd_timer_query_t *handle, snd_timer_ginfo_t *info)
| obtain the timer global information More...
int | snd_timer_query_params (snd_timer_query_t *handle, snd_timer_gparams_t *params)
| set the timer global parameters More...
int | snd_timer_query_status (snd_timer_query_t *handle, snd_timer_gstatus_t *status)
| get the timer global status More...
int | snd_timer_open (snd_timer_t **handle, const char *name, int mode)
| Opens a new connection to the timer interface. More...
int | snd_timer_open_lconf (snd_timer_t **handle, const char *name, int mode, snd_config_t *lconf)
| Opens a new connection to the timer interface using local configuration. More...
int | snd_timer_close (snd_timer_t *handle)
| close timer handle More...
int | snd_async_add_timer_handler (snd_async_handler_t **handler, snd_timer_t *timer, snd_async_callback_t callback, void *private_data)
| Add an async handler for a timer. More...
snd_timer_t * | snd_async_handler_get_timer (snd_async_handler_t *handler)
| Return timer handle related to an async handler. More...
int | snd_timer_poll_descriptors_count (snd_timer_t *handle)
| get count of poll descriptors for timer handle More...
int | snd_timer_poll_descriptors (snd_timer_t *handle, struct pollfd *pfds, unsigned int space)
| get poll descriptors More...
int | snd_timer_poll_descriptors_revents (snd_timer_t *timer, struct pollfd *pfds, unsigned int nfds, unsigned short *revents)
| get returned events from poll descriptors More...
int | snd_timer_info (snd_timer_t *handle, snd_timer_info_t *timer)
| get information about timer handle More...
int | snd_timer_params (snd_timer_t *handle, snd_timer_params_t *params)
| set parameters for timer handle More...
int | snd_timer_status (snd_timer_t *handle, snd_timer_status_t *status)
| get status from timer handle More...
int | snd_timer_start (snd_timer_t *handle)
| start the timer More...
int | snd_timer_stop (snd_timer_t *handle)
| stop the timer More...
int | snd_timer_continue (snd_timer_t *handle)
| continue the timer More...
ssize_t | snd_timer_read (snd_timer_t *handle, void *buffer, size_t size)
| read bytes using timer handle More...
size_t | snd_timer_id_sizeof (void)
| get size of the snd_timer_id_t structure in bytes More...
int | snd_timer_id_malloc (snd_timer_id_t **ptr)
| allocate a new snd_timer_id_t structure More...
void | snd_timer_id_free (snd_timer_id_t *obj)
| frees the snd_timer_id_t structure More...
void | snd_timer_id_copy (snd_timer_id_t *dst, const snd_timer_id_t *src)
| copy one snd_timer_id_t structure to another More...
void | snd_timer_id_set_class (snd_timer_id_t *id, int dev_class)
| set timer class More...
int | snd_timer_id_get_class (snd_timer_id_t *id)
| get timer class More...
void | snd_timer_id_set_sclass (snd_timer_id_t *id, int dev_sclass)
| set timer sub-class More...
int | snd_timer_id_get_sclass (snd_timer_id_t *id)
| get timer sub-class More...
void | snd_timer_id_set_card (snd_timer_id_t *id, int card)
| set timer card More...
int | snd_timer_id_get_card (snd_timer_id_t *id)
| get timer card More...
void | snd_timer_id_set_device (snd_timer_id_t *id, int device)
| set timer device More...
int | snd_timer_id_get_device (snd_timer_id_t *id)
| get timer device More...
void | snd_timer_id_set_subdevice (snd_timer_id_t *id, int subdevice)
| set timer subdevice More...
int | snd_timer_id_get_subdevice (snd_timer_id_t *id)
| get timer subdevice More...
size_t | snd_timer_ginfo_sizeof (void)
| get size of the snd_timer_ginfo_t structure in bytes More...
int | snd_timer_ginfo_malloc (snd_timer_ginfo_t **ptr)
| allocate a new snd_timer_ginfo_t structure More...
void | snd_timer_ginfo_free (snd_timer_ginfo_t *obj)
| frees the snd_timer_ginfo_t structure More...
void | snd_timer_ginfo_copy (snd_timer_ginfo_t *dst, const snd_timer_ginfo_t *src)
| copy one snd_timer_info_t structure to another More...
int | snd_timer_ginfo_set_tid (snd_timer_ginfo_t *obj, snd_timer_id_t *tid)
| set timer identification More...
snd_timer_id_t * | snd_timer_ginfo_get_tid (snd_timer_ginfo_t *obj)
| get timer identification More...
unsigned int | snd_timer_ginfo_get_flags (snd_timer_ginfo_t *obj)
| get timer flags More...
int | snd_timer_ginfo_get_card (snd_timer_ginfo_t *obj)
| get associated card with timer More...
char * | snd_timer_ginfo_get_id (snd_timer_ginfo_t *obj)
