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diff --git a/c-user/regulator/directives.rst b/c-user/regulator/directives.rst new file mode 100644 index 0000000..eea3fff --- /dev/null +++ b/c-user/regulator/directives.rst @@ -0,0 +1,549 @@ +.. SPDX-License-Identifier: CC-BY-SA-4.0 + +.. Copyright (C) 2023 On-Line Applications Research Corporation (OAR) + +.. _RegulatorManagerDirectives: + +Directives +========== + +This section details the directives of the Regulator Manager. A subsection is +dedicated to each of this manager's directives and lists the calling sequence, +parameters, description, return values, and notes of the directive. + +.. *** START of rtems_regulator_create() + +.. raw:: latex + + \clearpage + +.. index:: rtems_regulator_create() +.. index:: create a regulator + +.. _InterfaceRtemsRegulatorCreate: + +rtems_regulator_create() +------------------------ + +Creates a regulator. + +.. rubric:: CALLING SEQUENCE: + +.. code-block:: c + + rtems_status_code rtems_regulator_create( + rtems_regulator_attributes *attributes, + rtems_regulator_instance **regulator + ); + +.. rubric:: PARAMETERS: + +``attributes`` + This parameter is the attributes associated with the regulator + being created. + +``regulator`` + This parameter is the pointer to a regulator instance. When the + directive call is successful, a pointer to the created regulator + will be stored in this object. + +.. rubric:: DESCRIPTION: + +This function creates an instance of a regulator. It uses the provided +``attributes`` to create the instance return in ``regulator``. This instance +will allocate the buffers associated with the regulator instance as well +as the Delivery Thread. + +The ``attributes`` parameter points to an instance of +:ref:`InterfaceRtemsRegulatorAttributes` which is filled in to reflect +the desired configuration of the regulator instance. It defines multiple +characteristics of the the Delivery thread dedicated to this regulator +instance including the priority and stack size. It also defines the +period of the Delivery thread and the maximum number of messages that may +be delivered per period via invocation of the delivery function. + +For each regulator instance, the following resources are allocated: + +* A memory area for the regulator control block using ``malloc()``. + +* A RTEMS Classic API Message Queue is constructed with message + buffer memory allocated using ``malloc()``. Each message consists + of a pointer to the contents and a length field. + +* A RTEMS Classic API Partition. + +* A RTEMS Classic API Rate Monotonic Period. + +.. rubric:: RETURN VALUES: + +:c:macro:`RTEMS_SUCCESSFUL` + The requested operation was successful. + +:c:macro:`RTEMS_INVALID_ADDRESS` + The ``attributes`` parameter was `NULL + <https://en.cppreference.com/w/c/types/NULL>`_. + +:c:macro:`RTEMS_INVALID_ADDRESS` + The ``regulator`` parameter was `NULL + <https://en.cppreference.com/w/c/types/NULL>`_. + +:c:macro:`RTEMS_INVALID_ADDRESS` + The ``deliverer`` field in the structure pointed to by the + ``attributes`` parameter was `NULL + <https://en.cppreference.com/w/c/types/NULL>`_. + +:c:macro:`RTEMS_INVALID_SIZE` + The ``maximum_messages`` field in the structure pointed to by the + ``attributes`` parameter was 0. + +:c:macro:`RTEMS_INVALID_NUMBER` + The ``maximum_to_dequeue_per_period`` field in the structure pointed + to by the ``attributes`` parameter was 0. + +:c:macro:`RTEMS_NO_MEMORY` + The allocation of memory for the regulator instance failed. + +:c:macro:`RTEMS_NO_MEMORY` + The allocation of memory for the buffers failed. + +:c:macro:`RTEMS_NO_MEMORY` + The allocation of memory for the internal message queue failed. + +.. rubric:: NOTES: + +:ref:`InterfaceRtemsRegulatorCreate` uses +:ref:`InterfaceRtemsPartitionCreate`, +:ref:`InterfaceRtemsMessageQueueConstruct`, +:ref:`InterfaceRtemsTaskCreate`, and :ref:`InterfaceRtemsTaskStart`. If +any of those directives return a status indicating failure, it will be +returned to the caller. + +.. rubric:: CONSTRAINTS: + +The following constraints apply to this directive: + +* The directive may be called from