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Diffstat (limited to 'cpukit/score/include/rtems/score/chainimpl.h')
| -rw-r--r-- | cpukit/score/include/rtems/score/chainimpl.h | 1123 |
1 files changed, 0 insertions, 1123 deletions
diff --git a/cpukit/score/include/rtems/score/chainimpl.h b/cpukit/score/include/rtems/score/chainimpl.h deleted file mode 100644 index c94c051198..0000000000 --- a/cpukit/score/include/rtems/score/chainimpl.h +++ /dev/null @@ -1,1123 +0,0 @@ -/** - * @file - * - * @brief Chain Handler API - */ - -/* - * Copyright (c) 2010 embedded brains GmbH. - * - * COPYRIGHT (c) 1989-2014. - * 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.org/license/LICENSE. - */ - -#ifndef _RTEMS_SCORE_CHAINIMPL_H -#define _RTEMS_SCORE_CHAINIMPL_H - -#include <rtems/score/chain.h> -#include <rtems/score/address.h> -#include <rtems/score/assert.h> - -#ifdef __cplusplus -extern "C" { -#endif - -/** - * @addtogroup ScoreChain - */ -/**@{**/ - -/** - * @brief Chain initializer for an empty chain with designator @a name. - */ -#define CHAIN_INITIALIZER_EMPTY(name) \ - { { { &(name).Tail.Node, NULL }, &(name).Head.Node } } - -/** - * @brief Chain initializer for a chain with one @a node. - * - * @see CHAIN_NODE_INITIALIZER_ONE_NODE_CHAIN(). - */ -#define CHAIN_INITIALIZER_ONE_NODE( node ) \ - { { { (node), NULL }, (node) } } - -/** - * @brief Chain node initializer for a @a chain containing exactly this node. - * - * @see CHAIN_INITIALIZER_ONE_NODE(). - */ -#define CHAIN_NODE_INITIALIZER_ONE_NODE_CHAIN( chain ) \ - { &(chain)->Tail.Node, &(chain)->Head.Node } - -/** - * @brief Chain definition for an empty chain with designator @a name. - */ -#define CHAIN_DEFINE_EMPTY(name) \ - Chain_Control name = CHAIN_INITIALIZER_EMPTY(name) - -/** - * @brief Initialize a chain header. - * - * This routine initializes @a the_chain structure to manage the - * contiguous array of @a number_nodes nodes which starts at - * @a starting_address. Each node is of @a node_size bytes. - * - * @param[in] the_chain specifies the chain to initialize - * @param[in] starting_address is the starting address of the array - * of elements - * @param[in] number_nodes is the numebr of nodes that will be in the chain - * @param[in] node_size is the size of each node - */ -void _Chain_Initialize( - Chain_Control *the_chain, - void *starting_address, - size_t number_nodes, - size_t node_size -); - -/** - * @brief Returns the node count of the chain. - * - * @param[in] chain The chain. - * - * @note It does NOT disable interrupts to ensure the atomicity of the - * operation. - * - * @retval The node count of the chain. - */ -size_t _Chain_Node_count_unprotected( const Chain_Control *chain ); - -/** - * @brief Set off chain. - * - * This function sets the next field of the @a node to NULL indicating the @a - * node is not part of a chain. - * - * @param[in] node the node set to off chain. - */ -RTEMS_INLINE_ROUTINE void _Chain_Set_off_chain( - Chain_Node *node -) -{ - node->next = NULL; -#if defined(RTEMS_DEBUG) - node->previous = NULL; -#endif -} - -/** - * @brief Initializes a chain node. - * - * In debug configurations, the node is set off chain. In all other - * configurations, this function does nothing. - * - * @param[in] the_node The chain node to initialize. - */ -RTEMS_INLINE_ROUTINE void _Chain_Initialize_node( Chain_Node *the_node ) -{ -#if defined(RTEMS_DEBUG) - _Chain_Set_off_chain( the_node ); -#else - (void) the_node; -#endif -} - -/** - * @brief Is the node off chain. - * - * This function returns true if the @a node is not on a chain. A @a node is - * off chain if the next field is set to NULL. - * - * @param[in] node is the node off chain. - * - * @retval true The @a node is off chain. - * @retval false The @a node is not off chain. - */ -RTEMS_INLINE_ROUTINE bool _Chain_Is_node_off_chain( - const Chain_Node *node -) -{ - return node->next == NULL; -} - -/** - * @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. - * - * @retval true @a left and @a right are equal. - * @retval false @a left and @a right are not equal. - */ -RTEMS_INLINE_ROUTINE bool _Chain_Are_nodes_equal( - const Chain_Node *left, - const Chain_Node *right -) -{ - return left == right; -} - -/** - * @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. - * - * @retval true @a the_node is @c NULL. - * @retval false @a the_node is not @c NULL. - */ -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 head 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 &the_chain->Head.Node; -} - -/** - * @brief Return pointer to immutable chain head. - * - * This function returns a pointer to the head 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 const Chain_Node *_Chain_Immutable_head( - const Chain_Control *the_chain -) -{ - return &the_chain->Head.Node; -} - -/** - * @brief Return pointer to chain tail. - * - * This function returns a pointer to the tail 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 &the_chain->Tail.Node; -} - -/** - * @brief Return pointer to immutable chain tail. - * - * This function returns a pointer to the tail 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 const Chain_Node *_Chain_Immutable_tail( - const Chain_Control *the_chain -) -{ - return &the_chain->Tail.Node; -} - -/** - * @brief Return pointer to chain's first node. - * - * This function returns a pointer to the first node on the chain after the - * head. - * - * @param[in] the_chain is the chain to be operated upon. - * - * @return This method returns the first node of the chain. - */ -RTEMS_INLINE_ROUTINE Chain_Node *_Chain_First( - const Chain_Control *the_chain -) -{ - return _Chain_Immutable_head( the_chain )->next; -} - -/** - * @brief Return pointer to immutable chain's first node. - * - * This function returns a pointer to the first node on the chain after the - * head. - * - * @param[in] the_chain is the chain to be operated upon. - * - * @return This method returns the first node of the chain. - */ -RTEMS_INLINE_ROUTINE const Chain_Node *_Chain_Immutable_first( - const Chain_Control *the_chain -) -{ - return _Chain_Immutable_head( the_chain )->next; -} - -/** - * @brief Return pointer to chain's last node. - * - * This function returns a pointer to the last node on the chain just before - * the tail. - * - * @param[in] the_chain is the chain to be operated upon. - * - * @return This method returns the last node of the chain. - */ -RTEMS_INLINE_ROUTINE Chain_Node *_Chain_Last( - const Chain_Control *the_chain -) -{ - return _Chain_Immutable_tail( the_chain )->previous; -} - -/** - * @brief Return pointer to immutable chain's last node. - * - * This function returns a pointer to the last node on the chain just before - * the tail. - * - * @param[in] the_chain is the chain to be operated upon. - * - * @return This method returns the last node of the chain. - */ -RTEMS_INLINE_ROUTINE const Chain_Node *_Chain_Immutable_last( - const Chain_Control *the_chain -) -{ - return _Chain_Immutable_tail( the_chain )->previous; -} - -/** - * @brief Return pointer the next node from this node. - * - * This function returns a pointer to the next node after this node. - * - * @param[in] the_node is the node to be operated upon. - * - * @return This method returns the next node on the chain. - */ -RTEMS_INLINE_ROUTINE Chain_Node *_Chain_Next( - const Chain_Node *the_node -) -{ - return the_node->next; -} - -/** - * @brief Return pointer the immutable next node from this node. - * - * This function returns a pointer to the next node after this node. - * - * @param[in] the_node is the node to be operated upon. - * - * @return This method returns the next node on the chain. - */ -RTEMS_INLINE_ROUTINE const Chain_Node *_Chain_Immutable_next( - const