[PATCH 02/16] c-user: Split up event manager

Sebastian Huber sebastian.huber at embedded-brains.de
Thu Aug 20 10:18:51 UTC 2020


This makes it easier to automatically generate parts of the manager
documentation in the future.

Update #3993.
---
 c-user/event/background.rst   |  96 +++++++++++
 c-user/event/directives.rst   | 142 ++++++++++++++++
 c-user/event/index.rst        |  15 ++
 c-user/event/introduction.rst |  13 ++
 c-user/event/operations.rst   |  63 +++++++
 c-user/event_manager.rst      | 309 ----------------------------------
 c-user/index.rst              |   2 +-
 7 files changed, 330 insertions(+), 310 deletions(-)
 create mode 100644 c-user/event/background.rst
 create mode 100644 c-user/event/directives.rst
 create mode 100644 c-user/event/index.rst
 create mode 100644 c-user/event/introduction.rst
 create mode 100644 c-user/event/operations.rst
 delete mode 100644 c-user/event_manager.rst

diff --git a/c-user/event/background.rst b/c-user/event/background.rst
new file mode 100644
index 0000000..f14e55f
--- /dev/null
+++ b/c-user/event/background.rst
@@ -0,0 +1,96 @@
+.. SPDX-License-Identifier: CC-BY-SA-4.0
+
+.. Copyright (C) 1988, 2008 On-Line Applications Research Corporation (OAR)
+
+Background
+==========
+
+.. index:: event flag, definition
+.. index:: event set, definition
+.. index:: rtems_event_set
+
+Event Sets
+----------
+
+An event flag is used by a task (or ISR) to inform another task of the
+occurrence of a significant situation.  Thirty-two event flags are associated
+with each task.  A collection of one or more event flags is referred to as an
+event set.  The data type ``rtems_event_set`` is used to manage event sets.
+
+The application developer should remember the following key characteristics of
+event operations when utilizing the event manager:
+
+- Events provide a simple synchronization facility.
+
+- Events are aimed at tasks.
+
+- Tasks can wait on more than one event simultaneously.
+
+- Events are independent of one another.
+
+- Events do not hold or transport data.
+
+- Events are not queued.  In other words, if an event is sent more than once to
+  a task before being received, the second and subsequent send operations to
+  that same task have no effect.
+
+An event set is posted when it is directed (or sent) to a task.  A pending
+event is an event that has been posted but not received.  An event condition is
+used to specify the event set 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 ``RTEMS_EVENT_ANY`` algorithm states that an event
+condition is satisfied when at least a single requested event is posted.  The
+``RTEMS_EVENT_ALL`` algorithm states that an event condition is satisfied when
+every requested event is posted.
+
+.. index:: event condition, building
+.. index:: event set, building
+
+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 ``RTEMS_EVENT_0`` through ``RTEMS_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 ``RTEMS_EVENT_6``,
+``RTEMS_EVENT_15``, and ``RTEMS_EVENT_31``, the event parameter to the
+``rtems_event_send`` directive should be ``RTEMS_EVENT_6 | RTEMS_EVENT_15 |
+RTEMS_EVENT_31``.
+
+Building an EVENT_RECEIVE Option Set
+------------------------------------
+
+In general, an option is built by a bitwise OR of the desired option
+components.  The set of valid options for the ``rtems_event_receive`` directive
+are listed in the following table:
+
+.. list-table::
+ :class: rtems-table
+
+ * - ``RTEMS_WAIT``
+   - task will wait for event (default)
+ * - ``RTEMS_NO_WAIT``
+   - task should not wait
+ * - ``RTEMS_EVENT_ALL``
+   - return after all events (default)
+ * - ``RTEMS_EVENT_ANY``
+   - return after any events
+
+Option values are specifically designed to be mutually exclusive, therefore
+bitwise OR and addition operations 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
+``RTEMS_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
+``rtems_event_receive`` directive should be either ``RTEMS_EVENT_ALL |
+RTEMS_NO_WAIT`` or ``RTEMS_NO_WAIT``.  The option parameter can be set to
+``RTEMS_NO_WAIT`` because ``RTEMS_EVENT_ALL`` is the default condition for
+``rtems_event_receive``.
diff --git a/c-user/event/directives.rst b/c-user/event/directives.rst
new file mode 100644
index 0000000..ef94115
--- /dev/null
+++ b/c-user/event/directives.rst
@@ -0,0 +1,142 @@
+.. SPDX-License-Identifier: CC-BY-SA-4.0
+
+.. Copyright (C) 1988, 2008 On-Line Applications Research Corporation (OAR)
+
+Directives
+==========
+
+This section details the event manager's directives.  A subsection is dedicated
+to each of this manager's directives and describes the calling sequence,
+related constants, usage, and status codes.