| get timer identification More...
char * | snd_timer_ginfo_get_name (snd_timer_ginfo_t *obj)
| get timer name More...
unsigned long | snd_timer_ginfo_get_resolution (snd_timer_ginfo_t *obj)
| get timer resolution in ns More...
unsigned long | snd_timer_ginfo_get_resolution_min (snd_timer_ginfo_t *obj)
| get timer minimal resolution in ns More...
unsigned long | snd_timer_ginfo_get_resolution_max (snd_timer_ginfo_t *obj)
| get timer maximal resolution in ns More...
unsigned int | snd_timer_ginfo_get_clients (snd_timer_ginfo_t *obj)
| get current timer clients More...
size_t | snd_timer_info_sizeof (void)
| get size of the snd_timer_info_t structure in bytes More...
int | snd_timer_info_malloc (snd_timer_info_t **ptr)
| allocate a new snd_timer_info_t structure More...
void | snd_timer_info_free (snd_timer_info_t *obj)
| frees the snd_timer_info_t structure More...
void | snd_timer_info_copy (snd_timer_info_t *dst, const snd_timer_info_t *src)
| copy one snd_timer_info_t structure to another More...
int | snd_timer_info_is_slave (snd_timer_info_t *info)
| determine, if timer is slave More...
int | snd_timer_info_get_card (snd_timer_info_t *info)
| get timer card More...
const char * | snd_timer_info_get_id (snd_timer_info_t *info)
| get timer id More...
const char * | snd_timer_info_get_name (snd_timer_info_t *info)
| get timer name More...
long | snd_timer_info_get_resolution (snd_timer_info_t *info)
| get timer resolution in us More...
size_t | snd_timer_params_sizeof (void)
| get size of the snd_timer_params_t structure in bytes More...
int | snd_timer_params_malloc (snd_timer_params_t **ptr)
| allocate a new snd_timer_params_t structure More...
void | snd_timer_params_free (snd_timer_params_t *obj)
| frees the snd_timer_params_t structure More...
void | snd_timer_params_copy (snd_timer_params_t *dst, const snd_timer_params_t *src)
| copy one snd_timer_params_t structure to another More...
int | snd_timer_params_set_auto_start (snd_timer_params_t *params, int auto_start)
| set timer auto start More...
int | snd_timer_params_get_auto_start (snd_timer_params_t *params)
| determine if timer has auto start flag More...
int | snd_timer_params_set_exclusive (snd_timer_params_t *params, int exclusive)
| set timer exclusive use More...
int | snd_timer_params_get_exclusive (snd_timer_params_t *params)
| determine if timer has exclusive flag More...
int | snd_timer_params_set_early_event (snd_timer_params_t *params, int early_event)
| set timer early event More...
int | snd_timer_params_get_early_event (snd_timer_params_t *params)
| determine if timer has early event flag More...
void | snd_timer_params_set_ticks (snd_timer_params_t *params, long ticks)
| set timer ticks More...
long | snd_timer_params_get_ticks (snd_timer_params_t *params)
| get timer ticks More...
void | snd_timer_params_set_queue_size (snd_timer_params_t *params, long queue_size)
| set timer queue size (32-1024) More...
long | snd_timer_params_get_queue_size (snd_timer_params_t *params)
| get queue size More...
void | snd_timer_params_set_filter (snd_timer_params_t *params, unsigned int filter)
| set timer event filter More...
unsigned int | snd_timer_params_get_filter (snd_timer_params_t *params)
| get timer event filter More...
size_t | snd_timer_status_sizeof (void)
| get size of the snd_timer_status_t structure in bytes More...
int | snd_timer_status_malloc (snd_timer_status_t **ptr)
| allocate a new snd_timer_status_t structure More...
void | snd_timer_status_free (snd_timer_status_t *obj)
| frees the snd_timer_status_t structure More...
void | snd_timer_status_copy (snd_timer_status_t *dst, const snd_timer_status_t *src)
| copy one snd_timer_status_t structure to another More...
snd_htimestamp_t | snd_timer_status_get_timestamp (snd_timer_status_t *status)
| get timestamp More...
long | snd_timer_status_get_resolution (snd_timer_status_t *status)
| get resolution in us More...
long | snd_timer_status_get_lost (snd_timer_status_t *status)
| get master tick lost count More...
long | snd_timer_status_get_overrun (snd_timer_status_t *status)
| get overrun count More...
long | snd_timer_status_get_queue (snd_timer_status_t *status)
| get count of used queue elements More...
long | snd_timer_info_get_ticks (snd_timer_info_t *info)
| (DEPRECATED) get maximum timer ticks More...

