third_party/tcmalloc/chromium/src/free_list.h

// Copyright (c) 2011, Google Inc.
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// --- 
// Author: Rebecca Shapiro <bxx@google.com>
//
// This file contains declarations of functions that implement doubly
// linked lists and definitions of functions that implement singly
// linked lists.  It also contains macros to tell the SizeMap class
// how much space a node in the freelist needs so that SizeMap can
// create large enough size classes.

#ifndef TCMALLOC_FREE_LIST_H_
#define TCMALLOC_FREE_LIST_H_

#include <stddef.h>
#include "internal_logging.h"
#include "linked_list.h"

// Remove to enable singly linked lists (the default for open source tcmalloc).
#define TCMALLOC_USE_DOUBLYLINKED_FREELIST

namespace tcmalloc {

#if defined(TCMALLOC_USE_DOUBLYLINKED_FREELIST)

// size class information for common.h.
static const bool kSupportsDoublyLinkedList = true;

void *FL_Next(void *t);
void FL_Init(void *t);
void FL_Push(void **list, void *element);
void *FL_Pop(void **list);
void FL_PopRange(void **head, int n, void **start, void **end);
void FL_PushRange(void **head, void *start, void *end);
size_t FL_Size(void *head);

#else // TCMALLOC_USE_DOUBLYLINKED_FREELIST not defined
static const bool kSupportsDoublyLinkedList = false;

inline void *FL_Next(void *t) {
  return SLL_Next(t);
}

inline void FL_Init(void *t) {
  SLL_SetNext(t, NULL);
}

inline void FL_Push(void **list, void *element) {
  if(*list != element) {
    SLL_Push(list,element);
    return;
  }
  Log(kCrash, __FILE__, __LINE__, "Double Free of %p detected", element);
}

inline void *FL_Pop(void **list) {
  return SLL_Pop(list);
}

// Removes |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 FL_PopRange(void **head, int n, void **start, void **end) {
  SLL_PopRange(head, n, start, end);
}

inline void FL_PushRange(void **head, void *start, void *end) {
  SLL_PushRange(head,start,end);
}

inline size_t FL_Size(void *head) {
  return SLL_Size(head);
}

#endif // TCMALLOC_USE_DOUBLYLINKED_FREELIST

} // namespace tcmalloc

#endif // TCMALLOC_FREE_LIST_H_