1 /*
2 * Copyright (C) 2010 The Android Open Source Project
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
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <list>
30
31 namespace android {
32
swap(ListNodeBase & a,ListNodeBase & b)33 void ListNodeBase::swap(ListNodeBase& a, ListNodeBase& b) {
34 if (a.mNext != &a) {
35 if (b.mNext != &b) {
36 // a and b are not empty.
37 std::swap(a.mNext, b.mNext);
38 std::swap(a.mPrev, b.mPrev);
39 a.mNext->mPrev = a.mPrev->mNext = &a;
40 b.mNext->mPrev = b.mPrev->mNext = &b;
41 } else {
42 // a not empty but b is.
43 b.mNext = a.mNext;
44 b.mPrev = a.mPrev;
45 b.mNext->mPrev = b.mPrev->mNext = &b;
46 a.mNext = a.mPrev = &a; // empty a
47 }
48 } else if (b.mNext != &b) {
49 // a is empty but b is not.
50 a.mNext = b.mNext;
51 a.mPrev = b.mPrev;
52 a.mNext->mPrev = a.mPrev->mNext = &a;
53 b.mNext = b.mPrev = &b; // empty b
54 }
55 }
56
hook(ListNodeBase * const pos)57 void ListNodeBase::hook(ListNodeBase *const pos) {
58 mNext = pos;
59 mPrev = pos->mPrev;
60 pos->mPrev->mNext = this;
61 pos->mPrev = this;
62 }
63
unhook()64 void ListNodeBase::unhook() {
65 ListNodeBase *const next = mNext;
66 ListNodeBase *const prev = mPrev;
67 prev->mNext = next;
68 next->mPrev = prev;
69 }
70
71 } // namespace android
72