## Detailed Description

Timer Interface. See Timer interface page for more details.

## Macro Definition Documentation

#define SND_TIMER_DLSYM_VERSION _dlsym_timer_001

dlsym version for interface entry callback

#define snd_timer_ginfo_alloca | ( |  | ptr | ) | __snd_alloca(ptr, snd_timer_ginfo)

allocate snd_timer_ginfo_t container on stack

#define SND_TIMER_GLOBAL_HPET 2

global timer - HPET

#define SND_TIMER_GLOBAL_HRTIMER 3

global timer - HRTIMER

#define SND_TIMER_GLOBAL_RTC 1 /* Obsoleted, due to enough legacy. */

global timer - RTC

#define SND_TIMER_GLOBAL_SYSTEM 0

global timer - system

Examples:
  /test/timer.c.

#define snd_timer_id_alloca | ( |  | ptr | ) | __snd_alloca(ptr, snd_timer_id)

allocate snd_timer_id_t container on stack

Examples:
  /test/timer.c.

#define snd_timer_info_alloca | ( |  | ptr | ) | __snd_alloca(ptr, snd_timer_info)

allocate snd_timer_info_t container on stack

Examples:
  /test/timer.c.

#define SND_TIMER_OPEN_NONBLOCK (1<<0)

timer open mode flag - non-blocking behaviour

Examples:
  /test/timer.c.

#define SND_TIMER_OPEN_TREAD (1<<1)

use timestamps and event notification - enhanced read

#define snd_timer_params_alloca | ( |  | ptr | ) | __snd_alloca(ptr, snd_timer_params)

allocate snd_timer_params_t container on stack

Examples:
  /test/timer.c.

#define SND_TIMER_QUERY_DLSYM_VERSION _dlsym_timer_query_001

dlsym version for interface entry callback

#define snd_timer_status_alloca | ( |  | ptr | ) | __snd_alloca(ptr, snd_timer_status)

allocate snd_timer_status_t container on stack

Examples:
  /test/timer.c.

## Typedef Documentation

typedef struct _snd_timer_ginfo snd_timer_ginfo_t

timer global info structure

typedef struct _snd_timer_gparams snd_timer_gparams_t

timer global params structure

typedef struct _snd_timer_gstatus snd_timer_gstatus_t

timer global status structure

typedef struct _snd_timer_id snd_timer_id_t

timer identification structure

typedef struct _snd_timer_info snd_timer_info_t

timer info structure

typedef struct _snd_timer_params snd_timer_params_t

timer params structure

typedef struct _snd_timer_query snd_timer_query_t

timer query handle

typedef struct _snd_timer_status snd_timer_status_t

timer status structure

typedef struct _snd_timer snd_timer_t

timer handle

## Enumeration Type Documentation

enum snd_timer_class_t

timer master class

Enumerator
SND_TIMER_CLASS_NONE | invalid
SND_TIMER_CLASS_SLAVE | slave timer
SND_TIMER_CLASS_GLOBAL | global timer
SND_TIMER_CLASS_CARD | card timer
SND_TIMER_CLASS_PCM | PCM timer
SND_TIMER_CLASS_LAST | last timer

enum snd_timer_event_t

timer read event identification

enum snd_timer_slave_class_t

timer slave class

Enumerator
SND_TIMER_SCLASS_NONE | none
SND_TIMER_SCLASS_APPLICATION | for internal use
SND_TIMER_SCLASS_SEQUENCER | sequencer timer
SND_TIMER_SCLASS_OSS_SEQUENCER | OSS sequencer timer
SND_TIMER_SCLASS_LAST | last slave timer

enum snd_timer_type_t

timer handle type

Enumerator
SND_TIMER_TYPE_HW | Kernel level HwDep
SND_TIMER_TYPE_SHM | Shared memory client timer (not yet implemented)
SND_TIMER_TYPE_INET | INET client timer (not yet implemented)

## Function Documentation

int snd_async_add_timer_handler | ( | snd_async_handler_t ** | handler,
|  | snd_timer_t * | timer,
|  | snd_async_callback_t | callback,
|  | void * | private_data
| ) |  |

Add an async handler for a timer.

