1 files changed, 168 insertions, 0 deletions
diff --git a/cpukit/score/include/rtems/score/chain.h b/cpukit/score/include/rtems/score/chain.h
new file mode 100644
index 0000000000..a1c8675fae
--- /dev/null
+++ b/cpukit/score/include/rtems/score/chain.h
@@ -0,0 +1,168 @@
+/*  chain.h
+ *
+ *  This include file contains all the constants and structures associated
+ *  with the Doubly Linked Chain Handler.
+ *
+ *  COPYRIGHT (c) 1989-1997.
+ *  On-Line Applications Research Corporation (OAR).
+ *  Copyright assigned to U.S. Government, 1994.
+ *
+ *  The license and distribution terms for this file may in
+ *  the file LICENSE in this distribution or at
+ *  http://www.OARcorp.com/rtems/license.html.
+ *
+ *  $Id$
+ */
+
+#ifndef __RTEMS_CHAIN_h
+#define __RTEMS_CHAIN_h
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <rtems/score/address.h>
+
+/*
+ *  This is used to manage each element (node) which is placed
+ *  on a chain.
+ *
+ *  NOTE:  Typically, a more complicated structure will use the
+ *         chain package.  The more complicated structure will
+ *         include a chain node as the first element in its
+ *         control structure.  It will then call the chain package
+ *         with a pointer to that node element.  The node pointer
+ *         and the higher level structure start at the same address
+ *         so the user can cast the pointers back and forth.
+ *
+ */
+
+typedef struct Chain_Node_struct Chain_Node;
+
+struct Chain_Node_struct {
+  Chain_Node *next;
+  Chain_Node *previous;
+};
+
+/*
+ *  This is used to manage a chain.  A chain consists of a doubly
+ *  linked list of zero or more nodes.
+ *
+ *  NOTE:  This implementation does not require special checks for
+ *         manipulating the first and last elements on the chain.
+ *         To accomplish this the chain control structure is
+ *         treated as two overlapping chain nodes.  The permanent
+ *         head of the chain overlays a node structure on the
+ *         first and permanent_null fields.  The permanent tail
+ *         of the chain overlays a node structure on the
+ *         permanent_null and last elements of the structure.
+ *
+ */
+
+typedef struct {
+  Chain_Node *first;
+  Chain_Node *permanent_null;
+  Chain_Node *last;
+} Chain_Control;
+
+/*
+ *  _Chain_Initialize
+ *
+ *  DESCRIPTION:
+ *
+ *  This routine initializes the_chain structure to manage the
+ *  contiguous array of number_nodes nodes which starts at
+ *  starting_address.  Each node is of node_size bytes.
+ *
+ */
+
+void _Chain_Initialize(
+  Chain_Control *the_chain,
+  void          *starting_address,
+  unsigned32     number_nodes,
+  unsigned32     node_size
+);
+
+/*
+ *  _Chain_Get_first_unprotected
+ */
+ 
+#ifndef USE_INLINES
+Chain_Node *_Chain_Get_first_unprotected(
+  Chain_Control *the_chain
+);
+#endif
+
+/*
+ *  _Chain_Extract
+ *
+ *  DESCRIPTION:
+ *
+ *  This routine extracts the_node from the chain on which it resides.
+ *  It disables interrupts to insure the atomicity of the
+ *  extract operation.
+ *
+ */
+
+void _Chain_Extract(
+  Chain_Node *the_node
+);
+
+/*
+ *  _Chain_Get
+ *
+ *  DESCRIPTION:
+ *
+ *  This function removes the first node from the_chain and returns
+ *  a pointer to that node.  If the_chain is empty, then NULL is returned.
+ *  It disables interrupts to insure the atomicity of the
+ *  get operation.
+ *
+ */
+
+Chain_Node *_Chain_Get(
+  Chain_Control *the_chain
+);
+
+/*
+ *  _Chain_Insert
+ *
+ *  DESCRIPTION:
+ *
+ *  This routine inserts the_node on a chain immediately following
+ *  after_node.  It disables interrupts to insure the atomicity
+ *  of the extract operation.
+ *
+ */
+
+void _Chain_Insert(
+  Chain_Node *after_node,
+  Chain_Node *the_node
+);
+
+/*
+ *  _Chain_Append
+ *
+ *  DESCRIPTION:
+ *
+ *  This routine appends the_node onto the end of the_chain.
+ *  It disables interrupts to insure the atomicity of the
+ *  append operation.
+ *
+ */
+
+void _Chain_Append(
+  Chain_Control *the_chain,
+  Chain_Node    *the_node
+);
+
+#ifndef __RTEMS_APPLICATION__
+#include <rtems/score/chain.inl>
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+/* end of include file */