FD.io VPP  v19.08.3-2-gbabecb413
Vector Packet Processing
dlist.h
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1 /*
2  * Copyright (c) 2016 Cisco and/or its affiliates.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  *
6  * You may obtain a copy of the License at:
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15 */
16 
17 #ifndef included_dlist_h
18 #define included_dlist_h
19 
20 #include <stdarg.h>
21 #include <vppinfra/clib.h>
22 #include <vppinfra/vec.h>
23 #include <vppinfra/pool.h>
24 #include <vppinfra/error.h>
25 #include <vppinfra/format.h>
26 #include <vppinfra/cache.h>
27 
28 typedef struct
29 {
33 } dlist_elt_t;
34 
35 static inline void
37 {
38  dlist_elt_t *head = pool_elt_at_index (pool, index);
39  clib_memset (head, 0xFF, sizeof (*head));
40 }
41 
42 static inline void
43 clib_dlist_addtail (dlist_elt_t * pool, u32 head_index, u32 new_index)
44 {
45  dlist_elt_t *head = pool_elt_at_index (pool, head_index);
46  u32 old_last_index;
47  dlist_elt_t *old_last;
48  dlist_elt_t *new;
49 
50  ASSERT (head->value == ~0);
51 
52  new = pool_elt_at_index (pool, new_index);
53 
54  if (PREDICT_FALSE (head->next == ~0))
55  {
56  head->next = head->prev = new_index;
57  new->next = new->prev = head_index;
58  return;
59  }
60 
61  old_last_index = head->prev;
62  old_last = pool_elt_at_index (pool, old_last_index);
63 
64  new->next = old_last->next;
65  new->prev = old_last_index;
66  old_last->next = new_index;
67  head->prev = new_index;
68 }
69 
70 static inline void
71 clib_dlist_addhead (dlist_elt_t * pool, u32 head_index, u32 new_index)
72 {
73  dlist_elt_t *head = pool_elt_at_index (pool, head_index);
74  dlist_elt_t *old_first;
75  u32 old_first_index;
76  dlist_elt_t *new;
77 
78  ASSERT (head->value == ~0);
79 
80  new = pool_elt_at_index (pool, new_index);
81 
82  if (PREDICT_FALSE (head->next == ~0))
83  {
84  head->next = head->prev = new_index;
85  new->next = new->prev = head_index;
86  return;
87  }
88 
89  old_first_index = head->next;
90  old_first = pool_elt_at_index (pool, old_first_index);
91 
92  new->next = old_first_index;
93  new->prev = old_first->prev;
94  old_first->prev = new_index;
95  head->next = new_index;
96 }
97 
98 static inline void
100 {
101  dlist_elt_t *elt = pool_elt_at_index (pool, index);
102  dlist_elt_t *next_elt, *prev_elt;
103 
104  /* listhead, not so much */
105  ASSERT (elt->value != ~0);
106 
107  next_elt = pool_elt_at_index (pool, elt->next);
108  prev_elt = pool_elt_at_index (pool, elt->prev);
109 
110  next_elt->prev = elt->prev;
111  prev_elt->next = elt->next;
112 
113  elt->prev = elt->next = ~0;
114 }
115 
116 static inline u32
118 {
119  dlist_elt_t *head = pool_elt_at_index (pool, head_index);
120  u32 rv;
121 
122  ASSERT (head->value == ~0);
123 
124  if (head->next == ~0 || (head->next == head_index))
125  return ~0;
126 
127  rv = head->next;
128  clib_dlist_remove (pool, rv);
129  return rv;
130 }
131 
132 static inline u32
134 {
135  dlist_elt_t *head = pool_elt_at_index (pool, head_index);
136  u32 rv;
137 
138  ASSERT (head->value == ~0);
139 
140  if (head->prev == ~0)
141  return ~0;
142 
143  rv = head->prev;
144  clib_dlist_remove (pool, rv);
145  return rv;
146 }
147 
148 #endif /* included_dlist_h */
149 
150 /*
151  * fd.io coding-style-patch-verification: ON
152  *
153  * Local Variables:
154  * eval: (c-set-style "gnu")
155  * End:
156  */
u32 next
Definition: dlist.h:30
static void clib_dlist_init(dlist_elt_t *pool, u32 index)
Definition: dlist.h:36
static u32 clib_dlist_remove_tail(dlist_elt_t *pool, u32 head_index)
Definition: dlist.h:133
Fixed length block allocator.
clib_memset(h->entries, 0, sizeof(h->entries[0]) *entries)
unsigned int u32
Definition: types.h:88
#define pool_elt_at_index(p, i)
Returns pointer to element at given index.
Definition: pool.h:514
static void clib_dlist_addtail(dlist_elt_t *pool, u32 head_index, u32 new_index)
Definition: dlist.h:43
#define PREDICT_FALSE(x)
Definition: clib.h:112
static void clib_dlist_addhead(dlist_elt_t *pool, u32 head_index, u32 new_index)
Definition: dlist.h:71
#define ASSERT(truth)
static void clib_dlist_remove(dlist_elt_t *pool, u32 index)
Definition: dlist.h:99
u32 prev
Definition: dlist.h:31
u32 value
Definition: dlist.h:32
CLIB vectors are ubiquitous dynamically resized arrays with by user defined "headers".
static u32 clib_dlist_remove_head(dlist_elt_t *pool, u32 head_index)
Definition: dlist.h:117