Merged revision(s) 72437 from trunk: Lock-free sp_counted_base for SNC/PS3, thanks Peter Dimov

[SVN r81898]

include/boost/smart_ptr/detail/sp_counted_base.hpp

@@ -32,6 +32,9 @@
 #elif defined( BOOST_DISABLE_THREADS ) && !defined( BOOST_SP_ENABLE_THREADS ) && !defined( BOOST_DISABLE_WIN32 )
 # include <boost/smart_ptr/detail/sp_counted_base_nt.hpp>
 
+#elif defined( __SNC__ )
+# include <boost/smart_ptr/detail/sp_counted_base_snc_ps3.hpp>
+
 #elif defined( __GNUC__ ) && ( defined( __i386__ ) || defined( __x86_64__ ) ) && !defined(__PATHSCALE__)
 # include <boost/smart_ptr/detail/sp_counted_base_gcc_x86.hpp>
 

include/boost/smart_ptr/detail/sp_counted_base_snc_ps3.hpp

@@ -0,0 +1,161 @@
+#ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_SNC_PS3_HPP_INCLUDED
+#define BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_SNC_PS3_HPP_INCLUDED
+
+// MS compatible compilers support #pragma once
+#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+# pragma once
+#endif
+
+//  detail/sp_counted_base_gcc_sparc.hpp - g++ on Sparc V8+
+//
+//  Copyright (c) 2006 Piotr Wyderski
+//  Copyright (c) 2006 Tomas Puverle
+//  Copyright (c) 2006 Peter Dimov
+//  Copyright (c) 2011 Emil Dotchevski
+//
+//  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
+//
+//  Thanks to Michael van der Westhuizen
+
+#include <boost/detail/sp_typeinfo.hpp>
+#include <inttypes.h> // uint32_t
+
+namespace boost
+{
+
+namespace detail
+{
+
+inline uint32_t compare_and_swap( uint32_t * dest_, uint32_t compare_, uint32_t swap_ )
+{
+	return __builtin_cellAtomicCompareAndSwap32(dest_,compare_,swap_);
+}
+
+inline uint32_t atomic_fetch_and_add( uint32_t * pw, uint32_t dv )
+{
+    // long r = *pw;
+    // *pw += dv;
+    // return r;
+
+    for( ;; )
+    {
+        uint32_t r = *pw;
+
+        if( __builtin_expect((compare_and_swap(pw, r, r + dv) == r), 1) )
+        {
+            return r;
+        }
+    }
+}
+
+inline void atomic_increment( uint32_t * pw )
+{
+    (void) __builtin_cellAtomicIncr32( pw );
+}
+
+inline uint32_t atomic_decrement( uint32_t * pw )
+{
+    return __builtin_cellAtomicDecr32( pw );
+}
+
+inline uint32_t atomic_conditional_increment( uint32_t * pw )
+{
+    // long r = *pw;
+    // if( r != 0 ) ++*pw;
+    // return r;
+
+    for( ;; )
+    {
+        uint32_t r = *pw;
+
+        if( r == 0 )
+        {
+            return r;
+        }
+
+        if( __builtin_expect( ( compare_and_swap( pw, r, r + 1 ) == r ), 1 ) )
+        {
+            return r;
+        }
+    }    
+}
+
+class sp_counted_base
+{
+private:
+
+    sp_counted_base( sp_counted_base const & );
+    sp_counted_base & operator= ( sp_counted_base const & );
+
+    uint32_t use_count_;        // #shared
+    uint32_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;
+
+    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_ ) == 1 )
+        {
+            dispose();
+            weak_release();
+        }
+    }
+
+    void weak_add_ref() // nothrow
+    {
+        atomic_increment( &weak_count_ );
+    }
+
+    void weak_release() // nothrow
+    {
+        if( atomic_decrement( &weak_count_ ) == 1 )
+        {
+            destroy();
+        }
+    }
+
+    long use_count() const // nothrow
+    {
+        return const_cast< uint32_t const volatile & >( use_count_ );
+    }
+};
+
+} // namespace detail
+
+} // namespace boost
+
+#endif  // #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_SNC_PS3_HPP_INCLUDED