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+/*
+ * Copyright (c) 1996-1997
+ * Silicon Graphics Computer Systems, Inc.
+ *
+ * Permission to use, copy, modify, distribute and sell this software
+ * and its documentation for any purpose is hereby granted without fee,
+ * provided that the above copyright notice appear in all copies and
+ * that both that copyright notice and this permission notice appear
+ * in supporting documentation. Silicon Graphics makes no
+ * representations about the suitability of this software for any
+ * purpose. It is provided "as is" without express or implied warranty.
+ *
+ * Copyright (c) 2002
+ * Hewlett-Packard Company
+ *
+ * Permission to use, copy, modify, distribute and sell this software
+ * and its documentation for any purpose is hereby granted without fee,
+ * provided that the above copyright notice appear in all copies and
+ * that both that copyright notice and this permission notice appear
+ * in supporting documentation. Hewlett-Packard Company makes no
+ * representations about the suitability of this software for any
+ * purpose. It is provided "as is" without express or implied warranty.
+ */
+
+/*
+ * This implements standard-conforming allocators that interact with
+ * the garbage collector. Gc_alloctor<T> allocates garbage-collectable
+ * objects of type T. Traceable_allocator<T> allocates objects that
+ * are not temselves garbage collected, but are scanned by the
+ * collector for pointers to collectable objects. Traceable_alloc
+ * should be used for explicitly managed STL containers that may
+ * point to collectable objects.
+ *
+ * This code was derived from an earlier version of the GNU C++ standard
+ * library, which itself was derived from the SGI STL implementation.
+ */
+
+/* First some helpers to allow us to dispatch on whether or not a type
+ * is known to be pointerfree.
+ * These are private, except that the client may invoke the
+ * GC_DECLARE_PTRFREE macro.
+ */
+
+struct GC_true_type {};
+struct GC_false_type {};
+
+template <class GC_tp>
+struct GC_type_traits {
+ GC_false_type GC_is_ptr_free;
+};
+
+# define GC_DECLARE_PTRFREE(T) \
+template<> struct GC_type_traits<T> { GC_true_type GC_is_ptr_free; }
+
+GC_DECLARE_PTRFREE(signed char);
+GC_DECLARE_PTRFREE(unsigned char);
+GC_DECLARE_PTRFREE(signed short);
+GC_DECLARE_PTRFREE(unsigned short);
+GC_DECLARE_PTRFREE(signed int);
+GC_DECLARE_PTRFREE(unsigned int);
+GC_DECLARE_PTRFREE(signed long);
+GC_DECLARE_PTRFREE(unsigned long);
+GC_DECLARE_PTRFREE(float);
+GC_DECLARE_PTRFREE(double);
+/* The client may want to add others. */
+
+// In the following GC_Tp is GC_true_type iff we are allocating a
+// pointerfree object.
+template <class GC_Tp>
+inline void * GC_selective_alloc(size_t n, GC_Tp) {
+ return GC_MALLOC(n);
+}
+
+template <>
+inline void * GC_selective_alloc<GC_true_type>(size_t n, GC_true_type) {
+ return GC_MALLOC_ATOMIC(n);
+}
+
+/* Now the public gc_allocator<T> class:
+ */
+template <class GC_Tp>
+class gc_allocator {
+public:
+ typedef size_t size_type;
+ typedef ptrdiff_t difference_type;
+ typedef GC_Tp* pointer;
+ typedef const GC_Tp* const_pointer;
+ typedef GC_Tp& reference;
+ typedef const GC_Tp& const_reference;
+ typedef GC_Tp value_type;
+
+ template <class GC_Tp1> struct rebind {
+ typedef gc_allocator<GC_Tp1> other;
+ };
+
+ gc_allocator() {}
+# ifndef _MSC_VER
+ // I'm not sure why this is needed here in addition to the following.
+ // The standard specifies it for the standard allocator, but VC++ rejects
+ // it. -HB
+ gc_allocator(const gc_allocator&) throw() {}
+# endif
+ template <class GC_Tp1> gc_allocator(const gc_allocator<GC_Tp1>&) throw() {}
+ ~gc_allocator() throw() {}
+
+ pointer address(reference GC_x) const { return &GC_x; }
+ const_pointer address(const_reference GC_x) const { return &GC_x; }
+
+ // GC_n is permitted to be 0. The C++ standard says nothing about what
+ // the return value is when GC_n == 0.