Parameters

  handler | Returned handler handle
  timer | timer handle
  callback | Callback function
  private_data | Callback private data

Returns
  0 otherwise a negative error code on failure

The asynchronous callback is called when new timer event occurs.

Examples:
  /test/timer.c.

snd_timer_t* snd_async_handler_get_timer | ( | snd_async_handler_t * | handler | ) |

Return timer handle related to an async handler.

Parameters

  handler | Async handler handle

Returns
  timer handle

Examples:
  /test/timer.c.

int snd_timer_close | ( | snd_timer_t * | timer | ) |

close timer handle

Parameters

  timer | timer handle

Returns
  0 on success otherwise a negative error code

Closes the specified timer handle and frees all associated resources.

Examples:
  /test/timer.c.

int snd_timer_continue | ( | snd_timer_t * | timer | ) |

continue the timer

Parameters

  timer | timer handle

Returns
  0 on success otherwise a negative error code

void snd_timer_ginfo_copy | ( | snd_timer_ginfo_t * | dst,
|  | const snd_timer_ginfo_t * | src
| ) |  |

copy one snd_timer_info_t structure to another

Parameters

  dst | destination snd_timer_info_t structure
  src | source snd_timer_info_t structure

void snd_timer_ginfo_free | ( | snd_timer_ginfo_t * | info | ) |

frees the snd_timer_ginfo_t structure

Parameters

  info | pointer to the snd_timer_ginfo_t structure to free

Frees the given snd_timer_info_t structure using the standard free C library function.

int snd_timer_ginfo_get_card | ( | snd_timer_ginfo_t * | obj | ) |

get associated card with timer

Parameters

  obj | pointer to snd_timer_ginfo_t structure

Returns
  associated card

unsigned int snd_timer_ginfo_get_clients | ( | snd_timer_ginfo_t * | obj | ) |

get current timer clients

Parameters

  obj | pointer to snd_timer_ginfo_t structure

Returns
  current timer clients

unsigned int snd_timer_ginfo_get_flags | ( | snd_timer_ginfo_t * | obj | ) |

get timer flags

Parameters

  obj | pointer to snd_timer_ginfo_t structure

Returns
  timer flags

char* snd_timer_ginfo_get_id | ( | snd_timer_ginfo_t * | obj | ) |

get timer identification

Parameters

  obj | pointer to snd_timer_ginfo_t structure

Returns
  timer identification

char* snd_timer_ginfo_get_name | ( | snd_timer_ginfo_t * | obj | ) |

get timer name

Parameters

  obj | pointer to snd_timer_ginfo_t structure

Returns
  timer name

unsigned long snd_timer_ginfo_get_resolution | ( | snd_timer_ginfo_t * | obj | ) |

get timer resolution in ns

Parameters

  obj | pointer to snd_timer_ginfo_t structure

Returns
  timer resolution in ns

unsigned long snd_timer_ginfo_get_resolution_max | ( | snd_timer_ginfo_t * | obj | ) |

get timer maximal resolution in ns

Parameters

  obj | pointer to snd_timer_ginfo_t structure

Returns
  timer maximal resolution in ns

unsigned long snd_timer_ginfo_get_resolution_min | ( | snd_timer_ginfo_t * | obj | ) |

get timer minimal resolution in ns

Parameters

  obj | pointer to snd_timer_ginfo_t structure

Returns
  timer minimal resolution in ns

snd_timer_id_t* snd_timer_ginfo_get_tid | ( | snd_timer_ginfo_t * | obj | ) |

get timer identification

Parameters

  obj | pointer to snd_timer_ginfo_t structure

Returns
  pointer to snd_timer_id_t

int snd_timer_ginfo_malloc | ( | snd_timer_ginfo_t ** | info | ) |

allocate a new snd_timer_ginfo_t structure

Parameters

  info | returned pointer

Returns
  0 on success otherwise a negative error code if fails

Allocates a new snd_timer_info_t structure using the standard malloc C library function.

int snd_timer_ginfo_set_tid | ( | snd_timer_ginfo_t * | obj,
|  | snd_timer_id_t * | tid
| ) |  |

set timer identification

Parameters

  obj | pointer to snd_timer_ginfo_t structure
  tid | pointer to snd_timer_id_t structure

