[rtems-docs commit] c-user: Clarify message buffer configuration
Sebastian Huber
sebh at rtems.org
Fri Mar 13 12:29:15 UTC 2020
Module: rtems-docs
Branch: master
Commit: 03a735f89611d7fc031190b0e460f062a25a42d4
Changeset: http://git.rtems.org/rtems-docs/commit/?id=03a735f89611d7fc031190b0e460f062a25a42d4
Author: Sebastian Huber <sebastian.huber at embedded-brains.de>
Date: Thu Mar 12 13:40:45 2020 +0100
c-user: Clarify message buffer configuration
The help macro CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE() is not a
configuration option. Move it into the documentatation of the
CONFIGURE_MESSAGE_BUFFER_MEMORY configuration option. Move this option
to the general system configuration group.
Update #3836.
---
c-user/config/general.rst | 73 ++++++++++++++++++++++++++++++
c-user/config/index.rst | 1 -
c-user/config/msg-queue-buffer.rst | 93 --------------------------------------
3 files changed, 73 insertions(+), 94 deletions(-)
diff --git a/c-user/config/general.rst b/c-user/config/general.rst
index f6d7531..f5f44d3 100644
--- a/c-user/config/general.rst
+++ b/c-user/config/general.rst
@@ -324,6 +324,79 @@ NOTES:
Typically the memory allocation will be too low when an application does
not account for all message queue buffers or task stacks.
+.. index:: CONFIGURE_MESSAGE_BUFFER_MEMORY
+.. index:: configure message queue buffer memory
+.. index:: CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE
+.. index:: memory for a single message queue's buffers
+
+.. _CONFIGURE_MESSAGE_BUFFER_MEMORY:
+
+CONFIGURE_MESSAGE_BUFFER_MEMORY
+-------------------------------
+
+CONSTANT:
+ ``CONFIGURE_MESSAGE_BUFFER_MEMORY``
+
+DATA TYPE:
+ integer summation macro
+
+RANGE:
+ undefined (zero) or calculation resulting in a positive integer
+
+DEFAULT VALUE:
+ The default value is zero.
+
+DESCRIPTION:
+ The value of this configuration option defines the number of bytes
+ resereved for message queue buffers in the RTEMS Workspace.
+
+NOTES:
+ The configuration options :ref:`CONFIGURE_MAXIMUM_MESSAGE_QUEUES` and
+ :ref:`CONFIGURE_MAXIMUM_POSIX_MESSAGE_QUEUES` define only how many message
+ queues can be created by the application. The memory for the message
+ buffers is configured by this option. For each message queue you have to
+ reserve some memory for the message buffers. The size dependes on the
+ maximum number of pending messages and the maximum size of the messages of
+ a message queue. Use the ``CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE()`` macro
+ to specify the message buffer memory for each message queue and sum them up
+ to define the value for ``CONFIGURE_MAXIMUM_MESSAGE_QUEUES``.
+
+ The interface for the ``CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE()`` help
+ macro is as follows:
+
+ .. code-block:: c
+
+ CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE( max_messages, max_msg_size )
+
+ Where ``max_messages`` is the maximum number of pending messages and
+ ``max_msg_size`` is the maximum size in bytes of the messages of the
+ corresponding message queue. Both parameters shall be compile time
+ constants. Not using this help macro (e.g. just using
+ ``max_messages * max_msg_size``) may result in an underestimate of the
+ RTEMS Workspace size.
+
+ The following example illustrates how the
+ `CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE()` help macro can be used to assist in
+ calculating the message buffer memory required. In this example, there are
+ two message queues used in this application. The first message queue has a
+ maximum of 24 pending messages with the message structure defined by the
+ type ``one_message_type``. The other message queue has a maximum of 500
+ pending messages with the message structure defined by the type
+ ``other_message_type``.
