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
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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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