1 // Copyright (c) 2008, Google Inc. 2 // All rights reserved. 3 // 4 // Redistribution and use in source and binary forms, with or without 5 // modification, are permitted provided that the following conditions are 6 // met: 7 // 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 11 // copyright notice, this list of conditions and the following disclaimer 12 // in the documentation and/or other materials provided with the 13 // distribution. 14 // * Neither the name of Google Inc. nor the names of its 15 // contributors may be used to endorse or promote products derived from 16 // this software without specific prior written permission. 17 // 18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 30 // --- 31 // Author: Sanjay Ghemawat <opensource (at) google.com> 32 33 #include <config.h> 34 #include "span.h" 35 36 #include <string.h> // for NULL, memset 37 38 #include "internal_logging.h" // for ASSERT 39 #include "page_heap_allocator.h" // for PageHeapAllocator 40 #include "static_vars.h" // for Static 41 42 namespace tcmalloc { 43 44 #ifdef SPAN_HISTORY 45 void Event(Span* span, char op, int v = 0) { 46 span->history[span->nexthistory] = op; 47 span->value[span->nexthistory] = v; 48 span->nexthistory++; 49 if (span->nexthistory == sizeof(span->history)) span->nexthistory = 0; 50 } 51 #endif 52 53 Span* NewSpan(PageID p, Length len) { 54 Span* result = Static::span_allocator()->New(); 55 memset(result, 0, sizeof(*result)); 56 result->start = p; 57 result->length = len; 58 #ifdef SPAN_HISTORY 59 result->nexthistory = 0; 60 #endif 61 return result; 62 } 63 64 void DeleteSpan(Span* span) { 65 #ifndef NDEBUG 66 // In debug mode, trash the contents of deleted Spans 67 memset(span, 0x3f, sizeof(*span)); 68 #endif 69 Static::span_allocator()->Delete(span); 70 } 71 72 void DLL_Init(Span* list) { 73 list->next = list; 74 list->prev = list; 75 } 76 77 void DLL_Remove(Span* span) { 78 span->prev->next = span->next; 79 span->next->prev = span->prev; 80 span->prev = NULL; 81 span->next = NULL; 82 } 83 84 int DLL_Length(const Span* list) { 85 int result = 0; 86 for (Span* s = list->next; s != list; s = s->next) { 87 result++; 88 } 89 return result; 90 } 91 92 void DLL_Prepend(Span* list, Span* span) { 93 ASSERT(span->next == NULL); 94 ASSERT(span->prev == NULL); 95 span->next = list->next; 96 span->prev = list; 97 list->next->prev = span; 98 list->next = span; 99 } 100 101 } // namespace tcmalloc 102
