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Small buffer optimization for Boost.Function

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[SVN r32282]
This commit is contained in:
Douglas Gregor
2006-01-10 23:52:35 +00:00
parent 93c691fbdf
commit 78f6b385d5
6 changed files with 347 additions and 283 deletions
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7
doc/history.xml
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@ -5,6 +5,13 @@
<title>History &amp; Compatibility Notes</title>
<itemizedlist spacing="compact">
<listitem><para><bold>Version 1.34.0</bold>: </para>
<itemizedlist spacing="compact">
<listitem><para>Boost.Function now implements a small buffer optimization, which can drastically improve the performance when copying or construction Boost.Function objects storing small function objects. For instance, <code>bind(&amp;X:foo, &amp;x, _1, _2)</code> requires no heap allocation when placed into a Boost.Function object. Note that some exception-safety guarantees have changed: assignment provides the basic exception guarantee and <code>swap()</code> may throw.</para></listitem>
</itemizedlist>
</listitem>
<listitem><para><bold>Version 1.30.0</bold>: </para>
<itemizedlist spacing="compact">
<listitem><para>All features deprecated in version 1.29.0 have

46
doc/reference.xml
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@ -118,6 +118,12 @@
<returns><simpara><code>true</code> if <code>this-&gt;<methodname>target</methodname>&lt;Functor&gt;()</code> is non-NULL and <code><functionname>function_equal</functionname>(*(this-&gt;target&lt;Functor&gt;()), f)</code></simpara></returns>
</method>
<method name="target_type" cv="const">
<type>const std::type_info&amp;</type>
<returns><simpara><code>typeid</code> of the target function object, or <code>typeid(void)</code> if <code>this-&gt;<methodname>empty</methodname>()</code>.</simpara></returns>
<throws><simpara>Will not throw.</simpara></throws>
</method>
</method-group>
</class>
@ -182,7 +188,7 @@
</struct>
<constructor>
<postconditions><simpara><code>this-><methodname>empty</methodname>()</code></simpara></postconditions>
<postconditions><simpara><code>this-&gt;<methodname>empty</methodname>()</code></simpara></postconditions>
<throws><simpara>Will not throw.</simpara></throws>
</constructor>
@ -201,11 +207,10 @@
<parameter name="f"><paramtype>F</paramtype></parameter>
<requires><simpara>F is a function object Callable from <code>this</code>.</simpara></requires>
<postconditions><simpara><code>*this</code> targets a copy of <code>f</code> if <code>f</code> is nonempty, or <code>this-&gt;<methodname>empty</methodname>()</code> if <code>f</code> is empty.</simpara></postconditions>
<throws><simpara>Will not throw when <code>f</code> is a stateless function object.</simpara></throws>
</constructor>
<destructor>
<effects><simpara>If <code>!this-><methodname>empty</methodname>()</code>, destroys the target of this.</simpara></effects>
<effects><simpara>If <code>!this-&gt;<methodname>empty</methodname>()</code>, destroys the target of this.</simpara></effects>
</destructor>
@ -213,8 +218,7 @@
<parameter name="f">
<paramtype>const <classname>functionN</classname>&amp;</paramtype>
</parameter>
<postconditions><simpara><code>*this</code> targets a copy of <code>f</code>'s target, if it has one, or is empty if <code>f.<methodname>empty</methodname>()</code>.</simpara></postconditions>
<throws><simpara>Will not throw when the target of <code>f</code> is a stateless function object or a reference to the function object.</simpara></throws>
<postconditions><simpara>If copy construction does not throw, <code>*this</code> targets a copy of <code>f</code>'s target, if it has one, or is empty if <code>f.<methodname>empty</methodname>()</code>. If copy construction does throw, <code>this-&gt;<methodname>empty</methodname>()</code>.</simpara></postconditions>
</copy-assignment>
<method-group name="modifiers">
@ -222,13 +226,11 @@
<type>void</type>
<parameter name="f"><paramtype>const <classname>functionN</classname>&amp;</paramtype></parameter>
<effects><simpara>Interchanges the targets of <code>*this</code> and <code>f</code>.</simpara></effects>
<throws><simpara>Will not throw.</simpara></throws>
</method>
<method name="clear">
<type>void</type>
<postconditions><simpara>this-&gt;<methodname>empty</methodname>()</simpara></postconditions>
<throws><simpara>Will not throw.</simpara></throws>
</method>
</method-group>
@ -286,6 +288,13 @@
<returns><simpara><code>true</code> if <code>this-&gt;<methodname>target</methodname>&lt;Functor&gt;()</code> is non-NULL and <code><functionname>function_equal</functionname>(*(this-&gt;target&lt;Functor&gt;()), f)</code></simpara></returns>
</method>
<method name="target_type" cv="const">
<type>const std::type_info&amp;</type>
<returns><simpara><code>typeid</code> of the target function object, or <code>typeid(void)</code> if <code>this-&gt;<methodname>empty</methodname>()</code>.</simpara></returns>
<throws><simpara>Will not throw.</simpara></throws>
</method>
</method-group>
<method-group name="invocation">
@ -314,7 +323,6 @@
<parameter name="f1"><paramtype><classname>functionN</classname>&lt;T1, T2, ..., TN, Allocator&gt;&amp;</paramtype></parameter>
<parameter name="f2"><paramtype><classname>functionN</classname>&lt;T1, T2, ..., TN, Allocator&gt;&amp;</paramtype></parameter>
<effects><simpara><code>f1.<methodname>swap</methodname>(f2)</code></simpara></effects>
<throws><simpara>Will not throw.</simpara></throws>
</function>
</free-function-group>
@ -589,7 +597,7 @@
</struct>
<constructor>
<postconditions><simpara><code>this-><methodname>empty</methodname>()</code></simpara></postconditions>
<postconditions><simpara><code>this-&gt;<methodname>empty</methodname>()</code></simpara></postconditions>
