blob: ca9b3d3c4253ea1966292ce40e7ba823b5e74fa7 (
plain) (
tree)
|
|
/**
* @file rtems/score/chain.inl
*
* This include file contains the bodies of the routines which are
* associated with doubly linked chains and inlined.
*
* @note The routines in this file are ordered from simple
* to complex. No other Chain Handler routine is referenced
* unless it has already been defined.
*/
/*
* COPYRIGHT (c) 1989-2006.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*
* $Id$
*/
#ifndef _RTEMS_SCORE_CHAIN_H
# error "Never use <rtems/score/chain.inl> directly; include <rtems/score/chain.h> instead."
#endif
#ifndef _RTEMS_SCORE_CHAIN_INL
#define _RTEMS_SCORE_CHAIN_INL
/**
* @addtogroup ScoreChain
* @{
*/
/** @brief Are Two Nodes Equal
*
* This function returns TRUE if @a left and @a right are equal,
* and FALSE otherwise.
*
* @param[in] left is the node on the left hand side of the comparison.
* @param[in] right is the node on the left hand side of the comparison.
*
* @return This function returns TRUE if @a left and @a right are equal,
* and FALSE otherwise.
*/
RTEMS_INLINE_ROUTINE bool _Chain_Are_nodes_equal(
const Chain_Node *left,
const Chain_Node *right
)
{
return left == right;
}
/** @brief Is this Chain Control Pointer Null
*
* This function returns TRUE if the_chain is NULL and FALSE otherwise.
*
* @param[in] the_chain is the chain to be checked for empty status.
*
* @return This method returns TRUE if the_chain is NULL and FALSE otherwise.
*/
RTEMS_INLINE_ROUTINE bool _Chain_Is_null(
const Chain_Control *the_chain
)
{
return (the_chain == NULL);
}
/** @brief Is the Chain Node Pointer NULL
*
* This function returns TRUE if the_node is NULL and FALSE otherwise.
*
* @param[in] the_node is the node pointer to check.
*
* @return This method returns TRUE if the_node is NULL and FALSE otherwise.
*/
RTEMS_INLINE_ROUTINE bool _Chain_Is_null_node(
const Chain_Node *the_node
)
{
return (the_node == NULL);
}
/** @brief Return pointer to Chain Head
*
* This function returns a pointer to the first node on the chain.
*
* @param[in] the_chain is the chain to be operated upon.
*
* @return This method returns the permanent head node of the chain.
*/
RTEMS_INLINE_ROUTINE Chain_Node *_Chain_Head(
Chain_Control *the_chain
)
{
return (Chain_Node *) the_chain;
}
/** @brief Return pointer to Chain Tail
*
* This function returns a pointer to the last node on the chain.
*
* @param[in] the_chain is the chain to be operated upon.
*
* @return This method returns the permanent tail node of the chain.
*/
RTEMS_INLINE_ROUTINE Chain_Node *_Chain_Tail(
Chain_Control *the_chain
)
{
return (Chain_Node *) &the_chain->permanent_null;
}
/** @brief Is the Chain Empty
*
* This function returns TRUE if there a no nodes on @a the_chain and
* FALSE otherwise.
*
* @param[in] the_chain is the chain to be operated upon.
*
* @return This function returns TRUE if there a no nodes on @a the_chain and
* FALSE otherwise.
*/
RTEMS_INLINE_ROUTINE bool _Chain_Is_empty(
Chain_Control *the_chain
)
{
return (the_chain->first == _Chain_Tail(the_chain));
}
/** @brief Is this the First Node on the Chain
*
* This function returns TRUE if the_node is the first node on a chain and
* FALSE otherwise.
*
* @param[in] the_node is the node the caller wants to know if it is
* the first node on a chain.
*
* @return This function returns TRUE if @a the_node is the first node on
* a chain and FALSE otherwise.
*/
RTEMS_INLINE_ROUTINE bool _Chain_Is_first(
const Chain_Node *the_node
)
{
return (the_node->previous == NULL);
}
/** @brief Is this the Last Node on the Chain
*
* This function returns TRUE if @a the_node is the last node on a chain and
* FALSE otherwise.
*
* @param[in] the_node is the node to check as the last node.
*
* @return This function returns TRUE if @a the_node is the last node on
* a chain and FALSE otherwise.
*/
RTEMS_INLINE_ROUTINE bool _Chain_Is_last(
const Chain_Node *the_node
)
{
return (the_node->next == NULL);
}
/** @brief Does this Chain have only One Node
*
* This function returns TRUE if there is only one node on @a the_chain and
* FALSE otherwise.
*
* @param[in] the_chain is the chain to be operated upon.
*
* @return This function returns TRUE if there is only one node on
* @a the_chain and FALSE otherwise.
*/
RTEMS_INLINE_ROUTINE bool _Chain_Has_only_one_node(
const Chain_Control *the_chain
)
{
return (the_chain->first == the_chain->last);
}
/** @brief Is this Node the Chain Head
*
* This function returns TRUE if @a the_node is the head of the_chain and
* FALSE otherwise.
*
* @param[in] the_chain is the chain to be operated upon.
* @param[in] the_node is the node to check for being the Chain Head.
*
* @return This function returns TRUE if @a the_node is the head of
* @a the_chain and FALSE otherwise.
