NAME    [Toc]    [Back]

       EvmConnControl  -  Controls information for an EVM connection

SYNOPSIS    [Toc]    [Back]

       #include <evm/evm.h>

       EvmStatus_t EvmConnControl(
               EvmConnection_t connection,
               EvmInt32_t request,
               void *arg );

OPERANDS    [Toc]    [Back]

       The connection to be controlled. See the  EvmConnCreate(3)
       reference  page.   The  control  action requested. See the
       DESCRIPTION section for the available requests.  The value
       and use of arg depends on the request. See the DESCRIPTION
       section for the available meanings and the association  to
       a request.

DESCRIPTION    [Toc]    [Back]

       The EvmConnControl() routine allows you to set or get control
 information for a connection.

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


       Gets the size of the connection's receive buffer. The  arg
       argument  is  a  pointer to an EvmInt32_t field to receive
       the size value.  Sets the size of the connection's receive
       buffer.  Changing this value also causes the EVM daemon to
       make a corresponding  change  to  the  size  of  its  send
       buffer.   The  arg  argument is an EvmInt32_t value.  Gets
       the size of the connection's send buffer. The arg argument
       is  a  pointer  to an EvmInt32_t field to receive the size
       value.  Sets the size of  the  connection's  send  buffer.
       Changing  this  value also causes the EVM daemon to make a
       corresponding change to the size of  its  receive  buffer.
       The arg argument is an EvmInt32_t value.  Enables checksum
       generation for posted events. This is  the  default  state
       when  a connection is established. The arg argument should
       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 daemon. The arg argument should be set to NULL.
       Queries the connection to find out whether checksum generation
  is  enabled.   The  arg argument is a pointer to an
       EvmBoolean_t 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 EvmItemMask_t value, containing a bitmap of item values
 to be inserted.  Item enumeration values can  be  converted
 to bitmap form by using the EvmItem Mask_() macro -
       for example,  EvmItemMask_(EvmITEM_TIMESTAMP)  |  EvmItemMask_(EvmITEM_USER_NAME).
   Restores  the  default  set of
       environmental  data  items  inserted  automatically   into
       events posted to the supplied connection. The arg argument
       should be set to NULL. This request clears the effects  of
       any  prior  EvmCONN_POST_ITEM_MASK_SET 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 EvmFALSE (the default state when the
       connection is established), the process will block as necessary
 to synchronize message transfer to the EVM  daemon.
       If  it  is  set  to EvmTRUE, EvmEventPost() returns EvmERROR_QUEUED
 if an event cannot be sent fully without blocking,
  and  the  process must invoke EvmConnFlush() a short
       time later, to avoid unsent messages accumulating in  memory.
  Further  calls to EvmEventPost() will also flush the
       queue. Refer to the  EvmConnFlush(3)  reference  page  for
       more details.

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

              The arg argument is an EvmBoolean_t value. A  value
              of  EvmFALSE  allows the process to block if necessary,
 while EvmTRUE prevents blocking  and  enables
              message queueing.

RETURN VALUES    [Toc]    [Back]

       The  operation  was  completed  without error.  One of the
       arguments to the function  was  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    [Toc]    [Back]

       None

LIBRARY    [Toc]    [Back]

       EVM Support Library (libevm.so, libevm.a)

FILES    [Toc]    [Back]

       None

SEE ALSO    [Toc]    [Back]

       Functions: connect(2), select(2)

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

       Files: kevm(7)

       Event Management: EVM(5)

       Event Connection: EvmConnection(5)



                                                EvmConnControl(3)