<throws><simpara>Will not throw.</simpara></throws>
</constructor>
@ -616,28 +624,26 @@
<parameter name="f"><paramtype>F</paramtype></parameter>
<requires><simpara>F is a function object Callable from <code>this</code>.</simpara></requires>
<postconditions><simpara><code>*this</code> targets a copy of <code>f</code> if <code>f</code> is nonempty, or <code>this-&gt;<methodname>empty</methodname>()</code> if <code>f</code> is empty.</simpara></postconditions>
<throws><simpara>Will not throw when <code>f</code> is a stateless function object.</simpara></throws>
</constructor>
<destructor>
<effects><simpara>If <code>!this-><methodname>empty</methodname>()</code>, destroys the target of <code>this</code>.</simpara></effects>
<effects><simpara>If <code>!this-&gt;<methodname>empty</methodname>()</code>, destroys the target of <code>this</code>.</simpara></effects>
</destructor>
<copy-assignment>
<parameter name="f">
<paramtype>const <classname>functionN</classname>&amp;</paramtype>
<paramtype>const <classname>function</classname>&amp;</paramtype>
</parameter>
<postconditions><simpara><code>*this</code> targets a copy of <code>f</code>'s target, if it has one, or is empty if <code>f.<methodname>empty</methodname>()</code></simpara></postconditions>
<throws><simpara>Will not throw when the target of <code>f</code> is a stateless function object or a reference to the function object.</simpara></throws>
<postconditions><simpara>If copy construction does not throw, <code>*this</code> targets a copy of <code>f</code>'s target, if it has one, or is empty if <code>f.<methodname>empty</methodname>()</code>. If copy construction does throw, <code>this-&gt;<methodname>empty</methodname>()</code>.</simpara></postconditions>
</copy-assignment>
<copy-assignment>
<parameter name="f">
<paramtype>const <classname>function</classname>&amp;</paramtype>
</parameter>
<postconditions><simpara><code>*this</code> targets a copy of <code>f</code>'s target, if it has one, or is empty if <code>f.<methodname>empty</methodname>()</code></simpara></postconditions>
<throws><simpara>Will not throw when the target of <code>f</code> is a stateless function object or a reference to the function object.</simpara></throws>
<postconditions><simpara>If copy construction of the target of <code>f</code> does not throw, <code>*this</code> targets a copy of <code>f</code>'s target, if it has one, or is empty if <code>f.<methodname>empty</methodname>()</code>. </simpara></postconditions>
<throws><simpara>Will not throw when the target of <code>f</code> is a stateless function object or a reference to the function object. If copy construction does throw, <code>this-&gt;<methodname>empty</methodname>()</code>.</simpara></throws>
</copy-assignment>
<method-group name="modifiers">
@ -645,7 +651,6 @@
<type>void</type>
<parameter name="f"><paramtype>const <classname>function</classname>&amp;</paramtype></parameter>
<effects><simpara>Interchanges the targets of <code>*this</code> and <code>f</code>.</simpara></effects>
<throws><simpara>Will not throw.</simpara></throws>
</method>
<method name="clear">
@ -708,6 +713,12 @@
<returns><simpara><code>true</code> if <code>this-&gt;<methodname>target</methodname>&lt;Functor&gt;()</code> is non-NULL and <code><functionname>function_equal</functionname>(*(this-&gt;target&lt;Functor&gt;()), f)</code></simpara></returns>
</method>
<method name="target_type" cv="const">
<type>const std::type_info&amp;</type>
<returns><simpara><code>typeid</code> of the target function object, or <code>typeid(void)</code> if <code>this-&gt;<methodname>empty</methodname>()</code>.</simpara></returns>
<throws><simpara>Will not throw.</simpara></throws>
</method>
</method-group>
<method-group name="invocation">
@ -733,7 +744,6 @@
<parameter name="f1"><paramtype><classname>function</classname>&lt;Signature, Allocator&gt;&amp;</paramtype></parameter>
<parameter name="f2"><paramtype><classname>function</classname>&lt;Signature, Allocator&gt;&amp;</paramtype></parameter>
<effects><simpara><code>f1.<methodname>swap</methodname>(f2)</code></simpara></effects>
<throws><simpara>Will not throw.</simpara></throws>
</function>
</free-function-group>

314
include/boost/function/function_base.hpp
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@ -1,6 +1,6 @@
// Boost.Function library
// Copyright Douglas Gregor 2001-2004. Use, modification and
// Copyright Douglas Gregor 2001-2006. Use, modification and
// distribution is subject to 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)
@ -19,10 +19,10 @@
#include <boost/assert.hpp>
#include <boost/type_traits/is_integral.hpp>
#include <boost/type_traits/composite_traits.hpp>
#include <boost/type_traits/is_stateless.hpp>
#include <boost/ref.hpp>
#include <boost/pending/ct_if.hpp>
#include <boost/mpl/if.hpp>
#include <boost/detail/workaround.hpp>
#include <boost/type_traits/alignment_of.hpp>
#ifndef BOOST_NO_SFINAE
# include "boost/utility/enable_if.hpp"
#else
@ -105,42 +105,36 @@ inline void swap(function<Signature, Allocator>& f1,
namespace boost {
namespace detail {
namespace function {
class X;
/**
* A union of a function pointer and a void pointer. This is necessary
* because 5.2.10/6 allows reinterpret_cast<> to safely cast between
* function pointer types and 5.2.9/10 allows static_cast<> to safely
* cast between a void pointer and an object pointer. But it is not legal
* to cast between a function pointer and a void* (in either direction),
* so function requires a union of the two. */
union any_pointer
* A buffer used to store small function objects in
* boost::function. It is a union containing function pointers,
* object pointers, and a structure that resembles a bound
* member function pointer.
