mirror of
https://bitbucket.org/chromiumembedded/cef
synced 2024-12-11 09:08:06 +01:00
83cb82d50f
This fixes duplicate symbol errors when building CEF sample applications as part of the Chromium build. These applications pick up a link-time dependency on base.lib via the //sandbox and/or //testing/gtest targets which then conflict with the symbols provided by the libcef_dll_wrapper target.
276 lines
10 KiB
C++
276 lines
10 KiB
C++
// Copyright (c) 2012 Google Inc. All rights reserved.
|
|
//
|
|
// Redistribution and use in source and binary forms, with or without
|
|
// modification, are permitted provided that the following conditions are
|
|
// met:
|
|
//
|
|
// * Redistributions of source code must retain the above copyright
|
|
// notice, this list of conditions and the following disclaimer.
|
|
// * Redistributions in binary form must reproduce the above
|
|
// copyright notice, this list of conditions and the following disclaimer
|
|
// in the documentation and/or other materials provided with the
|
|
// distribution.
|
|
// * Neither the name of Google Inc. nor the name Chromium Embedded
|
|
// Framework nor the names of its contributors may be used to endorse
|
|
// or promote products derived from this software without specific prior
|
|
// written permission.
|
|
//
|
|
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
|
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
|
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
// Do not include this header file directly. Use base/cef_bind.h or
|
|
// base/cef_callback.h instead.
|
|
|
|
// This file contains utility functions and classes that help the
|
|
// implementation, and management of the Callback objects.
|
|
|
|
#ifndef CEF_INCLUDE_BASE_INTERNAL_CEF_CALLBACK_INTERNAL_H_
|
|
#define CEF_INCLUDE_BASE_INTERNAL_CEF_CALLBACK_INTERNAL_H_
|
|
|
|
#include "include/base/cef_callback_forward.h"
|
|
#include "include/base/cef_ref_counted.h"
|
|
|
|
namespace base {
|
|
|
|
struct FakeBindState;
|
|
|
|
namespace cef_internal {
|
|
|
|
class BindStateBase;
|
|
class FinallyExecutorCommon;
|
|
class ThenAndCatchExecutorCommon;
|
|
|
|
template <typename ReturnType>
|
|
class PostTaskExecutor;
|
|
|
|
template <typename Functor, typename... BoundArgs>
|
|
struct BindState;
|
|
|
|
class CallbackBase;
|
|
class CallbackBaseCopyable;
|
|
|
|
struct BindStateBaseRefCountTraits {
|
|
static void Destruct(const BindStateBase*);
|
|
};
|
|
|
|
template <typename T>
|
|
using PassingType = std::conditional_t<std::is_scalar<T>::value, T, T&&>;
|
|
|
|
// BindStateBase is used to provide an opaque handle that the Callback
|
|
// class can use to represent a function object with bound arguments. It
|
|
// behaves as an existential type that is used by a corresponding
|
|
// DoInvoke function to perform the function execution. This allows
|
|
// us to shield the Callback class from the types of the bound argument via
|
|
// "type erasure."
|
|
// At the base level, the only task is to add reference counting data. Avoid
|
|
// using or inheriting any virtual functions. Creating a vtable for every
|
|
// BindState template instantiation results in a lot of bloat. Its only task is
|
|
// to call the destructor which can be done with a function pointer.
|
|
class BindStateBase
|
|
: public RefCountedThreadSafe<BindStateBase, BindStateBaseRefCountTraits> {
|
|
public:
|
|
REQUIRE_ADOPTION_FOR_REFCOUNTED_TYPE();
|
|
|
|
enum CancellationQueryMode {
|
|
IS_CANCELLED,
|
|
MAYBE_VALID,
|
|
};
|
|
|
|
using InvokeFuncStorage = void (*)();
|
|
|
|
BindStateBase(const BindStateBase&) = delete;
|
|
BindStateBase& operator=(const BindStateBase&) = delete;
|
|
|
|
private:
|
|
BindStateBase(InvokeFuncStorage polymorphic_invoke,
|
|
void (*destructor)(const BindStateBase*));
|
|
BindStateBase(InvokeFuncStorage polymorphic_invoke,
|
|
void (*destructor)(const BindStateBase*),
|
|
bool (*query_cancellation_traits)(const BindStateBase*,
|
|
CancellationQueryMode mode));
|
|
|
|
~BindStateBase() = default;
|
|
|
|
friend struct BindStateBaseRefCountTraits;
|
|
friend class RefCountedThreadSafe<BindStateBase, BindStateBaseRefCountTraits>;
|
|
|
|
friend class CallbackBase;
|
|
friend class CallbackBaseCopyable;
|
|
|
|
// Allowlist subclasses that access the destructor of BindStateBase.
