[Boost-commit] svn:boost r54460 - in sandbox/monotonic/boost: heterogenous monotonic

Subject: [Boost-commit] svn:boost r54460 - in sandbox/monotonic/boost: heterogenous monotonic
From: christian.schladetsch_at_[hidden]
Date: 2009-06-28 05:18:39

Author: cschladetsch
Date: 2009-06-28 05:18:38 EDT (Sun, 28 Jun 2009)
New Revision: 54460
URL: http://svn.boost.org/trac/boost/changeset/54460

Log:
added alignment parameter to deallocate, so it can adjust back any padding added in allocate

Text files modified: 
   sandbox/monotonic/boost/heterogenous/abstract_allocator.hpp   |    11 ++++++++++-                             
   sandbox/monotonic/boost/heterogenous/base.hpp                 |     2 +-                                      
   sandbox/monotonic/boost/heterogenous/make_clone_allocator.hpp |    20 +++++++++++++++-----                    
   sandbox/monotonic/boost/monotonic/allocator_base.hpp          |     4 ++--                                    
   4 files changed, 28 insertions(+), 9 deletions(-)

Modified: sandbox/monotonic/boost/heterogenous/abstract_allocator.hpp
==============================================================================
--- sandbox/monotonic/boost/heterogenous/abstract_allocator.hpp	(original)
+++ sandbox/monotonic/boost/heterogenous/abstract_allocator.hpp	2009-06-28 05:18:38 EDT (Sun, 28 Jun 2009)
@@ -19,7 +19,16 @@
 
                         virtual pointer allocate_bytes(size_t num_bytes, size_t alignment) = 0;
 
-			virtual void deallocate_bytes(pointer) = 0;
+			virtual void deallocate_bytes(pointer, size_t alignment) = 0;
+
+			static size_t calc_padding(pointer ptr, size_t alignment)
+			{
+				ptrdiff_t index = ptr - pointer(0);
+				size_t extra = index & (alignment - 1);	// assumes 2^n alignment!
+				if (extra > 0)
+					extra = alignment - extra;
+				return extra;
+			}
                 };
 
         } // namespace heterogenous

Modified: sandbox/monotonic/boost/heterogenous/base.hpp
==============================================================================
--- sandbox/monotonic/boost/heterogenous/base.hpp	(original)
+++ sandbox/monotonic/boost/heterogenous/base.hpp	2009-06-28 05:18:38 EDT (Sun, 28 Jun 2009)
@@ -39,7 +39,7 @@
                         void deallocate(common_base *object, abstract_allocator &alloc) const
                         {
                                 Derived *ptr = static_cast<Derived *>(object);
-				alloc.deallocate_bytes(reinterpret_cast<abstract_allocator::pointer>(ptr));
+				alloc.deallocate_bytes(reinterpret_cast<abstract_allocator::pointer>(ptr), alignment);
                         }
 
                         virtual base<Derived> *create(abstract_allocator &alloc) const 

Modified: sandbox/monotonic/boost/heterogenous/make_clone_allocator.hpp
==============================================================================
--- sandbox/monotonic/boost/heterogenous/make_clone_allocator.hpp	(original)
+++ sandbox/monotonic/boost/heterogenous/make_clone_allocator.hpp	2009-06-28 05:18:38 EDT (Sun, 28 Jun 2009)
@@ -21,18 +21,29 @@
                         {
                                 typedef typename Alloc::template rebind<char>::other CharAlloc;
 
+				clone_allocator() { }
+				clone_allocator(Alloc &a) : Alloc(a) { }
+
                                 abstract_allocator::pointer allocate_bytes(size_t num_bytes, size_t alignment)
                                 {
                                         CharAlloc alloc(*this);
-					// TODO: alignment; this is done already for monotonic, copy that here
-					return alloc.allocate(num_bytes);
+					size_t required = num_bytes;
+					if (num_bytes < alignment)
+						required = alignment;
+					else
+						required = num_bytes + alignment;	// TODO: don't really need this much
+					abstract_allocator::pointer ptr = alloc.allocate(required);
+					size_t extra = calc_padding(ptr, alignment);
+					return ptr + extra;
                                 }
 
-				void deallocate_bytes(abstract_allocator::pointer ptr)
+				void deallocate_bytes(abstract_allocator::pointer ptr, size_t alignment)
                                 {
                                         CharAlloc alloc(*this);
-					alloc.deallocate(ptr, 1);
+					size_t extra = calc_padding(ptr, alignment);
+					alloc.deallocate(ptr - extra, 1);
                                 }
+
                         };
 
                         template <class Alloc, bool>
@@ -44,7 +55,6 @@
                         template <class Alloc>
                         struct make_clone_allocator<Alloc, true>
                         {
-				BOOST_STATIC_ASSERT(0);
                                 typedef Alloc type;
                         };
                 }

Modified: sandbox/monotonic/boost/monotonic/allocator_base.hpp
==============================================================================
--- sandbox/monotonic/boost/monotonic/allocator_base.hpp	(original)
+++ sandbox/monotonic/boost/monotonic/allocator_base.hpp	2009-06-28 05:18:38 EDT (Sun, 28 Jun 2009)
@@ -28,7 +28,7 @@
         {
                 /// common to other monotonic allocators for type T of type Derived
                 template <class T, class Derived>
-		struct allocator_base// : heterogenous::abstract_allocator
+		struct allocator_base : heterogenous::abstract_allocator
                 {
                         typedef size_t size_type;
                         typedef ptrdiff_t difference_type;
@@ -54,7 +54,7 @@
                                 return reinterpret_cast<heterogenous::abstract_allocator::pointer>(ptr);
                         }
 
-			virtual void deallocate_bytes(char * /*bytes*/)
+			virtual void deallocate_bytes(char * /*bytes*/, size_t /*alignment*/ )
                         {
                                 // do nothing
                         }