Chain_Node *the_node -) -{ - return the_node->next; -} - -/** - * @brief Return pointer the previous node from this node. - * - * This function returns a pointer to the previous node on this chain. - * - * @param[in] the_node is the node to be operated upon. - * - * @return This method returns the previous node on the chain. - */ -RTEMS_INLINE_ROUTINE Chain_Node *_Chain_Previous( - const Chain_Node *the_node -) -{ - return the_node->previous; -} - -/** - * @brief Return pointer the immutable previous node from this node. - * - * This function returns a pointer to the previous node on this chain. - * - * @param[in] the_node is the node to be operated upon. - * - * @return This method returns the previous node on the chain. - */ -RTEMS_INLINE_ROUTINE const Chain_Node *_Chain_Immutable_previous( - const Chain_Node *the_node -) -{ - return the_node->previous; -} - -/** - * @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. - * - * @retval true There are no nodes on @a the_chain. - * @retval false There are nodes on @a the_chain. - */ -RTEMS_INLINE_ROUTINE bool _Chain_Is_empty( - const Chain_Control *the_chain -) -{ - return _Chain_Immutable_first( the_chain ) - == _Chain_Immutable_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. - * - * @retval true @a the_node is the first node on a chain. - * @retval false @a the_node is not the first node on a chain. - */ -RTEMS_INLINE_ROUTINE bool _Chain_Is_first( - const Chain_Node *the_node -) -{ - return (the_node->previous->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. - * - * @retval true @a the_node is the last node on a chain. - * @retval false @a the_node is not the last node on a chain. - */ -RTEMS_INLINE_ROUTINE bool _Chain_Is_last( - const Chain_Node *the_node -) -{ - return (the_node->next->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. - * - * @retval true There is only one node on @a the_chain. - * @retval false There is more than one node on @a the_chain. - */ -RTEMS_INLINE_ROUTINE bool _Chain_Has_only_one_node( - const Chain_Control *the_chain -) -{ - return _Chain_Immutable_first( the_chain ) - == _Chain_Immutable_last( the_chain ); -} - -/** - * @brief Is this node the chain head. - * - * This function returns true if @a the_node is the head of @a 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. - * - * @retval true @a the_node is the head of @a the_chain. - * @retval false @a the_node is not the head of @a the_chain. - */ -RTEMS_INLINE_ROUTINE bool _Chain_Is_head( - const Chain_Control *the_chain, - const Chain_Node *the_node -) -{ - return (the_node == _Chain_Immutable_head( the_chain )); -} - -/** - * @brief Is this node the chail tail. - * - * This function returns true if @a the_node is the tail of @a 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. - * - * @retval true @a the_node is the tail of @a the_chain. - * @retval false @a the_node is not the tail of @a the_chain. - */ -RTEMS_INLINE_ROUTINE bool _Chain_Is_tail( - const Chain_Control *the_chain, - const Chain_Node *the_node -) -{ - return (the_node == _Chain_Immutable_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 -) -{ - Chain_Node *head; - Chain_Node *tail; - - _Assert( the_chain != NULL ); - - head = _Chain_Head( the_chain ); - tail = _Chain_Tail( the_chain ); - - head->next = tail; - head->previous = NULL; - tail->previous = head; -} - -/** - * @brief Initializes this chain to contain exactly the specified node. - * - * @param[in] the_chain The chain control. - * @param[in] the_node The one and only node. - */ -RTEMS_INLINE_ROUTINE void _Chain_Initialize_one( - Chain_Control *the_chain, - Chain_Node *the_node -) -{ - Chain_Node *head; - Chain_Node *tail; - - _Assert( _Chain_Is_node_off_chain( the_node ) ); - - head = _Chain_Head( the_chain ); - tail = _Chain_Tail( the_chain ); - - the_node->next = tail; - the_node->previous = head; - - head->next = the_node; - head->previous = NULL; - tail->previous = the_node; -} - -/** - * @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; - -#if defined(RTEMS_DEBUG) - _Chain_Set_off_chain( the_node ); -#endif -} - -/** - * @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 *head; - Chain_Node *old_first; - Chain_Node *new_first; - - _Assert( !