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Diffstat (limited to 'third_party/libwebrtc/pc/proxy.h')
| -rw-r--r-- | third_party/libwebrtc/pc/proxy.h | 455 |
1 files changed, 455 insertions, 0 deletions
diff --git a/third_party/libwebrtc/pc/proxy.h b/third_party/libwebrtc/pc/proxy.h new file mode 100644 index 0000000000..2be115fdf3 --- /dev/null +++ b/third_party/libwebrtc/pc/proxy.h @@ -0,0 +1,455 @@ +/* + * Copyright 2013 The WebRTC project authors. All Rights Reserved. + * + * Use of this source code is governed by a BSD-style license + * that can be found in the LICENSE file in the root of the source + * tree. An additional intellectual property rights grant can be found + * in the file PATENTS. All contributing project authors may + * be found in the AUTHORS file in the root of the source tree. + */ + +// This file contains Macros for creating proxies for webrtc MediaStream and +// PeerConnection classes. + +// The proxied objects are initialized with either one or two thread +// objects that operations can be proxied to: The primary and secondary +// threads. +// In common usage, the primary thread will be the PeerConnection's +// signaling thread, and the secondary thread will be either the +// PeerConnection's worker thread or the PeerConnection's network thread. + +// +// Example usage: +// +// class TestInterface : public rtc::RefCountInterface { +// public: +// std::string FooA() = 0; +// std::string FooB(bool arg1) const = 0; +// std::string FooC(bool arg1) = 0; +// }; +// +// Note that return types can not be a const reference. +// +// class Test : public TestInterface { +// ... implementation of the interface. +// }; +// +// BEGIN_PROXY_MAP(Test) +// PROXY_PRIMARY_THREAD_DESTRUCTOR() +// PROXY_METHOD0(std::string, FooA) +// PROXY_CONSTMETHOD1(std::string, FooB, arg1) +// PROXY_SECONDARY_METHOD1(std::string, FooC, arg1) +// END_PROXY_MAP() +// +// Where the destructor and first two methods are invoked on the primary +// thread, and the third is invoked on the secondary thread. +// +// The proxy can be created using +// +// TestProxy::Create(Thread* signaling_thread, Thread* worker_thread, +// TestInterface*). +// +// The variant defined with BEGIN_PRIMARY_PROXY_MAP is unaware of +// the secondary thread, and invokes all methods on the primary thread. +// + +#ifndef PC_PROXY_H_ +#define PC_PROXY_H_ + +#include <stddef.h> + +#include <memory> +#include <string> +#include <tuple> +#include <type_traits> +#include <utility> + +#include "api/scoped_refptr.h" +#include "api/task_queue/task_queue_base.h" +#include "rtc_base/event.h" +#include "rtc_base/string_utils.h" +#include "rtc_base/system/rtc_export.h" +#include "rtc_base/thread.h" + +#if !defined(RTC_DISABLE_PROXY_TRACE_EVENTS) && !defined(WEBRTC_CHROMIUM_BUILD) +#define RTC_DISABLE_PROXY_TRACE_EVENTS +#endif + +namespace webrtc { +namespace proxy_internal { + +// Class for tracing the lifetime of MethodCall::Marshal. +class ScopedTrace { + public: + explicit ScopedTrace(const char* class_and_method_name); + ~ScopedTrace(); + + private: + [[maybe_unused]] const char* const class_and_method_name_; +}; +} // namespace proxy_internal + +template <typename R> +class ReturnType { + public: + template <typename C, typename M, typename... Args> + void Invoke(C* c, M m, Args&&... args) { + r_ = (c->*m)(std::forward<Args>(args)...); + } + + R moved_result() { return std::move(r_); } + + private: + R r_; +}; + +template <> +class ReturnType<void> { + public: + template <typename C, typename M, typename... Args> + void Invoke(C* c, M m, Args&&... args) { + (c->*m)(std::forward<Args>(args)...); + } + + void moved_result() {} +}; + +template <typename C, typename R, typename... Args> +class MethodCall { + public: + typedef R (C::*Method)(Args...); + MethodCall(C* c, Method m, Args&&... args) + : c_(c), + m_(m), + args_(std::forward_as_tuple(std::forward<Args>(args)...)) {} + + R Marshal(rtc::Thread* t) { + if (t->IsCurrent()) { + Invoke(std::index_sequence_for<Args...