15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Copyright (c) 2008, Google Inc. 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// All rights reserved. 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Redistribution and use in source and binary forms, with or without 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// modification, are permitted provided that the following conditions are 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// met: 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// * Redistributions of source code must retain the above copyright 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// notice, this list of conditions and the following disclaimer. 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// * Redistributions in binary form must reproduce the above 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// copyright notice, this list of conditions and the following disclaimer 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// in the documentation and/or other materials provided with the 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// distribution. 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// * Neither the name of Google Inc. nor the names of its 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// contributors may be used to endorse or promote products derived from 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// this software without specific prior written permission. 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// --- 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Author: Sanjay Ghemawat <opensource@google.com> 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// A Span is a contiguous run of pages. 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#ifndef TCMALLOC_SPAN_H_ 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#define TCMALLOC_SPAN_H_ 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <config.h> 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "common.h" 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace tcmalloc { 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Information kept for a span (a contiguous run of pages). 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)struct Span { 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) PageID start; // Starting page number 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Length length; // Number of pages in span 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Span* next; // Used when in link list 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Span* prev; // Used when in link list 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void* objects; // Linked list of free objects 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) unsigned int refcount : 16; // Number of non-free objects 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) unsigned int sizeclass : 8; // Size-class for small objects (or 0) 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) unsigned int location : 2; // Is the span on a freelist, and if so, which? 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) unsigned int sample : 1; // Sampled object? 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#undef SPAN_HISTORY 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#ifdef SPAN_HISTORY 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // For debugging, we can keep a log events per span 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int nexthistory; 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) char history[64]; 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int value[64]; 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // What freelist the span is on: IN_USE if on none, or normal or returned 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) enum { IN_USE, ON_NORMAL_FREELIST, ON_RETURNED_FREELIST }; 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#ifdef SPAN_HISTORY 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void Event(Span* span, char op, int v = 0); 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#else 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#define Event(s,o,v) ((void) 0) 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Allocator/deallocator for spans 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)Span* NewSpan(PageID p, Length len); 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void DeleteSpan(Span* span); 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// ------------------------------------------------------------------------- 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Doubly linked list of spans. 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// ------------------------------------------------------------------------- 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Initialize *list to an empty list. 825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void DLL_Init(Span* list); 835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Remove 'span' from the linked list in which it resides, updating the 855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// pointers of adjacent Spans and setting span's next and prev to NULL. 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void DLL_Remove(Span* span); 875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Return true iff "list" is empty. 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)inline bool DLL_IsEmpty(const Span* list) { 905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return list->next == list; 915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Add span to the front of list. 945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void DLL_Prepend(Span* list, Span* span); 955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Return the length of the linked list. O(n) 975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)int DLL_Length(const Span* list); 985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace tcmalloc 1005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif // TCMALLOC_SPAN_H_ 102