Add base to the repository.

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@8 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 129 insertions, 0 deletions

diff --git a/base/tracked.h b/base/tracked.h
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+++ b/base/tracked.h
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+// Copyright 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.
+
+//------------------------------------------------------------------------------
+// Tracked is the base class for all tracked objects.  During construction, it
+// registers the fact that an instance was created, and at destruction time, it
+// records that event.  The instance may be tagged with a name, which is refered
+// to as its Location.  The Location is a file and line number, most
+// typically indicated where the object was constructed.  In some cases, as the
+// object's significance is refined (for example, a Task object is augmented to
+// do additonal things), its Location may be redefined to that later location.
+
+// Tracking includes (for each instance) recording the birth thread, death
+// thread, and duration of life (from construction to destruction).  All this
+// data is accumulated and filtered for review at about:objects.
+
+#ifndef BASE_TRACKED_H__
+#define BASE_TRACKED_H__
+
+#include <string>
+
+#include "base/time.h"
+
+#ifndef NDEBUG
+#define TRACK_ALL_TASK_OBJECTS
+#endif
+
+namespace tracked_objects {
+
+//------------------------------------------------------------------------------
+// Location provides basic info where of an object was constructed, or was
+// significantly brought to life.
+
+class Location {
+ public:
+  // Constructor should be called with a long-lived char*, such as __FILE__.
+  // It assumes the provided value will persist as a global constant, and it
+  // will not make a copy of it.
+  Location(const char* function_name, const char* file_name, int line_number)
+      : function_name_(function_name),
+        file_name_(file_name),
+        line_number_(line_number) { }
+
+  // Provide a default constructor for easy of debugging.
+  Location()
+      : function_name_("Unknown"),
+        file_name_("Unknown"),
+        line_number_(-1) { }
+
+  // Comparison operator for insertion into a std::map<> hash tables.
+  // All we need is *some* (any) hashing distinction.  Strings should already
+  // be unique, so we don't bother with strcmp or such.
+  // Use line number as the primary key (because it is fast, and usually gets us
+  // a difference), and then pointers as secondary keys (just to get some
+  // distinctions).
+  bool operator < (const Location& other) const {
+    if (line_number_ != other.line_number_)
+      return line_number_ < other.line_number_;
+    if (file_name_ != other.file_name_)
+      return file_name_ != other.file_name_;
+    return function_name_ < other.function_name_;
+  }
+
+  const char* function_name() const { return function_name_; }
+  const char* file_name()     const { return file_name_; }
+  int line_number()           const { return line_number_; }
+
+  void Write(bool display_filename, bool display_function_name,
+           std::string* output) const;
+
+  // Write function_name_ in HTML with '<' and '>' properly encoded.
+  void WriteFunctionName(std::string* output) const;
+
+ private:
+  const char* const function_name_;
+  const char* const file_name_;
+  const int line_number_;
+};
+
+
+//------------------------------------------------------------------------------
+
+
+class Births;
+
+class Tracked {
+ public:
+  Tracked();
+  virtual ~Tracked();
+  void SetBirthPlace(const Location& from_here);
+
+  bool MissingBirthplace() const;
+
+ private:
+  Births* tracked_births_;  // At same birthplace, and same thread.
+  const Time tracked_birth_time_;
+
+  DISALLOW_EVIL_CONSTRUCTORS(Tracked);
+};
+
+}  // namespace tracked_objects
+
+#endif  // BASE_TRACKED_H__