5fc3b5d6c8
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@10683 6f19259b-4bc3-4df7-8a09-765794883524
551 lines
17 KiB
C
551 lines
17 KiB
C
/** @file
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Linked List Library Functions.
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Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
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This program and the accompanying materials
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are licensed and made available under the terms and conditions of the BSD License
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which accompanies this distribution. The full text of the license may be found at
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http://opensource.org/licenses/bsd-license.php.
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THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
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WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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**/
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#include "BaseLibInternals.h"
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/**
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Worker function that locates the Node in the List.
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By searching the List, finds the location of the Node in List. At the same time,
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verifies the validity of this list.
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If List is NULL, then ASSERT().
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If List->ForwardLink is NULL, then ASSERT().
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If List->backLink is NULL, then ASSERT().
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If Node is NULL, then ASSERT().
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If PcdVerifyNodeInList is TRUE and DoMembershipCheck is TRUE and Node
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is in not a member of List, then return FALSE
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If PcdMaximumLinkedListLenth is not zero, and List contains more than
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PcdMaximumLinkedListLenth nodes, then ASSERT().
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@param List A pointer to a node in a linked list.
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@param Node A pointer to a node in a linked list.
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@param VerifyNodeInList TRUE if a check should be made to see if Node is a
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member of List. FALSE if no membership test should
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be performed.
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@retval TRUE if PcdVerifyNodeInList is FALSE
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@retval TRUE if DoMembershipCheck is FALSE
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@retval TRUE if PcdVerifyNodeInList is TRUE and DoMembershipCheck is TRUE
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and Node is a member of List.
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@retval FALSE if PcdVerifyNodeInList is TRUE and DoMembershipCheck is TRUE
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and Node is in not a member of List.
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**/
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BOOLEAN
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EFIAPI
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InternalBaseLibIsNodeInList (
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IN CONST LIST_ENTRY *List,
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IN CONST LIST_ENTRY *Node,
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IN BOOLEAN VerifyNodeInList
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)
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{
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UINTN Count;
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CONST LIST_ENTRY *Ptr;
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//
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// Test the validity of List and Node
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//
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ASSERT (List != NULL);
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ASSERT (List->ForwardLink != NULL);
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ASSERT (List->BackLink != NULL);
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ASSERT (Node != NULL);
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Count = 0;
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Ptr = List;
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if (FeaturePcdGet (PcdVerifyNodeInList) && VerifyNodeInList) {
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//
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// Check to see if Node is a member of List.
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// Exit early if the number of nodes in List >= PcdMaximumLinkedListLength
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//
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do {
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Ptr = Ptr->ForwardLink;
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if (PcdGet32 (PcdMaximumLinkedListLength) > 0) {
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Count++;
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//
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// ASSERT() if the linked list is too long
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//
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ASSERT (Count < PcdGet32 (PcdMaximumLinkedListLength));
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//
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// Return if the linked list is too long
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//
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if (Count >= PcdGet32 (PcdMaximumLinkedListLength)) {
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return (BOOLEAN)(Ptr == Node);
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}
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}
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} while ((Ptr != List) && (Ptr != Node));
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if (Ptr != Node) {
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return FALSE;
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}
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}
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if (PcdGet32 (PcdMaximumLinkedListLength) > 0) {
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//
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// Count the total number of nodes in List.
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// Exit early if the number of nodes in List >= PcdMaximumLinkedListLength
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//
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do {
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Ptr = Ptr->ForwardLink;
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Count++;
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} while ((Ptr != List) && (Count < PcdGet32 (PcdMaximumLinkedListLength)));
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//
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// ASSERT() if the linked list is too long
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//
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ASSERT (Count < PcdGet32 (PcdMaximumLinkedListLength));
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}
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return TRUE;
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}
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/**
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Initializes the head node of a doubly-linked list, and returns the pointer to
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the head node of the doubly-linked list.
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Initializes the forward and backward links of a new linked list. After
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initializing a linked list with this function, the other linked list
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functions may be used to add and remove nodes from the linked list. It is up
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to the caller of this function to allocate the memory for ListHead.
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If ListHead is NULL, then ASSERT().
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@param ListHead A pointer to the head node of a new doubly-linked list.
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@return ListHead
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**/
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LIST_ENTRY *
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EFIAPI
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InitializeListHead (
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IN OUT LIST_ENTRY *ListHead
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)
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{
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ASSERT (ListHead != NULL);
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ListHead->ForwardLink = ListHead;
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ListHead->BackLink = ListHead;
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return ListHead;
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}
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/**
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Adds a node to the beginning of a doubly-linked list, and returns the pointer
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to the head node of the doubly-linked list.
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Adds the node Entry at the beginning of the doubly-linked list denoted by
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ListHead, and returns ListHead.
