Double linked list structure

 1 // Double linked list structure. Can be used as either a list head, or as link words.
 2 
 3 // @struct USBH_DLIST |
 4 //   The USBH_DLIST structure is the link element of the double linked list. It is used as either a list head, or as link entry.
 5 // @field  struct tDLIST * | Flink |
 6 //   Pointer to the successor (forward link).
 7 // @field  struct tDLIST * | pPrev |
 8 //   Pointer to the predecessor (backward link).
 9 // @comm By means of such elements any structures may be handled as a double linked list. The USBH_DLIST structure is to be inserted
10 //   into the structure which is to be handled. A pointer to the original structure can be obtained by means of the macro <f STRUCT_BASE_POINTER>.
11 typedef struct USBH_DLIST USBH_DLIST;
12 struct USBH_DLIST {
13   USBH_DLIST * pNext;
14   USBH_DLIST * pPrev;
15 };
16 
17 void         USBH_DLIST_Append     (USBH_DLIST * ListHead, USBH_DLIST * List);
18 void         USBH_DLIST_InsertTail (USBH_DLIST * ListHead, USBH_DLIST * Entry);
19 void         USBH_DLIST_InsertHead (USBH_DLIST * ListHead, USBH_DLIST * Entry);
20 void         USBH_DLIST_InsertEntry(USBH_DLIST * Entry,    USBH_DLIST * NewEntry);
21 void         USBH_DLIST_RemoveTail (USBH_DLIST * ListHead, USBH_DLIST ** Entry);
22 void         USBH_DLIST_RemoveHead (USBH_DLIST * ListHead, USBH_DLIST ** Entry);
23 void         USBH_DLIST_RemoveEntry(USBH_DLIST * Entry);
24 USBH_DLIST * USBH_DLIST_GetPrev    (USBH_DLIST * Entry);
25 USBH_DLIST * USBH_DLIST_GetNext    (USBH_DLIST * Entry);
26 int          USBH_DLIST_IsEmpty    (USBH_DLIST * ListHead);
27 void         USBH_DLIST_Init       (USBH_DLIST * ListHead);
28 
29 
30 /*********************************************************************
31 *
32 *       USBH_DLIST
33 */
34 typedef struct USBH_DLIST_ITEM {
35   struct USBH_DLIST_ITEM * pNext;
36   struct USBH_DLIST_ITEM * pPrev;
37 } USBH_DLIST_ITEM;
38 
39 typedef struct {
40   struct USBH_DLIST_ITEM * pFirst;
41   int NumItems;
42 } USBH_DLIST_HEAD;
43 
44 void USBH_DLIST_Remove(USBH_DLIST_HEAD * pHead, USBH_DLIST_ITEM * pItem);
45 void USBH_DLIST_Add   (USBH_DLIST_HEAD * pHead, USBH_DLIST_ITEM * pNew);

  1 typedef struct USBH_DLIST USBH_DLIST;
  2 struct USBH_DLIST
  3 {
  4   USBH_DLIST * pNext;
  5   USBH_DLIST * pPrev;
  6 };
  7 
  8 // USBH_DLIST_Init
  9 //     STR     R0, [R0,#4]
 10 //     STR     R0, [R0]
 11 //     BX      LR
 12 void USBH_DLIST_Init(USBH_DLIST * ListHead)
 13 {
 14   ListHead->pPrev = ListHead;
 15   ListHead->pNext = ListHead;
 16 }
 17 
 18 // USBH_DLIST_Append
 19 //     LDR     R2, [R0,#4]
 20 //     STR     R1, [R2]
 21 //     LDR     R3, [R1,#4]
 22 //     STR     R0, [R3]
 23 //     LDR     R3, [R1,#4]
 24 //     STR     R3, [R0,#4]
 25 //     STR     R2, [R1,#4]
 26 //     BX      LR
 27 
 28 //  /---<<<<<<<<<<<<<<<<<<<<<<pNext---\         /---<<<<<<<<<<<<<<<<<<pNext---\
 29 //  ListHead <----> 0 <----> 1 <----> N         List <----> 0 <----> 1 <----> N
