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

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. 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.

  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. 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.

  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(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
  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

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

FILES
  None

SEE ALSO
  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)

Index for Section 3

Alphabetical listing for E

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