src/hash.c

   1 /*
   2  * Copyright (C) 2003, 2004, 2005, 2006, 2007
   3  * Robert Lougher <rob@lougher.org.uk>.
   4  *
   5  * This file is part of JamVM.
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version 2,
  10  * or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  */
  21
  22 #include <string.h>
  23 #include <stdlib.h>
  24 #include "jam.h"
  25 #include "hash.h"
  26
  27 void lockHashTable0(HashTable *table, Thread *self) {
  28     if(!tryLockVMLock(table->lock, self)) {
  29         disableSuspend(self);
  30         lockVMLock(table->lock, self);
  31         enableSuspend(self);
  32     }
  33     fastDisableSuspend(self);
  34 }
  35
  36 void unlockHashTable0(HashTable *table, Thread *self) {
  37     fastEnableSuspend(self);
  38     unlockVMLock(table->lock, self);
  39 }
  40
  41 void resizeHash(HashTable *table, int new_size) {
  42     HashEntry *new_table = (HashEntry*)gcMemMalloc(sizeof(HashEntry)*new_size);
  43     int i;
  44
  45     memset(new_table, 0, sizeof(HashEntry)*new_size);
  46
  47     for(i = table->hash_size-1; i >= 0; i--) {
  48         void *ptr = table->hash_table[i].data;
  49         if(ptr != NULL) {
  50             int hash = table->hash_table[i].hash;
  51             int new_index = hash & (new_size - 1);
  52
  53             while(new_table[new_index].data != NULL)
  54                 new_index = (new_index+1) & (new_size - 1);
  55
  56             new_table[new_index].hash = hash;
  57             new_table[new_index].data = ptr;
  58         }
  59     }
  60
  61     gcMemFree(table->hash_table);
  62     table->hash_table = new_table;
  63     table->hash_size = new_size;
  64 }