alloc.h

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#ifndef NDNDPDK_DISK_ALLOC_H
#define NDNDPDK_DISK_ALLOC_H
 
#include "../core/common.h"
#include <rte_bitmap.h>
 
typedef struct DiskAlloc {
  uint64_t min;
  uint64_t max;
  uint64_t slab;
  uint32_t pos;
  struct rte_bitmap bmp[0] __rte_cache_aligned;
} __rte_cache_aligned DiskAlloc;
static_assert(offsetof(DiskAlloc, bmp[0]) % RTE_CACHE_LINE_SIZE == 0, "");
 
__attribute__((nonnull)) static inline uint64_t
DiskAlloc_Alloc(DiskAlloc* a) {
  if (a->slab == 0) {
    int found = rte_bitmap_scan(a->bmp, &a->pos, &a->slab);
    if (unlikely(found == 0)) {
      return 0;
    }
  }
 
  uint64_t offset = rte_bsf64(a->slab);
  a->slab &= ~((uint64_t)1 << offset);
  uint64_t pos = a->pos + offset;
  rte_bitmap_clear(a->bmp, pos);
  return a->min + pos;
}
 
__attribute__((nonnull)) static inline void
DiskAlloc_Free(DiskAlloc* a, uint64_t slotID) {
  NDNDPDK_ASSERT(slotID >= a->min && slotID <= a->max);
  uint32_t pos = slotID - a->min;
  NDNDPDK_ASSERT(rte_bitmap_get(a->bmp, pos) == 0);
  rte_bitmap_set(a->bmp, pos);
 
  // if s->slab reflects the modified bitmap slab, DiskAlloc_Alloc can't use it right away but
  // will pick up the newly available slotID during bitmap scan
}
 
__attribute__((returns_nonnull)) DiskAlloc*
DiskAlloc_New(uint64_t min, uint64_t max, int numaSocket);
 
#endif // NDNDPDK_DISK_ALLOC_H