EvmEventPost(3) Library Functions Manual EvmEventPost(3)
NAME
EvmEventPost(), EvmEventPostVa() - post an EVM event
SYNOPSIS
Library
EVM Support Library
Parameters
connection The connection through which events are posted. See EvmConnCreate(3).
event The event that is to be posted to the specified connection. See EvmEventCreate(3).
item_id The identifier for the event data item to be set. See EvmItemSet(3) for possible values for this operand, and the data con-
tained by the data item.
item_value The value to be stored in the associated item indicated by item_id.
DESCRIPTION
An EVM client program uses the routines described on this page to pass events to the EVM daemon, for distribution to subscribers.
posts an event that has already been created with or
creates, posts and destroys an event in a single call. It first creates a new event, adding any data items supplied in the call to it. If
the event operand is not NULL, the contents of the supplied event are then merged into the new event, and the new event is posted. The new
event is destroyed before the routine returns, and the supplied event (if any) is unchanged. See EvmItemSetVa(3) for details of the
item_ids and item_values that may be passed as operands to this routine.
If NULL is passed as the connection operand to either of these routines, the event is posted to the local daemon using a temporary connec-
tion. The temporary connection is destroyed before the routine returns. Because of the overhead associated with creating and destroying
an EVM connection, pass NULL only if your program rarely posts events.
If either routine is unable to pass the event to the daemon, the error is reported immediately through the return code. If the event is
passed to the daemon, the type of response depends on the response mode specified when the connection was created.
Notes
1. These routines do not destroy the event passed as the event operand. Explicitly call to destroy the event and free its memory
once it is no longer needed.
2. Avoid posting a large number of events in rapid succession, since this may cause the connection's send buffer to fill, and the
posting process to block until the EVM daemon has relieved some or all of the data. Although this is a normal part of process
synchronization, some high-performance processes may prefer to block as infrequently as possible. can be used to increase the
size of the send buffer. See EvmConnControl(3) for more information.
3. When using extended item_ids to supply names and values of variable items to be sure to supply the correct number of operands for
each. A variable name and value is required for all such items, and some variable types require an additional argument. See
EvmItemSetVa(3) for more information.
RETURN VALUE
The operation completed without error.
The EVM daemon rejected the event.
The most likely reasons are that no template has been registered for the event, or that the caller is not authorized to post the
event. See evmtemplate(4) and evm.auth(4) for more information.
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.
The connection's output buffer is full, and the event has
been queued in heap space. Another attempt is made to flush the queue when the next call is made to or when the caller invokes This
error code is only returned for connections for which has been invoked with the request argument set to
A read error occurred while reading from the EVM daemon connection.
The connection is no longer usable. The caller needs to invoke to destroy it.
A write error occurred while writing to the EVM daemon connection.
The connection is no longer usable. The caller needs to invoke to destroy it.
ERRORS
The value of is not set.
SEE ALSO
Routines
EvmConnControl(3), EvmConnCreate(3), EvmConnDestroy(3), EvmConnRegistrationGet(3), EvmEventCreate(3), EvmEventDestroy(3), EvmItemSetVa(3).
Event Management
EVM(5).
Event Connection
EvmConnection(5).
EVM Events
EvmEvent(5).
EvmEventPost(3)