// Copyright (c) 2008, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// ---
// Author: Sanjay Ghemawat <opensource@google.com>
//
// Some very basic linked list functions for dealing with using void * as
// storage.
#ifndef TCMALLOC_LINKED_LIST_H_
#define TCMALLOC_LINKED_LIST_H_
#include <stddef.h>
namespace tcmalloc {
inline void *SLL_Next(void *t) {
return *(reinterpret_cast<void**>(t));
}
inline void SLL_SetNext(void *t, void *n) {
*(reinterpret_cast<void**>(t)) = n;
}
inline void SLL_Push(void **list, void *element) {
SLL_SetNext(element, *list);
*list = element;
}
inline void *SLL_Pop(void **list) {
void *result = *list;
*list = SLL_Next(*list);
return result;
}
// Remove N elements from a linked list to which head points. head will be
// modified to point to the new head. start and end will point to the first
// and last nodes of the range. Note that end will point to NULL after this
// function is called.
inline void SLL_PopRange(void **head, int N, void **start, void **end) {
if (N == 0) {
*start = NULL;
*end = NULL;
return;
}
void *tmp = *head;
for (int i = 1; i < N; ++i) {
tmp = SLL_Next(tmp);
}
*start = *head;
*end = tmp;
*head = SLL_Next(tmp);
// Unlink range from list.
SLL_SetNext(tmp, NULL);
}
inline void SLL_PushRange(void **head, void *start, void *end) {
if (!start) return;
SLL_SetNext(end, *head);
*head = start;
}
inline size_t SLL_Size(void *head) {
int count = 0;
while (head) {
count++;
head = SLL_Next(head);
}
return count;
}
} // namespace tcmalloc
#endif // TCMALLOC_LINKED_LIST_H_