blob: 7fd63d89d0c256fe5fcab01c84653304d0f9db49 [file] [log] [blame]
$$ This is a pump file for generating file templates. Pump is a python
$$ script that is part of the Google Test suite of utilities. Description
$$ can be found here:
$$
$$ http://code.google.com/p/googletest/wiki/PumpManual
$$
$$ See comment for MAX_ARITY in base/bind.h.pump.
$var MAX_ARITY = 7
$range ARITY 0..MAX_ARITY
// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef BASE_BIND_INTERNAL_H_
#define BASE_BIND_INTERNAL_H_
#pragma once
#include "base/bind_helpers.h"
#include "base/callback_internal.h"
#include "base/memory/raw_scoped_refptr_mismatch_checker.h"
#include "base/memory/weak_ptr.h"
#include "base/template_util.h"
#include "build/build_config.h"
#if defined(OS_WIN)
#include "base/bind_internal_win.h"
#endif
namespace base {
namespace internal {
// CONCEPTS:
// Runnable -- A type (really a type class) that has a single Run() method
// and a RunType typedef that corresponds to the type of Run().
// A Runnable can declare that it should treated like a method
// call by including a typedef named IsMethod. The value of
// this typedef is NOT inspected, only the existence. When a
// Runnable declares itself a method, Bind() will enforce special
// refcounting + WeakPtr handling semantics for the first
// parameter which is expected to be an object.
// Functor -- A copyable type representing something that should be called.
// All function pointers, Callback<>, and Runnables are functors
// even if the invocation syntax differs.
// RunType -- A function type (as opposed to function _pointer_ type) for
// a Run() function. Usually just a convenience typedef.
// (Bound)ArgsType -- A function type that is being (ab)used to store the
// types of set of arguments. The "return" type is always
// void here. We use this hack so that we do not need
// a new type name for each arity of type. (eg.,
// BindState1, BindState2). This makes forward
// declarations and friending much much easier.
//
// Types:
// RunnableAdapter<> -- Wraps the various "function" pointer types into an
// object that adheres to the Runnable interface.
// There are |3*ARITY| RunnableAdapter types.
// FunctionTraits<> -- Type traits that unwrap a function signature into a
// a set of easier to use typedefs. Used mainly for
// compile time asserts.
// There are |ARITY| FunctionTraits types.
// ForceVoidReturn<> -- Helper class for translating function signatures to
// equivalent forms with a "void" return type.
// There are |ARITY| ForceVoidReturn types.
// FunctorTraits<> -- Type traits used determine the correct RunType and
// RunnableType for a Functor. This is where function
// signature adapters are applied.
// There are |ARITY| ForceVoidReturn types.
// MakeRunnable<> -- Takes a Functor and returns an object in the Runnable
// type class that represents the underlying Functor.
// There are |O(1)| MakeRunnable types.
// InvokeHelper<> -- Take a Runnable + arguments and actully invokes it.
// Handle the differing syntaxes needed for WeakPtr<> support,
// and for ignoring return values. This is separate from
// Invoker to avoid creating multiple version of Invoker<>
// which grows at O(n^2) with the arity.
// There are |k*ARITY| InvokeHelper types.
// Invoker<> -- Unwraps the curried parameters and executes the Runnable.
// There are |(ARITY^2 + ARITY)/2| Invoketypes.
// BindState<> -- Stores the curried parameters, and is the main entry point
// into the Bind() system, doing most of the type resolution.
// There are ARITY BindState types.
// RunnableAdapter<>
//
// The RunnableAdapter<> templates provide a uniform interface for invoking
// a function pointer, method pointer, or const method pointer. The adapter
// exposes a Run() method with an appropriate signature. Using this wrapper
// allows for writing code that supports all three pointer types without
// undue repetition. Without it, a lot of code would need to be repeated 3
// times.
//
// For method pointers and const method pointers the first argument to Run()
// is considered to be the received of the method. This is similar to STL's
// mem_fun().
//
// This class also exposes a RunType typedef that is the function type of the
// Run() function.
