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

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