+
+.. raw:: latex
+
+   \clearpage
+
+.. index:: send event set to a task
+.. index:: rtems_event_send
+
+.. _rtems_event_send:
+
+EVENT_SEND - Send event set to a task
+-------------------------------------
+
+CALLING SEQUENCE:
+    .. code-block:: c
+
+        rtems_status_code rtems_event_send (
+            rtems_id         id,
+            rtems_event_set  event_in
+        );
+
+DIRECTIVE STATUS CODES:
+    .. list-table::
+     :class: rtems-table
+
+     * - ``RTEMS_SUCCESSFUL``
+       - event set sent successfully
+     * - ``RTEMS_INVALID_ID``
+       - invalid task id
+
+DESCRIPTION:
+    This directive sends an event set, event_in, to the task specified by id.
+    If a blocked task's input event condition is satisfied by this directive,
+    then it will be made ready.  If its input event condition is not satisfied,
+    then the events satisfied are updated and the events not satisfied are left
+    pending.  If the task specified by id is not blocked waiting for events,
+    then the events sent are left pending.
+
+NOTES:
+    Specifying ``RTEMS_SELF`` for id results in the event set being sent to the
+    calling task.
+
+    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 ``rtems_event_receive`` 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.
+
+.. raw:: latex
+
+   \clearpage
+
+.. index:: receive event condition
+.. index:: rtems_event_receive
+
+.. _rtems_event_receive:
+
+EVENT_RECEIVE - Receive event condition
+---------------------------------------
+
+CALLING SEQUENCE:
+    .. code-block:: c
+
+        rtems_status_code rtems_event_receive (
+            rtems_event_set  event_in,
+            rtems_option     option_set,
+            rtems_interval   ticks,
+            rtems_event_set *event_out
+        );
+
+DIRECTIVE STATUS CODES:
+    .. list-table::
+     :class: rtems-table
+
+     * - ``RTEMS_SUCCESSFUL``
+       - event received successfully
+     * - ``RTEMS_UNSATISFIED``
+       - input event not satisfied (``RTEMS_NO_WAIT``)
+     * - ``RTEMS_INVALID_ADDRESS``
+       - ``event_out`` is NULL
+     * - ``RTEMS_TIMEOUT``
+       - timed out waiting for event
+
+DESCRIPTION:
+
+    This directive attempts to receive the event condition specified in
+    event_in.  If event_in is set to ``RTEMS_PENDING_EVENTS``, then the current
+    pending events are returned in event_out and left pending.  The
+    ``RTEMS_WAIT`` and ``RTEMS_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. ``RTEMS_EVENT_ANY`` and
+    ``RTEMS_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 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 ``RTEMS_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 ``RTEMS_NO_TIMEOUT``, then the calling task will wait forever.
+
+NOTES:
+    This directive only affects the events specified in event_in.  Any pending
+    events that do not correspond to any of the events specified in event_in
+    will be left pending.
+
+    The following event receive option constants are defined by RTEMS:
+
+    .. list-table::
+     :class: rtems-table
+
+     * - ``RTEMS_WAIT``
+       - task will wait for event (default)
+     * - ``RTEMS_NO_WAIT``
+       - task should not wait
+     * - ``RTEMS_EVENT_ALL``
+       - return after all events (default)
+     * - ``RTEMS_EVENT_ANY``
+       - return after any events
+
+    A clock tick is required to support the functionality of this directive.