|
|
template <typename Functor, typename... BoundArgs>
|
|
friend struct BindState;
|
|
friend struct ::base::FakeBindState;
|
|
|
|
bool IsCancelled() const {
|
|
return query_cancellation_traits_(this, IS_CANCELLED);
|
|
}
|
|
|
|
bool MaybeValid() const {
|
|
return query_cancellation_traits_(this, MAYBE_VALID);
|
|
}
|
|
|
|
// In C++, it is safe to cast function pointers to function pointers of
|
|
// another type. It is not okay to use void*. We create a InvokeFuncStorage
|
|
// that that can store our function pointer, and then cast it back to
|
|
// the original type on usage.
|
|
InvokeFuncStorage polymorphic_invoke_;
|
|
|
|
// Pointer to a function that will properly destroy |this|.
|
|
void (*destructor_)(const BindStateBase*);
|
|
bool (*query_cancellation_traits_)(const BindStateBase*,
|
|
CancellationQueryMode mode);
|
|
};
|
|
|
|
// Holds the Callback methods that don't require specialization to reduce
|
|
// template bloat.
|
|
// CallbackBase<MoveOnly> is a direct base class of MoveOnly callbacks, and
|
|
// CallbackBase<Copyable> uses CallbackBase<MoveOnly> for its implementation.
|
|
class CallbackBase {
|
|
public:
|
|
inline CallbackBase(CallbackBase&& c) noexcept;
|
|
CallbackBase& operator=(CallbackBase&& c) noexcept;
|
|
|
|
explicit CallbackBase(const CallbackBaseCopyable& c);
|
|
CallbackBase& operator=(const CallbackBaseCopyable& c);
|
|
|
|
explicit CallbackBase(CallbackBaseCopyable&& c) noexcept;
|
|
CallbackBase& operator=(CallbackBaseCopyable&& c) noexcept;
|
|
|
|
// Returns true if Callback is null (doesn't refer to anything).
|
|
bool is_null() const { return !bind_state_; }
|
|
explicit operator bool() const { return !is_null(); }
|
|
|
|
// Returns true if the callback invocation will be nop due to an cancellation.
|
|
// It's invalid to call this on uninitialized callback.
|
|
//
|
|
// Must be called on the Callback's destination sequence.
|
|
bool IsCancelled() const;
|
|
|
|
// If this returns false, the callback invocation will be a nop due to a
|
|
// cancellation. This may(!) still return true, even on a cancelled callback.
|
|
//
|
|
// This function is thread-safe.
|
|
bool MaybeValid() const;
|
|
|
|
// Returns the Callback into an uninitialized state.
|
|
void Reset();
|
|
|
|
protected:
|
|
friend class FinallyExecutorCommon;
|
|
friend class ThenAndCatchExecutorCommon;
|
|
|
|
template <typename ReturnType>
|
|
friend class PostTaskExecutor;
|
|
|
|
using InvokeFuncStorage = BindStateBase::InvokeFuncStorage;
|
|
|
|
// Returns true if this callback equals |other|. |other| may be null.
|
|
bool EqualsInternal(const CallbackBase& other) const;
|
|
|
|
constexpr inline CallbackBase();
|
|
|
|
// Allow initializing of |bind_state_| via the constructor to avoid default
|
|
// initialization of the scoped_refptr.
|
|
explicit inline CallbackBase(BindStateBase* bind_state);
|
|
|
|
InvokeFuncStorage polymorphic_invoke() const {
|
|
return bind_state_->polymorphic_invoke_;
|
|
}
|
|
|
|
// Force the destructor to be instantiated inside this translation unit so
|
|
// that our subclasses will not get inlined versions. Avoids more template
|
|
// bloat.