Returns
  zero on success otherwise a negative error number

size_t snd_timer_ginfo_sizeof | ( | void |  | ) |

get size of the snd_timer_ginfo_t structure in bytes

Returns
  size of the snd_timer_ginfo_t structure in bytes

void snd_timer_id_copy | ( | snd_timer_id_t * | dst,
|  | const snd_timer_id_t * | src
| ) |  |

copy one snd_timer_id_t structure to another

Parameters

  dst | destination snd_timer_id_t structure
  src | source snd_timer_id_t structure

void snd_timer_id_free | ( | snd_timer_id_t * | info | ) |

frees the snd_timer_id_t structure

Parameters

  info | pointer to the snd_timer_id_t structure to free

Frees the given snd_timer_id_t structure using the standard free C library function.

int snd_timer_id_get_card | ( | snd_timer_id_t * | tid | ) |

get timer card

Parameters

  tid | pointer to snd_timer_id_t structure

Returns
  timer card number

Examples:
  /test/timer.c.

int snd_timer_id_get_class | ( | snd_timer_id_t * | tid | ) |

get timer class

Parameters

  tid | pointer to snd_timer_id_t structure

Returns
  timer class

Examples:
  /test/timer.c.

int snd_timer_id_get_device | ( | snd_timer_id_t * | tid | ) |

get timer device

Parameters

  tid | pointer to snd_timer_id_t structure

Returns
  timer device number

Examples:
  /test/timer.c.

int snd_timer_id_get_sclass | ( | snd_timer_id_t * | tid | ) |

get timer sub-class

Parameters

  tid | pointer to snd_timer_id_t structure

Returns
  timer sub-class

Examples:
  /test/timer.c.

int snd_timer_id_get_subdevice | ( | snd_timer_id_t * | tid | ) |

get timer subdevice

Parameters

  tid | pointer to snd_timer_id_t structure

Returns
  timer subdevice number

Examples:
  /test/timer.c.

int snd_timer_id_malloc | ( | snd_timer_id_t ** | info | ) |

allocate a new snd_timer_id_t structure

Parameters

  info | returned pointer

Returns
  0 on success otherwise a negative error code if fails

Allocates a new snd_timer_id_t structure using the standard malloc C library function.

void snd_timer_id_set_card | ( | snd_timer_id_t * | tid,
|  | int | card
| ) |  |

set timer card

Parameters

  tid | pointer to snd_timer_id_t structure
  card | card number

void snd_timer_id_set_class | ( | snd_timer_id_t * | tid,
|  | int | dev_class
| ) |  |

set timer class

Parameters

  tid | pointer to snd_timer_id_t structure
  dev_class | class of timer device

Examples:
  /test/timer.c.

void snd_timer_id_set_device | ( | snd_timer_id_t * | tid,
|  | int | device
| ) |  |

set timer device

Parameters

  tid | pointer to snd_timer_id_t structure
  device | device number

void snd_timer_id_set_sclass | ( | snd_timer_id_t * | tid,
|  | int | dev_sclass
| ) |  |

set timer sub-class

Parameters

  tid | pointer to snd_timer_id_t structure
  dev_sclass | sub-class of timer device

void snd_timer_id_set_subdevice | ( | snd_timer_id_t * | tid,
|  | int | subdevice
| ) |  |

set timer subdevice

Parameters

  tid | pointer to snd_timer_id_t structure
  subdevice | subdevice number

size_t snd_timer_id_sizeof | ( | void |  | ) |

get size of the snd_timer_id_t structure in bytes

Returns
  size of the snd_timer_id_t structure in bytes

int snd_timer_info | ( | snd_timer_t * | timer,
|  | snd_timer_info_t * | info
| ) |  |

get information about timer handle

Parameters

  timer | timer handle
  info | pointer to a snd_timer_info_t structure to be filled

Returns
  0 on success otherwise a negative error code

Examples:
  /test/timer.c.

void snd_timer_info_copy | ( | snd_timer_info_t * | dst,
|  | const snd_timer_info_t * | src
| ) |  |

copy one snd_timer_info_t structure to another

Parameters

  dst | destination snd_timer_info_t structure
  src | source snd_timer_info_t structure

void snd_timer_info_free | ( | snd_timer_info_t * | info | ) |

frees the snd_timer_info_t structure

Parameters

  info | pointer to the snd_timer_info_t structure to free

Frees the given snd_timer_info_t structure using the standard free C library function.

int snd_timer_info_get_card | ( | snd_timer_info_t * | info | ) |

get timer card

Parameters

  info | pointer to snd_timer_info_t structure

Returns
  timer card number

Examples:
  /test/timer.c.

