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author | Gedare Bloom <gedare@rtems.org> | 2014-12-19 11:44:39 -0500 |
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committer | Gedare Bloom <gedare@rtems.org> | 2014-12-19 12:14:06 -0500 |
commit | 0a789927c54d63d043ab257378058ce896691dc3 (patch) | |
tree | b48dc8eba6b6ee35199001da322b3a5a2728635f /doc/user/rbtree.t | |
parent | posix: Delete unused _POSIX_Threads_Get() (diff) | |
download | rtems-0a789927c54d63d043ab257378058ce896691dc3.tar.bz2 |
doc: add some red-black tree documentation
closes #2059
Diffstat (limited to '')
-rw-r--r-- | doc/user/rbtree.t | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/doc/user/rbtree.t b/doc/user/rbtree.t new file mode 100644 index 0000000000..c90065b6ce --- /dev/null +++ b/doc/user/rbtree.t @@ -0,0 +1,92 @@ +@c +@c Copyright 2014 Gedare Bloom. +@c All rights reserved. + +@chapter Red-Black Trees + +@cindex rbtrees + +@section Introduction + +The Red-Black Tree API is an interface to the SuperCore (score) rbtree +implementation. Within RTEMS, red-black trees are used when a binary search +tree is needed, including dynamic priority thread queues and non-contiguous +heap memory. The Red-Black Tree API provided by RTEMS is: + +@itemize @bullet +@c build_id +@item @code{@value{DIRPREFIX}rtems_rbtree_node} - Red-Black Tree node embedded in another struct +@item @code{@value{DIRPREFIX}rtems_rbtree_control} - Red-Black Tree control node for an entire tree +@item @code{@value{DIRPREFIX}rtems_rbtree_initialize} - initialize the red-black tree with nodes +@item @code{@value{DIRPREFIX}rtems_rbtree_initialize_empty} - initialize the red-black tree as empty +@item @code{@value{DIRPREFIX}rtems_rbtree_set_off_tree} - Clear a node's links +@item @code{@value{DIRPREFIX}rtems_rbtree_root} - Return the red-black tree's root node +@item @code{@value{DIRPREFIX}rtems_rbtree_min} - Return the red-black tree's minimum node +@item @code{@value{DIRPREFIX}rtems_rbtree_max} - Return the red-black tree's maximum node +@item @code{@value{DIRPREFIX}rtems_rbtree_left} - Return a node's left child node +@item @code{@value{DIRPREFIX}rtems_rbtree_right} - Return a node's right child node +@item @code{@value{DIRPREFIX}rtems_rbtree_parent} - Return a node's parent node +@item @code{@value{DIRPREFIX}rtems_rbtree_are_nodes_equal} - Are the node's equal ? +@item @code{@value{DIRPREFIX}rtems_rbtree_is_empty} - Is the red-black tree empty ? +@item @code{@value{DIRPREFIX}rtems_rbtree_is_min} - Is the Node the minimum in the red-black tree ? +@item @code{@value{DIRPREFIX}rtems_rbtree_is_max} - Is the Node the maximum in the red-black tree ? +@item @code{@value{DIRPREFIX}rtems_rbtree_is_root} - Is the Node the root of the red-black tree ? +@item @code{@value{DIRPREFIX}rtems_rbtree_find} - Find the node with a matching key in the red-black tree +@item @code{@value{DIRPREFIX}rtems_rbtree_predecessor} - Return the in-order predecessor of a node. +@item @code{@value{DIRPREFIX}rtems_rbtree_successor} - Return the in-order successor of a node. +@item @code{@value{DIRPREFIX}rtems_rbtree_extract} - Remove the node from the red-black tree +@item @code{@value{DIRPREFIX}rtems_rbtree_get_min} - Remove the minimum node from the red-black tree +@item @code{@value{DIRPREFIX}rtems_rbtree_get_max} - Remove the maximum node from the red-black tree +@item @code{@value{DIRPREFIX}rtems_rbtree_peek_min} - Returns the minimum node from the red-black tree +@item @code{@value{DIRPREFIX}rtems_rbtree_peek_max} - Returns the maximum node from the red-black tree +@item @code{@value{DIRPREFIX}rtems_rbtree_find_control} - Returns the control node of a red-black tree given a node in the tree. +@item @code{@value{DIRPREFIX}rtems_rbtree_insert} - Add the node to the red-black tree +@end itemize + +@section Background + +The Red-Black Trees API is a thin layer above the SuperCore Red-Black Trees +implementation. A Red-Black Tree is defined by a control node with pointers to +the root, minimum, and maximum nodes in the tree. Each node in the tree +consists of a parent pointer, two children pointers, and a color attribute. A +tree is parameterized as either unique, meaning identical keys are rejected, or +not, in which case duplicate keys are allowed. + +Users must provide a comparison functor that gets passed to functions that need +to compare nodes. In addition, no internal synchronization is offered within +the red-black tree implementation, thus users must ensure at most one thread +accesses a red-black tree instance at a time. + +@subsection Nodes + +A red-black tree is made up from nodes that orginate from a red-black tree control +object. A node is of type @code{@value{DIRPREFIX}rtems_rbtree_node}. The node +is designed to be part of a user data structure. To obtain the encapsulating +structure users can use the @code{RTEMS_CONTAINER_OF} macro. +The node can be placed anywhere within the user's structure and the macro will +calculate the structure's address from the node's address. + +@subsection Controls + +A red-black tree is rooted with a control object. Red-Black Tree control +provide the user with access to the nodes on the red-black tree. The +implementation does not require special checks for manipulating the root of the +red-black tree. To accomplish this the +@code{@value{DIRPREFIX}rtems_rbtree_control} structure is treated as a +@code{@value{DIRPREFIX}rtems_rbtree_node} structure with a @code{NULL} parent +and left child pointing to the root. + +@section Operations + +Examples for using the red-black trees +can be found in the testsuites/sptests/sprbtree01/init.c file. + +@section Directives + +@subsection Documentation for the Red-Black Tree Directives + +@cindex rbtree doc + +Source documentation for the Red-Black Tree API can be found in the +generated Doxygen output for cpukit/sapi. + |