//
// If and only if the wrapper contains a method or const method pointer, an
// IsMethod typedef is exposed. The existence of this typedef (NOT the value)
// marks that the wrapper should be considered a method wrapper.
template <typename Functor>
class RunnableAdapter;
$for ARITY [[
$range ARG 1..ARITY
// Function: Arity $(ARITY).
template <typename R[[]]
$if ARITY > 0[[, ]] $for ARG , [[typename A$(ARG)]]>
class RunnableAdapter<R(*)($for ARG , [[A$(ARG)]])> {
public:
typedef R (RunType)($for ARG , [[A$(ARG)]]);
explicit RunnableAdapter(R(*function)($for ARG , [[A$(ARG)]]))
: function_(function) {
}
R Run($for ARG , [[typename CallbackParamTraits<A$(ARG)>::ForwardType a$(ARG)]]) {
return function_($for ARG , [[CallbackForward(a$(ARG))]]);
}
private:
R (*function_)($for ARG , [[A$(ARG)]]);
};
// Method: Arity $(ARITY).
template <typename R, typename T[[]]
$if ARITY > 0[[, ]] $for ARG , [[typename A$(ARG)]]>
class RunnableAdapter<R(T::*)($for ARG , [[A$(ARG)]])> {
public:
typedef R (RunType)(T*[[]]
$if ARITY > 0[[, ]] $for ARG , [[A$(ARG)]]);
typedef true_type IsMethod;
explicit RunnableAdapter(R(T::*method)($for ARG , [[A$(ARG)]]))
: method_(method) {
}
R Run(T* object[[]]
$if ARITY > 0[[, ]] $for ARG, [[typename CallbackParamTraits<A$(ARG)>::ForwardType a$(ARG)]]) {
return (object->*method_)($for ARG , [[CallbackForward(a$(ARG))]]);
}
private:
R (T::*method_)($for ARG , [[A$(ARG)]]);
};
// Const Method: Arity $(ARITY).
template <typename R, typename T[[]]
$if ARITY > 0[[, ]] $for ARG , [[typename A$(ARG)]]>
class RunnableAdapter<R(T::*)($for ARG , [[A$(ARG)]]) const> {
public:
typedef R (RunType)(const T*[[]]
$if ARITY > 0[[, ]] $for ARG , [[A$(ARG)]]);
typedef true_type IsMethod;
explicit RunnableAdapter(R(T::*method)($for ARG , [[A$(ARG)]]) const)
: method_(method) {
}
R Run(const T* object[[]]
$if ARITY > 0[[, ]] $for ARG, [[typename CallbackParamTraits<A$(ARG)>::ForwardType a$(ARG)]]) {
return (object->*method_)($for ARG , [[CallbackForward(a$(ARG))]]);
}
private:
R (T::*method_)($for ARG , [[A$(ARG)]]) const;
};
]] $$ for ARITY
// FunctionTraits<>
//
// Breaks a function signature apart into typedefs for easier introspection.
template <typename Sig>
struct FunctionTraits;
$for ARITY [[
$range ARG 1..ARITY
template <typename R[[]]
$if ARITY > 0[[, ]] $for ARG , [[typename A$(ARG)]]>
struct FunctionTraits<R($for ARG , [[A$(ARG)]])> {
typedef R ReturnType;
$for ARG [[
typedef A$(ARG) A$(ARG)Type;
]]
};
]]
// ForceVoidReturn<>
//
// Set of templates that support forcing the function return type to void.
template <typename Sig>
struct ForceVoidReturn;
$for ARITY [[
$range ARG 1..ARITY
template <typename R[[]]
$if ARITY > 0[[, ]] $for ARG , [[typename A$(ARG)]]>
struct ForceVoidReturn<R($for ARG , [[A$(ARG)]])> {
typedef void(RunType)($for ARG , [[A$(ARG)]]);
};
]] $$ for ARITY
// FunctorTraits<>
//
// See description at top of file.
template <typename T>
struct FunctorTraits {
typedef RunnableAdapter<T> RunnableType;
typedef typename RunnableType::RunType RunType;
};
template <typename T>
struct FunctorTraits<IgnoreResultHelper<T> > {
typedef typename FunctorTraits<T>::RunnableType RunnableType;
typedef typename ForceVoidReturn<
typename RunnableType::RunType>::RunType RunType;
};
template <typename T>
struct FunctorTraits<Callback<T> > {
typedef Callback<T> RunnableType;
typedef typename Callback<T>::RunType RunType;
};
// MakeRunnable<>
//
// Converts a passed in functor to a RunnableType using type inference.