*/
union function_buffer
{
// For pointers to function objects
void* obj_ptr;
// For pointers to std::type_info objects
// (get_functor_type_tag, check_functor_type_tag).
const void* const_obj_ptr;
void (*func_ptr)();
char data[1];
// For function pointers of all kinds
mutable void (*func_ptr)();
// For bound member pointers
struct bound_memfunc_ptr_t {
void (X::*memfunc_ptr)(int);
void* obj_ptr;
} bound_memfunc_ptr;
// To relax aliasing constraints
mutable char data;
};
inline any_pointer make_any_pointer(void* o)
{
any_pointer p;
p.obj_ptr = o;
return p;
}
inline any_pointer make_any_pointer(const void* o)
{
any_pointer p;
p.const_obj_ptr = o;
return p;
}
inline any_pointer make_any_pointer(void (*f)())
{
any_pointer p;
p.func_ptr = f;
return p;
}
/**
* The unusable class is a placeholder for unused function arguments
* It is also completely unusable except that it constructable from
@ -169,7 +163,8 @@ namespace boost {
enum functor_manager_operation_type {
clone_functor_tag,
destroy_functor_tag,
check_functor_type_tag
check_functor_type_tag,
get_functor_type_tag
};
// Tags used to decide between different types of functions
@ -177,55 +172,77 @@ namespace boost {
struct function_obj_tag {};
struct member_ptr_tag {};
struct function_obj_ref_tag {};
struct stateless_function_obj_tag {};
template<typename F>
class get_function_tag
{
typedef typename ct_if<(is_pointer<F>::value),
typedef typename mpl::if_c<(is_pointer<F>::value),
function_ptr_tag,
function_obj_tag>::type ptr_or_obj_tag;
typedef typename ct_if<(is_member_pointer<F>::value),
typedef typename mpl::if_c<(is_member_pointer<F>::value),
member_ptr_tag,
ptr_or_obj_tag>::type ptr_or_obj_or_mem_tag;
typedef typename ct_if<(is_reference_wrapper<F>::value),
typedef typename mpl::if_c<(is_reference_wrapper<F>::value),
function_obj_ref_tag,
ptr_or_obj_or_mem_tag>::type or_ref_tag;
public:
typedef typename ct_if<(is_stateless<F>::value),
stateless_function_obj_tag,
or_ref_tag>::type type;
typedef or_ref_tag type;
};
// The trivial manager does nothing but return the same pointer (if we
// are cloning) or return the null pointer (if we are deleting).
template<typename F>
struct trivial_manager
struct reference_manager
{
static inline any_pointer
get(any_pointer f, functor_manager_operation_type op)
static inline void
get(const function_buffer& in_buffer, function_buffer& out_buffer,
functor_manager_operation_type op)
{
switch (op) {
case clone_functor_tag: return f;
case clone_functor_tag:
out_buffer.obj_ptr = in_buffer.obj_ptr;
return;
case destroy_functor_tag:
return make_any_pointer(reinterpret_cast<void*>(0));
out_buffer.obj_ptr = 0;
return;
case check_functor_type_tag:
{
std::type_info* t = static_cast<std::type_info*>(f.obj_ptr);
return BOOST_FUNCTION_COMPARE_TYPE_ID(typeid(F), *t)?
f
: make_any_pointer(reinterpret_cast<void*>(0));
}
// DPG TBD: Since we're only storing a pointer, it's
// possible that the user could ask for a base class or
// derived class. Is that okay?
const std::type_info& check_type =
*static_cast<const std::type_info*>(out_buffer.const_obj_ptr);
if (BOOST_FUNCTION_COMPARE_TYPE_ID(check_type, typeid(F)))
out_buffer.obj_ptr = in_buffer.obj_ptr;
else
out_buffer.obj_ptr = 0;
}
return;
// Clears up a warning with GCC 3.2.3
return make_any_pointer(reinterpret_cast<void*>(0));
case get_functor_type_tag:
out_buffer.const_obj_ptr = &typeid(F);
return;
}
}
};
/**
* Determine if boost::function can use the small-object
* optimization with the function object type F.
*/
template<typename F>
struct function_allows_small_object_optimization
{
BOOST_STATIC_CONSTANT
(bool,
value = ((sizeof(F) <= sizeof(function_buffer) &&
(alignment_of<function_buffer>::value
% alignment_of<F>::value == 0))));
};
/**
@ -239,23 +256,51 @@ namespace boost {
typedef Functor functor_type;
// For function pointers, the manager is trivial
static inline any_pointer
manager(any_pointer function_ptr,
functor_manager_operation_type op,
function_ptr_tag)
static inline void
manager(const function_buffer& in_buffer, function_buffer& out_buffer,
functor_manager_operation_type op, function_ptr_tag)
{
if (op == clone_functor_tag)
return function_ptr;
out_buffer.func_ptr = in_buffer.func_ptr;
else if (op == destroy_functor_tag)
out_buffer.func_ptr = 0;
else /* op == check_functor_type_tag */ {
const std::type_info& check_type =
*static_cast<const std::type_info*>(out_buffer.const_obj_ptr);
if (BOOST_FUNCTION_COMPARE_TYPE_ID(check_type, typeid(Functor)))
out_buffer.obj_ptr = &in_buffer.func_ptr;
else
return make_any_pointer(static_cast<void (*)()>(0));
out_buffer.obj_ptr = 0;
}
}
// For function object pointers, we clone the pointer to each
// function has its own version.
