Mercurial > hg > sv-dependency-builds
diff win64-msvc/include/kj/threadlocal.h @ 63:0f2d93caa50c
Update Win64 capnp builds to v0.6
author | Chris Cannam |
---|---|
date | Mon, 22 May 2017 18:56:49 +0100 |
parents | d93140aac40b |
children |
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--- a/win64-msvc/include/kj/threadlocal.h Mon May 22 10:01:37 2017 +0100 +++ b/win64-msvc/include/kj/threadlocal.h Mon May 22 18:56:49 2017 +0100 @@ -1,136 +1,136 @@ -// Copyright (c) 2014, Jason Choy <jjwchoy@gmail.com> -// Copyright (c) 2013-2014 Sandstorm Development Group, Inc. and contributors -// Licensed under the MIT License: -// -// Permission is hereby granted, free of charge, to any person obtaining a copy -// of this software and associated documentation files (the "Software"), to deal -// in the Software without restriction, including without limitation the rights -// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell -// copies of the Software, and to permit persons to whom the Software is -// furnished to do so, subject to the following conditions: -// -// The above copyright notice and this permission notice shall be included in -// all copies or substantial portions of the Software. -// -// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR -// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, -// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE -// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER -// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, -// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN -// THE SOFTWARE. - -#ifndef KJ_THREADLOCAL_H_ -#define KJ_THREADLOCAL_H_ - -#if defined(__GNUC__) && !KJ_HEADER_WARNINGS -#pragma GCC system_header -#endif -// This file declares a macro `KJ_THREADLOCAL_PTR` for declaring thread-local pointer-typed -// variables. Use like: -// KJ_THREADLOCAL_PTR(MyType) foo = nullptr; -// This is equivalent to: -// thread_local MyType* foo = nullptr; -// This can only be used at the global scope. -// -// AVOID USING THIS. Use of thread-locals is discouraged because they often have many of the same -// properties as singletons: http://www.object-oriented-security.org/lets-argue/singletons -// -// Also, thread-locals tend to be hostile to event-driven code, which can be particularly -// surprising when using fibers (all fibers in the same thread will share the same threadlocals, -// even though they do not share a stack). -// -// That said, thread-locals are sometimes needed for runtime logistics in the KJ framework. For -// example, the current exception callback and current EventLoop are stored as thread-local -// pointers. Since KJ only ever needs to store pointers, not values, we avoid the question of -// whether these values' destructors need to be run, and we avoid the need for heap allocation. - -#include "common.h" - -#if !defined(KJ_USE_PTHREAD_THREADLOCAL) && defined(__APPLE__) -#include "TargetConditionals.h" -#if TARGET_OS_IPHONE -// iOS apparently does not support __thread (nor C++11 thread_local). -#define KJ_USE_PTHREAD_TLS 1 -#endif -#endif - -#if KJ_USE_PTHREAD_TLS -#include <pthread.h> -#endif - -namespace kj { - -#if KJ_USE_PTHREAD_TLS -// If __thread is unavailable, we'll fall back to pthreads. - -#define KJ_THREADLOCAL_PTR(type) \ - namespace { struct KJ_UNIQUE_NAME(_kj_TlpTag); } \ - static ::kj::_::ThreadLocalPtr< type, KJ_UNIQUE_NAME(_kj_TlpTag)> -// Hack: In order to ensure each thread-local results in a unique template instance, we declare -// a one-off dummy type to use as the second type parameter. - -namespace _ { // private - -template <typename T, typename> -class ThreadLocalPtr { - // Hacky type to emulate __thread T*. We need a separate instance of the ThreadLocalPtr template - // for every thread-local variable, because we don't want to require a global constructor, and in - // order to initialize the TLS on first use we need to use a local static variable (in getKey()). - // Each template instance will get a separate such local static variable, fulfilling our need. - -public: - ThreadLocalPtr() = default; - constexpr ThreadLocalPtr(decltype(nullptr)) {} - // Allow initialization to nullptr without a global constructor. - - inline ThreadLocalPtr& operator=(T* val) { - pthread_setspecific(getKey(), val); - return *this; - } - - inline operator T*() const { - return get(); - } - - inline T& operator*() const { - return *get(); - } - - inline T* operator->() const { - return get(); - } - -private: - inline T* get() const { - return reinterpret_cast<T*>(pthread_getspecific(getKey())); - } - - inline static pthread_key_t getKey() { - static pthread_key_t key = createKey(); - return key; - } - - static pthread_key_t createKey() { - pthread_key_t key; - pthread_key_create(&key, 