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If ListHead is NULL, then ASSERT().
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If Entry is NULL, then ASSERT().
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If ListHead was not initialized with INTIALIZE_LIST_HEAD_VARIABLE() or
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InitializeListHead(), then ASSERT().
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If PcdMaximumLinkedListLenth is not zero, and prior to insertion the number
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of nodes in ListHead, including the ListHead node, is greater than or
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equal to PcdMaximumLinkedListLength, then ASSERT().
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@param ListHead A pointer to the head node of a doubly-linked list.
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@param Entry A pointer to a node that is to be inserted at the beginning
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of a doubly-linked list.
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@return ListHead
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**/
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LIST_ENTRY *
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EFIAPI
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InsertHeadList (
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IN OUT LIST_ENTRY *ListHead,
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IN OUT LIST_ENTRY *Entry
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)
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{
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//
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// ASSERT List not too long and Entry is not one of the nodes of List
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//
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ASSERT (InternalBaseLibIsNodeInList (ListHead, Entry, FALSE));
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Entry->ForwardLink = ListHead->ForwardLink;
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Entry->BackLink = ListHead;
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Entry->ForwardLink->BackLink = Entry;
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ListHead->ForwardLink = Entry;
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return ListHead;
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}
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/**
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Adds a node to the end of a doubly-linked list, and returns the pointer to
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the head node of the doubly-linked list.
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Adds the node Entry to the end of the doubly-linked list denoted by ListHead,
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and returns ListHead.
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If ListHead is NULL, then ASSERT().
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If Entry is NULL, then ASSERT().
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If ListHead was not initialized with INTIALIZE_LIST_HEAD_VARIABLE() or
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InitializeListHead(), then ASSERT().
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If PcdMaximumLinkedListLenth is not zero, and prior to insertion the number
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of nodes in ListHead, including the ListHead node, is greater than or
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equal to PcdMaximumLinkedListLength, then ASSERT().
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@param ListHead A pointer to the head node of a doubly-linked list.
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@param Entry A pointer to a node that is to be added at the end of the
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doubly-linked list.
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@return ListHead
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**/
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LIST_ENTRY *
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EFIAPI
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InsertTailList (
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IN OUT LIST_ENTRY *ListHead,
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IN OUT LIST_ENTRY *Entry
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)
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{
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//
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// ASSERT List not too long and Entry is not one of the nodes of List
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//
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ASSERT (InternalBaseLibIsNodeInList (ListHead, Entry, FALSE));
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Entry->ForwardLink = ListHead;
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Entry->BackLink = ListHead->BackLink;
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Entry->BackLink->ForwardLink = Entry;
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ListHead->BackLink = Entry;
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return ListHead;
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}
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/**
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Retrieves the first node of a doubly-linked list.
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Returns the first node of a doubly-linked list. List must have been
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initialized with INTIALIZE_LIST_HEAD_VARIABLE() or InitializeListHead().
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If List is empty, then List is returned.
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If List is NULL, then ASSERT().
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If List was not initialized with INTIALIZE_LIST_HEAD_VARIABLE() or
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InitializeListHead(), then ASSERT().
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If PcdMaximumLinkedListLenth is not zero, and the number of nodes
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in List, including the List node, is greater than or equal to
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PcdMaximumLinkedListLength, then ASSERT().
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@param List A pointer to the head node of a doubly-linked list.
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@return The first node of a doubly-linked list.
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@retval NULL The list is empty.
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**/
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LIST_ENTRY *
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EFIAPI
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GetFirstNode (
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IN CONST LIST_ENTRY *List
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)
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{
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//
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// ASSERT List not too long
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//
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ASSERT (InternalBaseLibIsNodeInList (List, List, FALSE));
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return List->ForwardLink;
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}
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/**
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Retrieves the next node of a doubly-linked list.
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Returns the node of a doubly-linked list that follows Node.
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List must have been initialized with INTIALIZE_LIST_HEAD_VARIABLE()
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or InitializeListHead(). If List is empty, then List is returned.
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If List is NULL, then ASSERT().
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If Node is NULL, then ASSERT().
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If List was not initialized with INTIALIZE_LIST_HEAD_VARIABLE() or
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InitializeListHead(), then ASSERT().
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If PcdMaximumLinkedListLenth is not zero, and List contains more than
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PcdMaximumLinkedListLenth nodes, then ASSERT().
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If PcdVerifyNodeInList is TRUE and Node is not a node in List, then ASSERT().
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@param List A pointer to the head node of a doubly-linked list.
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@param Node A pointer to a node in the doubly-linked list.
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@return A pointer to the next node if one exists. Otherwise List is returned.
