text: #ifndef AUTOBOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_PT_HPP_INCLUDED
  #define AUTOBOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_PT_HPP_INCLUDED
  
  // MS compatible compilers support #pragma once
  
  #if defined(_MSC_VER) && (_MSC_VER >= 1020)
  # pragma once
  #endif
  
  //
  //  detail/sp_counted_base_pt.hpp
  //
  //  Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd.
  //  Copyright 2004-2005 Peter Dimov
  //
  // Distributed under the Boost Software License, Version 1.0. (See
  // accompanying file LICENSE_1_0.txt or copy at
  // http://www.boost.org/LICENSE_1_0.txt)
  //
  
  #include <autoboost/detail/sp_typeinfo.hpp>
  #include <autoboost/assert.hpp>
  #include <pthread.h>
  
  namespace autoboost
  {
  
  namespace detail
  {
  
  class sp_counted_base
  {
  private:
  
      sp_counted_base( sp_counted_base const & );
      sp_counted_base & operator= ( sp_counted_base const & );
  
      long use_count_;        // #shared
      long weak_count_;       // #weak + (#shared != 0)
  
      mutable pthread_mutex_t m_;
  
  public:
  
      sp_counted_base(): use_count_( 1 ), weak_count_( 1 )
      {
  // HPUX 10.20 / DCE has a nonstandard pthread_mutex_init
  
  #if defined(__hpux) && defined(_DECTHREADS_)
          AUTOBOOST_VERIFY( pthread_mutex_init( &m_, pthread_mutexattr_default ) == 0 );
  #else
          AUTOBOOST_VERIFY( pthread_mutex_init( &m_, 0 ) == 0 );
  #endif
      }
  
      virtual ~sp_counted_base() // nothrow
      {
          AUTOBOOST_VERIFY( pthread_mutex_destroy( &m_ ) == 0 );
      }
  
      // dispose() is called when use_count_ drops to zero, to release
      // the resources managed by *this.
  
      virtual void dispose() = 0; // nothrow
  
      // destroy() is called when weak_count_ drops to zero.
  
      virtual void destroy() // nothrow
      {
          delete this;
      }
  
      virtual void * get_deleter( sp_typeinfo const & ti ) = 0;
      virtual void * get_untyped_deleter() = 0;
  
      void add_ref_copy()
      {
          AUTOBOOST_VERIFY( pthread_mutex_lock( &m_ ) == 0 );
          ++use_count_;
          AUTOBOOST_VERIFY( pthread_mutex_unlock( &m_ ) == 0 );
      }
  
      bool add_ref_lock() // true on success
      {
          AUTOBOOST_VERIFY( pthread_mutex_lock( &m_ ) == 0 );
          bool r = use_count_ == 0? false: ( ++use_count_, true );
          AUTOBOOST_VERIFY( pthread_mutex_unlock( &m_ ) == 0 );
          return r;
      }
  
      void release() // nothrow
      {
          AUTOBOOST_VERIFY( pthread_mutex_lock( &m_ ) == 0 );
          long new_use_count = --use_count_;
          AUTOBOOST_VERIFY( pthread_mutex_unlock( &m_ ) == 0 );
  
          if( new_use_count == 0 )
          {
              dispose();
              weak_release();
          }
      }
  
      void weak_add_ref() // nothrow
      {
          AUTOBOOST_VERIFY( pthread_mutex_lock( &m_ ) == 0 );
          ++weak_count_;
          AUTOBOOST_VERIFY( pthread_mutex_unlock( &m_ ) == 0 );
      }
  
      void weak_release() // nothrow
      {
          AUTOBOOST_VERIFY( pthread_mutex_lock( &m_ ) == 0 );
          long new_weak_count = --weak_count_;
          AUTOBOOST_VERIFY( pthread_mutex_unlock( &m_ ) == 0 );
  
          if( new_weak_count == 0 )
          {
              destroy();
          }
      }
  
      long use_count() const // nothrow
      {
          AUTOBOOST_VERIFY( pthread_mutex_lock( &m_ ) == 0 );
          long r = use_count_;
          AUTOBOOST_VERIFY( pthread_mutex_unlock( &m_ ) == 0 );
  
          return r;
      }
  };
  
  } // namespace detail
  
  } // namespace autoboost
  
  #endif  // #ifndef AUTOBOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_PT_HPP_INCLUDED
  