[Ace-users] [tao-bugs] Crash in TAO_ORB_Core_Static_Resources::instance()

[J.T. Conklin]

    TAO VERSION: 1.6.1 (2007-10-29 svn snapshot)
    ACE VERSION: 5.6.1

    HOST MACHINE and OPERATING SYSTEM:

NetBSD orac.acorntoolworks.com 3.0_STABLE NetBSD 3.0_STABLE (ORAC) #0: Tue Feb 21 20:05:51 PST 2006  jtc at orac.acorntoolworks.com:/home/jtc/netbsd/NetBSD-3/src/sys/arch/i386/compile/ORAC i386

    TARGET MACHINE and OPERATING SYSTEM, if different from HOST:

NetBSD orac.acorntoolworks.com 3.0_STABLE NetBSD 3.0_STABLE (ORAC) #0: Tue Feb 21 20:05:51 PST 2006  jtc at orac.acorntoolworks.com:/home/jtc/netbsd/NetBSD-3/src/sys/arch/i386/compile/ORAC i386

    COMPILER NAME AND VERSION (AND PATCHLEVEL):

gcc version 3.3.3 (NetBSD nb3 20040520)

    THE $ACE_ROOT/ace/config.h FILE [if you use a link to a platform-
    specific file, simply state which one]:

config-netbsd.h

    THE $ACE_ROOT/include/makeinclude/platform_macros.GNU FILE [if you
    use a link to a platform-specific file, simply state which one
    (unless this isn't used in this case, e.g., with Microsoft Visual
    C++)]:

platform_netbsd.GNU

    CONTENTS OF $ACE_ROOT/bin/MakeProjectCreator/config/default.features
    (used by MPC when you generate your own makefiles):

N/A

    AREA/CLASS/EXAMPLE AFFECTED:

TAO_ORB_Core_Static_Resources::instance()

    DOES THE PROBLEM AFFECT:
        EXECUTION

    SYNOPSIS:

Core dump in TAO_ORB_Core_Static_Resources::instance()

    DESCRIPTION:

While the TAO unit tests look pretty good on my platform, many of my 
own applications dump core in a static constructor when initializing 
TAO_ORB_Core_Static_Resources::initialization_reference_ via the 
TAO_ORB_Core_Static_Resources::instance() factory method.

    TAO_ORB_Core_Static_Resources*
    TAO_ORB_Core_Static_Resources::instance (void)
    {
      ACE_Service_Gestalt *current = ACE_Service_Config::current();
      TAO_ORB_Core_Static_Resources* tocsr =
	ACE_Dynamic_Service<TAO_ORB_Core_Static_Resources>::instance
	(current,"TAO_ORB_Core_Static_Resources",true);

      if (tocsr == 0)
	{
	  // This new is never freed on purpose.  The data specified by
	  // it needs to be around for the last shared library that references
	  // this class.  This could occur in a destructor in a shared library
	  // that is unloaded after this one.  One solution to avoid this
	  // harmless memory leak would be to use reference counting.
	  current->process_directive(ace_svc_desc_TAO_ORB_Core_Static_Resources);
	  tocsr = ACE_Dynamic_Service<TAO_ORB_Core_Static_Resources>::instance
	    (current,"TAO_ORB_Core_Static_Resources",true);

	  ACE_Service_Gestalt *global = ACE_Service_Config::global();
	  if (current != global)
	    {
	      TAO_ORB_Core_Static_Resources* global_tocsr =
		ACE_Dynamic_Service<TAO_ORB_Core_Static_Resources>::instance
		(global,"TAO_ORB_Core_Static_Resources");
	      *tocsr = *global_tocsr;
	    }
	}

      //  return TAO_ORB_Core_Static_Resources::instance_;
      return tocsr;
    }

The crash occurs in the "*tocsr = *global_tocsr" assignment.  It appears 
that instance() method has been called on a non-global gestalt before it
was called on the global one.  So global_tocsr is null, and the assignment
fails when the fields are copied.

I'm not familiar with the new gestalt code, so I don't know whether an
invarient that requires that the global gestalt be initialized first
is being violated, or whether the ctor initialization order has
exposed a bug.  I'm also not clear to me what the purpose of the local
tocsr being initialized from the global_tocsr.  I forced to guess, I'd
say the intent is for the global one to be initialized first, possibly
modified, and ->process_directive() is called to create the gestalt, but 
the intent is to overwrite it.  But even that seems to assume ordering
of the initial creation of the global_toscr, it's initialization, and
the creation of "current" toscr's that doesn't seem manifest in the code.
But like I said, I'm not familiar with the gestalt code.

    REPEAT BY:

No test case yet.

    SAMPLE FIX/WORKAROUND:

-- 
J.T. Conklin