src/base/fast_alloc.cc

   1 /*
   2  * Copyright (c) 2000-2005 The Regents of The University of Michigan
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met: redistributions of source code must retain the above copyright
   8  * notice, this list of conditions and the following disclaimer;
   9  * 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  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  *
  28  * Authors: Steve Reinhardt
  29  */
  30
  31 /*
  32  * This code was originally written by Steve Reinhardt as part of
  33  * the Wisconsin Wind Tunnel simulator.  Relicensed as part of M5
  34  * by permission.
  35  */
  36
  37 #include <cassert>
  38
  39 #include "base/fast_alloc.hh"
  40
  41 #if USE_FAST_ALLOC
  42
  43 #ifdef __GNUC__
  44 #pragma implementation
  45 #endif
  46
  47 void *FastAlloc::freeLists[Num_Buckets];
  48
  49 #if FAST_ALLOC_STATS
  50 unsigned FastAlloc::newCount[Num_Buckets];
  51 unsigned FastAlloc::deleteCount[Num_Buckets];
  52 unsigned FastAlloc::allocCount[Num_Buckets];
  53 #endif
  54
  55 void *
  56 FastAlloc::moreStructs(int bucket)
  57 {
  58     assert(bucket > 0 && bucket < Num_Buckets);
  59
  60     int sz = bucket * Alloc_Quantum;
  61     const int nstructs = Num_Structs_Per_New;   // how many to allocate?
  62     char *p = ::new char[nstructs * sz];
  63
  64 #if FAST_ALLOC_STATS
  65     ++allocCount[bucket];
  66 #endif
  67
  68     freeLists[bucket] = p;
  69     for (int i = 0; i < (nstructs-2); ++i, p += sz)
  70         *(void **)p = p + sz;
  71     *(void **)p = 0;
  72
  73     return (p + sz);
  74 }
  75
  76 #endif // USE_FAST_ALLOC