 30 //  pPrev >>>>>>>>>>>>>>>>>>>>>>>>>---/         pPrev >>>>>>>>>>>>>>>>>>>>>---/
 31 //
 32 //  /---<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<pNext---\
 33 //  ListHead <----> 0 <----> 1 <----> N <---->  List <----> 0 <----> 1 <----> N
 34 //  pPrev >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>---/
 35 void USBH_DLIST_Append(USBH_DLIST * ListHead, USBH_DLIST * List)
 36 {
 37   ListHead->pPrev->pNext = List;
 38   List->pPrev->pNext = ListHead;
 39   ListHead->pPrev = List->pPrev;
 40   List->pPrev = ListHead->pPrev;
 41 }
 42 
 43 // USBH_DLIST_IsEmpty
 44 //     LDR     R1, [R0]
 45 //     CMP     R1, R0
 46 //     ITE EQ
 47 //     MOVEQ   R0, #1
 48 //     MOVNE   R0, #0
 49 //     BX      LR
 50 int USBH_DLIST_IsEmpty(USBH_DLIST * ListHead)
 51 {
 52   return ListHead == ListHead->pNext;
 53 }
 54 
 55 // USBH_DLIST_GetNext          USBH_DLIST_GetPrev
 56 //     LDR     R0, [R0]            LDR     R0, [R0,#4]
 57 //     BX      LR                  BX      LR
 58 USBH_DLIST * USBH_DLIST_GetNext(USBH_DLIST * Entry)
 59 {
 60   return Entry->pNext;
 61 }
 62 USBH_DLIST * USBH_DLIST_GetPrev(USBH_DLIST * Entry)
 63 {
 64   return Entry->pPrev;
 65 }
 66 
 67 //                             USBH_DLIST_RemoveHead     USBH_DLIST_RemoveTail
 68 //                                LDR     R0, [R0]          LDR     R0, [R0,#4]
 69 // USBH_DLIST_RemoveEntry         STR     R0, [R1]          STR     R0, [R1]
 70 //
 71 //    LDRD.W  R1, R2, [R0]        LDRD.W  R1, R2, [R0]      LDRD.W  R1, R2, [R0]
 72 //    STR     R1, [R2]            STR     R1, [R2]          STR     R1, [R2]
 73 //
 74 //    LDRD.W  R1, R2, [R0]        LDRD.W  R1, R2, [R0]      LDRD.W  R1, R2, [R0]
 75 //    STR     R2, [R1,#4]         STR     R2, [R1,#4]       STR     R2, [R1,#4]
 76 //
 77 //    STR     R0, [R0,#4]         STR     R0, [R0,#4]       STR     R0, [R0,#4]
 78 //    STR     R0, [R0]            STR     R0, [R0]          STR     R0, [R0]
 79 //    BX      LR                  BX      LR                BX      LR
 80 
 81 // pPrev [ Entry ] pNext ---> pPrev pNext
 82 void USBH_DLIST_RemoveEntry(USBH_DLIST * Entry)
 83 {
 84   Entry->pPrev->pNext = Entry->pNext;
 85   Entry->pNext->pPrev = Entry->pPrev;
 86   //USBH_DLIST_Init( Entry );
 87   Entry->pPrev = Entry;
 88   Entry->pNext = Entry;
 89 }
 90 
 91 
 92 void USBH_DLIST_RemoveHead(USBH_DLIST * ListHead, USBH_DLIST ** Entry)
 93 {
 94   (*Entry)->pNext = ListHead->pNext;
 95   USBH_DLIST_RemoveEntry( ListHead->pNext );
 96 }
 97 
 98 
 99 void USBH_DLIST_RemoveTail(USBH_DLIST * ListHead, USBH_DLIST ** Entry)
100 {
101   (*Entry)->pNext = ListHead->pPrev;
102   USBH_DLIST_RemoveEntry( ListHead->pPrev );
103 }
104 
105 //                                                       USBH_DLIST_InsertTail
106 // USBH_DLIST_InsertEntry      USBH_DLIST_InsertHead         LDR     R0, [R0,#4]
107 //     LDR     R2, [R0]            LDR     R2, [R0]          LDR     R2, [R0]