static inline any_pointer
manager(any_pointer function_obj_ptr,
functor_manager_operation_type op,
function_obj_tag)
// Function objects that fit in the small-object buffer.
static inline void
manager(const function_buffer& in_buffer, function_buffer& out_buffer,
functor_manager_operation_type op, mpl::true_)
{
if (op == clone_functor_tag) {
const functor_type* in_functor =
reinterpret_cast<const functor_type*>(&in_buffer.data);
new ((void*)&out_buffer.data) functor_type(*in_functor);
} else if (op == destroy_functor_tag) {
functor_type* out_functor =
reinterpret_cast<functor_type*>(&out_buffer.data);
out_functor->~functor_type();
} else /* op == check_functor_type_tag */ {
const std::type_info& check_type =
*static_cast<const std::type_info*>(out_buffer.const_obj_ptr);
if (BOOST_FUNCTION_COMPARE_TYPE_ID(check_type, typeid(Functor)))
out_buffer.obj_ptr = &in_buffer.data;
else
out_buffer.obj_ptr = 0;
}
}
// Function objects that require heap allocation
static inline void
manager(const function_buffer& in_buffer, function_buffer& out_buffer,
functor_manager_operation_type op, mpl::false_)
{
#ifndef BOOST_NO_STD_ALLOCATOR
typedef typename Allocator::template rebind<functor_type>::other
@ -270,8 +315,8 @@ namespace boost {
# endif // BOOST_NO_STD_ALLOCATOR
if (op == clone_functor_tag) {
functor_type* f =
static_cast<functor_type*>(function_obj_ptr.obj_ptr);
const functor_type* f =
static_cast<const functor_type*>(in_buffer.obj_ptr);
// Clone the functor
# ifndef BOOST_NO_STD_ALLOCATOR
@ -283,12 +328,11 @@ namespace boost {
# else
functor_type* new_f = new functor_type(*f);
# endif // BOOST_NO_STD_ALLOCATOR
return make_any_pointer(static_cast<void*>(new_f));
}
else {
out_buffer.obj_ptr = new_f;
} else if (op == destroy_functor_tag) {
/* Cast from the void pointer to the functor pointer type */
functor_type* f =
reinterpret_cast<functor_type*>(function_obj_ptr.obj_ptr);
static_cast<functor_type*>(out_buffer.obj_ptr);
# ifndef BOOST_NO_STD_ALLOCATOR
/* Cast from the functor pointer type to the allocator's pointer
@ -301,26 +345,43 @@ namespace boost {
# else
delete f;
# endif // BOOST_NO_STD_ALLOCATOR
out_buffer.obj_ptr = 0;
} else /* op == check_functor_type_tag */ {
const std::type_info& check_type =
*static_cast<const std::type_info*>(out_buffer.const_obj_ptr);
if (BOOST_FUNCTION_COMPARE_TYPE_ID(check_type, typeid(Functor)))
out_buffer.obj_ptr = in_buffer.obj_ptr;
else
out_buffer.obj_ptr = 0;
}
}
return make_any_pointer(static_cast<void*>(0));
}
// For function objects, we determine whether the function
// object can use the small-object optimization buffer or
// whether we need to allocate it on the heap.
static inline void
manager(const function_buffer& in_buffer, function_buffer& out_buffer,
functor_manager_operation_type op, function_obj_tag)
{
manager(in_buffer, out_buffer, op,
mpl::bool_<(function_allows_small_object_optimization<functor_type>::value)>());
}
public:
/* Dispatch to an appropriate manager based on whether we have a
function pointer or a function object pointer. */
static any_pointer
manage(any_pointer functor_ptr, functor_manager_operation_type op)
static inline void
manage(const function_buffer& in_buffer, function_buffer& out_buffer,
functor_manager_operation_type op)
{
if (op == check_functor_type_tag) {
std::type_info* type =
static_cast<std::type_info*>(functor_ptr.obj_ptr);
return (BOOST_FUNCTION_COMPARE_TYPE_ID(typeid(Functor), *type)?
functor_ptr
: make_any_pointer(reinterpret_cast<void*>(0)));
}
else {
typedef typename get_function_tag<functor_type>::type tag_type;
return manager(functor_ptr, op, tag_type());
switch (op) {
case get_functor_type_tag:
out_buffer.const_obj_ptr = &typeid(functor_type);
return;
default:
return manager(in_buffer, out_buffer, op, tag_type());
}
}
};
@ -394,7 +455,9 @@ namespace boost {
struct vtable_base
{
vtable_base() : manager(0) { }
any_pointer (*manager)(any_pointer, functor_manager_operation_type);
void (*manager)(const function_buffer& in_buffer,
function_buffer& out_buffer,
functor_manager_operation_type op);
};
} // end namespace function
} // end namespace detail
@ -408,27 +471,32 @@ namespace boost {
class function_base
{
public:
function_base() : vtable(0)
{
functor.obj_ptr = 0;
}
function_base() : vtable(0) { }
// Is this function empty?
