nginx/src/core/ngx_queue.h

   1
   2 /*
   3  * Copyright (C) Igor Sysoev
   4  */
   5
   6
   7 #include <ngx_config.h>
   8 #include <ngx_core.h>
   9
  10
  11 #ifndef _NGX_QUEUE_H_INCLUDED_
  12 #define _NGX_QUEUE_H_INCLUDED_
  13
  14
  15 typedef struct ngx_queue_s  ngx_queue_t;
  16
  17 struct ngx_queue_s {
  18     ngx_queue_t  *prev;
  19     ngx_queue_t  *next;
  20 };
  21
  22
  23 #define ngx_queue_init(q)                                                     \
  24     (q)->prev = q;                                                            \
  25     (q)->next = q
  26
  27
  28 #define ngx_queue_empty(h)                                                    \
  29     (h == (h)->prev)
  30
  31
  32 #define ngx_queue_insert_head(h, x)                                           \
  33     (x)->next = (h)->next;                                                    \
  34     (x)->next->prev = x;                                                      \
  35     (x)->prev = h;                                                            \
  36     (h)->next = x
  37
  38
  39 #define ngx_queue_insert_after   ngx_queue_insert_head
  40
  41
  42 #define ngx_queue_insert_tail(h, x)                                           \
  43     (x)->prev = (h)->prev;                                                    \
  44     (x)->prev->next = x;                                                      \
  45     (x)->next = h;                                                            \
  46     (h)->prev = x
  47
  48
  49 #define ngx_queue_head(h)                                                     \
  50     (h)->next
  51
  52
  53 #define ngx_queue_last(h)                                                     \
  54     (h)->prev
  55
  56
  57 #define ngx_queue_sentinel(h)                                                 \
  58     (h)
  59
  60
  61 #define ngx_queue_next(q)                                                     \
  62     (q)->next
  63
  64
  65 #define ngx_queue_prev(q)                                                     \
  66     (q)->prev
  67
  68
  69 #if (NGX_DEBUG)
  70
  71 #define ngx_queue_remove(x)                                                   \
  72     (x)->next->prev = (x)->prev;                                              \
  73     (x)->prev->next = (x)->next;                                              \
  74     (x)->prev = NULL;                                                         \
  75     (x)->next = NULL
  76
  77 #else
  78
  79 #define ngx_queue_remove(x)                                                   \
  80     (x)->next->prev = (x)->prev;                                              \
  81     (x)->prev->next = (x)->next
  82
  83 #endif
  84
  85
  86 #define ngx_queue_split(h, q, n)                                              \
  87     (n)->prev = (h)->prev;                                                    \
  88     (n)->prev->next = n;                                                      \
  89     (n)->next = q;                                                            \
  90     (h)->prev = (q)->prev;                                                    \
  91     (h)->prev->next = h;                                                      \
  92     (q)->prev = n;
  93
  94
  95 #define ngx_queue_add(h, n)                                                   \
  96     (h)->prev->next = (n)->next;                                              \
  97     (n)->next->prev = (h)->prev;                                              \
  98     (h)->prev = (n)->prev;                                                    \
  99     (h)->prev->next = h;
 100
 101
 102 #define ngx_queue_data(q, type, link)                                         \
 103     (type *) ((u_char *) q - offsetof(type, link))
 104
 105
 106 ngx_queue_t *ngx_queue_middle(ngx_queue_t *queue);
 107 void ngx_queue_sort(ngx_queue_t *queue,
 108     ngx_int_t (*cmp)(const ngx_queue_t *, const ngx_queue_t *));
 109
 110
 111 #endif /* _NGX_QUEUE_H_INCLUDED_ */