diff --git a/c-user/event/index.rst b/c-user/event/index.rst
new file mode 100644
index 0000000..6503c35
--- /dev/null
+++ b/c-user/event/index.rst
@@ -0,0 +1,15 @@
+.. SPDX-License-Identifier: CC-BY-SA-4.0
+
+.. Copyright (C) 2020 embedded brains GmbH (http://www.embedded-brains.de)
+
+.. index:: events
+
+Event Manager
+*************
+
+.. toctree::
+
+    introduction
+    background
+    operations
+    directives
diff --git a/c-user/event/introduction.rst b/c-user/event/introduction.rst
new file mode 100644
index 0000000..fb63e42
--- /dev/null
+++ b/c-user/event/introduction.rst
@@ -0,0 +1,13 @@
+.. SPDX-License-Identifier: CC-BY-SA-4.0
+
+.. Copyright (C) 1988, 2008 On-Line Applications Research Corporation (OAR)
+
+Introduction
+============
+
+The event manager provides a high performance method of intertask communication
+and synchronization.  The directives provided by the event manager are:
+
+- :ref:`rtems_event_send`
+
+- :ref:`rtems_event_receive`
diff --git a/c-user/event/operations.rst b/c-user/event/operations.rst
new file mode 100644
index 0000000..e01b6dc
--- /dev/null
+++ b/c-user/event/operations.rst
@@ -0,0 +1,63 @@
+.. SPDX-License-Identifier: CC-BY-SA-4.0
+
+.. Copyright (C) 1988, 2008 On-Line Applications Research Corporation (OAR)
+
+Operations
+==========
+
+Sending an Event Set
+--------------------
+
+The ``rtems_event_send`` directive allows a task (or an ISR) to direct an event
+set to a target task.  Based upon the state of the target task, one of the
+following situations applies:
+
+- Target Task is Blocked Waiting for Events
+
+  - If the waiting task's input event condition is satisfied, then the task is
+    made ready for execution.
+
+  - If the waiting task's input event condition is not satisfied, then the
+    event set is posted but left pending and the task remains blocked.
+
+- Target Task is Not Waiting for Events
+
+  - The event set is posted and left pending.
+
+Receiving an Event Set
+----------------------
+
+The ``rtems_event_receive`` directive is used by tasks to accept a specific
+input event condition.  The task also specifies whether the request is
+satisfied when all requested events are available or any single requested event
+is available.  If the requested event condition is satisfied by pending events,
+then a successful return code and the satisfying event set are returned
+immediately.  If the condition is not satisfied, then one of the following
+situations applies:
+
+- By default, the calling task will wait forever for the event condition to be
+  satisfied.
+
+- Specifying the ``RTEMS_NO_WAIT`` option forces an immediate return with an
+  error status code.
+
+- Specifying a timeout limits the period the task will wait before returning
+  with an error status code.
+
+Determining the Pending Event Set
+---------------------------------
+
+A task can determine the pending event set by calling the
+``rtems_event_receive`` directive with a value of ``RTEMS_PENDING_EVENTS`` for
+the input event condition.  The pending events are returned to the calling task
+but the event set is left unaltered.
+
+Receiving all Pending Events
+----------------------------
+
+A task can receive all of the currently pending events by calling the
+``rtems_event_receive`` directive with a value of ``RTEMS_ALL_EVENTS`` for the
+input event condition and ``RTEMS_NO_WAIT | RTEMS_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 ``RTEMS_UNSATISFIED`` status code
+will be returned.
diff --git a/c-user/event_manager.rst b/c-user/event_manager.rst
deleted file mode 100644
index f7593e5..0000000
--- a/c-user/event_manager.rst
+++ /dev/null
@@ -1,309 +0,0 @@
-.. SPDX-License-Identifier: CC-BY-SA-4.0
-
-.. Copyright (C) 1988, 2008 On-Line Applications Research Corporation (OAR)
-
-.. index:: events
-
-Event Manager
-*************
-
-Introduction
-============
-
-The event manager provides a high performance method of intertask communication
-and synchronization.  The directives provided by the event manager are:
-
-- rtems_event_send_ - Send event set to a task
-- rtems_event_receive_ - Receive event condition
-
-Background
-==========
-
-.. index:: event flag, definition
-.. index:: event set, definition
-.. index:: rtems_event_set
-
-Event Sets
-----------
-
-An event flag is used by a task (or ISR) to inform another task of the
-occurrence of a significant situation.  Thirty-two event flags are associated
-with each task.  A collection of one or more event flags is referred to as an
-event set.  The data type ``rtems_event_set`` is used to manage event sets.