/** Determine if the function is empty (i.e., has no target). */
bool empty() const { return !vtable; }
/** Retrieve the type of the stored function object, or typeid(void)
if this is empty. */
const std::type_info& target_type() const
{
if (!vtable) return typeid(void);
detail::function::function_buffer type;
vtable->manager(functor, type, detail::function::get_functor_type_tag);
return *static_cast<const std::type_info*>(type.const_obj_ptr);
}
template<typename Functor>
Functor* target()
{
if (!vtable) return 0;
detail::function::any_pointer result =
vtable->manager(detail::function::make_any_pointer(&typeid(Functor)),
detail::function::function_buffer type_result;
type_result.const_obj_ptr = &typeid(Functor);
vtable->manager(functor, type_result,
detail::function::check_functor_type_tag);
if (!result.obj_ptr) return 0;
else {
typedef typename detail::function::get_function_tag<Functor>::type tag;
return get_functor_pointer<Functor>(tag(), 0);
}
return static_cast<Functor*>(type_result.obj_ptr);
}
template<typename Functor>
@ -440,19 +508,11 @@ public:
{
if (!vtable) return 0;
detail::function::any_pointer result =
vtable->manager(detail::function::make_any_pointer(&typeid(Functor)),
detail::function::function_buffer type_result;
type_result.const_obj_ptr = &typeid(Functor);
vtable->manager(functor, type_result,
detail::function::check_functor_type_tag);
if (!result.obj_ptr) return 0;
else {
typedef typename detail::function::get_function_tag<Functor>::type tag;
#if defined(BOOST_MSVC) && BOOST_WORKAROUND(BOOST_MSVC, < 1300)
return get_functor_pointer(tag(), 0, (Functor*)0);
#else
return get_functor_pointer<Functor>(tag(), 0);
#endif
}
return static_cast<const Functor*>(type_result.obj_ptr);
}
template<typename F>
@ -495,41 +555,7 @@ public:
public: // should be protected, but GCC 2.95.3 will fail to allow access
detail::function::vtable_base* vtable;
detail::function::any_pointer functor;
private:
template<typename Functor>
#if defined(BOOST_MSVC) && BOOST_WORKAROUND(BOOST_MSVC, < 1300)
Functor* get_functor_pointer(detail::function::function_ptr_tag, int, Functor * = 0)
#else
Functor* get_functor_pointer(detail::function::function_ptr_tag, int)
#endif
{ return reinterpret_cast<Functor*>(&functor.func_ptr); }
template<typename Functor, typename Tag>
#if defined(BOOST_MSVC) && BOOST_WORKAROUND(BOOST_MSVC, < 1300)
Functor* get_functor_pointer(Tag, long, Functor * = 0)
#else
Functor* get_functor_pointer(Tag, long)
#endif
{ return static_cast<Functor*>(functor.obj_ptr); }
template<typename Functor>
const Functor*
#if defined(BOOST_MSVC) && BOOST_WORKAROUND(BOOST_MSVC, < 1300)
get_functor_pointer(detail::function::function_ptr_tag, int, Functor * = 0) const
#else
get_functor_pointer(detail::function::function_ptr_tag, int) const
#endif
{ return reinterpret_cast<const Functor*>(&functor.func_ptr); }
template<typename Functor, typename Tag>
#if defined(BOOST_MSVC) && BOOST_WORKAROUND(BOOST_MSVC, < 1300)
const Functor* get_functor_pointer(Tag, long, Functor * = 0) const
#else
const Functor* get_functor_pointer(Tag, long) const
#endif
{ return static_cast<const Functor*>(functor.const_obj_ptr); }
mutable detail::function::function_buffer functor;
};
/**

199
include/boost/function/function_template.hpp
View File

@ -1,6 +1,6 @@
// Boost.Function library
// Copyright Douglas Gregor 2001-2003. Use, modification and
// Copyright Douglas Gregor 2001-2006. Use, modification and
// distribution is subject to 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)
@ -50,16 +50,16 @@
BOOST_JOIN(function_obj_invoker,BOOST_FUNCTION_NUM_ARGS)
#define BOOST_FUNCTION_VOID_FUNCTION_OBJ_INVOKER \
BOOST_JOIN(void_function_obj_invoker,BOOST_FUNCTION_NUM_ARGS)
#define BOOST_FUNCTION_STATELESS_FUNCTION_OBJ_INVOKER \