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**/
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LIST_ENTRY *
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EFIAPI
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GetNextNode (
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IN CONST LIST_ENTRY *List,
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IN CONST LIST_ENTRY *Node
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)
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{
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//
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// ASSERT List not too long and Node is one of the nodes of List
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//
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ASSERT (InternalBaseLibIsNodeInList (List, Node, TRUE));
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return Node->ForwardLink;
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}
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/**
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Retrieves the previous node of a doubly-linked list.
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Returns the node of a doubly-linked list that precedes Node.
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List must have been initialized with INTIALIZE_LIST_HEAD_VARIABLE()
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or InitializeListHead(). If List is empty, then List is returned.
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If List is NULL, then ASSERT().
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If Node is NULL, then ASSERT().
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If List was not initialized with INTIALIZE_LIST_HEAD_VARIABLE() or
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InitializeListHead(), then ASSERT().
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If PcdMaximumLinkedListLenth is not zero, and List contains more than
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PcdMaximumLinkedListLenth nodes, then ASSERT().
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If PcdVerifyNodeInList is TRUE and Node is not a node in List, then ASSERT().
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@param List A pointer to the head node of a doubly-linked list.
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@param Node A pointer to a node in the doubly-linked list.
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@return A pointer to the previous node if one exists. Otherwise List is returned.
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**/
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LIST_ENTRY *
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EFIAPI
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GetPreviousNode (
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IN CONST LIST_ENTRY *List,
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IN CONST LIST_ENTRY *Node
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)
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{
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//
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// ASSERT List not too long and Node is one of the nodes of List
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//
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ASSERT (InternalBaseLibIsNodeInList (List, Node, TRUE));
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return Node->BackLink;
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}
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/**
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Checks to see if a doubly-linked list is empty or not.
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Checks to see if the doubly-linked list is empty. If the linked list contains
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zero nodes, this function returns TRUE. Otherwise, it returns FALSE.
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If ListHead is NULL, then ASSERT().
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If ListHead was not initialized with INTIALIZE_LIST_HEAD_VARIABLE() or
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InitializeListHead(), then ASSERT().
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If PcdMaximumLinkedListLenth is not zero, and the number of nodes
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in List, including the List node, is greater than or equal to
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PcdMaximumLinkedListLength, then ASSERT().
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@param ListHead A pointer to the head node of a doubly-linked list.
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@retval TRUE The linked list is empty.
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@retval FALSE The linked list is not empty.
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**/
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BOOLEAN
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EFIAPI
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IsListEmpty (
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IN CONST LIST_ENTRY *ListHead
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)
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{
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//
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// ASSERT List not too long
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//
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ASSERT (InternalBaseLibIsNodeInList (ListHead, ListHead, FALSE));
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return (BOOLEAN)(ListHead->ForwardLink == ListHead);
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}
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/**
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Determines if a node in a doubly-linked list is the head node of a the same
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doubly-linked list. This function is typically used to terminate a loop that
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traverses all the nodes in a doubly-linked list starting with the head node.
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Returns TRUE if Node is equal to List. Returns FALSE if Node is one of the
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nodes in the doubly-linked list specified by List. List must have been
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initialized with INTIALIZE_LIST_HEAD_VARIABLE() or InitializeListHead().
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If List is NULL, then ASSERT().
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If Node is NULL, then ASSERT().
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If List was not initialized with INTIALIZE_LIST_HEAD_VARIABLE() or InitializeListHead(),
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then ASSERT().
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If PcdMaximumLinkedListLenth is not zero, and the number of nodes
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in List, including the List node, is greater than or equal to
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PcdMaximumLinkedListLength, then ASSERT().
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If PcdVerifyNodeInList is TRUE and Node is not a node in List and Node is not
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equal to List, then ASSERT().
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@param List A pointer to the head node of a doubly-linked list.
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@param Node A pointer to a node in the doubly-linked list.
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@retval TRUE Node is one of the nodes in the doubly-linked list.
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@retval FALSE Node is not one of the nodes in the doubly-linked list.
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**/
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BOOLEAN
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EFIAPI
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IsNull (
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IN CONST LIST_ENTRY *List,
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IN CONST LIST_ENTRY *Node
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)
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{
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//
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// ASSERT List not too long and Node is one of the nodes of List
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//
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ASSERT (InternalBaseLibIsNodeInList (List, Node, TRUE));
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return (BOOLEAN)(Node == List);
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}
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/**
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Determines if a node the last node in a doubly-linked list.
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Returns TRUE if Node is the last node in the doubly-linked list specified by
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List. Otherwise, FALSE is returned. List must have been initialized with
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INTIALIZE_LIST_HEAD_VARIABLE() or InitializeListHead().
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If List is NULL, then ASSERT().
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If Node is NULL, then ASSERT().