_Chain_Is_empty( the_chain ) ); - - head = _Chain_Head( the_chain ); - old_first = head->next; - new_first = old_first->next; - - head->next = new_first; - new_first->previous = head; - -#if defined(RTEMS_DEBUG) - _Chain_Set_off_chain( old_first ); -#endif - - return old_first; -} - -/** - * @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; - - _Assert( _Chain_Is_node_off_chain( the_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 *tail; - Chain_Node *old_last; - - _Assert( _Chain_Is_node_off_chain( the_node ) ); - - tail = _Chain_Tail( the_chain ); - old_last = tail->previous; - - the_node->next = tail; - tail->previous = the_node; - old_last->next = the_node; - the_node->previous = old_last; -} - -/** - * @brief Append a node on the end of a chain if the node is in the off chain - * state (unprotected). - * - * @note It does NOT disable interrupts to ensure the atomicity of the - * append operation. - * - * @see _Chain_Append_unprotected() and _Chain_Is_node_off_chain(). - */ -RTEMS_INLINE_ROUTINE void _Chain_Append_if_is_off_chain_unprotected( - Chain_Control *the_chain, - Chain_Node *the_node -) -{ - if ( _Chain_Is_node_off_chain( the_node ) ) { - _Chain_Append_unprotected( the_chain, the_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 Append a node and check if the chain was empty before (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. - * - * @retval true The chain was empty before. - * @retval false The chain contained at least one node before. - */ -RTEMS_INLINE_ROUTINE bool _Chain_Append_with_empty_check_unprotected( - Chain_Control *the_chain, - Chain_Node *the_node -) -{ - bool was_empty = _Chain_Is_empty( the_chain ); - - _Chain_Append_unprotected( the_chain, the_node ); - - return was_empty; -} - -/** - * @brief Prepend a node and check if the chain was empty before (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. - * - * @retval true The chain was empty before. - * @retval false The chain contained at least one node before. - */ -RTEMS_INLINE_ROUTINE bool _Chain_Prepend_with_empty_check_unprotected( - Chain_Control *the_chain, - Chain_Node *the_node -) -{ - bool was_empty = _Chain_Is_empty( the_chain ); - - _Chain_Prepend_unprotected( the_chain, the_node ); - - return was_empty; -} - -/** - * @brief Get the first node and check if the chain is empty afterwards - * (unprotected). - * - * This function removes the first node from the_chain and returns - * a pointer to that node in @a the_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. - * @param[out] the_node is 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. - * - * @retval true The chain is empty now. - * @retval false The chain contains at least one node now. - */ -RTEMS_INLINE_ROUTINE bool _Chain_Get_with_empty_check_unprotected( - Chain_Control *the_chain, - Chain_Node **the_node -) -{ - bool is_empty_now = true; - Chain_Node *head = _Chain_Head( the_chain ); - Chain_Node *tail = _Chain_Tail( the_chain ); - Chain_Node *old_first = head->next; - - if ( old_first != tail ) { - Chain_Node *new_first = old_first->next; - - head->next = new_first; - new_first->previous = head; - - *the_node = old_first; - - is_empty_now = new_first == tail; - } else - *the_node = NULL; - - return is_empty_now; -} - -/** - * @brief Chain node order. - * - * @param[in] left The left hand side. - * @param[in] right The right hand side. - * - * @retval true According to the order the left node precedes the right node. - * @retval false Otherwise. - */ -typedef