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