// 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
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// 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,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// 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>
#include <config.h>
#include "span.h"
#include <string.h> // for NULL, memset
#include "internal_logging.h" // for ASSERT
#include "page_heap_allocator.h" // for PageHeapAllocator
#include "static_vars.h" // for Static
namespace tcmalloc {
#ifdef SPAN_HISTORY
void Event(Span* span, char op, int v = 0) {
span->history[span->nexthistory] = op;
span->value[span->nexthistory] = v;
span->nexthistory++;
if (span->nexthistory == sizeof(span->history)) span->nexthistory = 0;
}
#endif
Span* NewSpan(PageID p, Length len) {
Span* result = Static::span_allocator()->New();
memset(result, 0, sizeof(*result));
result->start = p;
result->length = len;
#ifdef SPAN_HISTORY
result->nexthistory = 0;
#endif
return result;
}
void DeleteSpan(Span* span) {
#ifndef NDEBUG
// In debug mode, trash the contents of deleted Spans
memset(span, 0x3f, sizeof(*span));
#endif
Static::span_allocator()->Delete(span);
}
void DLL_Init(Span* list) {
list->next = list;
list->prev = list;
}
void DLL_Remove(Span* span) {
span->prev->next = span->next;
span->next->prev = span->prev;
span->prev = NULL;
span->next = NULL;
}
int DLL_Length(const Span* list) {
int result = 0;
for (Span* s = list->next; s != list; s = s->next) {
result++;
}
return result;
}
void DLL_Prepend(Span* list, Span* span) {
ASSERT(span->next == NULL);
ASSERT(span->prev == NULL);
span->next = list->next;
span->prev = list;
list->next->prev = span;
list->next = span;
}
} // namespace tcmalloc