BOOST_JOIN(stateless_function_obj_invoker,BOOST_FUNCTION_NUM_ARGS)
#define BOOST_FUNCTION_STATELESS_VOID_FUNCTION_OBJ_INVOKER \
BOOST_JOIN(stateless_void_function_obj_invoker,BOOST_FUNCTION_NUM_ARGS)
#define BOOST_FUNCTION_FUNCTION_REF_INVOKER \
BOOST_JOIN(function_ref_invoker,BOOST_FUNCTION_NUM_ARGS)
#define BOOST_FUNCTION_VOID_FUNCTION_REF_INVOKER \
BOOST_JOIN(void_function_ref_invoker,BOOST_FUNCTION_NUM_ARGS)
#define BOOST_FUNCTION_GET_FUNCTION_INVOKER \
BOOST_JOIN(get_function_invoker,BOOST_FUNCTION_NUM_ARGS)
#define BOOST_FUNCTION_GET_FUNCTION_OBJ_INVOKER \
BOOST_JOIN(get_function_obj_invoker,BOOST_FUNCTION_NUM_ARGS)
#define BOOST_FUNCTION_GET_STATELESS_FUNCTION_OBJ_INVOKER \
BOOST_JOIN(get_stateless_function_obj_invoker,BOOST_FUNCTION_NUM_ARGS)
#define BOOST_FUNCTION_GET_FUNCTION_REF_INVOKER \
BOOST_JOIN(get_function_ref_invoker,BOOST_FUNCTION_NUM_ARGS)
#define BOOST_FUNCTION_VTABLE BOOST_JOIN(basic_vtable,BOOST_FUNCTION_NUM_ARGS)
#ifndef BOOST_NO_VOID_RETURNS
@ -80,7 +80,7 @@ namespace boost {
>
struct BOOST_FUNCTION_FUNCTION_INVOKER
{
static R invoke(any_pointer function_ptr BOOST_FUNCTION_COMMA
static R invoke(function_buffer& function_ptr BOOST_FUNCTION_COMMA
BOOST_FUNCTION_PARMS)
{
FunctionPtr f = reinterpret_cast<FunctionPtr>(function_ptr.func_ptr);
@ -96,7 +96,7 @@ namespace boost {
struct BOOST_FUNCTION_VOID_FUNCTION_INVOKER
{
static BOOST_FUNCTION_VOID_RETURN_TYPE
invoke(any_pointer function_ptr BOOST_FUNCTION_COMMA
invoke(function_buffer& function_ptr BOOST_FUNCTION_COMMA
BOOST_FUNCTION_PARMS)
{
@ -112,11 +112,15 @@ namespace boost {
>
struct BOOST_FUNCTION_FUNCTION_OBJ_INVOKER
{
static R invoke(any_pointer function_obj_ptr BOOST_FUNCTION_COMMA
static R invoke(function_buffer& function_obj_ptr BOOST_FUNCTION_COMMA
BOOST_FUNCTION_PARMS)
{
FunctionObj* f = (FunctionObj*)(function_obj_ptr.obj_ptr);
FunctionObj* f;
if (function_allows_small_object_optimization<FunctionObj>::value)
f = reinterpret_cast<FunctionObj*>(&function_obj_ptr.data);
else
f = reinterpret_cast<FunctionObj*>(function_obj_ptr.obj_ptr);
return (*f)(BOOST_FUNCTION_ARGS);
}
};
@ -129,11 +133,15 @@ namespace boost {
struct BOOST_FUNCTION_VOID_FUNCTION_OBJ_INVOKER
{
static BOOST_FUNCTION_VOID_RETURN_TYPE
invoke(any_pointer function_obj_ptr BOOST_FUNCTION_COMMA
invoke(function_buffer& function_obj_ptr BOOST_FUNCTION_COMMA
BOOST_FUNCTION_PARMS)
{
FunctionObj* f = (FunctionObj*)(function_obj_ptr.obj_ptr);
FunctionObj* f;
if (function_allows_small_object_optimization<FunctionObj>::value)
f = reinterpret_cast<FunctionObj*>(&function_obj_ptr.data);
else
f = reinterpret_cast<FunctionObj*>(function_obj_ptr.obj_ptr);
BOOST_FUNCTION_RETURN((*f)(BOOST_FUNCTION_ARGS));
}
};
@ -143,12 +151,15 @@ namespace boost {
typename R BOOST_FUNCTION_COMMA
BOOST_FUNCTION_TEMPLATE_PARMS
>
struct BOOST_FUNCTION_STATELESS_FUNCTION_OBJ_INVOKER
struct BOOST_FUNCTION_FUNCTION_REF_INVOKER
{
static R invoke(any_pointer BOOST_FUNCTION_COMMA BOOST_FUNCTION_PARMS)
static R invoke(function_buffer& function_obj_ptr BOOST_FUNCTION_COMMA
BOOST_FUNCTION_PARMS)
{
FunctionObj f = FunctionObj();
return f(BOOST_FUNCTION_ARGS);
FunctionObj* f =
reinterpret_cast<FunctionObj*>(function_obj_ptr.obj_ptr);
return (*f)(BOOST_FUNCTION_ARGS);
}
};
@ -157,14 +168,16 @@ namespace boost {
typename R BOOST_FUNCTION_COMMA
BOOST_FUNCTION_TEMPLATE_PARMS
>
struct BOOST_FUNCTION_STATELESS_VOID_FUNCTION_OBJ_INVOKER
struct BOOST_FUNCTION_VOID_FUNCTION_REF_INVOKER
{
static BOOST_FUNCTION_VOID_RETURN_TYPE
invoke(any_pointer BOOST_FUNCTION_COMMA BOOST_FUNCTION_PARMS)
invoke(function_buffer& function_obj_ptr BOOST_FUNCTION_COMMA
BOOST_FUNCTION_PARMS)
{
FunctionObj f = FunctionObj();
BOOST_FUNCTION_RETURN(f(BOOST_FUNCTION_ARGS));
FunctionObj* f =
