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Diffstat (limited to 'c/src/exec/score/headers/chain.h')
-rw-r--r-- | c/src/exec/score/headers/chain.h | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/c/src/exec/score/headers/chain.h b/c/src/exec/score/headers/chain.h new file mode 100644 index 0000000000..a1c8675fae --- /dev/null +++ b/c/src/exec/score/headers/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 */ |