within device driver initialization context. + +* The directive may be called from within task context. + +* The directive may obtain and release the object allocator mutex. This may + cause the calling task to be preempted. + +* The number of tasks available to the application is configured through the + :ref:`CONFIGURE_MAXIMUM_TASKS` application configuration option. + +* Where the object class corresponding to the directive is configured to use + unlimited objects, the directive may allocate memory from the RTEMS + Workspace. + +.. *** START of rtems_regulator_delete() + +.. raw:: latex + + \clearpage + +.. index:: rtems_regulator_delete() +.. index:: delete a regulator + +.. _InterfaceRtemsRegulatorDelete: + +rtems_regulator_delete() +------------------------ + +Deletes the regulator. + +.. rubric:: CALLING SEQUENCE: + +.. code-block:: c + + rtems_status_code rtems_regulator_delete( + rtems_regulator_instance *regulator, + rtems_interval ticks + ); + +.. rubric:: PARAMETERS: + +``regulator`` + This parameter points to the regulator instance. + +``ticks`` + This parameter specifies the maximum length of time to wait. + +.. rubric:: DESCRIPTION: + +This directive is used to delete the specified ``regulator`` +instance. It will deallocate the resources that were allocated by the +:ref:`InterfaceRtemsRegulatorCreate` directive. + + +This directive ensures that no buffers are outstanding either because the +Source is holding one of more buffers or because they are being held by +the regulator instance pending delivery. + +If the Delivery Thread has been created and is running, this directive will +request the thread to voluntarily exit. This call will wait up to ``ticks`` for the thread to exit. + +.. rubric:: RETURN VALUES: + +:c:macro:`RTEMS_SUCCESSFUL` + The requested operation was successful. + +:c:macro:`RTEMS_INVALID_ADDRESS` + The ``regulator`` parameter was `NULL + <https://en.cppreference.com/w/c/types/NULL>`_. + +:c:macro:`RTEMS_INCORRECT_STATE` + The ``regulator`` instance was not initialized. + +:c:macro:`RTEMS_RESOURCE_IN_USE` + The ``regulator`` instance has buffers outstanding. + +:c:macro:`RTEMS_TIMEOUT` + The ``regulator`` instance was not able to be deleted within the + specific number of ``ticks``. + +.. rubric:: NOTES: + +It is the responsibility of the user to ensure that any resources +such as sockets or open file descriptors used by the Source or delivery +function are also deleted if necessary. It is likely safer to delete those +delivery resources after deleting the regulator instance rather than before. + + +It is the responsibility of the user to ensure that all buffers associated +with this regulator instance have been released and that none are in +the process of being delivered. + +.. rubric:: CONSTRAINTS: + +The following constraints apply to this directive: + +* The directive may be called from within task context. + +* The directive may obtain and release the object allocator mutex. This may + cause the calling task to be preempted. + +* The calling task does not have to be the task that created the object. Any + local task that knows the object identifier can delete the object. + +* Where the object class corresponding to the directive is configured to use + unlimited objects, the directive may free memory to the RTEMS Workspace. + +.. *** START of rtems_regulator_obtain_buffer() + +.. raw:: latex + + \clearpage + +.. index:: rtems_regulator_obtain_buffer() +.. index:: obtain buffer from regulator + +.. _InterfaceRtemsRegulatorObtainBuffer: + +rtems_regulator_obtain_buffer() +------------------------------- + +Obtain buffer from regulator. + +.. rubric:: CALLING SEQUENCE: + +.. code-block:: c + + rtems_status_code rtems_regulator_obtain_buffer( + rtems_regulator_instance *regulator, + void **buffer + ); + +.. rubric:: PARAMETERS: + +``regulator`` + This parameter is the regulator instance to operate upon. + +``buffer`` + This parameter will point to the buffer allocated. + +.. rubric:: DESCRIPTION: + +This function is used to obtain a buffer from the regulator's pool. The +``buffer`` returned is assumed to be filled