LCOV - code coverage report
Current view: directory - xpcom/ds - nsFixedSizeAllocator.cpp (source / functions) Found Hit Coverage
Test: app.info Lines: 54 49 90.7 %
Date: 2012-06-02 Functions: 5 5 100.0 %

       1                 : /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
       2                 : /* ***** BEGIN LICENSE BLOCK *****
       3                 :  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
       4                 :  *
       5                 :  * The contents of this file are subject to the Mozilla Public License Version
       6                 :  * 1.1 (the "License"); you may not use this file except in compliance with
       7                 :  * the License. You may obtain a copy of the License at
       8                 :  * http://www.mozilla.org/MPL/
       9                 :  *
      10                 :  * Software distributed under the License is distributed on an "AS IS" basis,
      11                 :  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
      12                 :  * for the specific language governing rights and limitations under the
      13                 :  * License.
      14                 :  *
      15                 :  * The Original Code is mozilla.org code.
      16                 :  *
      17                 :  * The Initial Developer of the Original Code is
      18                 :  * Netscape Communications Corporation.
      19                 :  * Portions created by the Initial Developer are Copyright (C) 1998
      20                 :  * the Initial Developer. All Rights Reserved.
      21                 :  *
      22                 :  * Contributor(s):
      23                 :  *   Chris Waterson <waterson@netscape.com
      24                 :  *
      25                 :  * Alternatively, the contents of this file may be used under the terms of
      26                 :  * either of the GNU General Public License Version 2 or later (the "GPL"),
      27                 :  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
      28                 :  * in which case the provisions of the GPL or the LGPL are applicable instead
      29                 :  * of those above. If you wish to allow use of your version of this file only
      30                 :  * under the terms of either the GPL or the LGPL, and not to allow others to
      31                 :  * use your version of this file under the terms of the MPL, indicate your
      32                 :  * decision by deleting the provisions above and replace them with the notice
      33                 :  * and other provisions required by the GPL or the LGPL. If you do not delete
      34                 :  * the provisions above, a recipient may use your version of this file under
      35                 :  * the terms of any one of the MPL, the GPL or the LGPL.
      36                 :  *
      37                 :  * ***** END LICENSE BLOCK ***** */
      38                 : 
      39                 : /*
      40                 : 
      41                 :   Implementation for nsFixedSizeAllocator
      42                 : 
      43                 : */
      44                 : 
      45                 : #include "nsCRT.h"
      46                 : #include "nsFixedSizeAllocator.h"
      47                 : 
      48                 : nsFixedSizeAllocator::Bucket *
      49           23746 : nsFixedSizeAllocator::AddBucket(size_t aSize)
      50                 : {
      51                 :     void* p;
      52           23746 :     PL_ARENA_ALLOCATE(p, &mPool, sizeof(Bucket));
      53           23746 :     if (! p)
      54               0 :         return nsnull;
      55                 : 
      56           23746 :     Bucket* bucket = static_cast<Bucket*>(p);
      57           23746 :     bucket->mSize  = aSize;
      58           23746 :     bucket->mFirst = nsnull;
      59           23746 :     bucket->mNext  = mBuckets;
      60                 : 
      61           23746 :     mBuckets = bucket;
      62           23746 :     return bucket;
      63                 : }
      64                 : 
      65                 : nsresult
      66            7417 : nsFixedSizeAllocator::Init(const char* aName,
      67                 :                            const size_t* aBucketSizes,
      68                 :                            PRInt32 aNumBuckets,
      69                 :                            PRInt32 aInitialSize,
      70                 :                            PRInt32 aAlign)
      71                 : {
      72            7417 :     NS_PRECONDITION(aNumBuckets > 0, "no buckets");
      73            7417 :     if (aNumBuckets <= 0)
      74               0 :         return NS_ERROR_INVALID_ARG;
      75                 : 
      76                 :     // Blow away the old pool if we're being re-initialized.
      77            7417 :     if (mBuckets)
      78               0 :         PL_FinishArenaPool(&mPool);
      79                 : 
      80            7417 :     PRInt32 bucketspace = aNumBuckets * sizeof(Bucket);
      81            7417 :     PL_InitArenaPool(&mPool, aName, bucketspace + aInitialSize, aAlign);
      82                 : 
      83            7417 :     mBuckets = nsnull;
      84           31113 :     for (PRInt32 i = 0; i < aNumBuckets; ++i)
      85           23696 :         AddBucket(aBucketSizes[i]);
      86                 : 
      87            7417 :     return NS_OK;
      88                 : }
      89                 : 
      90                 : nsFixedSizeAllocator::Bucket *
      91          144769 : nsFixedSizeAllocator::FindBucket(size_t aSize)
      92                 : {
      93          144769 :     Bucket** link = &mBuckets;
      94                 :     Bucket* bucket;
      95                 : 
      96          315668 :     while ((bucket = *link) != nsnull) {
      97          170849 :         if (aSize == bucket->mSize) {
      98                 :             // Promote to the head of the list, under the assumption
      99                 :             // that we'll allocate same-sized object contemporaneously.
     100          144719 :             *link = bucket->mNext;
     101          144719 :             bucket->mNext = mBuckets;
     102          144719 :             mBuckets = bucket;
     103          144719 :             return bucket;
     104                 :         }
     105                 : 
     106           26130 :         link = &bucket->mNext;
     107                 :     }
     108              50 :     return nsnull;
     109                 : }
     110                 : 
     111                 : void*
     112           72620 : nsFixedSizeAllocator::Alloc(size_t aSize)
     113                 : {
     114           72620 :     Bucket* bucket = FindBucket(aSize);
     115           72620 :     if (! bucket) {
     116                 :         // Oops, we don't carry that size. Let's fix that.
     117              50 :         bucket = AddBucket(aSize);
     118              50 :         if (! bucket)
     119               0 :             return nsnull;
     120                 :     }
     121                 : 
     122                 :     void* next;
     123           72620 :     if (bucket->mFirst) {
     124           10466 :         next = bucket->mFirst;
     125           10466 :         bucket->mFirst = bucket->mFirst->mNext;
     126                 :     }
     127                 :     else {
     128           62154 :         PL_ARENA_ALLOCATE(next, &mPool, aSize);
     129           62154 :         if (!next)
     130               0 :             return nsnull;
     131                 :     }
     132                 : 
     133                 : #ifdef DEBUG
     134           72620 :     memset(next, 0xc8, aSize);
     135                 : #endif
     136                 : 
     137           72620 :     return next;
     138                 : }
     139                 : 
     140                 : void
     141           72149 : nsFixedSizeAllocator::Free(void* aPtr, size_t aSize)
     142                 : {
     143           72149 :     FreeEntry* entry = reinterpret_cast<FreeEntry*>(aPtr);
     144           72149 :     Bucket* bucket = FindBucket(aSize);
     145                 : 
     146                 : #ifdef DEBUG
     147           72149 :     NS_ASSERTION(bucket && bucket->mSize == aSize, "ack! corruption! bucket->mSize != aSize!");
     148           72149 :     memset(aPtr, 0xd8, bucket->mSize);
     149                 : #endif
     150                 : 
     151           72149 :     entry->mNext = bucket->mFirst;
     152           72149 :     bucket->mFirst = entry;
     153           72149 : }

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