libcoap 4.3.2rc2

Functions
Asynchronous Messaging
Application API

API for delayed "separate" messages. More...

## Functions
int | coap_async_is_supported (void)
| Returns `1` if libcoap was built with separate messages enabled, `0` otherwise. More...
coap_async_t * | coap_register_async (coap_session_t *session, const coap_pdu_t *request, coap_tick_t delay)
| Allocates a new coap_async_t object and fills its fields according to the given `request`. More...
void | coap_async_set_delay (coap_async_t *async, coap_tick_t delay)
| Update the delay timeout, so changing when the registered `async` triggers. More...
void | coap_async_trigger (coap_async_t *async)
| Trigger the registered `async`. More...
void | coap_free_async (coap_session_t *session, coap_async_t *async)
| Releases the memory that was allocated by coap_register_async() for the object `async`. More...
coap_async_t * | coap_find_async (coap_session_t *session, coap_bin_const_t token)
| Retrieves the object identified by `token` from the list of asynchronous transactions that are registered with `context`. More...
void | coap_async_set_app_data (coap_async_t *async, void *app_data)
| Set the application data pointer held in `async`. More...
void * | coap_async_get_app_data (const coap_async_t *async)
| Gets the application data pointer held in `async`. More...

## Detailed Description

API for delayed "separate" messages.

A coap_context_t object holds a list of coap_async_t objects that can be used to generate a separate response in the case a result of a request cannot be delivered immediately.

## Function Documentation

## ◆ coap_async_get_app_data()

void * coap_async_get_app_data | ( | const coap_async_t * | async | ) |

Gets the application data pointer held in `async`.

Parameters

  async | The async state object.

Returns
  The applicaton data pointer.

Definition at line 231 of file coap_async.c.

## ◆ coap_async_is_supported()

int coap_async_is_supported | ( | void |  | ) |

Returns `1` if libcoap was built with separate messages enabled, `0` otherwise.

Definition at line 190 of file coap_async.c.

## ◆ coap_async_set_app_data()

void coap_async_set_app_data | ( | coap_async_t * | async,
|  | void * | app_data
| ) |  |

Set the application data pointer held in `async`.

This overwrites any existing data pointer.

Parameters

  async | The async state object.
  app_data | The pointer to the data.

Definition at line 225 of file coap_async.c.

## ◆ coap_async_set_delay()

void coap_async_set_delay | ( | coap_async_t * | async,
|  | coap_tick_t | delay
| ) |  |

Update the delay timeout, so changing when the registered `async` triggers.

When the new delay expires, a copy of the original request will get sent to the appropriate request handler.

Parameters

  async | The object to update.
  delay | The amount of time to delay before sending response, 0 means wait forever.

Definition at line 205 of file coap_async.c.

## ◆ coap_async_trigger()

void coap_async_trigger | ( | coap_async_t * | async | ) |

Trigger the registered `async`.

A copy of the original request will get sent to the appropriate request handler.

Parameters

  async | The async object to trigger.

## ◆ coap_find_async()

coap_async_t * coap_find_async | ( | coap_session_t * | session,
|  | coap_bin_const_t | token
| ) |  |

Retrieves the object identified by `token` from the list of asynchronous transactions that are registered with `context`.

This function returns a pointer to that object or `NULL` if not found.

Parameters

  session | The session that is used for asynchronous transmissions.
  token | The PDU's token of the object to retrieve.

Returns
  A pointer to the object identified by `token` or `NULL` if not found.

Definition at line 217 of file coap_async.c.

## ◆ coap_free_async()

void coap_free_async | ( | coap_session_t * | session,
|  | coap_async_t * | async
| ) |  |

Releases the memory that was allocated by coap_register_async() for the object `async`.

Parameters

  session | The session to use.
  async | The object to delete.

Definition at line 211 of file coap_async.c.

## ◆ coap_register_async()

coap_async_t * coap_register_async | ( | coap_session_t * | session,
|  | const coap_pdu_t * | request,
|  | coap_tick_t | delay
| ) |  |

Allocates a new coap_async_t object and fills its fields according to the given `request`.

This function returns a pointer to the registered coap_async_t object or `NULL` on error. Note that this function will return `NULL` in case that an object with the same identifier is already registered.

When the delay expires, a copy of the `request` will get sent to the appropriate request handler.

Parameters

  session | The session that is used for asynchronous transmissions.
  request | The request that is handled asynchronously.
  delay | The amount of time to delay before sending response, 0 means wait forever.

Returns
  A pointer to the registered coap_async_t object or `NULL` in case of an error.

Definition at line 195 of file coap_async.c.