0); - return key; - } -}; - -} // namespace _ (private) - -#elif __GNUC__ - -#define KJ_THREADLOCAL_PTR(type) static __thread type* -// GCC's __thread is lighter-weight than thread_local and is good enough for our purposes. - -#else - -#define KJ_THREADLOCAL_PTR(type) static thread_local type* - -#endif // KJ_USE_PTHREAD_TLS - -} // namespace kj - -#endif // KJ_THREADLOCAL_H_ +// Copyright (c) 2014, Jason Choy <jjwchoy@gmail.com> +// Copyright (c) 2013-2014 Sandstorm Development Group, Inc. and contributors +// Licensed under the MIT License: +// +// Permission is hereby granted, free of charge, to any person obtaining a copy +// of this software and associated documentation files (the "Software"), to deal +// in the Software without restriction, including without limitation the rights +// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +// copies of the Software, and to permit persons to whom the Software is +// furnished to do so, subject to the following conditions: +// +// The above copyright notice and this permission notice shall be included in +// all copies or substantial portions of the Software. +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +// THE SOFTWARE. + +#ifndef KJ_THREADLOCAL_H_ +#define KJ_THREADLOCAL_H_ + +#if defined(__GNUC__) && !KJ_HEADER_WARNINGS +#pragma GCC system_header +#endif +// This file declares a macro `KJ_THREADLOCAL_PTR` for declaring thread-local pointer-typed +// variables. Use like: +// KJ_THREADLOCAL_PTR(MyType) foo = nullptr; +// This is equivalent to: +// thread_local MyType* foo = nullptr; +// This can only be used at the global scope. +// +// AVOID USING THIS. Use of thread-locals is discouraged because they often have many of the same +// properties as singletons: http://www.object-oriented-security.org/lets-argue/singletons +// +// Also, thread-locals tend to be hostile to event-driven code, which can be particularly +// surprising when using fibers (all fibers in the same thread will share the same threadlocals, +// even though they do not share a stack). +// +// That said, thread-locals are sometimes needed for runtime logistics in the KJ framework. For +// example, the current exception callback and current EventLoop are stored as thread-local +// pointers. Since KJ only ever needs to store pointers, not values, we avoid the question of +// whether these values' destructors need to be run, and we avoid the need for heap allocation. + +#include "common.h" + +#if !defined(KJ_USE_PTHREAD_THREADLOCAL) && defined(__APPLE__) +#include "TargetConditionals.h" +#if TARGET_OS_IPHONE +// iOS apparently does not support __thread (nor C++11 thread_local). +#define KJ_USE_PTHREAD_TLS 1 +#endif +#endif + +#if KJ_USE_PTHREAD_TLS +#include <pthread.h> +#endif + +namespace kj { + +#if KJ_USE_PTHREAD_TLS +// If __thread is unavailable, we'll fall back to pthreads. + +#define KJ_THREADLOCAL_PTR(type) \ + namespace { struct KJ_UNIQUE_NAME(_kj_TlpTag); } \ + static ::kj::_::ThreadLocalPtr< type, KJ_UNIQUE_NAME(_kj_TlpTag)> +// Hack: In order to ensure each thread-local results in a unique template instance, we declare +// a one-off dummy type to use as the second type parameter. + +namespace _ { // private + +template <typename T, typename> +class ThreadLocalPtr { + // Hacky type to emulate __thread T*. We need a separate instance of the ThreadLocalPtr template + // for every thread-local variable, because we don't want to require a global constructor, and in + // order to initialize the TLS on first use we need to use a local static variable (in getKey()). + // Each template instance will get a separate such local static variable, fulfilling our need. + +public: + ThreadLocalPtr() = default; + constexpr ThreadLocalPtr(decltype(nullptr)) {} + // Allow initialization to nullptr without a global constructor. + + inline ThreadLocalPtr& operator=(T* val) { + pthread_setspecific(getKey(), val); + return *this; + } + + inline operator T*() const { + return get(); + } + + inline T& operator*() const { + return *get(); + } + + inline T* operator->() const { + return get(); + } + +private: + inline T* get() const { + return reinterpret_cast<T*>(pthread_getspecific(getKey())); + } + + inline static pthread_key_t getKey() { + static pthread_key_t key = createKey(); + return key; + } + + static pthread_key_t createKey() { + pthread_key_t key; + pthread_key_create(&key, 0); + return key; + } +}; + +} // namespace _ (private) + +#elif __GNUC__ + +#define KJ_THREADLOCAL_PTR(type) static __thread type* +// GCC's __thread is lighter-weight than thread_local and is good enough for our purposes. + +#else + +#define KJ_THREADLOCAL_PTR(type) static thread_local type* + +#endif // KJ_USE_PTHREAD_TLS + +} // namespace kj + +#endif // KJ_THREADLOCAL_H_