-
-The application developer should remember the following key characteristics of
-event operations when utilizing the event manager:
-
-- Events provide a simple synchronization facility.
-
-- Events are aimed at tasks.
-
-- Tasks can wait on more than one event simultaneously.
-
-- Events are independent of one another.
-
-- Events do not hold or transport data.
-
-- Events are not queued.  In other words, if an event is sent more than once to
-  a task before being received, the second and subsequent send operations to
-  that same task have no effect.
-
-An event set is posted when it is directed (or sent) to a task.  A pending
-event is an event that has been posted but not received.  An event condition is
-used to specify the event set 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 ``RTEMS_EVENT_ANY`` algorithm states that an event
-condition is satisfied when at least a single requested event is posted.  The
-``RTEMS_EVENT_ALL`` algorithm states that an event condition is satisfied when
-every requested event is posted.
-
-.. index:: event condition, building
-.. index:: event set, building
-
-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 ``RTEMS_EVENT_0`` through ``RTEMS_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 ``RTEMS_EVENT_6``,
-``RTEMS_EVENT_15``, and ``RTEMS_EVENT_31``, the event parameter to the
-``rtems_event_send`` directive should be ``RTEMS_EVENT_6 | RTEMS_EVENT_15 |
-RTEMS_EVENT_31``.
-
-Building an EVENT_RECEIVE Option Set
-------------------------------------
-
-In general, an option is built by a bitwise OR of the desired option
-components.  The set of valid options for the ``rtems_event_receive`` directive
-are listed in the following table:
-
-.. list-table::
- :class: rtems-table
-
- * - ``RTEMS_WAIT``
-   - task will wait for event (default)
- * - ``RTEMS_NO_WAIT``
-   - task should not wait
- * - ``RTEMS_EVENT_ALL``
-   - return after all events (default)
- * - ``RTEMS_EVENT_ANY``
-   - return after any events
-
-Option values are specifically designed to be mutually exclusive, therefore
-bitwise OR and addition operations 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
-``RTEMS_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
-``rtems_event_receive`` directive should be either ``RTEMS_EVENT_ALL |
-RTEMS_NO_WAIT`` or ``RTEMS_NO_WAIT``.  The option parameter can be set to
-``RTEMS_NO_WAIT`` because ``RTEMS_EVENT_ALL`` is the default condition for
-``rtems_event_receive``.
-
-Operations
-==========
-
-Sending an Event Set
---------------------
-
-The ``rtems_event_send`` directive allows a task (or an ISR) to direct an event
-set to a target task.  Based upon the state of the target task, one of the
-following situations applies:
-
-- Target Task is Blocked Waiting for Events
-
-  - If the waiting task's input event condition is satisfied, then the task is
-    made ready for execution.
-
-  - If the waiting task's input event condition is not satisfied, then the
-    event set is posted but left pending and the task remains blocked.
-
-- Target Task is Not Waiting for Events
-
-  - The event set is posted and left pending.
-
-Receiving an Event Set
-----------------------
-
-The ``rtems_event_receive`` directive is used by tasks to accept a specific
-input event condition.  The task also specifies whether the request is
-satisfied when all requested events are available or any single requested event
-is available.  If the requested event condition is satisfied by pending events,
-then a successful return code and the satisfying event set are returned
-immediately.  If the condition is not satisfied, then one of the following
-situations applies:
-
-- By default, the calling task will wait forever for the event condition to be
-  satisfied.
-
-- Specifying the ``RTEMS_NO_WAIT`` option forces an immediate return with an
-  error status code.
-
-- Specifying a timeout limits the period the task will wait before returning
-  with an error status code.
-
-Determining the Pending Event Set
----------------------------------
-
-A task can determine the pending event set by calling the
-``rtems_event_receive`` directive with a value of ``RTEMS_PENDING_EVENTS`` for
-the input event condition.  The pending events are returned to the calling task
-but the event set is left unaltered.