|
|
~CallbackBase();
|
|
|
|
scoped_refptr<BindStateBase> bind_state_;
|
|
};
|
|
|
|
constexpr CallbackBase::CallbackBase() = default;
|
|
CallbackBase::CallbackBase(CallbackBase&&) noexcept = default;
|
|
CallbackBase::CallbackBase(BindStateBase* bind_state)
|
|
: bind_state_(AdoptRef(bind_state)) {}
|
|
|
|
// CallbackBase<Copyable> is a direct base class of Copyable Callbacks.
|
|
class CallbackBaseCopyable : public CallbackBase {
|
|
public:
|
|
CallbackBaseCopyable(const CallbackBaseCopyable& c);
|
|
CallbackBaseCopyable(CallbackBaseCopyable&& c) noexcept = default;
|
|
CallbackBaseCopyable& operator=(const CallbackBaseCopyable& c);
|
|
CallbackBaseCopyable& operator=(CallbackBaseCopyable&& c) noexcept;
|
|
|
|
protected:
|
|
constexpr CallbackBaseCopyable() = default;
|
|
explicit CallbackBaseCopyable(BindStateBase* bind_state)
|
|
: CallbackBase(bind_state) {}
|
|
~CallbackBaseCopyable() = default;
|
|
};
|
|
|
|
// Helpers for the `Then()` implementation.
|
|
template <typename OriginalCallback, typename ThenCallback>
|
|
struct ThenHelper;
|
|
|
|
// Specialization when original callback returns `void`.
|
|
template <template <typename> class OriginalCallback,
|
|
template <typename>
|
|
class ThenCallback,
|
|
typename... OriginalArgs,
|
|
typename ThenR,
|
|
typename... ThenArgs>
|
|
struct ThenHelper<OriginalCallback<void(OriginalArgs...)>,
|
|
ThenCallback<ThenR(ThenArgs...)>> {
|
|
static_assert(sizeof...(ThenArgs) == 0,
|
|
"|then| callback cannot accept parameters if |this| has a "
|
|
"void return type.");
|
|
|
|
static auto CreateTrampoline() {
|
|
return [](OriginalCallback<void(OriginalArgs...)> c1,
|
|
ThenCallback<ThenR(ThenArgs...)> c2, OriginalArgs... c1_args) {
|
|
std::move(c1).Run(std::forward<OriginalArgs>(c1_args)...);
|
|
return std::move(c2).Run();
|
|
};
|
|
}
|
|
};
|
|
|
|
// Specialization when original callback returns a non-void type.
|
|
template <template <typename> class OriginalCallback,
|
|
template <typename>
|
|
class ThenCallback,
|
|
typename OriginalR,
|
|
typename... OriginalArgs,
|
|
typename ThenR,
|
|
typename... ThenArgs>
|
|
struct ThenHelper<OriginalCallback<OriginalR(OriginalArgs...)>,
|
|
ThenCallback<ThenR(ThenArgs...)>> {
|
|
static_assert(sizeof...(ThenArgs) == 1,
|
|
"|then| callback must accept exactly one parameter if |this| "
|
|
"has a non-void return type.");
|
|
// TODO(dcheng): This should probably check is_convertible as well (same with
|
|
// `AssertBindArgsValidity`).
|
|
static_assert(std::is_constructible<ThenArgs..., OriginalR&&>::value,
|
|
"|then| callback's parameter must be constructible from "
|
|
"return type of |this|.");
|
|
|
|
static auto CreateTrampoline() {
|
|
return [](OriginalCallback<OriginalR(OriginalArgs...)> c1,
|
|
ThenCallback<ThenR(ThenArgs...)> c2, OriginalArgs... c1_args) {
|
|
return std::move(c2).Run(
|
|
std::move(c1).Run(std::forward<OriginalArgs>(c1_args)...));
|
|
};
|
|
}
|
|
};
|
|
|
|
} // namespace cef_internal
|
|
} // namespace base
|
|
|
|
#endif // CEF_INCLUDE_BASE_INTERNAL_CEF_CALLBACK_INTERNAL_H_
|