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authorJoel Sherrill <joel.sherrill@OARcorp.com>2008-06-06 20:55:21 +0000
committerJoel Sherrill <joel.sherrill@OARcorp.com>2008-06-06 20:55:21 +0000
commit7bec8d0a9a750b72b5a788e1cd693a87f7817de3 (patch)
treecce108ae48374b44ef1df2be94115a3cde83058e /doc/user/conf.t
parent2008-06-06 Joel Sherrill <joel.sherrill@OARcorp.com> (diff)
downloadrtems-7bec8d0a9a750b72b5a788e1cd693a87f7817de3.tar.bz2
2008-06-06 Joel Sherrill <joel.sherrill@oarcorp.com>
* started/buildc.t: Add paragraph on see CVS for latest patches. * user/conf.t: Add CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE and example of how to compute message CONFIGURE_MESSAGE_BUFFER_MEMORY using it.
Diffstat (limited to 'doc/user/conf.t')
-rw-r--r--doc/user/conf.t35
1 files changed, 34 insertions, 1 deletions
diff --git a/doc/user/conf.t b/doc/user/conf.t
index aab3ca6109..aeb79e390d 100644
--- a/doc/user/conf.t
+++ b/doc/user/conf.t
@@ -256,11 +256,44 @@ TRUE, the Workspace is zeroed. Otherwise, it is not.
Unless overridden by the BSP, the default value for this
field is FALSE.
+@findex CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE
+@item @code{CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE} 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:
+
+@example
+CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE(max_messages, size_per)
+@end example
+
+Where @code{max_messages} is the maximum number of pending messages
+and @code{size_per} is the size in bytes of the user message.
+
@findex CONFIGURE_MESSAGE_BUFFER_MEMORY
@item @code{CONFIGURE_MESSAGE_BUFFER_MEMORY} is set to the number of
bytes the application requires to be reserved for pending message queue
buffers. This value should include memory for all buffers across
-all APIs. The default value is 0.
+all APIs. The default value is 0.
+
+The following illustrates how the help macro
+@code{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 @code{one_message_type}. The other message queue
+has maximum of 500 pending messages with the message structure defined
+by the type @code{other_message_type}.
+
+@example
+
+#define CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE \
+ (CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE( \
+ 24, sizeof(one_message_type) + \
+ CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE( \
+ 500, sizeof(other_message_type) \
+ )
+@end example
@findex CONFIGURE_MEMORY_OVERHEAD
@item @code{CONFIGURE_MEMORY_OVERHEAD} is set to the number of