EvmConnControl(3)EvmConnControl(3)NAMEEvmConnControl() - control information for an EVM connection
SYNOPSIS
Library
EVM Support Library
Parameters
connection The EVM connection to be controlled. See the EvmConnCre‐
ate(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 daemon. 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 num‐
ber 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)