freelist.h 2.0 KB

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  1. /*
  2. * Copyright (c) 2007 Damien Miller. All rights reserved.
  3. *
  4. * Redistribution and use in source and binary forms, with or without
  5. * modification, are permitted provided that the following conditions
  6. * are met:
  7. * 1. Redistributions of source code must retain the above copyright
  8. * notice, this list of conditions and the following disclaimer.
  9. * 2. Redistributions in binary form must reproduce the above copyright
  10. * notice, this list of conditions and the following disclaimer in the
  11. * documentation and/or other materials provided with the distribution.
  12. *
  13. * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  14. * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  15. * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  16. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  17. * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  18. * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  19. * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  20. * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  21. * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  22. * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  23. */
  24. #ifndef _FREELIST_H
  25. #define _FREELIST_H
  26. #include "common.h"
  27. /* Simple freelist of fixed-sized allocations */
  28. struct freelist {
  29. size_t allocsz;
  30. size_t nalloc;
  31. size_t navail;
  32. void **free_entries;
  33. };
  34. /*
  35. * Initialise a freelist.
  36. * allocsz is the size of the individual allocations
  37. */
  38. void freelist_init(struct freelist *freelist, size_t allocsz);
  39. /*
  40. * Get an entry from a freelist.
  41. * Will allocate new entries if necessary
  42. * Returns pointer to allocated memory or NULL on failure.
  43. */
  44. void *freelist_get(struct freelist *freelist);
  45. /*
  46. * Returns an entry to the freelist.
  47. * p must be a pointer to an allocation from the freelist.
  48. */
  49. void freelist_put(struct freelist *freelist, void *p);
  50. #endif /* FREELIST_H */