const char* snd_timer_info_get_id | ( | snd_timer_info_t * | info | ) |

get timer id

Parameters

  info | pointer to snd_timer_info_t structure

Returns
  timer id

Examples:
  /test/timer.c.

const char* snd_timer_info_get_name | ( | snd_timer_info_t * | info | ) |

get timer name

Parameters

  info | pointer to snd_timer_info_t structure

Returns
  timer name

Examples:
  /test/timer.c.

long snd_timer_info_get_resolution | ( | snd_timer_info_t * | info | ) |

get timer resolution in us

Parameters

  info | pointer to snd_timer_info_t structure

Returns
  timer resolution

Examples:
  /test/timer.c.

long snd_timer_info_get_ticks | ( | snd_timer_info_t * | info | ) |

(DEPRECATED) get maximum timer ticks

Parameters

  info | pointer to snd_timer_info_t structure

Returns
  maximum timer ticks

int snd_timer_info_is_slave | ( | snd_timer_info_t * | info | ) |

determine, if timer is slave

Parameters

  info | pointer to snd_timer_info_t structure

Returns
  nonzero if timer is slave

Examples:
  /test/timer.c.

int snd_timer_info_malloc | ( | snd_timer_info_t ** | info | ) |

allocate a new snd_timer_info_t structure

Parameters

  info | returned pointer

Returns
  0 on success otherwise a negative error code if fails

Allocates a new snd_timer_info_t structure using the standard malloc C library function.

size_t snd_timer_info_sizeof | ( | void |  | ) |

get size of the snd_timer_info_t structure in bytes

Returns
  size of the snd_timer_info_t structure in bytes

int snd_timer_open | ( | snd_timer_t ** | timer,
|  | const char * | name,
|  | int | mode
| ) |  |

Opens a new connection to the timer interface.

Parameters

  timer | Returned handle (NULL if not wanted)
  name | ASCII identifier of the timer handle
  mode | Open mode

Returns
  0 on success otherwise a negative error code

Opens a new connection to the timer interface specified with an ASCII identifier and mode.

Examples:
  /test/timer.c.

int snd_timer_open_lconf | ( | snd_timer_t ** | timer,
|  | const char * | name,
|  | int | mode,
|  | snd_config_t * | lconf
| ) |  |

Opens a new connection to the timer interface using local configuration.

Parameters

  timer | Returned handle (NULL if not wanted)
  name | ASCII identifier of the timer handle
  mode | Open mode
  lconf | Local configuration

Returns
  0 on success otherwise a negative error code

Opens a new connection to the timer interface specified with an ASCII identifier and mode.

int snd_timer_params | ( | snd_timer_t * | timer,
|  | snd_timer_params_t * | params
| ) |  |

set parameters for timer handle

Parameters

  timer | timer handle
  params | pointer to a snd_timer_params_t structure

Returns
  0 on success otherwise a negative error code

Examples:
  /test/timer.c.

void snd_timer_params_copy | ( | snd_timer_params_t * | dst,
|  | const snd_timer_params_t * | src
| ) |  |

copy one snd_timer_params_t structure to another

Parameters

  dst | destination snd_timer_params_t structure
  src | source snd_timer_params_t structure

void snd_timer_params_free | ( | snd_timer_params_t * | params | ) |

frees the snd_timer_params_t structure

Parameters

  params | pointer to the snd_timer_params_t structure to free

Frees the given snd_timer_params_t structure using the standard free C library function.

int snd_timer_params_get_auto_start | ( | snd_timer_params_t * | params | ) |

determine if timer has auto start flag

Parameters

  params | pointer to snd_timer_params_t structure

Returns
  nonzero if timer has auto start flag

int snd_timer_params_get_early_event | ( | snd_timer_params_t * | params | ) |

determine if timer has early event flag

Parameters

  params | pointer to snd_timer_params_t structure

Returns
  nonzero if timer has early event flag set

int snd_timer_params_get_exclusive | ( | snd_timer_params_t * | params | ) |

determine if timer has exclusive flag

Parameters

  params | pointer to snd_timer_params_t structure

Returns
  nonzero if timer has exclusive flag

unsigned int snd_timer_params_get_filter | ( | snd_timer_params_t * | params | ) |

get timer event filter

Parameters

  params | pointer to snd_timer_params_t structure

Returns
  timer event filter

long snd_timer_params_get_queue_size | ( | snd_timer_params_t * | params | ) |

get queue size

Parameters

  params | pointer to snd_timer_params_t structure

Returns
  queue size

long snd_timer_params_get_ticks | ( | snd_timer_params_t * | params | ) |

get timer ticks

Parameters

  params | pointer to snd_timer_params_t structure

Returns
  timer ticks

Examples:
  /test/timer.c.

