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Diffstat (limited to '')
-rw-r--r-- | doc/user/concepts.t | 36 |
1 files changed, 29 insertions, 7 deletions
diff --git a/doc/user/concepts.t b/doc/user/concepts.t index 63e64343fb..e72e26f648 100644 --- a/doc/user/concepts.t +++ b/doc/user/concepts.t @@ -60,18 +60,12 @@ approach would be to name them the binary values one through one-hundred, respectively. @cindex object ID +@cindex object ID composition @need 3000 An object ID is a unique unsigned thirty-two bit entity composed of three parts: object class, node, and index. -The most significant six bits are the object class. The next -ten bits are the number of the node on which this object was -created. The node number is always one (1) in a single -processor system. The least significant sixteen bits form an -identifier within a particular object type. This identifier, -called the object index, ranges in value from 1 to the maximum -number of objects configured for this object type. @ifset use-ascii @example @@ -151,6 +145,14 @@ number of objects configured for this object type. @end html @end ifset +The most significant six bits are the object class. The next +ten bits are the number of the node on which this object was +created. The node number is always one (1) in a single +processor system. The least significant sixteen bits form an +identifier within a particular object type. This identifier, +called the object index, ranges in value from 1 to the maximum +number of objects configured for this object type. + The three components of an object ID make it possible to quickly locate any object in even the most complicated @@ -171,6 +173,26 @@ returned when the object is created, the object identification directives are not necessary in a properly designed single processor application. +In addition, services are provided to portably examine the +three subcomponents of an RTEMS ID. These services are +prototyped as follows: + +@cindex obtaining class from object ID +@cindex obtaining node from object ID +@cindex obtaining index from object ID +@cindex get class from object ID +@cindex get node from object ID +@cindex get index from object ID +@findex rtems_get_class +@findex rtems_get_node +@findex rtems_get_index + +@example +rtems_unsigned32 rtems_get_class( rtems_id ); +rtems_unsigned32 rtems_get_node( rtems_id ); +rtems_unsigned32 rtems_get_index( rtems_id ); +@end example + An object control block is a data structure defined by RTEMS which contains the information necessary to manage a particular object type. For efficiency reasons, the format of |