map.c

   1 #include "map.h"
   2
   3 static bool get_lock(Map *map, bool write)
   4 {
   5         bool success;
   6
   7         pthread_rwlock_rdlock(&map->clk);
   8
   9         if ((success = ! map->cnl)) {
  10                 if (write)
  11                         pthread_rwlock_wrlock(&map->tlk);
  12                 else
  13                         pthread_rwlock_rdlock(&map->tlk);
  14         }
  15
  16         pthread_rwlock_unlock(&map->clk);
  17
  18         return success;
  19 }
  20
  21 void map_ini(Map *map)
  22 {
  23         tree_ini(&map->tre);
  24         pthread_rwlock_init(&map->tlk, NULL);
  25         map->cnl = false;
  26         pthread_rwlock_init(&map->clk, NULL);
  27 }
  28
  29 void map_dst(Map *map)
  30 {
  31         pthread_rwlock_destroy(&map->tlk);
  32         pthread_rwlock_destroy(&map->clk);
  33 }
  34
  35 void map_cnl(Map *map, Iterator iter, void *arg, Transformer trans, TreeTraversionOrder order)
  36 {
  37         pthread_rwlock_wrlock(&map->clk);
  38         map->cnl = true;
  39
  40         pthread_rwlock_wrlock(&map->tlk);
  41         pthread_rwlock_unlock(&map->clk);
  42
  43         tree_clr(&map->tre, iter, arg, trans, order);
  44
  45         pthread_rwlock_unlock(&map->tlk);
  46 }
  47
  48 #define WRAP_TREE_FUNC(name, write) \
  49         void *map_ ## name(Map *map, void *dat, Comparator cmp, Transformer trans) \
  50         { \
  51                 if (! get_lock(map, write)) \
  52                         return NULL; \
  53  \
  54                 dat = tree_ ## name(&map->tre, dat, cmp, trans); \
  55                 pthread_rwlock_unlock(&map->tlk); \
  56                 return dat; \
  57         }
  58
  59 WRAP_TREE_FUNC(add, true)
  60 WRAP_TREE_FUNC(get, false)
  61 WRAP_TREE_FUNC(del, true)
  62
  63 void map_trv(Map *map, Iterator iter, void *arg, Transformer trans, TreeTraversionOrder order)
  64 {
  65         if (! get_lock(map, false))
  66                 return;
  67
  68         tree_trv(&map->tre, iter, arg, trans, order);
  69         pthread_rwlock_unlock(&map->tlk);
  70 }