Upgrade gperftools to 2.9 for GCP/GMC/GMP/GMD. (#2247)

trunk/3rdparty/gperftools-2-fit/src/span.h

@@ -0,0 +1,161 @@
+// -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*-
+// 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>
+//
+// A Span is a contiguous run of pages.
+
+#ifndef TCMALLOC_SPAN_H_
+#define TCMALLOC_SPAN_H_
+
+#include <config.h>
+#include <set>
+#include "common.h"
+#include "base/logging.h"
+#include "page_heap_allocator.h"
+
+namespace tcmalloc {
+
+struct SpanBestFitLess;
+struct Span;
+
+// Store a pointer to a span along with a cached copy of its length.
+// These are used as set elements to improve the performance of
+// comparisons during tree traversal: the lengths are inline with the
+// tree nodes and thus avoid expensive cache misses to dereference
+// the actual Span objects in most cases.
+struct SpanPtrWithLength {
+  explicit SpanPtrWithLength(Span* s);
+
+  Span* span;
+  Length length;
+};
+typedef std::set<SpanPtrWithLength, SpanBestFitLess, STLPageHeapAllocator<SpanPtrWithLength, void> > SpanSet;
+
+// Comparator for best-fit search, with address order as a tie-breaker.
+struct SpanBestFitLess {
+  bool operator()(SpanPtrWithLength a, SpanPtrWithLength b) const;
+};
+
+// Information kept for a span (a contiguous run of pages).
+struct Span {
+  PageID        start;          // Starting page number
+  Length        length;         // Number of pages in span
+  Span*         next;           // Used when in link list
+  Span*         prev;           // Used when in link list
+  union {
+    void* objects;              // Linked list of free objects
+
+    // Span may contain iterator pointing back at SpanSet entry of
+    // this span into set of large spans. It is used to quickly delete
+    // spans from those sets. span_iter_space is space for such
+    // iterator which lifetime is controlled explicitly.
+    char span_iter_space[sizeof(SpanSet::iterator)];
+  };
+  unsigned int  refcount : 16;  // Number of non-free objects
+  unsigned int  sizeclass : 8;  // Size-class for small objects (or 0)
+  unsigned int  location : 2;   // Is the span on a freelist, and if so, which?
+  unsigned int  sample : 1;     // Sampled object?
+  bool          has_span_iter : 1; // Iff span_iter_space has valid
+                                   // iterator. Only for debug builds.
+
+  // Sets iterator stored in span_iter_space.
+  // Requires has_span_iter == 0.
+  void SetSpanSetIterator(const SpanSet::iterator& iter);
+  // Copies out and destroys iterator stored in span_iter_space.
+  SpanSet::iterator ExtractSpanSetIterator();
+
+  // What freelist the span is on: IN_USE if on none, or normal or returned
+  enum { IN_USE, ON_NORMAL_FREELIST, ON_RETURNED_FREELIST };
+};
+
+inline SpanPtrWithLength::SpanPtrWithLength(Span* s)
+    : span(s),
+      length(s->length) {
+}
+
+inline bool SpanBestFitLess::operator()(SpanPtrWithLength a, SpanPtrWithLength b) const {
+  if (a.length < b.length)
+    return true;
+  if (a.length > b.length)
+    return false;
+  return a.span->start < b.span->start;
+}
+
+inline void Span::SetSpanSetIterator(const SpanSet::iterator& iter) {
+  ASSERT(!has_span_iter);
+  has_span_iter = 1;
+
+  new (span_iter_space) SpanSet::iterator(iter);
+}
+
+inline SpanSet::iterator Span::ExtractSpanSetIterator() {
+  typedef SpanSet::iterator iterator_type;
+
+  ASSERT(has_span_iter);
+  has_span_iter = 0;
+
+  iterator_type* this_iter =
+    reinterpret_cast<iterator_type*>(span_iter_space);
+  iterator_type retval = *this_iter;
+  this_iter->~iterator_type();
+  return retval;
+}
+
+// Allocator/deallocator for spans
+Span* NewSpan(PageID p, Length len);
+void DeleteSpan(Span* span);
+
+// -------------------------------------------------------------------------
+// Doubly linked list of spans.
+// -------------------------------------------------------------------------
+
+// Initialize *list to an empty list.
+void DLL_Init(Span* list);
+
+// Remove 'span' from the linked list in which it resides, updating the
+// pointers of adjacent Spans and setting span's next and prev to NULL.
+void DLL_Remove(Span* span);
+
+// Return true iff "list" is empty.
+inline bool DLL_IsEmpty(const Span* list) {
+  return list->next == list;
+}
+
+// Add span to the front of list.
+void DLL_Prepend(Span* list, Span* span);
+
+// Return the length of the linked list. O(n)
+int DLL_Length(const Span* list);
+
+}  // namespace tcmalloc
+
+#endif  // TCMALLOC_SPAN_H_