reinterpret_cast<FunctionObj*>(function_obj_ptr.obj_ptr);
BOOST_FUNCTION_RETURN((*f)(BOOST_FUNCTION_ARGS));
}
};
@ -175,7 +188,7 @@ namespace boost {
>
struct BOOST_FUNCTION_GET_FUNCTION_INVOKER
{
typedef typename ct_if<(is_void<R>::value),
typedef typename mpl::if_c<(is_void<R>::value),
BOOST_FUNCTION_VOID_FUNCTION_INVOKER<
FunctionPtr,
R BOOST_FUNCTION_COMMA
@ -196,7 +209,7 @@ namespace boost {
>
struct BOOST_FUNCTION_GET_FUNCTION_OBJ_INVOKER
{
typedef typename ct_if<(is_void<R>::value),
typedef typename mpl::if_c<(is_void<R>::value),
BOOST_FUNCTION_VOID_FUNCTION_OBJ_INVOKER<
FunctionObj,
R BOOST_FUNCTION_COMMA
@ -215,15 +228,15 @@ namespace boost {
typename R BOOST_FUNCTION_COMMA
BOOST_FUNCTION_TEMPLATE_PARMS
>
struct BOOST_FUNCTION_GET_STATELESS_FUNCTION_OBJ_INVOKER
struct BOOST_FUNCTION_GET_FUNCTION_REF_INVOKER
{
typedef typename ct_if<(is_void<R>::value),
BOOST_FUNCTION_STATELESS_VOID_FUNCTION_OBJ_INVOKER<
typedef typename mpl::if_c<(is_void<R>::value),
BOOST_FUNCTION_VOID_FUNCTION_REF_INVOKER<
FunctionObj,
R BOOST_FUNCTION_COMMA
BOOST_FUNCTION_TEMPLATE_ARGS
>,
BOOST_FUNCTION_STATELESS_FUNCTION_OBJ_INVOKER<
BOOST_FUNCTION_FUNCTION_REF_INVOKER<
FunctionObj,
R BOOST_FUNCTION_COMMA
BOOST_FUNCTION_TEMPLATE_ARGS
@ -244,7 +257,7 @@ namespace boost {
typedef typename function_return_type<R>::type result_type;
#endif // BOOST_NO_VOID_RETURNS
typedef result_type (*invoker_type)(any_pointer
typedef result_type (*invoker_type)(function_buffer&
BOOST_FUNCTION_COMMA
BOOST_FUNCTION_TEMPLATE_ARGS);
@ -255,16 +268,16 @@ namespace boost {
}
template<typename F>
bool assign_to(F f, any_pointer& functor)
bool assign_to(F f, function_buffer& functor)
{
typedef typename get_function_tag<F>::type tag;
return assign_to(f, functor, tag());
}
void clear(any_pointer& functor)
void clear(function_buffer& functor)
{
if (manager)
functor = manager(functor, destroy_functor_tag);
manager(functor, functor, destroy_functor_tag);
}
private:
@ -291,14 +304,14 @@ namespace boost {
}
template<typename FunctionPtr>
bool assign_to(FunctionPtr f, any_pointer& functor, function_ptr_tag)
bool
assign_to(FunctionPtr f, function_buffer& functor, function_ptr_tag)
{
this->clear(functor);
if (f) {
// should be a reinterpret cast, but some compilers insist
// on giving cv-qualifiers to free functions
functor = manager(make_any_pointer((void (*)())(f)),
clone_functor_tag);
functor.func_ptr = (void (*)())(f);
return true;
} else {
return false;
@ -310,12 +323,18 @@ namespace boost {
template<typename MemberPtr>
void init(MemberPtr f, member_ptr_tag)
{
// DPG TBD: Add explicit support for member function
// objects, so we invoke through mem_fn() but we retain the
// right target_type() values.
this->init(mem_fn(f));
}
template<typename MemberPtr>
bool assign_to(MemberPtr f, any_pointer& functor, member_ptr_tag)
bool assign_to(MemberPtr f, function_buffer& functor, member_ptr_tag)
{
// DPG TBD: Add explicit support for member function
// objects, so we invoke through mem_fn() but we retain the
// right target_type() values.
if (f) {
this->assign_to(mem_fn(f), functor);
return true;
@ -325,7 +344,7 @@ namespace boost {
}
#endif // BOOST_FUNCTION_NUM_ARGS > 0
// Stateful function objects
// Function objects
template<typename FunctionObj>
void init(FunctionObj f, function_obj_tag)
{
@ -340,24 +359,42 @@ namespace boost {
manager = &functor_manager<FunctionObj, Allocator>::manage;
}
// Assign to a function object using the small object optimization
template<typename FunctionObj>
bool assign_to(FunctionObj f, any_pointer& functor, function_obj_tag)
void
assign_functor(FunctionObj f, function_buffer& functor, mpl::true_)
{
new ((void*)&functor.data) FunctionObj(f);
}
// Assign to a function object allocated on the heap.