+ GC_Tp* allocate(size_type GC_n, const void* = 0) {
+ GC_type_traits<GC_Tp> traits;
+ return static_cast<GC_Tp *>
+ (GC_selective_alloc(GC_n * sizeof(GC_Tp),
+ traits.GC_is_ptr_free));
+ }
+
+ // __p is not permitted to be a null pointer.
+ void deallocate(pointer __p, size_type GC_n)
+ { GC_FREE(__p); }
+
+ size_type max_size() const throw()
+ { return size_t(-1) / sizeof(GC_Tp); }
+
+ void construct(pointer __p, const GC_Tp& __val) { new(__p) GC_Tp(__val); }
+ void destroy(pointer __p) { __p->~GC_Tp(); }
+};
+
+template<>
+class gc_allocator<void> {
+ typedef size_t size_type;
+ typedef ptrdiff_t difference_type;
+ typedef void* pointer;
+ typedef const void* const_pointer;
+ typedef void value_type;
+
+ template <class GC_Tp1> struct rebind {
+ typedef gc_allocator<GC_Tp1> other;
+ };
+};
+
+
+template <class GC_T1, class GC_T2>
+inline bool operator==(const gc_allocator<GC_T1>&, const gc_allocator<GC_T2>&)
+{
+ return true;
+}
+
+template <class GC_T1, class GC_T2>
+inline bool operator!=(const gc_allocator<GC_T1>&, const gc_allocator<GC_T2>&)
+{
+ return false;
+}
+
+/*
+ * And the public traceable_allocator class.
+ */
+
+// Note that we currently don't specialize the pointer-free case, since a
+// pointer-free traceable container doesn't make that much sense,
+// though it could become an issue due to abstraction boundaries.
+template <class GC_Tp>
+class traceable_allocator {
+public:
+ typedef size_t size_type;
+ typedef ptrdiff_t difference_type;
+ typedef GC_Tp* pointer;
+ typedef const GC_Tp* const_pointer;
+ typedef GC_Tp& reference;
+ typedef const GC_Tp& const_reference;
+ typedef GC_Tp value_type;
+
+ template <class GC_Tp1> struct rebind {
+ typedef traceable_allocator<GC_Tp1> other;
+ };
+
+ traceable_allocator() throw() {}
+# ifndef _MSC_VER
+ traceable_allocator(const traceable_allocator&) throw() {}
+# endif
+ template <class GC_Tp1> traceable_allocator
+ (const traceable_allocator<GC_Tp1>&) throw() {}
+ ~traceable_allocator() throw() {}
+
+ pointer address(reference GC_x) const { return &GC_x; }
+ const_pointer address(const_reference GC_x) const { return &GC_x; }
+
+ // GC_n is permitted to be 0. The C++ standard says nothing about what
+ // the return value is when GC_n == 0.
+ GC_Tp* allocate(size_type GC_n, const void* = 0) {
+ return static_cast<GC_Tp*>(GC_MALLOC_UNCOLLECTABLE(GC_n * sizeof(GC_Tp)));
+ }
+
+ // __p is not permitted to be a null pointer.
+ void deallocate(pointer __p, size_type GC_n)
+ { GC_FREE(__p); }
+
+ size_type max_size() const throw()
+ { return size_t(-1) / sizeof(GC_Tp); }
+
+ void construct(pointer __p, const GC_Tp& __val) { new(__p) GC_Tp(__val); }
+ void destroy(pointer __p) { __p->~GC_Tp(); }
+};
+
+template<>
+class traceable_allocator<void> {
+ typedef size_t size_type;
+ typedef ptrdiff_t difference_type;
+ typedef void* pointer;
+ typedef const void* const_pointer;
+ typedef void value_type;
+
+ template <class GC_Tp1> struct rebind {
+ typedef traceable_allocator<GC_Tp1> other;
+ };
+};
+
+
+template <class GC_T1, class GC_T2>
+inline bool operator==(const traceable_allocator<GC_T1>&, const traceable_allocator<GC_T2>&)
+{
+ return true;
+}
+
+template <class GC_T1, class GC_T2>
+inline bool operator!=(const traceable_allocator<GC_T1>&, const traceable_allocator<GC_T2>&)
+{
+ return false;
+}
+