template <typename T>
typename FunctorTraits<T>::RunnableType MakeRunnable(const T& t) {
return RunnableAdapter<T>(t);
}
template <typename T>
typename FunctorTraits<T>::RunnableType
MakeRunnable(const IgnoreResultHelper<T>& t) {
return MakeRunnable(t.functor_);
}
template <typename T>
const typename FunctorTraits<Callback<T> >::RunnableType&
MakeRunnable(const Callback<T>& t) {
return t;
}
// InvokeHelper<>
//
// There are 3 logical InvokeHelper<> specializations: normal, void-return,
// WeakCalls.
//
// The normal type just calls the underlying runnable.
//
// We need a InvokeHelper to handle void return types in order to support
// IgnoreResult(). Normally, if the Runnable's RunType had a void return,
// the template system would just accept "return functor.Run()" ignoring
// the fact that a void function is being used with return. This piece of
// sugar breaks though when the Runnable's RunType is not void. Thus, we
// need a partial specialization to change the syntax to drop the "return"
// from the invocation call.
//
// WeakCalls similarly need special syntax that is applied to the first
// argument to check if they should no-op themselves.
template <bool IsWeakCall, typename ReturnType, typename Runnable,
typename ArgsType>
struct InvokeHelper;
$for ARITY [[
$range ARG 1..ARITY
template <typename ReturnType, typename Runnable[[]]
$if ARITY > 0 [[,]] $for ARG , [[typename A$(ARG)]]>
struct InvokeHelper<false, ReturnType, Runnable,
void($for ARG , [[A$(ARG)]])> {
static ReturnType MakeItSo(Runnable runnable[[]]
$if ARITY > 0[[, ]] $for ARG , [[A$(ARG) a$(ARG)]]) {
return runnable.Run($for ARG , [[CallbackForward(a$(ARG))]]);
}
};
template <typename Runnable[[]]
$if ARITY > 0 [[,]] $for ARG , [[typename A$(ARG)]]>
struct InvokeHelper<false, void, Runnable,
void($for ARG , [[A$(ARG)]])> {
static void MakeItSo(Runnable runnable[[]]
$if ARITY > 0[[, ]] $for ARG , [[A$(ARG) a$(ARG)]]) {
runnable.Run($for ARG , [[CallbackForward(a$(ARG))]]);
}
};
$if ARITY > 0 [[
template <typename Runnable[[]], $for ARG , [[typename A$(ARG)]]>
struct InvokeHelper<true, void, Runnable,
void($for ARG , [[A$(ARG)]])> {
static void MakeItSo(Runnable runnable[[]]
$if ARITY > 0[[, ]] $for ARG , [[A$(ARG) a$(ARG)]]) {
if (!a1.get()) {
return;
}
runnable.Run($for ARG , [[CallbackForward(a$(ARG))]]);
}
};
]]
]] $$ for ARITY
#if !defined(_MSC_VER)
template <typename ReturnType, typename Runnable, typename ArgsType>
struct InvokeHelper<true, ReturnType, Runnable, ArgsType> {
// WeakCalls are only supported for functions with a void return type.
// Otherwise, the function result would be undefined if the the WeakPtr<>
// is invalidated.
COMPILE_ASSERT(is_void<ReturnType>::value,
weak_ptrs_can_only_bind_to_methods_without_return_values);
};
#endif
// Invoker<>
//
// See description at the top of the file.
template <int NumBound, typename Storage, typename RunType>
struct Invoker;
$for ARITY [[
$$ Number of bound arguments.
$range BOUND 0..ARITY
$for BOUND [[
$var UNBOUND = ARITY - BOUND
$range ARG 1..ARITY
$range BOUND_ARG 1..BOUND
$range UNBOUND_ARG (ARITY - UNBOUND + 1)..ARITY
// Arity $(ARITY) -> $(UNBOUND).
