EvmConnControl(3)					     Library Functions Manual						 EvmConnControl(3)

NAME

       EvmConnControl() - control information for an EVM connection

SYNOPSIS

   Library
       EVM Support Library

   Parameters
       connection  The EVM connection to be controlled. See the EvmConnCreate(3) manpage.

       request	   The control action requested.  See the section for the available requests.

       arg	   The value and use of arg depends on the request.  See the section for the available meanings and the association to a request.

DESCRIPTION

       The routine sets or gets control information for a connection.

       The following list shows the available values for the request argument and the associated value of the arg argument.

       request Argument    arg Argument Values

       Gets the size of the connection's receive buffer.
			   The arg argument is a pointer to an field to receive the size value.

       Gets the size of the connection's send buffer.
			   The arg argument is a pointer to an field to receive the size value.

       NOTE:  and  which set the receive and send buffer size, are not currently supported in HP-UX.  Instead, use to get the socket descriptor of
       the connection, and use to change the buffer size of the socket.

       Enables checksum generation for posted events.
			   This is the default state when a connection is established.	The arg argument must be set to NULL.

       Disables checksum generation for posted events.
			   This option is intended for use by high-performance applications that post events frequently using the local  EVM  dae-
			   mon.  The arg argument must be set to NULL.

       Queries the connection to find out if checksum generation is enabled.
			   The arg argument is a pointer to an field to receive a boolean value.

       Modifies the set of environmental data items that are inserted into
			   events  posted  to  the  supplied  connection.   The  arg  argument is a value containing a bitmap of item values to be
			   inserted.  Item enumeration values can be converted to bitmap form by using the macro.  For example,

       Restores the default set of environmental data items inserted
			   automatically into events posted to the supplied connection.  The arg argument must	be  set  to  NULL.   This  request
			   clears the effects of any prior requests.

       Controls the behavior of the calling process if an attempt to post an
			   event  would overflow the connection's send buffer.	If this option is set to (the default state when the connection is
			   established), the process blocks as necessary to synchronize message transfer to the EVM daemon.

			   If it is set to returns if an event cannot be sent fully without blocking.  In addition,  the  process  must  invoke  a
			   short  time	later,	to avoid unsent messages accumulating in memory.  Further calls to also flush the queue.  Refer to
			   the EvmConnFlush(3) manpage for more details.

			   This option cannot be used for any connection type other than a posting connection with a response mode of This  option
			   is  provided  for  critical	high-performance  processes which must post a large number of events in a very short time.
			   This option is not suitable for general use.

       The arg argument is an value.  A value of allows the process to block if necessary.  A value of prevents blocking and enables message queu-
       ing.

RETURN VALUE

       The operation completed without error.

       One of the arguments to the function is invalid.

       A value in a structure member is invalid.

       An operation failed because an attempt to acquire heap memory failed.

       An unexpected error occurred while attempting to acquire or control
	      a system resource.

       The current operation was interrupted by receipt of a signal.

ERRORS

       The value of is not set.

SEE ALSO

   Functions
       connect(2), select(2).

   Routines
       EvmConnCheck(3), EvmConnCreate(3), EvmConnSubscribe(3), EvmConnWait(3).

   Event Management
       EVM(5).

   Event Connection
       EvmConnection(5).

																 EvmConnControl(3)