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EvmConnControl(3)
NAME
  EvmConnControl - Controls information for an EVM connection

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

SYNOPSIS
  #include <evm/evm.h>

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

OPERANDS
  connection
	  The connection to be controlled.  See the EvmConnCreate(3)
	  reference page.

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

  arg	  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
  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.

  EvmCONN_RCV_SZ_GET
	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.

  EvmCONN_RCV_SZ_SET
	Sets the size of the connection's receive buffer.  The arg argument
	is an EvmInt32_t value.

  EvmCONN_SND_SZ_GET
	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.

  EvmCONN_SND_SZ_SET
	Sets the size of the connection's send buffer.	The arg argument is
	an EvmInt32_t value.

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

  EvmCONN_CHECKSUM_DISABLE
	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

  EvmCONN_CHECKSUM_IS_ENABLED
	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.

  EvmCONN_POST_ITEM_MASK_SET
	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).

  EvmCONN_POST_ITEM_MASK_RESET
	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.

  EvmCONN_POST_NONBLOCK_SET
	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 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
  EvmERROR_NONE
	The operation was completed without error.

  EvmERROR_INVALID_ARGUMENT
	One of the arguments to the function was invalid.

  EvmERROR_INVALID_VALUE
	A value in a structure member is invalid.

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

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

  EvmERROR_SIGNAL
	The current operation was interrupted by receipt of a signal.

ERRORS
  None

FILES
  None

SEE ALSO
  Functions: connect(2), select(2)

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

  Event Management: EVM(5)

  Event Connection: EvmConnection(5)

Index for Section 3

Alphabetical listing for E

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