dx_getevt( )

Description | Cautions | Example | Errors | See Also

Name:	int dx_getevt(chdev,eblkp,timeout)
Inputs:	int chdev	valid Dialogic channel device handle
	DX_EBLK *eblkp	Pointer to Event Block Structure
	int timeout	Timeout value in seconds
Returns:	0 if success
	-1 if failure
Includes:	srllib.h
	dxxxlib.h
Category:	Call Status Transition Event

Description

The dx_getevt( ) function monitors channel events synchronously for possible call status transition events in conjunction with dx_setevtmsk( ). dx_getevt( ) blocks and returns control to the program after one of the events set by dx_setevtmsk( ) occurs on the channel specified in the chdev parameter. The DX_EBLK structure contains the event that ended the blocking.

The function parameters are defined as follows:

Parameter	Description
chdev	specifies the valid channel device handle obtained when the channel was opened using dx_open( ).
eblkp	points to the Event Block Structure DX_EBLK, which will contain the event that ended the blocking.
timeout	specifies the maximum amount of time in seconds to wait for an event to occur. timeout can have one of the following values:
	# of seconds:	maximum length of time dx_getevt( ) will wait for an event. When the time specified has elapsed, the function will terminate and return an error.
	-1:	dx_getevt( ) will block until an event occurs; it will not time out.
	0:	The function will return -1 immediately if no event is present.
NOTE: When the time specified in timeout expires, dx_getevt( ) will terminate and return an error. The Standard Attribute function ATDV_LASTERR( ) can be used to determine the cause of the error, which in this case is EDX_TIMEOUT.

Cautions

We recommend enabling only one process per channel. The event that dx_getevt( ) is waiting for may change if another process sets a different event for that channel. See dx_setevtmsk( ) for more details.

Example

#include <stdio.h>  
#include <srllib.h>  
#include <dxxxlib.h>  
#include <windows.h>  
main()  
{  
   int chdev;          /* channel descriptor */  
   int timeout;        /* timeout for function */  
   DX_EBLK eblk;       /* Event Block Structure */  
   .  
   .  
   .  
   /* Open Channel */  
   if ((chdev = dx_open("dxxxB1C1",NULL)) == -1) {  
     /* process error */  
   }  
   /* Set RINGS or WINK as events to wait on */  
   if (dx_setevtmsk(chdev,DM_RINGS|DM_WINK) == -1) {  
     /* process error */  
   }  
   /* Set timeout to 5 seconds */  
   timeout = 5;  
   if (dx_getevt(chdev,&eblk,timeout) == -1){  
      /* process error */  
      if (ATDV_LASTERR(chdev) == EDX_TIMEOUT) {    /* check if timed out */  
         printf("Timed out waiting for event.\n");  
      }  
      else {  
         /* further error processing */  
         .  
         .  
      }  
   }  
   switch (eblk.ev_event) {  
   case DE_RINGS:  
      printf("Ring event occurred.\n");  
      break;  
   case DE_WINK:  
      printf("Wink event occurred.\n");  
      break;  
   }  
   .  
   .  
}

Errors

If this function returns -1 to indicate failure, use ATDV_LASTERR( ) and ATDV_ERRMSGP( ) to retrieve one of the following error reasons:

EDX_BADPARM	Invalid Parameter
EDX_SYSTEM	Error from operating system; use dx_fileerrno( ) to obtain error value
EDX_TIMEOUT	Timeout time limit is reached

See Also

• dx_setevtmsk( )
• DX_EBLK structure

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