template<typename FunctionObj>
void
assign_functor(FunctionObj f, function_buffer& functor, mpl::false_)
{
if (!boost::detail::function::has_empty_target(boost::addressof(f))) {
#ifndef BOOST_NO_STD_ALLOCATOR
typedef typename Allocator::template rebind<FunctionObj>::other
rebound_allocator_type;
typedef typename rebound_allocator_type::pointer pointer_type;
rebound_allocator_type allocator;
allocator_type;
typedef typename allocator_type::pointer pointer_type;
allocator_type allocator;
pointer_type copy = allocator.allocate(1);
allocator.construct(copy, f);
// Get back to the original pointer type
FunctionObj* new_f = static_cast<FunctionObj*>(copy);
functor.obj_ptr = static_cast<FunctionObj*>(copy);
# else
FunctionObj* new_f = new FunctionObj(f);
functor.obj_ptr = new FunctionObj(f);
# endif // BOOST_NO_STD_ALLOCATOR
functor = make_any_pointer(static_cast<void*>(new_f));
}
template<typename FunctionObj>
bool
assign_to(FunctionObj f, function_buffer& functor, function_obj_tag)
{
if (!boost::detail::function::has_empty_target(boost::addressof(f))) {
assign_functor(f, functor,
mpl::bool_<(function_allows_small_object_optimization<FunctionObj>::value)>());
return true;
} else {
return false;
@ -369,7 +406,7 @@ namespace boost {
void
init(const reference_wrapper<FunctionObj>& f, function_obj_ref_tag)
{
typedef typename BOOST_FUNCTION_GET_FUNCTION_OBJ_INVOKER<
typedef typename BOOST_FUNCTION_GET_FUNCTION_REF_INVOKER<
FunctionObj,
R BOOST_FUNCTION_COMMA
BOOST_FUNCTION_TEMPLATE_ARGS
@ -377,46 +414,20 @@ namespace boost {
actual_invoker_type;
invoker = &actual_invoker_type::invoke;
manager = &trivial_manager<FunctionObj>::get;
manager = &reference_manager<FunctionObj>::get;
}
template<typename FunctionObj>
bool
assign_to(const reference_wrapper<FunctionObj>& f, any_pointer& functor,
function_obj_ref_tag)
assign_to(const reference_wrapper<FunctionObj>& f,
function_buffer& functor, function_obj_ref_tag)
{
if (!boost::detail::function::has_empty_target(f.get_pointer())) {
functor = manager(make_any_pointer(
const_cast<FunctionObj*>(f.get_pointer())),
clone_functor_tag);
return true;
} else {
return false;
}
}
// Stateless function object
template<typename FunctionObj>
void
init(FunctionObj, stateless_function_obj_tag)
{
typedef
typename BOOST_FUNCTION_GET_STATELESS_FUNCTION_OBJ_INVOKER<
FunctionObj,
R BOOST_FUNCTION_COMMA
BOOST_FUNCTION_TEMPLATE_ARGS
>::type actual_invoker_type;
invoker = &actual_invoker_type::invoke;
manager = &trivial_manager<FunctionObj>::get;
}
template<typename FunctionObj>
bool
assign_to(FunctionObj f, any_pointer& functor,
stateless_function_obj_tag)
{
if (!boost::detail::function::has_empty_target(boost::addressof(f))) {
functor = make_any_pointer(this);
// DPG TBD: We might need to detect constness of
// FunctionObj to assign into obj_ptr or const_obj_ptr to
// be truly legit, but no platform in existence makes
// const void* different from void*.
functor.const_obj_ptr = f.get_pointer();
return true;
} else {
return false;
@ -539,7 +550,13 @@ namespace boost {
#endif
operator=(Functor BOOST_FUNCTION_TARGET_FIX(const &) f)
{
self_type(f).swap(*this);
this->clear();
try {
this->assign_to(f);
} catch (...) {
vtable = 0;
throw;
}
return *this;
}
@ -564,7 +581,13 @@ namespace boost {
if (&f == this)
return *this;
self_type(f).swap(*this);
this->clear();
try {
this->assign_to_own(f);
} catch (...) {
vtable = 0;
throw;
}
return *this;
}
@ -573,8 +596,9 @@ namespace boost {
if (&other == this)
return;
std::swap(this->functor, other.functor);
std::swap(this->vtable, other.vtable);
BOOST_FUNCTION_FUNCTION tmp = *this;
*this = other;
other = tmp;
}
// Clear out a target, if there is one
@ -610,8 +634,7 @@ namespace boost {
{
if (!f.empty()) {
this->vtable = f.vtable;
this->functor =
f.vtable->manager(f.functor,
f.vtable->manager(f.functor, this->functor,
boost::detail::function::clone_functor_tag);
}
}
@ -779,11 +802,11 @@ public:
#undef BOOST_FUNCTION_VOID_FUNCTION_INVOKER
#undef BOOST_FUNCTION_FUNCTION_OBJ_INVOKER
#undef BOOST_FUNCTION_VOID_FUNCTION_OBJ_INVOKER
#undef BOOST_FUNCTION_STATELESS_FUNCTION_OBJ_INVOKER
#undef BOOST_FUNCTION_STATELESS_VOID_FUNCTION_OBJ_INVOKER
#undef BOOST_FUNCTION_FUNCTION_REF_INVOKER
#undef BOOST_FUNCTION_VOID_FUNCTION_REF_INVOKER
#undef BOOST_FUNCTION_GET_FUNCTION_INVOKER
#undef BOOST_FUNCTION_GET_FUNCTION_OBJ_INVOKER
#undef BOOST_FUNCTION_GET_STATELESS_FUNCTION_OBJ_INVOKER
#undef BOOST_FUNCTION_GET_FUNCTION_REF_INVOKER
#undef BOOST_FUNCTION_GET_MEM_FUNCTION_INVOKER
#undef BOOST_FUNCTION_TEMPLATE_PARMS
#undef BOOST_FUNCTION_TEMPLATE_ARGS

4
test/allocator_test.cpp
View File

@ -45,7 +45,7 @@ struct plus_int
{
int operator()(int x, int y) const { return x + y; }
int unused_state_data;
int unused_state_data[32];
};
static int do_minus(int x, int y) { return x-y; }
@ -54,7 +54,7 @@ struct DoNothing
{
void operator()() const {}
int unused_state_data;
int unused_state_data[32];
};
static void do_nothing() {}

16
test/stateless_test.cpp
View File

@ -14,23 +14,21 @@
struct stateless_integer_add {
int operator()(int x, int y) const { return x+y; }
void* operator new(std::size_t, stateless_integer_add*)
void* operator new(std::size_t)
{
throw std::runtime_error("Cannot allocate a stateless_integer_add");
}
void operator delete(void*, stateless_integer_add*) throw()
void* operator new(std::size_t, void* p)
{
return p;
}
void operator delete(void*) throw()
{
}
};
namespace boost {
template<>
struct is_stateless<stateless_integer_add> {
BOOST_STATIC_CONSTANT(bool, value = true);
};
}
int test_main(int, char*[])
{
boost::function2<int, int, int> f;