+
+ .. code-block:: c
+
+ #define CONFIGURE_MESSAGE_BUFFER_MEMORY ( \
+ CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE( \
+ 24, \
+ sizeof( one_message_type ) \
+ ) \
+ + CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE( \
+ 500, \
+ sizeof( other_message_type ) \
+ ) \
+ )
+
.. index:: CONFIGURE_MICROSECONDS_PER_TICK
.. index:: tick quantum
diff --git a/c-user/config/index.rst b/c-user/config/index.rst
index 0d6c0dd..2318042 100644
--- a/c-user/config/index.rst
+++ b/c-user/config/index.rst
@@ -17,7 +17,6 @@ Configuring a System
posix-api
posix-init-thread
task-stack-alloc
- msg-queue-buffer
filesystem
bdbuf
bsp-related
diff --git a/c-user/config/msg-queue-buffer.rst b/c-user/config/msg-queue-buffer.rst
deleted file mode 100644
index 8d40149..0000000
--- a/c-user/config/msg-queue-buffer.rst
+++ /dev/null
@@ -1,93 +0,0 @@
-.. SPDX-License-Identifier: CC-BY-SA-4.0
-
-.. Copyright (C) 1988, 2008 On-Line Applications Research Corporation (OAR)
-
-Message Queue Buffer Configuration
-==================================
-
-This section describes the configuration parameters related to specifying the
-amount of memory reserved for message queue message buffers. See
-:ref:`CONFIGURE_MAXIMUM_MESSAGE_QUEUES` and
-:ref:`CONFIGURE_MAXIMUM_POSIX_MESSAGE_QUEUES`.
-
-.. index:: CONFIGURE_MESSAGE_BUFFER_MEMORY
-.. index:: configure message queue buffer memory
-
-.. _CONFIGURE_MESSAGE_BUFFER_MEMORY:
-
-CONFIGURE_MESSAGE_BUFFER_MEMORY
--------------------------------
-
-CONSTANT:
- ``CONFIGURE_MESSAGE_BUFFER_MEMORY``
-
-DATA TYPE:
- integer summation macro
-
-RANGE:
- undefined (zero) or calculation resulting in a positive integer
-
-DEFAULT VALUE:
- This is not defined by default, and zero (0) memory is reserved.
-
-DESCRIPTION:
- This macro is set to the number of bytes the application requires to be
- reserved for pending Classic API Message Queue buffers.
-
-NOTES:
- The following illustrates how the help macro
- :ref:`CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE` can be used to assist in
- calculating the message buffer memory required. In this example, there are
- two message queues used in this application. The first message queue has
- maximum of 24 pending messages with the message structure defined by the
- type ``one_message_type``. The other message queue has maximum of 500
- pending messages with the message structure defined by the type
- ``other_message_type``.
-
- .. code-block:: c
-
- #define CONFIGURE_MESSAGE_BUFFER_MEMORY \
- (CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE( \
- 24, sizeof(one_message_type) \
- ) + \
- CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE( \
- 500, sizeof(other_message_type) \
- )
-
-.. index:: CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE
-.. index:: memory for a single message queue's buffers
-
-.. _CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE:
-
-CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE
------------------------------------
-
-CONSTANT:
- ``CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE(max_messages, size_per)``
-
-DATA TYPE:
- Unsigned integer (``size_t``).
-
-RANGE:
- Positive.
-
-DEFAULT VALUE:
- The default value is None.
-
-DESCRIPTION:
- This is a helper macro which is used to assist in computing the total
- amount of memory required for message buffers. Each message queue will
- have its own configuration with maximum message size and maximum number of
- pending messages.
-
- The interface for this macro is as follows:
-
- .. code-block:: c
-
- CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE(max_messages, size_per)
-
- Where ``max_messages`` is the maximum number of pending messages and
- ``size_per`` is the size in bytes of the user message.
-
-NOTES:
- This macro is only used in support of :ref:`CONFIGURE_MESSAGE_BUFFER_MEMORY`.
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