template <typename StorageType, typename R[[]]
$if ARITY > 0 [[,]][[]]
$for ARG , [[typename X$(ARG)]]>
struct Invoker<$(BOUND), StorageType, R($for ARG , [[X$(ARG)]])> {
typedef R(RunType)(BindStateBase*[[]]
$if UNBOUND != 0 [[, ]]
$for UNBOUND_ARG , [[typename CallbackParamTraits<X$(UNBOUND_ARG)>::ForwardType]]);
typedef R(UnboundRunType)($for UNBOUND_ARG , [[X$(UNBOUND_ARG)]]);
static R Run(BindStateBase* base[[]]
$if UNBOUND != 0 [[, ]][[]]
$for UNBOUND_ARG , [[
typename CallbackParamTraits<X$(UNBOUND_ARG)>::ForwardType x$(UNBOUND_ARG)
]][[]]
) {
StorageType* storage = static_cast<StorageType*>(base);
// Local references to make debugger stepping easier. If in a debugger,
// you really want to warp ahead and step through the
// InvokeHelper<>::MakeItSo() call below.
$for BOUND_ARG
[[
typedef typename StorageType::Bound$(BOUND_ARG)UnwrapTraits Bound$(BOUND_ARG)UnwrapTraits;
]]
$for BOUND_ARG
[[
typename Bound$(BOUND_ARG)UnwrapTraits::ForwardType x$(BOUND_ARG) =
Bound$(BOUND_ARG)UnwrapTraits::Unwrap(storage->p$(BOUND_ARG)_);
]]
return InvokeHelper<StorageType::IsWeakCall::value, R,
typename StorageType::RunnableType,
void(
$for BOUND_ARG , [[
typename Bound$(BOUND_ARG)UnwrapTraits::ForwardType
]]
$if UNBOUND > 0 [[$if BOUND > 0 [[, ]]]][[]]
$for UNBOUND_ARG , [[
typename CallbackParamTraits<X$(UNBOUND_ARG)>::ForwardType x$(UNBOUND_ARG)
]]
)>
::MakeItSo(storage->runnable_
$if ARITY > 0[[, ]] $for ARG , [[CallbackForward(x$(ARG))]]);
}
};
]] $$ for BOUND
]] $$ for ARITY
// BindState<>
//
// This stores all the state passed into Bind() and is also where most
// of the template resolution magic occurs.
//
// Runnable is the functor we are binding arguments to.
// RunType is type of the Run() function that the Invoker<> should use.
// Normally, this is the same as the RunType of the Runnable, but it can
// be different if an adapter like IgnoreResult() has been used.
//
// BoundArgsType contains the storage type for all the bound arguments by
// (ab)using a function type.
template <typename Runnable, typename RunType, typename BoundArgsType>
struct BindState;
$for ARITY [[
$range ARG 1..ARITY
template <typename Runnable, typename RunType[[]]
$if ARITY > 0[[, ]] $for ARG , [[typename P$(ARG)]]>
struct BindState<Runnable, RunType, void($for ARG , [[P$(ARG)]])> : public BindStateBase {
typedef Runnable RunnableType;
$if ARITY > 0 [[
typedef IsWeakMethod<HasIsMethodTag<Runnable>::value, P1> IsWeakCall;
]] $else [[
typedef false_type IsWeakCall;
]]
typedef Invoker<$(ARITY), BindState, RunType> InvokerType;
typedef typename InvokerType::UnboundRunType UnboundRunType;
$if ARITY > 0 [[
// Convenience typedefs for bound argument types.
$for ARG [[
typedef UnwrapTraits<P$(ARG)> Bound$(ARG)UnwrapTraits;
]] $$ for ARG
]] $$ if ARITY > 0
$$ The extra [[ ]] is needed to massage spacing. Silly pump.py.
[[ ]]$if ARITY == 0 [[explicit ]]BindState(const Runnable& runnable
$if ARITY > 0 [[, ]] $for ARG , [[const P$(ARG)& p$(ARG)]])
: runnable_(runnable)[[]]
$if ARITY == 0 [[
{
]] $else [[
, $for ARG , [[
p$(ARG)_(p$(ARG))
]] {
MaybeRefcount<HasIsMethodTag<Runnable>::value, P1>::AddRef(p1_);
]]
}
virtual ~BindState() {
$if ARITY > 0 [[
MaybeRefcount<HasIsMethodTag<Runnable>::value, P1>::Release(p1_);
]]
}
RunnableType runnable_;
$for ARG [[
P$(ARG) p$(ARG)_;
]]
};
]] $$ for ARITY
} // namespace internal
} // namespace base
#endif // BASE_BIND_INTERNAL_H_