sr_waitevt( )

Description | Cautions | Example | Errors

Name:	long sr_waitevt(timeout)
Inputs:	long timeout	timeout in milliseconds (msec)
Returns:	time left before timeout
	-1 if timeout
Includes:	srllib.h
Type:	Event Control function

Description

The function sr_waitevt( ), for a specified period of time, waits for any event to occur on any Dialogic device

Parameter	Description
timeout	A timeout value of -1 instructs sr_waitevt( ) to wait indefinitely for the next event. Use timeout 0 when the SRL event must return imediately, regardlesss of whether or not an event is present in the SRL event queue.

The sr_waitevt( ) function returns a value when the next event occurs, or when a timeout is reached. If an event occurs, the value returned is the number of milliseconds before the timeout. If no event occurs before the timeout, the value returned is -1. If the function times out, a timeout event occurs on the SRL_DEVICE. The sr_getevtdev(0) function returns SRL_DEVICE, the Dialogic device handle associated with the current event. The sr_getevttype(0) function returns SR_TMOUTEVT, which is the current event type.

Cautions

When an application receives an event, the event must be handled immediately and event-specific information should be retrieved before the next call to sr_waitevt( ) because sr_waitevt( ) automatically removes the current event before waiting for the next event; previous information is overwritten.

The sr_waitevt( ) function cannot be called from within a handler.

You cannot use sr_waitevt( ) and sr_waitevtEx( ) functions in the same thread.

If you use the sr_waitevt( ) function to retrieve events, pass 0 as a parameter when using the following functions:

• sr_getevtdatap(0)
• sr_getevtdev(0)
• sr_getevtlen(0)
• sr_getevttype(0)

Example

#include <windows.h>  
   
#include <srllib.h>  
#include <dxxxlib.h>
  
int dx_handler(unsigned long evhandle)  
{  
   printf( "Got event 0x%x on device %s, data length = %d, datap = 0x%x\n",  
          sr_getevttype(evhandle), ATDV_NAMEP( sr_getevtdev()), sr_getevtlen(evhandle),  
          sr_getevtdatap(evhandle));
  
   /* Tell SRL to keep the event */  
   return( 1 );  
}
  
main()  
{  
   int dxxxdev;  
   int mode = SR_STASYNC;  
     /* Set SRL to turn off creation of internal thread */  
   if( sr_setparm( SRL_DEVICE, SR_MODELTYPE, &mode ) == -1 ){  
      printf( "Error: cannot set srl mode\n" );  
      exit( 1 );  
   }  
     /* Open a dxxx channel device */  
   if(( dxxxdev = dx_open( "dxxxB1C1", 0 )) == -1 ){  
      printf( "Error: cannot open device\n" );  
      exit( 1 );  
   }
  
     /* enable a handler for all events on the device */  
   if( sr_enbhdlr( dxxxdev, EV_ANYEVT, dx_handler ) == -1 ){  
      printf( "Error: could not enable handler\n" );  
      exit( 1 );  
   }
  
     /* Perform an async function on the device */  
   if( dx_sethook( dxxxdev, DL_ONHOOK, EV_ASYNC ) == -1 ){  
      printf( "dx_sethook failed: error = %s\n", ATDV_ERRMSGP( dxxxdev ));  
      exit( 1 );  
   }
  
   /* Wait 10 seconds for an event */  
   if( sr_waitevt( 10000 ) == -1 ){  
      printf( "sr_waitevt, %s\n",  
             ATDV_ERRMSGP( SRL_DEVICE ));  
      exit( 1 );  
   }
  
   /* Disable the handler */  
   if( sr_dishdlr( dxxxdev, EV_ANYEVT, dx_handler ) == -1 ){  
      printf( "Error: could not disable handler\n" );  
      exit( 1 );  
   }
  
   if( dx_close( dxxxdev ) == -1 ){  
      printf( "Error: could not close dxxxdev\n" );  
      exit( 1 );  
   }
  
   exit( 0 );  
}

Errors

If this function returns -1 to indicate failure, obtain the reason for the error by calling the SRL standard attribute function ATDV_LASTERR(SRL_DEVICE) or ATDV_ERRMSGP(SRL_DEVICE) to retrieve either the error code or a pointer to the error description, respectively. One of the following errors may be returned:

ESR_SYS

Error from operating system; use dx_fileerrno( ) to obtain error value.

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