Updated boost to v1.55.0

[rsem.git] / boost / smart_ptr / detail / sp_counted_base_aix.hpp

diff --git a/boost/smart_ptr/detail/sp_counted_base_aix.hpp b/boost/smart_ptr/detail/sp_counted_base_aix.hpp
new file mode 100644 (file)
index 0000000..fe6c727
--- /dev/null
+++ b/boost/smart_ptr/detail/sp_counted_base_aix.hpp
@@ -0,0 +1,143 @@
+#ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_AIX_HPP_INCLUDED
+#define BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_AIX_HPP_INCLUDED
+
+//
+//  detail/sp_counted_base_aix.hpp
+//   based on: detail/sp_counted_base_w32.hpp
+//
+//  Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd.
+//  Copyright 2004-2005 Peter Dimov
+//  Copyright 2006 Michael van der Westhuizen
+//
+//  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)
+//
+//
+//  Lock-free algorithm by Alexander Terekhov
+//
+//  Thanks to Ben Hitchings for the #weak + (#shared != 0)
+//  formulation
+//
+
+#include <boost/detail/sp_typeinfo.hpp>
+#include <builtins.h>
+#include <sys/atomic_op.h>
+
+namespace boost
+{
+
+namespace detail
+{
+
+inline void atomic_increment( int32_t* pw )
+{
+    // ++*pw;
+
+    fetch_and_add( pw, 1 );
+}
+
+inline int32_t atomic_decrement( int32_t * pw )
+{
+    // return --*pw;
+
+    int32_t originalValue;
+
+    __lwsync();
+    originalValue = fetch_and_add( pw, -1 );
+    __isync();
+
+    return (originalValue - 1);
+}
+
+inline int32_t atomic_conditional_increment( int32_t * pw )
+{
+    // if( *pw != 0 ) ++*pw;
+    // return *pw;
+
+    int32_t tmp = fetch_and_add( pw, 0 );
+    for( ;; )
+    {
+        if( tmp == 0 ) return 0;
+        if( compare_and_swap( pw, &tmp, tmp + 1 ) ) return (tmp + 1);
+    }
+}
+
+class sp_counted_base
+{
+private:
+
+    sp_counted_base( sp_counted_base const & );
+    sp_counted_base & operator= ( sp_counted_base const & );
+
+    int32_t use_count_;        // #shared
+    int32_t weak_count_;       // #weak + (#shared != 0)
+
+public:
+
+    sp_counted_base(): use_count_( 1 ), weak_count_( 1 )
+    {
+    }
+
+    virtual ~sp_counted_base() // nothrow
+    {
+    }
+
+    // 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()
+    {
+        atomic_increment( &use_count_ );
+    }
+
+    bool add_ref_lock() // true on success
+    {
+        return atomic_conditional_increment( &use_count_ ) != 0;
+    }
+
+    void release() // nothrow
+    {
+        if( atomic_decrement( &use_count_ ) == 0 )
+        {
+            dispose();
+            weak_release();
+        }
+    }
+
+    void weak_add_ref() // nothrow
+    {
+        atomic_increment( &weak_count_ );
+    }
+
+    void weak_release() // nothrow
+    {
+        if( atomic_decrement( &weak_count_ ) == 0 )
+        {
+            destroy();
+        }
+    }
+
+    long use_count() const // nothrow
+    {
+        return fetch_and_add( const_cast<int32_t*>(&use_count_), 0 );
+    }
+};
+
+} // namespace detail
+
+} // namespace boost
+
+#endif  // #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_AIX_HPP_INCLUDED