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pub unsafe fn sd_ble_evt_get(p_dest: *mut u8, p_len: *mut u16) -> u32
Expand description

@brief Get an event from the pending events queue.

@param[out] p_dest Pointer to buffer to be filled in with an event, or NULL to retrieve the event length. This buffer must be aligned to the extend defined by @ref BLE_EVT_PTR_ALIGNMENT. The buffer should be interpreted as a @ref ble_evt_t struct. @param[in, out] p_len Pointer the length of the buffer, on return it is filled with the event length.

@details This call allows the application to pull a BLE event from the BLE stack. The application is signaled that an event is available from the BLE stack by the triggering of the SD_EVT_IRQn interrupt. The application is free to choose whether to call this function from thread mode (main context) or directly from the Interrupt Service Routine that maps to SD_EVT_IRQn. In any case however, and because the BLE stack runs at a higher priority than the application, this function should be called in a loop (until @ref NRF_ERROR_NOT_FOUND is returned) every time SD_EVT_IRQn is raised to ensure that all available events are pulled from the BLE stack. Failure to do so could potentially leave events in the internal queue without the application being aware of this fact.

Sizing the p_dest buffer is equally important, since the application needs to provide all the memory necessary for the event to be copied into application memory. If the buffer provided is not large enough to fit the entire contents of the event, @ref NRF_ERROR_DATA_SIZE will be returned and the application can then call again with a larger buffer size. The maximum possible event length is defined by @ref BLE_EVT_LEN_MAX. The application may also “peek” the event length by providing p_dest as a NULL pointer and inspecting the value of *p_len upon return:

 \code
 uint16_t len;
 errcode = sd_ble_evt_get(NULL, &len);
 \endcode

@mscs @mmsc{@ref BLE_COMMON_IRQ_EVT_MSC} @mmsc{@ref BLE_COMMON_THREAD_EVT_MSC} @endmscs

@retval ::NRF_SUCCESS Event pulled and stored into the supplied buffer. @retval ::NRF_ERROR_INVALID_ADDR Invalid or not sufficiently aligned pointer supplied. @retval ::NRF_ERROR_NOT_FOUND No events ready to be pulled. @retval ::NRF_ERROR_DATA_SIZE Event ready but could not fit into the supplied buffer.