git.sesse.net Git - bcachefs-tools-debian/blob - libbcachefs/fifo.h

   1 #ifndef _BCACHEFS_FIFO_H
   2 #define _BCACHEFS_FIFO_H
   3
   4 #include "util.h"
   5
   6 #define FIFO(type)                                                      \
   7 struct {                                                                \
   8         size_t front, back, size, mask;                                 \
   9         type *data;                                                     \
  10 }
  11
  12 #define DECLARE_FIFO(type, name)        FIFO(type) name
  13
  14 #define fifo_buf_size(fifo)                                             \
  15         ((fifo)->size                                                   \
  16          ? roundup_pow_of_two((fifo)->size) * sizeof((fifo)->data[0])   \
  17          : 0)
  18
  19 #define init_fifo(fifo, _size, _gfp)                                    \
  20 ({                                                                      \
  21         (fifo)->front   = (fifo)->back = 0;                             \
  22         (fifo)->size    = (_size);                                      \
  23         (fifo)->mask    = (fifo)->size                                  \
  24                 ? roundup_pow_of_two((fifo)->size) - 1                  \
  25                 : 0;                                                    \
  26         (fifo)->data    = kvpmalloc(fifo_buf_size(fifo), (_gfp));       \
  27 })
  28
  29 #define free_fifo(fifo)                                                 \
  30 do {                                                                    \
  31         kvpfree((fifo)->data, fifo_buf_size(fifo));                     \
  32         (fifo)->data = NULL;                                            \
  33 } while (0)
  34
  35 #define fifo_swap(l, r)                                                 \
  36 do {                                                                    \
  37         swap((l)->front, (r)->front);                                   \
  38         swap((l)->back, (r)->back);                                     \
  39         swap((l)->size, (r)->size);                                     \
  40         swap((l)->mask, (r)->mask);                                     \
  41         swap((l)->data, (r)->data);                                     \
  42 } while (0)
  43
  44 #define fifo_move(dest, src)                                            \
  45 do {                                                                    \
  46         typeof(*((dest)->data)) _t;                                     \
  47         while (!fifo_full(dest) &&                                      \
  48                fifo_pop(src, _t))                                       \
  49                 fifo_push(dest, _t);                                    \
  50 } while (0)
  51
  52 #define fifo_used(fifo)         (((fifo)->back - (fifo)->front))
  53 #define fifo_free(fifo)         ((fifo)->size - fifo_used(fifo))
  54
  55 #define fifo_empty(fifo)        ((fifo)->front == (fifo)->back)
  56 #define fifo_full(fifo)         (fifo_used(fifo) == (fifo)->size)
  57
  58 #define fifo_peek_front(fifo)   ((fifo)->data[(fifo)->front & (fifo)->mask])
  59 #define fifo_peek_back(fifo)    ((fifo)->data[((fifo)->back - 1) & (fifo)->mask])
  60
  61 #define fifo_entry_idx_abs(fifo, p)                                     \
  62         ((((p) >= &fifo_peek_front(fifo)                                \
  63            ? (fifo)->front : (fifo)->back) & ~(fifo)->mask) +           \
  64            (((p) - (fifo)->data)))
  65
  66 #define fifo_entry_idx(fifo, p) (((p) - &fifo_peek_front(fifo)) & (fifo)->mask)
  67 #define fifo_idx_entry(fifo, i) (fifo)->data[((fifo)->front + (i)) & (fifo)->mask]
  68
  69 #define fifo_push_back_ref(f)                                           \
  70         (fifo_full((f)) ? NULL : &(f)->data[(f)->back++ & (f)->mask])
  71
  72 #define fifo_push_front_ref(f)                                          \
  73         (fifo_full((f)) ? NULL : &(f)->data[--(f)->front & (f)->mask])
  74
  75 #define fifo_push_back(fifo, new)                                       \
  76 ({                                                                      \
  77         typeof((fifo)->data) _r = fifo_push_back_ref(fifo);             \
  78         if (_r)                                                         \
  79                 *_r = (new);                                            \
  80         _r != NULL;                                                     \
  81 })
  82
  83 #define fifo_push_front(fifo, new)                                      \
  84 ({                                                                      \
  85         typeof((fifo)->data) _r = fifo_push_front_ref(fifo);            \
  86         if (_r)                                                         \
  87                 *_r = (new);                                            \
  88         _r != NULL;                                                     \
  89 })
  90
  91 #define fifo_pop_front(fifo, i)                                         \
  92 ({                                                                      \
  93         bool _r = !fifo_empty((fifo));                                  \
  94         if (_r)                                                         \
  95                 (i) = (fifo)->data[(fifo)->front++ & (fifo)->mask];     \
  96         _r;                                                             \
  97 })
  98
  99 #define fifo_pop_back(fifo, i)                                          \
 100 ({                                                                      \
 101         bool _r = !fifo_empty((fifo));                                  \
 102         if (_r)                                                         \
 103                 (i) = (fifo)->data[--(fifo)->back & (fifo)->mask]       \
 104         _r;                                                             \
 105 })
 106
 107 #define fifo_push_ref(fifo)     fifo_push_back_ref(fifo)
 108 #define fifo_push(fifo, i)      fifo_push_back(fifo, (i))
 109 #define fifo_pop(fifo, i)       fifo_pop_front(fifo, (i))
 110 #define fifo_peek(fifo)         fifo_peek_front(fifo)
 111
 112 #define fifo_for_each_entry(_entry, _fifo, _iter)                       \
 113         for (typecheck(typeof((_fifo)->front), _iter),                  \
 114              (_iter) = (_fifo)->front;                                  \
 115              ((_iter != (_fifo)->back) &&                               \
 116               (_entry = (_fifo)->data[(_iter) & (_fifo)->mask], true)); \
 117              (_iter)++)
 118
 119 #define fifo_for_each_entry_ptr(_ptr, _fifo, _iter)                     \
 120         for (typecheck(typeof((_fifo)->front), _iter),                  \
 121              (_iter) = (_fifo)->front;                                  \
 122              ((_iter != (_fifo)->back) &&                               \
 123               (_ptr = &(_fifo)->data[(_iter) & (_fifo)->mask], true));  \
 124              (_iter)++)
 125
 126 #endif /* _BCACHEFS_FIFO_H */