int snd_timer_params_malloc | ( | snd_timer_params_t ** | params | ) |

allocate a new snd_timer_params_t structure

Parameters

  params | returned pointer

Returns
  0 on success otherwise a negative error code if fails

Allocates a new snd_timer_params_t structure using the standard malloc C library function.

int snd_timer_params_set_auto_start | ( | snd_timer_params_t * | params,
|  | int | auto_start
| ) |  |

set timer auto start

Parameters

  params | pointer to snd_timer_params_t structure
  auto_start | The boolean value to set

Examples:
  /test/timer.c.

int snd_timer_params_set_early_event | ( | snd_timer_params_t * | params,
|  | int | early_event
| ) |  |

set timer early event

Parameters

  params | pointer to snd_timer_params_t structure
  early_event | The boolean value to set

int snd_timer_params_set_exclusive | ( | snd_timer_params_t * | params,
|  | int | exclusive
| ) |  |

set timer exclusive use

Parameters

  params | pointer to snd_timer_params_t structure
  exclusive | The boolean value to set

void snd_timer_params_set_filter | ( | snd_timer_params_t * | params,
|  | unsigned int | filter
| ) |  |

set timer event filter

Parameters

  params | pointer to snd_timer_params_t structure
  filter | The event filter bits to set

void snd_timer_params_set_queue_size | ( | snd_timer_params_t * | params,
|  | long | queue_size
| ) |  |

set timer queue size (32-1024)

Parameters

  params | pointer to snd_timer_params_t structure
  queue_size | The queue size to set

void snd_timer_params_set_ticks | ( | snd_timer_params_t * | params,
|  | long | ticks
| ) |  |

set timer ticks

Parameters

  params | pointer to snd_timer_params_t structure
  ticks | Ticks to set

Examples:
  /test/timer.c.

size_t snd_timer_params_sizeof | ( | void |  | ) |

get size of the snd_timer_params_t structure in bytes

Returns
  size of the snd_timer_params_t structure in bytes

int snd_timer_poll_descriptors | ( | snd_timer_t * | timer,
|  | struct pollfd * | pfds,
|  | unsigned int | space
| ) |  |

get poll descriptors

Parameters

  timer | timer handle
  pfds | array of poll descriptors
  space | space in the poll descriptor array

Returns
  count of filled descriptors

Examples:
  /test/timer.c.

int snd_timer_poll_descriptors_count | ( | snd_timer_t * | timer | ) |

get count of poll descriptors for timer handle

Parameters

  timer | timer handle

Returns
  count of poll descriptors

Examples:
  /test/timer.c.

int snd_timer_poll_descriptors_revents | ( | snd_timer_t * | timer,
|  | struct pollfd * | pfds,
|  | unsigned int | nfds,
|  | unsigned short * | revents
| ) |  |

get returned events from poll descriptors

Parameters

  timer | timer handle
  pfds | array of poll descriptors
  nfds | count of poll descriptors
  revents | returned events

Returns
  zero if success, otherwise a negative error code

int snd_timer_query_close | ( | snd_timer_query_t * | timer | ) |

close timer query handle

Parameters

  timer | timer handle

Returns
  0 on success otherwise a negative error code

Closes the specified timer handle and frees all associated resources.

Examples:
  /test/timer.c.

int snd_timer_query_info | ( | snd_timer_query_t * | timer,
|  | snd_timer_ginfo_t * | info
| ) |  |

obtain the timer global information

Parameters

  timer | timer handle
  info | timer information

Returns
  0 on success otherwise a negative error code

int snd_timer_query_next_device | ( | snd_timer_query_t * | timer,
|  | snd_timer_id_t * | tid
| ) |  |

obtain the next timer identification

Parameters

  timer | timer handle
  tid | timer identification

Returns
  0 on success otherwise a negative error code

if tid->dev_class is -1, then the first device is returned if result tid->dev_class is -1, no more devices are left

Examples:
  /test/timer.c.

int snd_timer_query_open | ( | snd_timer_query_t ** | timer,
|  | const char * | name,
|  | int | mode
| ) |  |

Opens a new connection to the timer query interface.

