SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
brief: |
  Sends the event set to the task.
copyrights:
- Copyright (C) 2020 embedded brains GmbH (http://www.embedded-brains.de)
- Copyright (C) 1988, 2008 On-Line Applications Research Corporation (OAR)
definition:
  default:
    attributes: null
    body: null
    params:
    - ${../../type/if/id:/name} ${.:/params[0]/name}
    - ${set:/name} ${.:/params[1]/name}
    return: ${../../status/if/code:/name}
  variants: []
description: |
  This directive sends the event set, ${.:/params[1]/name}, to the target
  task identified by ${.:/params[0]/name}.  Based upon the state of the
  target task, one of the following situations applies:

  * The target task is blocked waiting for events, then

    * if the waiting task's input event condition is satisfied, then the task
      is made ready for execution, or

    * otherwise, the event set is posted but left pending and the task remains
      blocked.

  * The target task is not waiting for events, then the event set is posted and
    left pending.
enabled-by: true
index-entries: []
interface-type: function
links:
- role: interface-placement
  uid: header
- role: interface-ingroup
  uid: group
name: rtems_event_send
notes: |
  Events can be sent by tasks or an ${/glossary/isr:/term}.

  Specifying ${../../task/if/self-define:/name} for ${.:/params[0]/name} results
  in the event set being sent to the calling task.

  The event set to send shall be built by a *bitwise or* of the desired events.
  The set of valid events is ${event-00:/name} through ${event-31:/name}.  If
  an event is not explicitly specified in the set, then it is not present.

  Identical events sent to a task are not queued.  In other words, the second,
  and subsequent, posting of an event to a task before it can perform an
  ${receive:/name} has no effect.

  The calling task will be preempted if it has preemption enabled and a higher
  priority task is unblocked as the result of this directive.

  Sending an event set to a global task which does not reside on the local node
  will generate a request telling the remote node to send the event set to the
  appropriate task.
params:
- description: is the identifier of the target task to receive the event set.
  dir: null
  name: id
- description: is the event set to send.
  dir: null
  name: event_in
return:
  return: null
  return-values:
  - description: |
      The requested operation was successful.
    value: ${../../status/if/successful:/name}
  - description: |
      There was no task associated with the identifier specified by
      ${.:/params[0]/name}.
    value: ${../../status/if/invalid-id:/name}
type: interface