in with contents and used +in a subsequent call to :ref:`InterfaceRtemsRegulatorSend`. + +When the ``buffer`` is delivered, it is expected to be released. If the +``buffer`` is not successfully accepted by this method, then it should +be returned using :ref:`InterfaceRtemsRegulatorReleaseBuffer` or used +to send another message. + +The ``buffer`` returned is of the maximum_message_size specified in the +attributes passed in to :ref:`InterfaceRtemsRegulatorCreate`. + +.. rubric:: RETURN VALUES: + +:c:macro:`RTEMS_SUCCESSFUL` + The requested operation was successful. + +:c:macro:`RTEMS_INVALID_ADDRESS` + The ``regulator`` parameter was `NULL + <https://en.cppreference.com/w/c/types/NULL>`_. + +:c:macro:`RTEMS_INCORRECT_STATE` + The ``regulator`` instance was not initialized. + +.. rubric:: NOTES: + +:ref:`InterfaceRtemsRegulatorObtainBuffer` uses +:ref:`InterfaceRtemsPartitionGetBuffer` and if it returns a status +indicating failure, it will be returned to the caller. + +.. rubric:: CONSTRAINTS: + +The following constraints apply to this directive: + +* The directive may be called from within device driver initialization context. + +* The directive may be called from within task context. + +.. *** START of rtems_regulator_release_buffer() + +.. raw:: latex + + \clearpage + +.. index:: rtems_regulator_release_buffer() +.. index:: release buffer back to regulator + +.. _InterfaceRtemsRegulatorReleaseBuffer: + +rtems_regulator_release_buffer() +-------------------------------- + +Release buffer to regulator. + +.. rubric:: CALLING SEQUENCE: + +.. code-block:: c + + rtems_status_code rtems_regulator_release_buffer( + rtems_regulator_instance *regulator, + void *buffer + ); + +.. rubric:: PARAMETERS: + +``regulator`` + This parameter is the regulator instance to operate upon. + +``buffer`` + This parameter will point to the buffer to be released. + +.. rubric:: DESCRIPTION: + +This function is used to release a buffer to the regulator's pool. It is +assumed that the ``buffer`` returned will not be used by the application +anymore. + +The ``buffer`` must have previously been allocated by +:ref:`InterfaceRtemsRegulatorObtainBuffer` and NOT yet passed to +:ref:`InterfaceRtemsRegulatorSend`, or it has been sent and delivery +has been completed by the delivery function. + +If a subsequent :ref:`InterfaceRtemsRegulatorSend` using this ``buffer`` +is successful, the ``buffer`` will eventually be processed by the delivery +thread and released. + +.. rubric:: RETURN VALUES: + +:c:macro:`RTEMS_SUCCESSFUL` + The requested operation was successful. + +:c:macro:`RTEMS_INVALID_ADDRESS` + The ``regulator`` parameter was `NULL + <https://en.cppreference.com/w/c/types/NULL>`_. + +:c:macro:`RTEMS_INCORRECT_STATE` + The ``regulator`` instance was not initialized. + +.. rubric:: NOTES: + +:ref:`InterfaceRtemsRegulatorReleaseBuffer` uses +:ref:`InterfaceRtemsPartitionReturnBuffer` and if it returns a status +indicating failure, it will be returned to the caller. + +.. rubric:: CONSTRAINTS: + +The following constraints apply to this directive: + +* The directive may be called from within device driver initialization context. + +* The directive may be called from within task context. + +.. *** START of rtems_regulator_send() + +.. raw:: latex + + \clearpage + +.. index:: rtems_regulator_send() +.. index:: send buffer to regulator for delivery + +.. _InterfaceRtemsRegulatorSend: + +rtems_regulator_send() +---------------------- + +Send buffer to regulator. + +.. rubric:: CALLING SEQUENCE: + +.. code-block:: c + + rtems_status_code rtems_regulator_send( + rtems_regulator_instance *regulator, + void *message, + size_t length + ); + +.. rubric:: PARAMETERS: + +``regulator`` + This parameter is the regulator instance to operate upon. + +``message`` + This parameter points to the buffer to send. + +``length`` + This parameter specifies the number of bytes in the ``message``. + +.. rubric:: DESCRIPTION: + +This method is used by the producer to send a ``message`` to the +``regulator`` for later delivery by the delivery thread. The message is +contained in the memory pointed to by ``message`` and is ``length`` +bytes in length. + +It is required that the message buffer was obtained via +:ref:`InterfaceRtemsRegulatorObtainBuffer`. + +It is assumed that the ``message`` buffer has been filled in with +application content to deliver. + +If the :ref:`InterfaceRtemsRegulatorSend` is successful, the ``message`` +buffer is enqueued inside the regulator instance for subsequent delivery. +After the ``message`` is delivered, it may be released by either delivery +function or other application code depending on the implementation. + +The status ``RTEMS_TOO_MANY`` is returned if the regulator's +internal queue is full. This indicates that the configured +maximum number of messages was insufficient. It is the +responsibility of the caller to decide whether to hold messages, +drop them, or print a message that the maximum number of messages +should be increased + +.. rubric:: RETURN VALUES: + +:c:macro:`RTEMS_SUCCESSFUL` + The requested operation was successful. + +:c:macro:`RTEMS_INVALID_ADDRESS` + The ``regulator`` parameter was `NULL + <https://en.cppreference.com/w/c/types/NULL>`_. + +:c:macro:`RTEMS_INCORRECT_STATE` + The ``regulator`` instance was not initialized. + +.. rubric:: NOTES: + +:ref:`InterfaceRtemsRegulatorSend` uses +:ref:`InterfaceRtemsMessageQueueSend` and if it returns a status +indicating failure, it will be returned to the caller. + + +.. rubric:: CONSTRAINTS: + +The following constraints apply to this directive: + +* The directive may be called from within device driver initialization context. + +* The directive may be called from within task context. + +.. *** START of rtems_regulator_get_statistics() + +.. raw:: latex + + \clearpage + +.. index:: rtems_regulator_get_statistics() +.. index:: obtain statistics from regulator + +.. _InterfaceRtemsRegulatorGetStatistics: + +rtems_regulator_get_statistics() +-------------------------------- + +Obtain statistics from regulator. + +.. rubric:: CALLING SEQUENCE: + +.. code-block:: c + + rtems_status_code rtems_regulator_get_statistics( + rtems_regulator_instance *regulator, + rtems_regulator_statistics *statistics + ); + +.. rubric:: PARAMETERS: + +``regulator`` + This parameter is the regulator instance to operate upon. + +``statistics`` + This parameter points to the statistics structure to be filled in. + +.. rubric:: DESCRIPTION: + +This method is used by the application to obtain the current +``statistics`` for this ``regulator``. The statistics information +provided includes: + +* the number of buffers obtained via + :ref:`InterfaceRtemsRegulatorObtainBuffer` +* the number of buffers released via + :ref:`InterfaceRtemsRegulatorReleaseBuffer` +* the number of buffers delivered by the Delivery + Thread via the ``deliverer`` function specified in the + :ref:`InterfaceRtemsRegulatorAttributes` structure provided to + :ref:`InterfaceRtemsRegulatorCreate`` via the ``attibutes`` parameter. +* the ``period_statistics`` for the Delivery Thread. For more details on + period statistics, see :ref:`InterfaceRtemsRateMonotonicPeriodStatistics`. + +.. rubric:: RETURN VALUES: + +:c:macro:`RTEMS_SUCCESSFUL` + The requested operation was successful. + +:c:macro:`RTEMS_INVALID_ADDRESS` + The ``regulator`` or ``statistics`` parameter was `NULL + <https://en.cppreference.com/w/c/types/NULL>`_. + +:c:macro:`RTEMS_INCORRECT_STATE` + The ``regulator`` instance was not initialized. + +.. rubric:: NOTES: + +The number of buffers outstanding is ``released`` minus +``obtained``. The regulator instance cannot be deleted using +:ref:`InterfaceRtemsRegulatorDelete` until all buffers are released. + +The ``obtained`` and ``released`` values are cumulative over +the life of the Regulator instance and are likely to larger than the +``maximum_messages`` value in the ``attributes`` structure +(:ref:`InterfaceRtemsRegulatorAttributes` +provided to :ref:`InterfaceRtemsRegulatorCreate`. + +.. rubric:: CONSTRAINTS: + +The following constraints apply to this directive: + +* The directive may be called from within device driver initialization context. + +* The directive may be called from within task context. + |