bool ( *Chain_Node_order )( - const void *left, - const Chain_Node *right -); - -/** - * @brief Inserts a node into the chain according to the order relation. - * - * After the operation the chain contains the node to insert and the order - * relation holds for all nodes from the head up to the inserted node. Nodes - * after the inserted node are not moved. - * - * @param[in] the_chain The chain. - * @param[in] to_insert The node to insert. - * @param[in] left The left hand side passed to the order relation. It must - * correspond to the node to insert. The separate left hand side parameter - * may help the compiler to generate better code if it is stored in a local - * variable. - * @param[in] order The order relation. - */ -RTEMS_INLINE_ROUTINE void _Chain_Insert_ordered_unprotected( - Chain_Control *the_chain, - Chain_Node *to_insert, - const void *left, - Chain_Node_order order -) -{ - const Chain_Node *tail = _Chain_Immutable_tail( the_chain ); - Chain_Node *next = _Chain_First( the_chain ); - - while ( next != tail && !( *order )( left, next ) ) { - next = _Chain_Next( next ); - } - - _Chain_Insert_unprotected( _Chain_Previous( next ), to_insert ); -} - -/** - * @brief The chain iterator direction. - */ -typedef enum { - /** - * @brief Iteration from head to tail. - */ - CHAIN_ITERATOR_FORWARD, - - /** - * @brief Iteration from tail to head. - */ - CHAIN_ITERATOR_BACKWARD -} Chain_Iterator_direction; - -/** - * @brief A chain iterator which is updated during node extraction if it is - * properly registered. - * - * @see _Chain_Iterator_initialize(). - */ -typedef struct { - /** - * @brief Node for registration. - * - * Used during _Chain_Iterator_initialize() and _Chain_Iterator_destroy(). - */ - Chain_Node Registry_node; - - /** - * @brief The direction of this iterator. - * - * Immutable after initialization via _Chain_Iterator_initialize(). - */ - Chain_Iterator_direction direction; - - /** - * @brief The current position of this iterator. - * - * The position is initialized via _Chain_Iterator_initialize(). It must be - * explicitly set after one valid iteration step, e.g. in case a next node in - * the iterator direction existed. It is updated through the registration in - * case a node is extracted via _Chain_Iterator_registry_update(). - */ - Chain_Node *position; -} Chain_Iterator; - -/** - * @brief A registry for chain iterators. - * - * Should be attached to a chain control to enable safe iteration through a - * chain in case of concurrent node extractions. - */ -typedef struct { - Chain_Control Iterators; -} Chain_Iterator_registry; - -/** - * @brief Chain iterator registry initializer for static initialization. - * - * @param name The designator of the chain iterator registry. - */ -#define CHAIN_ITERATOR_REGISTRY_INITIALIZER( name ) \ - { CHAIN_INITIALIZER_EMPTY( name.Iterators ) } - -/** - * @brief Initializes a chain iterator registry. - */ -RTEMS_INLINE_ROUTINE void _Chain_Iterator_registry_initialize( - Chain_Iterator_registry *the_registry -) -{ - _Chain_Initialize_empty( &the_registry->Iterators ); -} - -/** - * @brief Updates all iterators present in the chain iterator registry in case - * of a node extraction. - * - * Must be called before _Chain_Extract_unprotected(). - * - * @warning This function will look at all registered chain iterators to - * determine if an update is necessary. - */ -RTEMS_INLINE_ROUTINE void _Chain_Iterator_registry_update( - Chain_Iterator_registry *the_registry, - Chain_Node *the_node_to_extract -) -{ - Chain_Node *iter_node; - Chain_Node *iter_tail; - - iter_node = _Chain_Head( &the_registry->Iterators ); - iter_tail = _Chain_Tail( &the_registry->Iterators ); - - while ( ( iter_node = _Chain_Next( iter_node ) ) != iter_tail ) { - Chain_Iterator *iter; - - iter = (Chain_Iterator *) iter_node; - - if ( iter->position == the_node_to_extract ) { - if ( iter->direction == CHAIN_ITERATOR_FORWARD ) { - iter->position = _Chain_Previous( the_node_to_extract ); - } else { - iter->position = _Chain_Next( the_node_to_extract ); - } - } - } -} - -/** - * @brief Initializes the chain iterator. - * - * In the following example nodes inserted during the iteration are visited in - * case they are inserted after the current position in iteration order. - * - * @code - * #include <rtems/score/chainimpl.h> - * #include <rtems/score/isrlock.h> - * - * typedef struct { - * Chain_Control Chain; - * Chain_Iterator_registry Iterators; - * ISR_LOCK_MEMBER( Lock ) - * } Some_Control; - * - * void iterate( - * Some_Control *the_some, - * void ( *visitor )( Chain_Node * ) - * ) - * { - * ISR_lock_Context lock_context; - * Chain_Iterator iter; - * Chain_Node *node; - * const Chain_Node *end; - * - * end = _Chain_Immutable_tail( &the_some->Chain ); - * - * _ISR_lock_ISR_disable_and_acquire( &the_some->Lock, &lock_context ); - * - * _Chain_Iterator_initialize( - * &the_some->Chain, - * &the_some->Iterators, - * &iter, - * CHAIN_ITERATOR_FORWARD - * ); - * - * while ( ( node = _Chain_Iterator_next( &iter ) ) != end ) { - * _Chain_Iterator_set_position( &iter, node ); - * _ISR_lock_Release_and_ISR_enable( &the_some->Lock, &lock_context ); - * ( *visitor )( node ); - * _ISR_lock_ISR_disable_and_acquire( &the_some->Lock, &lock_context ); - * } - * - * _Chain_Iterator_destroy( &iter ); - * _ISR_lock_Release_and_ISR_enable( &the_some->Lock, &lock_context ); - * } - * @endcode - * - * @param the_chain The chain to iterate. - * @param the_registry The registry for the chain iterator. - * @param the_iterator The chain iterator to initialize. - * @param direction The iteration direction. - * - * @see _Chain_Iterator_next(), _Chain_Iterator_set_position() and - * Chain_Iterator_destroy(). - * - * @warning Think twice before you use a chain iterator. Its current - * implementation is unfit for use in performance relevant components, due to - * the linear time complexity in _Chain_Iterator_registry_update(). - */ -RTEMS_INLINE_ROUTINE void _Chain_Iterator_initialize( - Chain_Control *the_chain, - Chain_Iterator_registry *the_registry, - Chain_Iterator *the_iterator, - Chain_Iterator_direction direction -) -{ - _Chain_Initialize_node( &the_iterator->Registry_node ); - _Chain_Append_unprotected( - &the_registry->Iterators, - &the_iterator->Registry_node - ); - - the_iterator->direction = direction; - - if ( direction == CHAIN_ITERATOR_FORWARD ) { - the_iterator->position = _Chain_Head( the_chain ); - } else { - the_iterator->position = _Chain_Tail( the_chain ); - } -} - -/** - * @brief Returns the next node in the iterator direction. - * - * In case a next node exists, then the iterator should be updated via - * _Chain_Iterator_set_position() to continue with the next iteration step. - * - * @param the_iterator The chain iterator. - */ -RTEMS_INLINE_ROUTINE Chain_Node *_Chain_Iterator_next( - const Chain_Iterator *the_iterator -) -{ - if ( the_iterator->direction == CHAIN_ITERATOR_FORWARD ) { - return _Chain_Next( the_iterator->position ); - } else { - return _Chain_Previous( the_iterator->position ); - } -} - -/** - * @brief Sets the iterator position. - * - * @param the_iterator The chain iterator. - * @param the_node The new iterator position. - */ -RTEMS_INLINE_ROUTINE void _Chain_Iterator_set_position( - Chain_Iterator *the_iterator, - Chain_Node *the_node -) -{ - the_iterator->position = the_node; -} - -/** - * @brief Destroys the iterator. - * - * Removes the iterator from its registry. - * - * @param the_iterator The chain iterator. - */ -RTEMS_INLINE_ROUTINE void _Chain_Iterator_destroy( - Chain_Iterator *the_iterator -) -{ - _Chain_Extract_unprotected( &the_iterator->Registry_node ); -} - -/** @} */ - -#ifdef __cplusplus -} -#endif - -#endif -/* end of include file */ |