diff options
Diffstat (limited to 'doc/user/event.t')
| -rw-r--r-- | doc/user/event.t | 57 |
1 files changed, 30 insertions, 27 deletions
diff --git a/doc/user/event.t b/doc/user/event.t index 7fa45e4b22..9c656e0e82 100644 --- a/doc/user/event.t +++ b/doc/user/event.t @@ -78,9 +78,9 @@ not received. An event condition is used to specify the events which the task desires to receive and the algorithm which will be used to determine when the request is satisfied. An event condition is satisfied based upon one of two algorithms which -are selected by the user. The EVENT_ANY algorithm states that +are selected by the user. The @code{EVENT_ANY} algorithm states that an event condition is satisfied when at least a single requested -event is posted. The EVENT_ALL algorithm states that an event +event is posted. The @code{EVENT_ALL} algorithm states that an event condition is satisfied when every requested event is posted. @ifinfo @@ -89,16 +89,17 @@ condition is satisfied when every requested event is posted. @subsection Building an Event Set or Condition An event set or condition is built by a bitwise OR of -the desired events. The set of valid events is EVENT_0 through -EVENT_31. If an event is not explicitly specified in the set or +the desired events. The set of valid events is @code{EVENT_0} through +@code{EVENT_31}. If an event is not explicitly specified in the set or condition, then it is not present. Events are specifically designed to be mutually exclusive, therefore bitwise OR and addition operations are equivalent as long as each event appears exactly once in the event set list. For example, when sending the event set consisting of -EVENT_6, EVENT_15, and EVENT_31, the event parameter to the -event_send directive should be EVENT_6 | EVENT_15 | EVENT_31. +@code{EVENT_6}, @code{EVENT_15}, and @code{EVENT_31}, +the event parameter to the event_send directive should be +@code{EVENT_6 @value{OR} EVENT_15 @value{OR} EVENT_31}. @ifinfo @node Building an EVENT_RECEIVE Option Set, Event Manager Operations, Building an Event Set or Condition, Event Manager Background @@ -110,10 +111,10 @@ desired option components. The set of valid options for the event_receive directive are listed in the following table: @itemize @bullet -@item WAIT - task will wait for event (default) -@item NO_WAIT - task should not wait -@item EVENT_ALL - return after all events (default) -@item EVENT_ANY - return after any events +@item @code{WAIT} - task will wait for event (default) +@item @code{NO_WAIT} - task should not wait +@item @code{EVENT_ALL} - return after all events (default) +@item @code{EVENT_ANY} - return after any events @end itemize Option values are specifically designed to be @@ -122,14 +123,15 @@ are equivalent as long as each option appears exactly once in the component list. An option listed as a default is not required to appear in the option list, although it is a good programming practice to specify default options. If all -defaults are desired, the option DEFAULT_OPTIONS should be +defaults are desired, the option @code{DEFAULT_OPTIONS} should be specified on this call. This example demonstrates the option parameter needed to poll for all events in a particular event condition to arrive. The option parameter passed to the event_receive -directive should be either EVENT_ALL | NO_WAIT or NO_WAIT. The -option parameter can be set to NO_WAIT because EVENT_ALL is the +directive should be either @code{EVENT_ALL @value{OR} NO_WAIT} +or @code{NO_WAIT}. The option parameter can be set to +@code{NO_WAIT} because @code{EVENT_ALL} is the default condition for event_receive. @ifinfo @@ -194,7 +196,7 @@ satisfied, then one of the following situations applies: @item By default, the calling task will wait forever for the event condition to be satisfied. -@item Specifying the NO_WAIT option forces an immediate return +@item Specifying the @code{NO_WAIT} option forces an immediate return with an error status code. @item Specifying a timeout limits the period the task will @@ -218,10 +220,11 @@ the calling task but the event set is left unaltered. A task can receive all of the currently pending events by calling the event_receive directive with a value of -ALL_EVENTS for the input event condition and NO_WAIT | EVENT_ANY +@code{ALL_EVENTS} for the input event condition and +@code{NO_WAIT @value{OR} EVENT_ANY} for the option set. The pending events are returned to the calling task and the event set is cleared. If no events are -pending then the UNSATISFIED status code will be returned. +pending then the @code{UNSATISFIED} status code will be returned. @ifinfo @node Event Manager Directives, EVENT_SEND - Send event set to a task, Receiving all Pending Events, Event Manager @@ -282,7 +285,7 @@ events, then the events sent are left pending. @subheading NOTES: -Specifying SELF for id results in the event set being +Specifying @code{SELF} for id results in the event set being sent to the calling task. Identical events sent to a task are not queued. In @@ -330,18 +333,18 @@ procedure Event_Receive ( @subheading DIRECTIVE STATUS CODES: @code{SUCCESSFUL} - event received successfully@* -@code{UNSATISFIED} - input event not satisfied (NO_WAIT)@* +@code{UNSATISFIED} - input event not satisfied (@code{NO_WAIT})@* @code{TIMEOUT} - timed out waiting for event @subheading DESCRIPTION: This directive attempts to receive the event condition specified in event_in. If event_in is set to -PENDING_EVENTS, then the current pending events are returned in -event_out and left pending. The WAIT and NO_WAIT options in the +@code{PENDING_EVENTS}, then the current pending events are returned in +event_out and left pending. The @code{WAIT} and @code{NO_WAIT} options in the option_set parameter are used to specify whether or not the task is willing to wait for the event condition to be satisfied. -EVENT_ANY and EVENT_ALL are used in the option_set parameter are +@code{EVENT_ANY} and @code{EVENT_ALL} are used in the option_set parameter are used to specify whether a single event or the complete event set is necessary to satisfy the event condition. The event_out parameter is returned to the calling task with the value that @@ -350,13 +353,13 @@ corresponds to the events in event_in that were satisfied. If pending events satisfy the event condition, then event_out is set to the satisfied events and the pending events in the event condition are cleared. If the event condition is -not satisfied and NO_WAIT is specified, then event_out is set to +not satisfied and @code{NO_WAIT} is specified, then event_out is set to the currently satisfied events. If the calling task chooses to wait, then it will block waiting for the event condition. If the calling task must wait for the event condition to be satisfied, then the timeout parameter is used to specify -the maximum interval to wait. If it is set to NO_TIMEOUT, then +the maximum interval to wait. If it is set to @code{NO_TIMEOUT}, then the calling task will wait forever. @subheading NOTES: @@ -369,9 +372,9 @@ The following event receive option constants are defined by RTEMS: @itemize @bullet -@item WAIT task will wait for event (default) -@item NO_WAIT task should not wait -@item EVENT_ALL return after all events (default) -@item EVENT_ANY return after any events +@item @code{WAIT} task will wait for event (default) +@item @code{NO_WAIT} task should not wait +@item @code{EVENT_ALL} return after all events (default) +@item @code{EVENT_ANY} return after any events @end itemize |