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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Chris Waterson <waterson@netscape.com
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/*
Implementation for nsFixedSizeAllocator
*/
#include "nsCRT.h"
#include "nsFixedSizeAllocator.h"
nsFixedSizeAllocator::Bucket *
nsFixedSizeAllocator::AddBucket(size_t aSize)
{
void* p;
PL_ARENA_ALLOCATE(p, &mPool, sizeof(Bucket));
if (! p)
return nsnull;
Bucket* bucket = NS_STATIC_CAST(Bucket*, p);
bucket->mSize = aSize;
bucket->mFirst = nsnull;
bucket->mNext = mBuckets;
mBuckets = bucket;
return bucket;
}
nsresult
nsFixedSizeAllocator::Init(const char* aName,
const size_t* aBucketSizes,
PRInt32 aNumBuckets,
PRInt32 aInitialSize,
PRInt32 aAlign)
{
NS_PRECONDITION(aNumBuckets > 0, "no buckets");
if (aNumBuckets <= 0)
return NS_ERROR_INVALID_ARG;
// Blow away the old pool if we're being re-initialized.
if (mBuckets)
PL_FinishArenaPool(&mPool);
PRInt32 bucketspace = aNumBuckets * sizeof(Bucket);
PL_InitArenaPool(&mPool, aName, bucketspace + aInitialSize, aAlign);
mBuckets = nsnull;
for (PRInt32 i = 0; i < aNumBuckets; ++i)
AddBucket(aBucketSizes[i]);
return NS_OK;
}
nsFixedSizeAllocator::Bucket *
nsFixedSizeAllocator::FindBucket(size_t aSize)
{
Bucket** link = &mBuckets;
Bucket* bucket;
while ((bucket = *link) != nsnull) {
if (aSize == bucket->mSize) {
// Promote to the head of the list, under the assumption
// that we'll allocate same-sized object contemporaneously.
*link = bucket->mNext;
bucket->mNext = mBuckets;
mBuckets = bucket;
return bucket;
}
link = &bucket->mNext;
}
return nsnull;
}
void*
nsFixedSizeAllocator::Alloc(size_t aSize)
{
Bucket* bucket = FindBucket(aSize);
if (! bucket) {
// Oops, we don't carry that size. Let's fix that.
bucket = AddBucket(aSize);
if (! bucket)
return nsnull;
}
void* next;
if (bucket->mFirst) {
next = bucket->mFirst;
bucket->mFirst = bucket->mFirst->mNext;
}
else {
PL_ARENA_ALLOCATE(next, &mPool, aSize);
if (!next)
return nsnull;
}
#ifdef DEBUG
memset(next, 0xc8, aSize);
#endif
return next;
}
void
nsFixedSizeAllocator::Free(void* aPtr, size_t aSize)
{
FreeEntry* entry = NS_REINTERPRET_CAST(FreeEntry*, aPtr);
Bucket* bucket = FindBucket(aSize);
#ifdef DEBUG
NS_ASSERTION(bucket && bucket->mSize == aSize, "ack! corruption! bucket->mSize != aSize!");
memset(aPtr, 0xd8, bucket->mSize);
#endif
entry->mNext = bucket->mFirst;
bucket->mFirst = entry;
}
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