>()); + } else { + t->PostTask([this] { + Invoke(std::index_sequence_for<Args...>()); + event_.Set(); + }); + event_.Wait(rtc::Event::kForever); + } + return r_.moved_result(); + } + + private: + template <size_t... Is> + void Invoke(std::index_sequence<Is...>) { + r_.Invoke(c_, m_, std::move(std::get<Is>(args_))...); + } + + C* c_; + Method m_; + ReturnType<R> r_; + std::tuple<Args&&...> args_; + rtc::Event event_; +}; + +template <typename C, typename R, typename... Args> +class ConstMethodCall { + public: + typedef R (C::*Method)(Args...) const; + ConstMethodCall(const C* c, Method m, Args&&... args) + : c_(c), + m_(m), + args_(std::forward_as_tuple(std::forward<Args>(args)...)) {} + + R Marshal(rtc::Thread* t) { + if (t->IsCurrent()) { + Invoke(std::index_sequence_for<Args...>()); + } else { + t->PostTask([this] { + Invoke(std::index_sequence_for<Args...>()); + event_.Set(); + }); + event_.Wait(rtc::Event::kForever); + } + return r_.moved_result(); + } + + private: + template <size_t... Is> + void Invoke(std::index_sequence<Is...>) { + r_.Invoke(c_, m_, std::move(std::get<Is>(args_))...); + } + + const C* c_; + Method m_; + ReturnType<R> r_; + std::tuple<Args&&...> args_; + rtc::Event event_; +}; + +#define PROXY_STRINGIZE_IMPL(x) #x +#define PROXY_STRINGIZE(x) PROXY_STRINGIZE_IMPL(x) + +// Helper macros to reduce code duplication. +#define PROXY_MAP_BOILERPLATE(class_name) \ + template <class INTERNAL_CLASS> \ + class class_name##ProxyWithInternal; \ + typedef class_name##ProxyWithInternal<class_name##Interface> \ + class_name##Proxy; \ + template <class INTERNAL_CLASS> \ + class class_name##ProxyWithInternal : public class_name##Interface { \ + protected: \ + static constexpr char proxy_name_[] = #class_name "Proxy"; \ + typedef class_name##Interface C; \ + \ + public: \ + const INTERNAL_CLASS* internal() const { return c(); } \ + INTERNAL_CLASS* internal() { return c(); } + +// clang-format off +// clang-format would put the semicolon alone, +// leading to a presubmit error (cpplint.py) +#define END_PROXY_MAP(class_name) \ + }; \ + template <class INTERNAL_CLASS> \ + constexpr char class_name##ProxyWithInternal<INTERNAL_CLASS>::proxy_name_[]; +// clang-format on + +#define PRIMARY_PROXY_MAP_BOILERPLATE(class_name) \ + protected: \ + class_name##ProxyWithInternal(rtc::Thread* primary_thread, \ + rtc::scoped_refptr<INTERNAL_CLASS> c) \ + : primary_thread_(primary_thread), c_(std::move(c)) {} \ + \ + private: \ + mutable rtc::Thread* primary_thread_; + +#define SECONDARY_PROXY_MAP_BOILERPLATE(class_name) \ + protected: \ + class_name##ProxyWithInternal(rtc::Thread* primary_thread, \ + rtc::Thread* secondary_thread, \ + rtc::scoped_refptr<INTERNAL_CLASS> c) \ + : primary_thread_(primary_thread), \ + secondary_thread_(secondary_thread), \ + c_(std::move(c)) {} \ + \ + private: \ + mutable rtc::Thread* primary_thread_; \ + mutable rtc::Thread* secondary_thread_; + +// Note that the destructor is protected so that the proxy can only be +// destroyed via RefCountInterface. +#define REFCOUNTED_PROXY_MAP_BOILERPLATE(class_name) \ + protected: \ + ~class_name##ProxyWithInternal() { \ + MethodCall<class_name##ProxyWithInternal, void> call( \ + this, &class_name##ProxyWithInternal::DestroyInternal); \ + call.Marshal(destructor_thread()); \ + } \ + \ + private: \ + const INTERNAL_CLASS* c() const { return c_.get(); } \ + INTERNAL_CLASS* c() { return c_.get(); } \ + void DestroyInternal() { c_ = nullptr; } \ + rtc::scoped_refptr<INTERNAL_CLASS> c_; + +// Note: This doesn't use a unique_ptr, because it intends to handle a corner +// case where an object's deletion triggers a callback that calls back into +// this proxy object. If relying on a unique_ptr to delete the object, its +// inner pointer would be set to null before this reentrant callback would have +// a chance to run, resulting in a segfault. +#define OWNED_PROXY_MAP_BOILERPLATE(class_name) \ + public: \ + ~class_name##ProxyWithInternal() { \ + MethodCall<class_name##ProxyWithInternal, void> call( \ + this, &class_name##ProxyWithInternal::DestroyInternal); \ + call.Marshal(destructor_thread()); \ + } \ + \ + private: \ + const INTERNAL_CLASS* c() const { return c_; } \ + INTERNAL_CLASS* c() { return c_; } \ + void DestroyInternal() { delete c_; } \ + INTERNAL_CLASS* c_; + +#define BEGIN_PRIMARY_PROXY_MAP(class_name) \ + PROXY_MAP_BOILERPLATE(class_name) \ + PRIMARY_PROXY_MAP_BOILERPLATE(class_name) \ + REFCOUNTED_PROXY_MAP_BOILERPLATE(class_name) \ + public: \ + static rtc::scoped_refptr<class_name##ProxyWithInternal> Create( \ + rtc::Thread* primary_thread, rtc::scoped_refptr<INTERNAL_CLASS> c) { \ + return rtc::make_ref_counted<class_name##ProxyWithInternal>( \ + primary_thread, std::move(c)); \ + } + +#define BEGIN_PROXY_MAP(class_name) \ + PROXY_MAP_BOILERPLATE(class_name) \ + SECONDARY_PROXY_MAP_BOILERPLATE(class_name) \ + REFCOUNTED_PROXY_MAP_BOILERPLATE(class_name) \ + public: \ + static rtc::scoped_refptr<class_name##ProxyWithInternal> Create( \ + rtc::Thread* primary_thread, rtc::Thread* secondary_thread, \ + rtc::scoped_refptr<INTERNAL_CLASS> c) { \ + return rtc::make_ref_counted<class_name##ProxyWithInternal>( \ + primary_thread, secondary_thread, std::move(c)); \ + } + +#define PROXY_PRIMARY_THREAD_DESTRUCTOR() \ + private: \ + rtc::Thread* destructor_thread() const { return primary_thread_; } \ + \ + public: // NOLINTNEXTLINE + +#define PROXY_SECONDARY_THREAD_DESTRUCTOR() \ + private: \ + rtc::Thread* destructor_thread() const { return secondary_thread_; } \ + \ + public: // NOLINTNEXTLINE + +#if defined(RTC_DISABLE_PROXY_TRACE_EVENTS) +#define TRACE_BOILERPLATE(method) \ + do { \ + } while (0) +#else // if defined(RTC_DISABLE_PROXY_TRACE_EVENTS) +#define TRACE_BOILERPLATE(method) \ + static constexpr auto class_and_method_name = \ + rtc::MakeCompileTimeString(proxy_name_) \ + .Concat(rtc::MakeCompileTimeString("::")) \ + .Concat(rtc::MakeCompileTimeString(#method)); \ + proxy_internal::ScopedTrace scoped_trace(class_and_method_name.string) + +#endif // if defined(RTC_DISABLE_PROXY_TRACE_EVENTS) + +#define PROXY_METHOD0(r, method) \ + r method() override { \ + TRACE_BOILERPLATE(method); \ + MethodCall<C, r> call(c(), &C::method); \ + return call.Marshal(primary_thread_); \ + } + +#define PROXY_CONSTMETHOD0(r, method) \ + r method() const override { \ + TRACE_BOILERPLATE(method); \ + ConstMethodCall<C, r> call(c(), &C::method); \ + return call.Marshal(primary_thread_); \ + } + +#define PROXY_METHOD1(r, method, t1) \ + r method(t1 a1) override { \ + TRACE_BOILERPLATE(method); \ + MethodCall<C, r, t1> call(c(), &C::method, std::move(a1)); \ + return call.Marshal(primary_thread_); \ + } + +#define PROXY_CONSTMETHOD1(r, method, t1) \ + r method(t1 a1) const override { \ + TRACE_BOILERPLATE(method); \ + ConstMethodCall<C, r, t1> call(c(), &C::method, std::move(a1)); \ + return call.Marshal(primary_thread_); \ + } + +#define PROXY_METHOD2(r, method, t1, t2) \ + r method(t1 a1, t2 a2) override { \ + TRACE_BOILERPLATE(method); \ + MethodCall<C, r, t1, t2> call(c(), &C::method, std::move(a1), \ + std::move(a2)); \ + return call.Marshal(primary_thread_); \ + } + +#define PROXY_METHOD3(r, method, t1, t2, t3) \ + r method(t1 a1, t2 a2, t3 a3) override { \ + TRACE_BOILERPLATE(method); \ + MethodCall<C, r, t1, t2, t3> call(c(), &C::method, std::move(a1), \ + std::move(a2), std::move(a3)); \ + return call.Marshal(primary_thread_); \ + } + +#define PROXY_METHOD4(r, method, t1, t2, t3, t4) \ + r method(t1 a1, t2 a2, t3 a3, t4 a4) override { \ + TRACE_BOILERPLATE(method); \ + MethodCall<C, r, t1, t2, t3, t4> call(c(), &C::method, std::move(a1), \ + std::move(a2), std::move(a3), \ + std::move(a4)); \ + return call.Marshal(primary_thread_); \ + } + +#define PROXY_METHOD5(r, method, t1, t2, t3, t4, t5) \ + r method(t1 a1, t2 a2, t3 a3, t4 a4, t5 a5) override { \ + TRACE_BOILERPLATE(method); \ + MethodCall<C, r, t1, t2, t3, t4, t5> call(c(), &C::method, std::move(a1), \ + std::move(a2), std::move(a3), \ + std::move(a4), std::move(a5)); \ + return call.Marshal(primary_thread_); \ + } + +// Define methods which should be invoked on the secondary thread. +#define PROXY_SECONDARY_METHOD0(r, method) \ + r method() override { \ + TRACE_BOILERPLATE(method); \ + MethodCall<C, r> call(c(), &C::method); \ + return call.Marshal(secondary_thread_); \ + } + +#define PROXY_SECONDARY_CONSTMETHOD0(r, method) \ + r method() const override { \ + TRACE_BOILERPLATE(method); \ + ConstMethodCall<C, r> call(c(), &C::method); \ + return call.Marshal(secondary_thread_); \ + } + +#define PROXY_SECONDARY_METHOD1(r, method, t1) \ + r method(t1 a1) override { \ + TRACE_BOILERPLATE(method); \ + MethodCall<C, r, t1> call(c(), &C::method, std::move(a1)); \ + return call.Marshal(secondary_thread_); \ + } + +#define PROXY_SECONDARY_CONSTMETHOD1(r, method, t1) \ + r method(t1 a1) const override { \ + TRACE_BOILERPLATE(method); \ + ConstMethodCall<C, r, t1> call(c(), &C::method, std::move(a1)); \ + return call.Marshal(secondary_thread_); \ + } + +#define PROXY_SECONDARY_METHOD2(r, method, t1, t2) \ + r method(t1 a1, t2 a2) override { \ + TRACE_BOILERPLATE(method); \ + MethodCall<C, r, t1, t2> call(c(), &C::method, std::move(a1), \ + std::move(a2)); \ + return call.Marshal(secondary_thread_); \ + } + +#define PROXY_SECONDARY_CONSTMETHOD2(r, method, t1, t2) \ + r method(t1 a1, t2 a2) const override { \ + TRACE_BOILERPLATE(method); \ + ConstMethodCall<C, r, t1, t2> call(c(), &C::method, std::move(a1), \ + std::move(a2)); \ + return call.Marshal(secondary_thread_); \ + } + +#define PROXY_SECONDARY_METHOD3(r, method, t1, t2, t3) \ + r method(t1 a1, t2 a2, t3 a3) override { \ + TRACE_BOILERPLATE(method); \ + MethodCall<C, r, t1, t2, t3> call(c(), &C::method, std::move(a1), \ + std::move(a2), std::move(a3)); \ + return call.Marshal(secondary_thread_); \ + } + +#define PROXY_SECONDARY_CONSTMETHOD3(r, method, t1, t2) \ + r method(t1 a1, t2 a2, t3 a3) const override { \ + TRACE_BOILERPLATE(method); \ + ConstMethodCall<C, r, t1, t2, t3> call(c(), &C::method, std::move(a1), \ + std::move(a2), std::move(a3)); \ + return call.Marshal(secondary_thread_); \ + } + +// For use when returning purely const state (set during construction). +// Use with caution. This method should only be used when the return value will +// always be the same. +#define BYPASS_PROXY_CONSTMETHOD0(r, method) \ + r method() const override { \ + TRACE_BOILERPLATE(method); \ + return c_->method(); \ + } + +} // namespace webrtc + +#endif // PC_PROXY_H_ |