*/
RTEMS_INLINE_ROUTINE bool _Chain_Is_head(
Chain_Control *the_chain,
const Chain_Node *the_node
)
{
return (the_node == _Chain_Head(the_chain));
}
/** @brief Is this Node the Chail Tail
*
* This function returns TRUE if the_node is the tail of the_chain and
* FALSE otherwise.
*
* @param[in] the_chain is the chain to be operated upon.
* @param[in] the_node is the node to check for being the Chain Tail.
*/
RTEMS_INLINE_ROUTINE bool _Chain_Is_tail(
Chain_Control *the_chain,
const Chain_Node *the_node
)
{
return (the_node == _Chain_Tail(the_chain));
}
/** @brief Initialize this Chain as Empty
*
* This routine initializes the specified chain to contain zero nodes.
*
* @param[in] the_chain is the chain to be initialized.
*/
RTEMS_INLINE_ROUTINE void _Chain_Initialize_empty(
Chain_Control *the_chain
)
{
the_chain->first = _Chain_Tail(the_chain);
the_chain->permanent_null = NULL;
the_chain->last = _Chain_Head(the_chain);
}
/** @brief Extract this Node (unprotected)
*
* This routine extracts the_node from the chain on which it resides.
* It does NOT disable interrupts to ensure the atomicity of the
* extract operation.
*
* @param[in] the_node is the node to be extracted.
*/
RTEMS_INLINE_ROUTINE void _Chain_Extract_unprotected(
Chain_Node *the_node
)
{
Chain_Node *next;
Chain_Node *previous;
next = the_node->next;
previous = the_node->previous;
next->previous = previous;
previous->next = next;
}
/** @brief Get the First Node (unprotected)
*
* This function removes the first node from the_chain and returns
* a pointer to that node. It does NOT disable interrupts to ensure
* the atomicity of the get operation.
*
* @param[in] the_chain is the chain to attempt to get the first node from.
*
* @return This method returns the first node on the chain even if it is
* the Chain Tail.
*
* @note This routine assumes that there is at least one node on the chain
* and always returns a node even if it is the Chain Tail.
*/
RTEMS_INLINE_ROUTINE Chain_Node *_Chain_Get_first_unprotected(
Chain_Control *the_chain
)
{
Chain_Node *return_node;
Chain_Node *new_first;
return_node = the_chain->first;
new_first = return_node->next;
the_chain->first = new_first;
new_first->previous = _Chain_Head(the_chain);
return return_node;
}
/** @brief Get the First Node (unprotected)
*
* 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.
*
* @param[in] the_chain is the chain to attempt to get the first node from.
*
* @return This method returns the first node on the chain or NULL if the
* chain is empty.
*
* @note It does NOT disable interrupts to ensure the atomicity of the
* get operation.
*/
RTEMS_INLINE_ROUTINE Chain_Node *_Chain_Get_unprotected(
Chain_Control *the_chain
)
{
if ( !_Chain_Is_empty(the_chain))
return _Chain_Get_first_unprotected(the_chain);
else
return NULL;
}
/** @brief Insert a Node (unprotected)
*
* This routine inserts the_node on a chain immediately following
* after_node.
*
* @param[in] after_node is the node which will precede @a the_node on the
* chain.
* @param[in] the_node is the node to be inserted.
*
* @note It does NOT disable interrupts to ensure the atomicity
* of the extract operation.
*/
RTEMS_INLINE_ROUTINE void _Chain_Insert_unprotected(
Chain_Node *after_node,
Chain_Node *the_node
)
{
Chain_Node *before_node;
the_node->previous = after_node;
before_node = after_node->next;
after_node->next = the_node;
the_node->next = before_node;
before_node->previous = the_node;
}
/** @brief Append a Node (unprotected)
*
* This routine appends the_node onto the end of the_chain.
*
* @param[in] the_chain is the chain to be operated upon.
* @param[in] the_node is the node to be appended.
*
* @note It does NOT disable interrupts to ensure the atomicity of the
* append operation.
*/
RTEMS_INLINE_ROUTINE void _Chain_Append_unprotected(
Chain_Control *the_chain,
Chain_Node *the_node
)
{
Chain_Node *old_last_node;
the_node->next = _Chain_Tail(the_chain);
old_last_node = the_chain->last;
the_chain->last = the_node;
old_last_node->next = the_node;
the_node->previous = old_last_node;
}
/** @brief Prepend a Node (unprotected)
*
* This routine prepends the_node onto the front of the_chain.
*
* @param[in] the_chain is the chain to be operated upon.
* @param[in] the_node is the node to be prepended.
*
* @note It does NOT disable interrupts to ensure the atomicity of the
* prepend operation.
*/
RTEMS_INLINE_ROUTINE void _Chain_Prepend_unprotected(
Chain_Control *the_chain,
Chain_Node *the_node
)
{
_Chain_Insert_unprotected(_Chain_Head(the_chain), the_node);
}
/** @brief Prepend a Node (protected)
*
* This routine prepends the_node onto the front of the_chain.
*
* @param[in] the_chain is the chain to be operated upon.
* @param[in] the_node is the node to be prepended.
*
* @note It disables interrupts to ensure the atomicity of the
* prepend operation.
*/
RTEMS_INLINE_ROUTINE void _Chain_Prepend(
Chain_Control *the_chain,
Chain_Node *the_node
)
{
_Chain_Insert(_Chain_Head(the_chain), the_node);
}
/**@}*/
#endif
/* end of include file */
|