Implement ShutdownProtobufLibrary().

By popular demand, implement a way to shut down the C++ protobuf library, deleting all dynamically-allocated global objects.  I tested this using google-perftools' heapchecker with HEAPCHECK=draconian.

[kenton, 2009-04-29 01:54:16]

Hi Jason,

I'd like you to do a code review.

I implemented this directly against the open source release since it's primarily
requested by open source users.

[jasonh, 2009-05-06 01:03:13]

Sorry about the delay. Mostly looks good, just a few nits

http://codereview.appspot.com/53053/diff/1/5
File google/protobuf/compiler/cpp/cpp_file.cc (right):

http://codereview.appspot.com/53053/diff/1/5#newcode401
Line 401: 
Indent() for prettier generated code?

http://codereview.appspot.com/53053/diff/1/6
File google/protobuf/compiler/cpp/cpp_message.cc (right):

http://codereview.appspot.com/53053/diff/1/6#newcode608
Line 608: "delete $classname$::default_instance_;\n"
Set these to NULL for consistency with other parts of the library?

http://codereview.appspot.com/53053/diff/1/13
File google/protobuf/extension_set.cc (right):

http://codereview.appspot.com/53053/diff/1/13#newcode84
Line 84: delete registry_;
registry_ = NULL;?

http://codereview.appspot.com/53053/diff/1/9
File google/protobuf/stubs/common.cc (right):

http://codereview.appspot.com/53053/diff/1/9#newcode323
Line 323: // We don't need to lock shutdown_fucntions_mutex because it's up to
the
s/fucntions/functions/

[kenton, 2009-05-06 19:05:36]

Addressed comments (see below) and synced, new patch set uploaded.

http://codereview.appspot.com/53053/diff/1/5
File google/protobuf/compiler/cpp/cpp_file.cc (right):

http://codereview.appspot.com/53053/diff/1/5#newcode401
Line 401: 
On 2009/05/06 01:03:14, jasonh wrote:
> Indent() for prettier generated code?

Done.

http://codereview.appspot.com/53053/diff/1/6
File google/protobuf/compiler/cpp/cpp_message.cc (right):

http://codereview.appspot.com/53053/diff/1/6#newcode608
Line 608: "delete $classname$::default_instance_;\n"
On 2009/05/06 01:03:14, jasonh wrote:
> Set these to NULL for consistency with other parts of the library?

I figured I'd skip it and save some bytes of code size.

http://codereview.appspot.com/53053/diff/1/13
File google/protobuf/extension_set.cc (right):

http://codereview.appspot.com/53053/diff/1/13#newcode84
Line 84: delete registry_;
On 2009/05/06 01:03:14, jasonh wrote:
> registry_ = NULL;?

Done.

http://codereview.appspot.com/53053/diff/1/9
File google/protobuf/stubs/common.cc (right):

http://codereview.appspot.com/53053/diff/1/9#newcode323
Line 323: // We don't need to lock shutdown_fucntions_mutex because it's up to
the
On 2009/05/06 01:03:14, jasonh wrote:
> s/fucntions/functions/

Done.

[jasonh, 2009-05-06 19:26:14]

Looks good!

On 2009/05/06 19:05:36, kenton wrote:
> Addressed comments (see below) and synced, new patch set uploaded.
> 
> http://codereview.appspot.com/53053/diff/1/5
> File google/protobuf/compiler/cpp/cpp_file.cc (right):
> 
> http://codereview.appspot.com/53053/diff/1/5#newcode401
> Line 401: 
> On 2009/05/06 01:03:14, jasonh wrote:
> > Indent() for prettier generated code?
> 
> Done.
> 
> http://codereview.appspot.com/53053/diff/1/6
> File google/protobuf/compiler/cpp/cpp_message.cc (right):
> 
> http://codereview.appspot.com/53053/diff/1/6#newcode608
> Line 608: "delete $classname$::default_instance_;\n"
> On 2009/05/06 01:03:14, jasonh wrote:
> > Set these to NULL for consistency with other parts of the library?
> 
> I figured I'd skip it and save some bytes of code size.
> 
> http://codereview.appspot.com/53053/diff/1/13
> File google/protobuf/extension_set.cc (right):
> 
> http://codereview.appspot.com/53053/diff/1/13#newcode84
> Line 84: delete registry_;
> On 2009/05/06 01:03:14, jasonh wrote:
> > registry_ = NULL;?
> 
> Done.
> 
> http://codereview.appspot.com/53053/diff/1/9
> File google/protobuf/stubs/common.cc (right):
> 
> http://codereview.appspot.com/53053/diff/1/9#newcode323
> Line 323: // We don't need to lock shutdown_fucntions_mutex because it's up to
> the
> On 2009/05/06 01:03:14, jasonh wrote:
> > s/fucntions/functions/
> 
> Done.