Parameters

  timer | Returned handle (NULL if not wanted)
  name | ASCII identifier of the RawMidi handle
  mode | Open mode

Returns
  0 on success otherwise a negative error code

Opens a new connection to the RawMidi interface specified with an ASCII identifier and mode.

Examples:
  /test/timer.c.

int snd_timer_query_open_lconf | ( | snd_timer_query_t ** | timer,
|  | const char * | name,
|  | int | mode,
|  | snd_config_t * | lconf
| ) |  |

Opens a new connection to the timer query interface using local configuration.

Parameters

  timer | Returned handle (NULL if not wanted)
  name | ASCII identifier of the RawMidi handle
  mode | Open mode
  lconf | Local configuration

Returns
  0 on success otherwise a negative error code

Opens a new connection to the RawMidi interface specified with an ASCII identifier and mode.

int snd_timer_query_params | ( | snd_timer_query_t * | timer,
|  | snd_timer_gparams_t * | params
| ) |  |

set the timer global parameters

Parameters

  timer | timer handle
  params | timer parameters

Returns
  0 on success otherwise a negative error code

int snd_timer_query_status | ( | snd_timer_query_t * | timer,
|  | snd_timer_gstatus_t * | status
| ) |  |

get the timer global status

Parameters

  timer | timer handle
  status | timer status

Returns
  0 on success otherwise a negative error code

ssize_t snd_timer_read | ( | snd_timer_t * | timer,
|  | void * | buffer,
|  | size_t | size
| ) |  |

read bytes using timer handle

Parameters

  timer | timer handle
  buffer | buffer to store the input bytes
  size | input buffer size in bytes

Examples:
  /test/timer.c.

int snd_timer_start | ( | snd_timer_t * | timer | ) |

start the timer

Parameters

  timer | timer handle

Returns
  0 on success otherwise a negative error code

Examples:
  /test/timer.c.

int snd_timer_status | ( | snd_timer_t * | timer,
|  | snd_timer_status_t * | status
| ) |  |

get status from timer handle

Parameters

  timer | timer handle
  status | pointer to a snd_timer_status_t structure to be filled

Returns
  0 on success otherwise a negative error code

Examples:
  /test/timer.c.

void snd_timer_status_copy | ( | snd_timer_status_t * | dst,
|  | const snd_timer_status_t * | src
| ) |  |

copy one snd_timer_status_t structure to another

Parameters

  dst | destination snd_timer_status_t structure
  src | source snd_timer_status_t structure

void snd_timer_status_free | ( | snd_timer_status_t * | status | ) |

frees the snd_timer_status_t structure

Parameters

  status | pointer to the snd_timer_status_t structure to free

Frees the given snd_timer_status_t structure using the standard free C library function.

long snd_timer_status_get_lost | ( | snd_timer_status_t * | status | ) |

get master tick lost count

Parameters

  status | pointer to snd_timer_status_t structure

Returns
  master tick lost count

Examples:
  /test/timer.c.

long snd_timer_status_get_overrun | ( | snd_timer_status_t * | status | ) |

get overrun count

Parameters

  status | pointer to snd_timer_status_t structure

Returns
  overrun count

Examples:
  /test/timer.c.

long snd_timer_status_get_queue | ( | snd_timer_status_t * | status | ) |

get count of used queue elements

Parameters

  status | pointer to snd_timer_status_t structure

Returns
  count of used queue elements

Examples:
  /test/timer.c.

long snd_timer_status_get_resolution | ( | snd_timer_status_t * | status | ) |

get resolution in us

Parameters

  status | pointer to snd_timer_status_t structure

Returns
  resolution

Examples:
  /test/timer.c.

snd_htimestamp_t snd_timer_status_get_timestamp | ( | snd_timer_status_t * | status | ) |

get timestamp

Parameters

  status | pointer to snd_timer_status_t structure

Returns
  timestamp

int snd_timer_status_malloc | ( | snd_timer_status_t ** | status | ) |

allocate a new snd_timer_status_t structure

Parameters

  status | returned pointer

Returns
  0 on success otherwise a negative error code if fails

Allocates a new snd_timer_status_t structure using the standard malloc C library function.

size_t snd_timer_status_sizeof | ( | void |  | ) |

get size of the snd_timer_status_t structure in bytes

Returns
  size of the snd_timer_status_t structure in bytes

int snd_timer_stop | ( | snd_timer_t * | timer | ) |

stop the timer

Parameters

  timer | timer handle

Returns
  0 on success otherwise a negative error code

Examples:
  /test/timer.c.