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If List was not initialized with INTIALIZE_LIST_HEAD_VARIABLE() or
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InitializeListHead(), then ASSERT().
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If PcdMaximumLinkedListLenth is not zero, and the number of nodes
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in List, including the List node, is greater than or equal to
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PcdMaximumLinkedListLength, then ASSERT().
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If PcdVerifyNodeInList is TRUE and Node is not a node in List, then ASSERT().
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@param List A pointer to the head node of a doubly-linked list.
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@param Node A pointer to a node in the doubly-linked list.
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@retval TRUE Node is the last node in the linked list.
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@retval FALSE Node is not the last node in the linked list.
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**/
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BOOLEAN
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EFIAPI
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IsNodeAtEnd (
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IN CONST LIST_ENTRY *List,
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IN CONST LIST_ENTRY *Node
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)
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{
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//
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// ASSERT List not too long and Node is one of the nodes of List
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//
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ASSERT (InternalBaseLibIsNodeInList (List, Node, TRUE));
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return (BOOLEAN)(!IsNull (List, Node) && List->BackLink == Node);
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}
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/**
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Swaps the location of two nodes in a doubly-linked list, and returns the
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first node after the swap.
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If FirstEntry is identical to SecondEntry, then SecondEntry is returned.
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Otherwise, the location of the FirstEntry node is swapped with the location
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of the SecondEntry node in a doubly-linked list. SecondEntry must be in the
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same double linked list as FirstEntry and that double linked list must have
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been initialized with INTIALIZE_LIST_HEAD_VARIABLE() or InitializeListHead().
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SecondEntry is returned after the nodes are swapped.
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If FirstEntry is NULL, then ASSERT().
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If SecondEntry is NULL, then ASSERT().
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If PcdVerifyNodeInList is TRUE and SecondEntry and FirstEntry are not in the
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same linked list, then ASSERT().
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If PcdMaximumLinkedListLength is not zero, and the number of nodes in the
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linked list containing the FirstEntry and SecondEntry nodes, including
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the FirstEntry and SecondEntry nodes, is greater than or equal to
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PcdMaximumLinkedListLength, then ASSERT().
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@param FirstEntry A pointer to a node in a linked list.
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@param SecondEntry A pointer to another node in the same linked list.
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@return SecondEntry.
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**/
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LIST_ENTRY *
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EFIAPI
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SwapListEntries (
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IN OUT LIST_ENTRY *FirstEntry,
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IN OUT LIST_ENTRY *SecondEntry
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)
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{
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LIST_ENTRY *Ptr;
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if (FirstEntry == SecondEntry) {
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return SecondEntry;
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}
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//
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// ASSERT Entry1 and Entry2 are in the same linked list
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//
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ASSERT (InternalBaseLibIsNodeInList (FirstEntry, SecondEntry, TRUE));
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//
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// Ptr is the node pointed to by FirstEntry->ForwardLink
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//
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Ptr = RemoveEntryList (FirstEntry);
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//
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// If FirstEntry immediately follows SecondEntry, FirstEntry will be placed
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// immediately in front of SecondEntry
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//
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if (Ptr->BackLink == SecondEntry) {
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return InsertTailList (SecondEntry, FirstEntry);
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}
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//
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// Ptr == SecondEntry means SecondEntry immediately follows FirstEntry,
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// then there are no further steps necessary
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//
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if (Ptr == InsertHeadList (SecondEntry, FirstEntry)) {
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return Ptr;
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}
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//
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// Move SecondEntry to the front of Ptr
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//
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RemoveEntryList (SecondEntry);
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InsertTailList (Ptr, SecondEntry);
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return SecondEntry;
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}
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/**
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Removes a node from a doubly-linked list, and returns the node that follows
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the removed node.
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Removes the node Entry from a doubly-linked list. It is up to the caller of
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this function to release the memory used by this node if that is required. On
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exit, the node following Entry in the doubly-linked list is returned. If
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Entry is the only node in the linked list, then the head node of the linked
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list is returned.
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If Entry is NULL, then ASSERT().
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If Entry is the head node of an empty list, then ASSERT().
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If PcdMaximumLinkedListLength is not zero, and the number of nodes in the
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linked list containing Entry, including the Entry node, is greater than
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or equal to PcdMaximumLinkedListLength, then ASSERT().
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@param Entry A pointer to a node in a linked list.
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@return Entry.
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**/
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LIST_ENTRY *
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EFIAPI
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RemoveEntryList (
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IN CONST LIST_ENTRY *Entry
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)
|
|
{
|
|
ASSERT (!IsListEmpty (Entry));
|
|
|
|
Entry->ForwardLink->BackLink = Entry->BackLink;
|
|
Entry->BackLink->ForwardLink = Entry->ForwardLink;
|
|
return Entry->ForwardLink;
|
|
}
|