Asynchronous Events

An ASCB application can register condition(s) to be monitored by the firmware.

When a callback handler is defined, the condition(s) are reported to the application asynchronously from the firmware to the handler.

The way to define a handler is as follows:

• Initialize the application as usual.
• A callback handler must be registered using the mxfAsyncEventHandlerInit() function.
• The conditions to monitor must be defined using the mxfAsyncEventConditionsSet() function.

List of conditions

The event conditions that can be monitored for a BC channel are as follows:

Condition	Description
MXF_ASYNCEVENT_COND_TXPERIODIC_UPDATEMSG_BUFFER_THRESHOLD	Periodic update message buffer threshold reached.

#define ALMOST_FULL  20
#define ALMOST_EMPTY 10

uint32 rc;
HMXF_SERVER server;
HMXF_CHANNEL bc;
HMXF_BUFFER bcBufferTx;
HMXF_ASYNCEVENT asyncEvent=0;
MXF_ASYNCEVENT_CONDITION condition;
MXF_ASCB_DATAREC* txBuffer;

   ...

   // Configures periodic update asynchronous event condition
   if(!rc)
      rc = mxfAsyncEventHandlerInit(server, &txHandler, txBuffer, &asyncEvent);

   if(!rc)
   {
      condition.reserved = 0;
      condition.condID = MXF_ASYNCEVENT_COND_TXAPERIODIC_BUFFER_THRESHOLD;
      condition.condition.txPeriodicUpdateMsgBufferThreshold.almostEmpty = ALMOST_EMPTY;
      condition.condition.txPeriodicUpdateMsgBufferThreshold.almostFull = ALMOST_FULL;
      condition.condition.txPeriodicUpdateMsgBufferThreshold.channel = bc;
      rc = mxfAsyncEventConditionsSet(asyncEvent, TRUE, 1, &condition);
   }   

   // Select periodic update buffer   
   if(!rc)
      rc = mxfAsyncEventTxPeriodicUpdateMsgSelectSet(asyncEvent, bc, MXF_MSG_SELECT_ONLY, 1, &bcBufferTx);

   ...

   // Disables asynchronous event condition
   if(!rc)
      rc = mxfAsyncEventConditionsSet(asyncEvent, FALSE, 1, &condition);

   if(!rc)
      rc = mxfAsyncEventHandlerTerminate(asyncEvent);

   ...