-
-Receiving all Pending Events
-----------------------------
-
-A task can receive all of the currently pending events by calling the
-``rtems_event_receive`` directive with a value of ``RTEMS_ALL_EVENTS`` for the
-input event condition and ``RTEMS_NO_WAIT | RTEMS_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 ``RTEMS_UNSATISFIED`` status code
-will be returned.
-
-Directives
-==========
-
-This section details the event manager's directives.  A subsection is dedicated
-to each of this manager's directives and describes the calling sequence,
-related constants, usage, and status codes.
-
-.. raw:: latex
-
-   \clearpage
-
-.. index:: send event set to a task
-.. index:: rtems_event_send
-
-.. _rtems_event_send:
-
-EVENT_SEND - Send event set to a task
--------------------------------------
-
-CALLING SEQUENCE:
-    .. code-block:: c
-
-        rtems_status_code rtems_event_send (
-            rtems_id         id,
-            rtems_event_set  event_in
-        );
-
-DIRECTIVE STATUS CODES:
-    .. list-table::
-     :class: rtems-table
-
-     * - ``RTEMS_SUCCESSFUL``
-       - event set sent successfully
-     * - ``RTEMS_INVALID_ID``
-       - invalid task id
-
-DESCRIPTION:
-    This directive sends an event set, event_in, to the task specified by id.
-    If a blocked task's input event condition is satisfied by this directive,
-    then it will be made ready.  If its input event condition is not satisfied,
-    then the events satisfied are updated and the events not satisfied are left
-    pending.  If the task specified by id is not blocked waiting for events,
-    then the events sent are left pending.
-
-NOTES:
-    Specifying ``RTEMS_SELF`` for id results in the event set being sent to the
-    calling task.
-
-    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 ``rtems_event_receive`` 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.
-
-.. raw:: latex
-
-   \clearpage
-
-.. index:: receive event condition
-.. index:: rtems_event_receive
-
-.. _rtems_event_receive:
-
-EVENT_RECEIVE - Receive event condition
----------------------------------------
-
-CALLING SEQUENCE:
-    .. code-block:: c
-
-        rtems_status_code rtems_event_receive (
-            rtems_event_set  event_in,
-            rtems_option     option_set,
-            rtems_interval   ticks,
-            rtems_event_set *event_out
-        );
-
-DIRECTIVE STATUS CODES:
-    .. list-table::
-     :class: rtems-table
-
-     * - ``RTEMS_SUCCESSFUL``
-       - event received successfully
-     * - ``RTEMS_UNSATISFIED``
-       - input event not satisfied (``RTEMS_NO_WAIT``)
-     * - ``RTEMS_INVALID_ADDRESS``
-       - ``event_out`` is NULL
-     * - ``RTEMS_TIMEOUT``
-       - timed out waiting for event
-
-DESCRIPTION:
-
-    This directive attempts to receive the event condition specified in
-    event_in.  If event_in is set to ``RTEMS_PENDING_EVENTS``, then the current
-    pending events are returned in event_out and left pending.  The
-    ``RTEMS_WAIT`` and ``RTEMS_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. ``RTEMS_EVENT_ANY`` and
-    ``RTEMS_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 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 ``RTEMS_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 ``RTEMS_NO_TIMEOUT``, then the calling task will wait forever.
-
-NOTES:
-    This directive only affects the events specified in event_in.  Any pending
-    events that do not correspond to any of the events specified in event_in
-    will be left pending.
-
-    The following event receive option constants are defined by RTEMS:
-
-    .. list-table::
-     :class: rtems-table
-
-     * - ``RTEMS_WAIT``
-       - task will wait for event (default)
-     * - ``RTEMS_NO_WAIT``
-       - task should not wait
-     * - ``RTEMS_EVENT_ALL``
-       - return after all events (default)
-     * - ``RTEMS_EVENT_ANY``
-       - return after any events
-
-    A clock tick is required to support the functionality of this directive.
diff --git a/c-user/index.rst b/c-user/index.rst
index 64eac08..412fadc 100644
--- a/c-user/index.rst
+++ b/c-user/index.rst
@@ -38,7 +38,7 @@ RTEMS Classic API Guide (|version|).
 	sem/index
 	barrier_manager
 	message_manager
-	event_manager
+	event/index
 	signal_manager
 	partition_manager
 	region_manager
-- 
2.26.2



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