108 //     STRD.W  R2, R0, [R1]        STRD.W  R2, R0, [R1]      STRD.W  R2, R0, [R1]
109 //     LDR     R2, [R0]            LDR     R2, [R0]          LDR     R2, [R0]
110 //     STR     R1, [R2,#4]         STR     R1, [R2,#4]       STR     R1, [R2,#4]
111 //     STR     R1, [R0]            STR     R1, [R0]          STR     R1, [R0]
112 //     BX      LR                  BX      LR                BX      LR
113 
114 void USBH_DLIST_InsertEntry(USBH_DLIST * Entry, USBH_DLIST * NewEntry)
115 {
116   NewEntry->pNext = Entry->pNext;
117   NewEntry->pPrev = Entry;
118 
119   Entry->pNext->pPrev = NewEntry;
120   Entry->pNext = NewEntry;
121 }
122 
123 void USBH_DLIST_InsertHead(USBH_DLIST * ListHead, USBH_DLIST * Entry)
124 {
125   USBH_DLIST_InsertEntry( ListHead, Entry );
126 }
127 
128 void USBH_DLIST_InsertTail(USBH_DLIST * ListHead, USBH_DLIST * Entry)
129 {
130   USBH_DLIST_InsertEntry( ListHead->pPrev, Entry );
131 }
132 
133 // -------------------------------------------------------------------------------
134  typedef struct USBH_DLIST_ITEM {
135    struct USBH_DLIST_ITEM * pNext;
136    struct USBH_DLIST_ITEM * pPrev;
137  } USBH_DLIST_ITEM;
138 
139  typedef struct {
140    struct USBH_DLIST_ITEM * pFirst;
141    int NumItems;
142  } USBH_DLIST_HEAD;
143 
144 
145 void USBH_DLIST_InitHead(USBH_DLIST_HEAD * pHead)
146 {
147   pHead->pFirst = 0;
148   pHead->NumItems = 0;
149 }
150 
151 // USBH_DLIST_Add
152 //     MOVS    R2, #0
153 //     STR     R2, [R1,#4]   ; pNew->pPrev = 0;
154 //
155 //     LDR     R2, [R0]
156 //     STR     R2, [R1]      ; pNew->pNext = pHead->pFirst;
157 //
158 //     LDR     R2, [R0]
159 //     CMP     R2, #0
160 //     IT NE                 ; pHead->pFirst != 0
161 //     STRNE   R1, [R2,#4]   ; pHead->pFirst->pPrev = pNew;
162 //
163 //     STR     R1, [R0]      ; pHead->pFirst = pNew;
164 //     BX      LR
165 //
166 //  pFirst --> pNew
167 //  0 <------- pNew ----> 0
168 //
169 //  0 <------- pNew ----> pOld
170 //  pNew <---- pOld ----> 0
171 //
172 void USBH_DLIST_Add(USBH_DLIST_HEAD * pHead, USBH_DLIST_ITEM * pNew)
173 {
174   pNew->pPrev = 0;
175   pNew->pNext = 0;
176   if (pHead->pFirst != 0)
177   {
178     pNew->pNext = pHead->pFirst;
179     pHead->pFirst->pPrev = pNew;
180   }
181   pHead->pFirst = pNew;
182   //pHead->NumItems++;
183 }
184 
185 // USBH_DLIST_Remove
186 //     LDR     R3, [R0]
187 //     LDR     R2, [R1]
188 //
189 //     CMP     R3, R1
190 //     IT NE
191 //     LDRNE   R0, [R1,#4]
192 //     STR     R2, [R0]
193 //
194 //     LDR     R0, [R1]
195 //     CMP     R0, #0
196 //     ITT NE
197 //     LDRNE   R1, [R1,#4]
198 //     STRNE   R1, [R0,#4]
199 //
200 //     BX      LR
201 
202 //
203 void USBH_DLIST_Remove(USBH_DLIST_HEAD * pHead, USBH_DLIST_ITEM * pItem)
204 {
205   if (pHead->pFirst == pItem)
206     pHead->pFirst->pNext = pItem->pNext;
207   else
208     pItem->pPrev->pNext = pItem->pNext;
209 
210   if (pItem->pNext != 0)
211   {
212     pHead->NumItems = (int)pItem->pPrev;
213   }
214 }