receive_buffer.c File Reference

This file contains the implementation of the receive payload delay buffer. More...

#include "receive_buffer.h"
#include "cdi_os_api.h"
#include "configuration.h"
#include "internal.h"
#include <stdint.h>
#include <stdlib.h>

Data Structures
struct	ReceiveBufferState

Functions
static uint64_t	TaiNowMicroseconds ()
CDI_THREAD	ReceiveBufferThread (void *ptr)
CdiReturnStatus	RxBufferInit (CdiLogHandle log_handle, CdiPoolHandle error_message_pool, int buffer_delay_ms, int max_rx_payloads, CdiQueueHandle output_queue_handle, ReceiveBufferHandle *receive_buffer_handle_ptr, CdiQueueHandle *input_queue_handle_ptr)
void	RxBufferDestroy (ReceiveBufferHandle receive_buffer_handle)

Variables
static const int	kMaxMissed = 100
	The number of consecutive payloads with time stamps out of the buffering window before offset is reset.

Detailed Description

This file contains the implementation of the receive payload delay buffer.

Function Documentation

ReceiveBufferThread()

CDI_THREAD ReceiveBufferThread

(

void *

ptr

)

The main function for the receive delay buffer thread. It takes application callback structures from its input queue and sends them to the configured queue after a configurable delay based on the timestamps associated with each payload.

Parameters

ptr	Pointer to thread specific data. In this case, a pointer to ReceiveBufferState.

Returns

The return value is not used.

RxBufferDestroy()

void RxBufferDestroy

(

ReceiveBufferHandle

receive_buffer_handle

)

Destroys the receive delay buffer specified by the handle. Payloads currently in the delay line are pushed to the output queue then the associate thread is shut down and joined and all resources allocated are freed.

Parameters

receive_buffer_handle

Handle for the receive delay buffer to destroy.

RxBufferInit()

CdiReturnStatus RxBufferInit	(	CdiLogHandle	log_handle,
		CdiPoolHandle	error_message_pool,
		int	buffer_delay_ms,
		int	max_rx_payloads,
		CdiQueueHandle	output_queue_handle,
		ReceiveBufferHandle *	receive_buffer_handle_ptr,
		CdiQueueHandle *	input_queue_handle_ptr )

Creates a receive delay buffer of the specified length, allocating all of the associated resources.

Parameters

log_handle	Handle to the logger to be used for any messages from this module.
error_message_pool	Handle to the pool to which error messages are to be freed in the event that an internal error prevents an input payload from being sent to the next stage.
buffer_delay_ms	The number of milliseconds to delay each payload, more or less, depending on each payload's timestamp value.
max_rx_payloads	The number of objects to allocate for holding payloads in the delay buffer.
output_queue_handle	Handle to which the receive delay buffer is to send payloads after they've been delayed.
receive_buffer_handle_ptr	Address of where to write the receive delay buffer's handle if successfully created.
input_queue_handle_ptr	Address to write the handle for the receive delay buffer's input queue if creation was successful.

Returns

CdiReturnStatus kCdiStatusOk if the recieve delay buffer was successfully created or kCdiStatusNotEnoughMemory if memory was insufficient to allocate all of the required resources.

TaiNowMicroseconds()

static uint64_t TaiNowMicroseconds ( )

inlinestatic

Convenience function to get the TAI based PTP timestamp and convert it to a single integer value representing the number of microseconds from the epoch.

Returns

uint64_t The number of microseconds since the epoch according to the hosts real time clock.