Line data    Source code

       1             : /* src/toolbox/hashtable.c - functions for internal hashtables
       2             : 
       3             :    Copyright (C) 1996-2013
       4             :    CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO
       5             : 
       6             :    This file is part of CACAO.
       7             : 
       8             :    This program is free software; you can redistribute it and/or
       9             :    modify it under the terms of the GNU General Public License as
      10             :    published by the Free Software Foundation; either version 2, or (at
      11             :    your option) any later version.
      12             : 
      13             :    This program is distributed in the hope that it will be useful, but
      14             :    WITHOUT ANY WARRANTY; without even the implied warranty of
      15             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      16             :    General Public License for more details.
      17             : 
      18             :    You should have received a copy of the GNU General Public License
      19             :    along with this program; if not, write to the Free Software
      20             :    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
      21             :    02110-1301, USA.
      22             : 
      23             : */
      24             : 
      25             : 
      26             : #include "toolbox/hashtable.hpp"
      27             : #include "threads/mutex.hpp"            // for Mutex
      28             : #include "vm/types.hpp"                 // for u4
      29             : 
      30             : 
      31             : /* hashtable_create ************************************************************
      32             : 
      33             :    Initializes a hashtable structure and allocates memory. The
      34             :    parameter size specifies the initial size of the hashtable.
      35             : 
      36             : *******************************************************************************/
      37             : 
      38         489 : void hashtable_create(hashtable *hash, u4 size)
      39             : {
      40             :         /* initialize locking pointer */
      41             : 
      42             :         /* We need to seperately allocate a mutex here, as we need to
      43             :            store the lock object in the new hashtable if it's resized.
      44             :            Otherwise we get an IllegalMonitorStateException. */
      45             : 
      46         489 :         hash->mutex   = new Mutex();
      47             : 
      48             :         /* set initial hash values */
      49             : 
      50         489 :         hash->size    = size;
      51         489 :         hash->entries = 0;
      52         489 :         hash->ptr     = MNEW(void*, size);
      53             : 
      54             :         /* MNEW always allocates memory zeroed out, no need to clear the table */
      55         489 : }
      56             : 
      57             : 
      58             : /* hashtable_resize ************************************************************
      59             : 
      60             :    Creates a new hashtable with specified size and moves the important
      61             :    stuff from the old hashtable.
      62             : 
      63             : *******************************************************************************/
      64             : 
      65           0 : hashtable *hashtable_resize(hashtable *hash, u4 size)
      66             : {
      67             :         hashtable *newhash;
      68             : 
      69             :         /* create new hashtable with specified size */
      70             : 
      71           0 :         newhash = NEW(hashtable);
      72             : 
      73           0 :         hashtable_create(newhash, size);
      74             : 
      75             :         /* We need to store the old lock object in the new hashtable.
      76             :            Otherwise we get an IllegalMonitorStateException. */
      77             : 
      78           0 :         delete newhash->mutex;
      79             : 
      80           0 :         newhash->mutex = hash->mutex;
      81             : 
      82             :         /* store the number of entries in the new hashtable */
      83             : 
      84           0 :         newhash->entries = hash->entries;
      85             : 
      86           0 :         return newhash;
      87             : }
      88             : 
      89             : 
      90             : /* hashtable_free **************************************************************
      91             : 
      92             :    Simply frees the hashtable.
      93             : 
      94             :    ATTENTION: It does NOT free the lock object!
      95             : 
      96             : *******************************************************************************/
      97             : 
      98           0 : void hashtable_free(hashtable *hash)
      99             : {
     100           0 :         MFREE(hash->ptr, void*, hash->size);
     101           0 :         FREE(hash, hashtable);
     102           0 : }
     103             : 
     104             : 
     105             : /*
     106             :  * These are local overrides for various environment variables in Emacs.
     107             :  * Please do not remove this and leave it at the end of the file, where
     108             :  * Emacs will automagically detect them.
     109             :  * ---------------------------------------------------------------------
     110             :  * Local variables:
     111             :  * mode: c++
     112             :  * indent-tabs-mode: t
     113             :  * c-basic-offset: 4
     114             :  * tab-width: 4
     115             :  * End:
     116             :  * vim:noexpandtab:sw=4:ts=4:
     117             :  */