118 lines
2.3 KiB
C
118 lines
2.3 KiB
C
/*++
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Copyright (c) 1993 Microsoft Corporation
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Module Name:
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BILINK.C
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Abstract:
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Management for doubly linked lists
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Author:
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George Joy
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Environment:
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32-bit 'C'
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Revision History:
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--*/
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#include <windows.h>
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#include "dpsp.h"
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#include <dpf.h>
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#include "bilink.h"
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// Note: serialization of access to BILINK structures must
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// take place in the calling code. Operations are
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// not intrinsically atomic.
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#ifdef DEBUG
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int FindObject(
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BILINK *link,
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BILINK *list
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)
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{
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BILINK *p = list->next;
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while(p != link && p != list)
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p= p->next;
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return (p==link);
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}
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#endif
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void InsertAfter(
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BILINK *in,
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BILINK *after
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)
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/*=========================================================================
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* Description:
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* Insert an object after a specified object in the doubly linked list.
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* The after object could be the Head BILINK for adding to the head of a
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* queue.
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* Returns:
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*
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*/
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{
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#ifdef DEBUG
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if(FindObject(in,after)) {
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DPF(0,"Attempt to re-insert object in BILINK queue\n");
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DEBUG_BREAK();
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}
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#endif
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in->next = after->next;
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in->prev = after;
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after->next->prev = in;
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after->next = in;
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}
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void InsertBefore(
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BILINK *in,
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BILINK *before
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)
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/*=========================================================================
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* Description:
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* Inserts an object before a specified object in the doubly linked list.
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* The before object could be the Head BILINK for adding to the end
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* of the queue
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* CALLED WITH INTERRUPTS_OFF
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*
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* Returns:
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*
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*/
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{
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#ifdef DEBUG
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if(FindObject(in,before)) {
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DPF(0,"Attempt to re-insert object in BILINK queue\n");
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DEBUG_BREAK();
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}
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#endif
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in->next = before;
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in->prev = before->prev;
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before->prev->next = in;
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before->prev = in;
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}
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void Delete(
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BILINK *p
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)
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/*=========================================================================
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* Description:
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*
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* Delete a object from a doubly linked list. Make sure it IS on a list!
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* CALLED WITH INTERRUPTS OFF (must be atomic).
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*
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* Returns:
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*
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*/
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{
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ASSERT(p && p->prev && p->next);
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ASSERT(p->prev->next == p && p->next->prev == p);
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p->next->prev = p->prev;
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p->prev->next = p->next;
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// p->next = p->prev = 0;
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}
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