EvmEventPost, EvmEventPostVa - Posts an event
#include <evm/evm.h>
EvmStatus_t EvmEventPost(
EvmConnection_t connection,
const EvmEvent_t event ); EvmStatus_t EvmEventPostVa(
EvmConnection_t connection,
const EvmEvent_t event,
[EvmItemId_t item_id,
const EvmItemValue_t item_id]...,
EvmITEM_NONE );
The connection through which events are posted. See EvmConnCreate(3). The event that is to be posted to the
specified connection. See EvmEventCreate(3). The identifier
for the event data item to be set. See EvmItemSet(3)
for possible values for this operand, and the data contained
by the data item. The value to be stored in the
associated item indicated by item_id.
An EVM client program uses the routines described on this
page to pass events to the EVM daemon, for distribution to
subscribers.
EvmEventPost() posts an event that has already been created
with EvmEventCreate() or EvmEventCreateVa().
EvmEventPostVa() allows you to create, post and destroy an
event in a single call. It first creates a new event,
adding to it any data items supplied in the call. 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 you pass NULL as the connection operand to either of
these routines the event is posted to the local daemon,
using a temporary connection, which is destroyed before
the routine returns. Because of the overhead associated
with creating and destroying an EVM connection, you should
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.
These routines do not destroy the event passed as the
event operand. You must explicitly call EvmEventDestroy()
to destroy the event and free its memory once it is no
longer needed. You should 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. EvmConnControl() can
be used to increase the size of the send buffer. See EvmConnControl(3) for more information. If you use extended
item_ids to supply names and values of variable items to
EvmEventPostVa(), 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.
None
The operation was completed without error. The connection
was lost and is no longer usable. The caller should invoke
EvmConnDestroy() to destroy it, then reestablish the connection.
The EVM daemon rejected the event. The most
likely reasons for this to happen 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 was 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 will be made to flush the queue
when the next call is made to EvmEventPost(3), or when the
caller invokes EvmConnFlush(3). This error code is only
returned for connections for which EvmConnControl(3) has
been invoked with the request argument set to EvmCONN_POST_NONBLOCK_SET.
A read error occurred while reading
from the EVM daemon connection. The connection is no
longer usable, and the caller should invoke EvmConnDestroy()
to destroy it. A write error occurred while writing
to the EVM daemon connection. The connection is no
longer usable, and the caller should invoke EvmConnDestroy()
to destroy it.
None
EVM Support Library (libevm.so, libevm.a)
None
Routines: EvmConnControl(3), EvmConnCreate(3), EvmConnDestroy(3), EvmConnRegistrationGet(3), EvmEventCreate(3),
EvmEventDestroy(3), EvmItemSetVa(3)
Files: kevm(7)
Event Management: EVM(5)
Event Connection: EvmConnection(5)
EVM Events: EvmEvent(5)
EvmEventPost(3)
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