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 !NO_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 #if FAST_ALLOC_DEBUG
  77
  78 #include <map>
  79 #include <string>
  80 #include <typeinfo>
  81
  82 #include "base/cprintf.hh"
  83 #include "sim/core.hh"   // for curTick
  84
  85 using namespace std;
  86
  87 // count of in-use FastAlloc objects
  88 int FastAlloc::numInUse;
  89
  90 // dummy head & tail object for doubly linked list of in-use FastAlloc
  91 // objects
  92 FastAlloc FastAlloc::inUseHead(&FastAlloc::inUseHead, &FastAlloc::inUseHead);
  93
  94 // special constructor for dummy head: make inUsePrev & inUseNext
  95 // point to self
  96 FastAlloc::FastAlloc(FastAlloc *prev, FastAlloc *next)
  97 {
  98     inUsePrev = prev;
  99     inUseNext = next;
 100 }
 101
 102 // constructor: marks as in use, add to in-use list
 103 FastAlloc::FastAlloc()
 104 {
 105     // mark this object in use
 106     inUse = true;
 107     whenAllocated = curTick;
 108
 109     // update count
 110     ++numInUse;
 111
 112     // add to tail of list of in-use objects ("before" dummy head)
 113     FastAlloc *myNext = &inUseHead;
 114     FastAlloc *myPrev = inUseHead.inUsePrev;
 115
 116     inUsePrev = myPrev;
 117     inUseNext = myNext;
 118     myPrev->inUseNext = this;
 119     myNext->inUsePrev = this;
 120 }
 121
 122 // destructor: mark not in use, remove from in-use list
 123 FastAlloc::~FastAlloc()
 124 {
 125     assert(inUse);
 126     inUse = false;
 127
 128     --numInUse;
 129     assert(numInUse >= 0);
 130
 131     // remove me from in-use list
 132     inUsePrev->inUseNext = inUseNext;
 133     inUseNext->inUsePrev = inUsePrev;
 134 }
 135
 136
 137 // Note that in all the display functions below we suppress anything
 138 // with a zero allocation timestamp... there are a bunch of static or
 139 // quasi-static structures that get allocated during initialization
 140 // and we generally don't care about them so this gets them out of the
 141 // way.
 142
 143 // summarize in-use list
 144 void
 145 FastAlloc::dump_summary()
 146 {
 147     map<string, int> typemap;
 148
 149     for (FastAlloc *p = inUseHead.inUseNext; p != &inUseHead; p = p->inUseNext)
 150     {
 151         if (p->whenAllocated != 0)
 152             ++typemap[typeid(*p).name()];
 153     }
 154
 155     map<string, int>::const_iterator mapiter;
 156
 157     cprintf(" count  type\n"
 158             " -----  ----\n");
 159     for (mapiter = typemap.begin(); mapiter != typemap.end(); ++mapiter)
 160         cprintf("%6d  %s\n",mapiter->second, mapiter->first);
 161 }
 162
 163
 164 // show oldest n items on in-use list
 165 void
 166 FastAlloc::dump_oldest(int n)
 167 {
 168     // sanity check: don't want to crash the debugger if you forget to
 169     // pass in a parameter
 170     if (n < 0 || n > numInUse) {
 171         cprintf("FastAlloc::dump_oldest: bad arg %d (%d objects in use)\n",
 172                 n, numInUse);
 173         return;
 174     }
 175
 176     for (FastAlloc *p = inUseHead.inUseNext;
 177          p != &inUseHead && n > 0;
 178          p = p->inUseNext, --n) {
 179         if (p->whenAllocated != 0)
 180             cprintf("%x %15d %s\n", p, p->whenAllocated, typeid(*p).name());
 181     }
 182 }
 183
 184
 185 // show oldest n items on in-use list for specified type
 186 void
 187 FastAlloc::dump_oldest_of_type(int n, const char *type_name)
 188 {
 189     // sanity check: don't want to crash the debugger if you forget to
 190     // pass in a parameter
 191     if (n < 0 || n > numInUse) {
 192         cprintf("FastAlloc::dump_oldest_of_type: bad arg %d "
 193                 "(%d objects in use)\n",
 194                 n, numInUse);
 195         return;
 196     }
 197
 198     for (FastAlloc *p = inUseHead.inUseNext;
 199          p != &inUseHead && n > 0;
 200          p = p->inUseNext) {
 201         if (p->whenAllocated != 0 &&
 202             strcmp(typeid(*p).name(), type_name) == 0) {
 203             cprintf("%x %15d\n", p, p->whenAllocated);
 204             --n;
 205         }
 206     }
 207 }
 208
 209
 210 //
 211 // C interfaces to FastAlloc::dump_summary() and FastAlloc::dump_oldest().
 212 // gdb seems to have trouble with calling C++ functions directly.
 213 //
 214 void
 215 fast_alloc_summary()
 216 {
 217     FastAlloc::dump_summary();
 218 }
 219
 220 void
 221 fast_alloc_oldest(int n)
 222 {
 223     FastAlloc::dump_oldest(n);
 224 }
 225
 226 #endif // FAST_ALLOC_DEBUG
 227
 228 #endif // NO_FAST_ALLOC