Add a new GetInstance() method for singleton classes, take 2.

base/global_descriptors_posix.h

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_GLOBAL_DESCRIPTORS_POSIX_H_
 #define BASE_GLOBAL_DESCRIPTORS_POSIX_H_
 #pragma once
 
 #include "build/build_config.h"
 
@@ skipping 23 matching lines @@
 // It maps from an abstract key to a descriptor. If independent modules each
 // need to define keys, then values should be chosen randomly so as not to
 // collide.
 class GlobalDescriptors {
  public:
   typedef uint32_t Key;
   // Often we want a canonical descriptor for a given Key. In this case, we add
   // the following constant to the key value:
   static const int kBaseDescriptor = 3;  // 0, 1, 2 are already taken.
 
+  // Returns a pointer to the singleton object constructed with default traits.
+  static GlobalDescriptors* GetInstance();

[M-A Ruel, 2010/12/07 17:32:21]

You realize that you're creating two objects here? Why not just use the Leaky
one? The other one is for unit tests? If so, just put one of them in #if
defined(UNIT_TEST)

[Satish, 2010/12/07 17:45:27]

The leaky instance is created in src/chrome/app/chrome_main:LowLevelInit() for
mac and linux, so that lives through the lifetime of the app. In addition to
this various places in the code create the GlobalDescriptors singleton with
default traits. I have not modified this behavior as it looks to be done
intentionally, instead just added these 2 methods to wrap around them.

[M-A Ruel, 2010/12/07 17:49:17]

Ok, adding Evan to know if it was intentional.

[Evan Martin, 2010/12/07 17:55:16]

Ugh, no, this was definitely not intentional.  :(
Please let me fix the mess, and don't propagate it here.

+
+  // Returns a pointer to the singleton object constructed with leaky traits,
+  // i.e. one which won't be freed on shutdown.
+  static GlobalDescriptors* GetLeakyInstance();
+
   // Get a descriptor given a key. It is a fatal error if the key is not known.
   int Get(Key key) const;
   // Get a descriptor give a key. Returns -1 on error.
   int MaybeGet(Key key) const;
 
   typedef std::vector<std::pair<Key, int> > Mapping;
 
   // Set the descriptor for the given key.
   void Set(Key key, int fd);
 
   void Reset(const Mapping& mapping) {
     descriptors_ = mapping;
   }
 
  private:
   GlobalDescriptors();
   ~GlobalDescriptors();
   friend struct DefaultSingletonTraits<GlobalDescriptors>;
 
   Mapping descriptors_;
 };
 
 }  // namespace base
 
 #endif  // BASE_GLOBAL_DESCRIPTORS_POSIX_H_