/*
- * Copyright 2013 Facebook, Inc.
+ * Copyright 2015 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#ifndef FOLLY_THREADLOCAL_H_
#define FOLLY_THREADLOCAL_H_
-#include "folly/Portability.h"
+#include <folly/Portability.h>
#include <boost/iterator/iterator_facade.hpp>
-#include "folly/Likely.h"
+#include <folly/Likely.h>
#include <type_traits>
-// Use noexcept on gcc 4.6 or higher
-#undef FOLLY_NOEXCEPT
-#ifdef __GNUC__
-# ifdef HAVE_FEATURES_H
-# include <features.h>
-# if __GNUC_PREREQ(4,6)
-# define FOLLY_NOEXCEPT noexcept
-# define FOLLY_ASSERT(x) x
-# endif
-# endif
-#endif
-
-#ifndef FOLLY_NOEXCEPT
-# define FOLLY_NOEXCEPT
-# define FOLLY_ASSERT(x) /**/
-#endif
namespace folly {
enum class TLPDestructionMode {
};
} // namespace
-#include "folly/detail/ThreadLocalDetail.h"
+#include <folly/detail/ThreadLocalDetail.h>
namespace folly {
template<class T, class Tag=void>
class ThreadLocal {
public:
- ThreadLocal() { }
+ constexpr ThreadLocal() : constructor_([]() {
+ return new T();
+ }) {}
+
+ explicit ThreadLocal(std::function<T*()> constructor) :
+ constructor_(constructor) {
+ }
T* get() const {
T* ptr = tlp_.get();
ThreadLocal& operator=(const ThreadLocal&) = delete;
T* makeTlp() const {
- T* ptr = new T();
+ auto ptr = constructor_();
tlp_.reset(ptr);
return ptr;
}
mutable ThreadLocalPtr<T,Tag> tlp_;
+ std::function<T*()> constructor_;
};
/*
* We use a single global pthread_key_t per Tag to manage object destruction and
* memory cleanup upon thread exit because there is a finite number of
* pthread_key_t's available per machine.
+ *
+ * NOTE: Apple platforms don't support the same semantics for __thread that
+ * Linux does (and it's only supported at all on i386). For these, use
+ * pthread_setspecific()/pthread_getspecific() for the per-thread
+ * storage. Windows (MSVC and GCC) does support the same semantics
+ * with __declspec(thread)
*/
template<class T, class Tag=void>
class ThreadLocalPtr {
+ private:
+ typedef threadlocal_detail::StaticMeta<Tag> StaticMeta;
public:
- ThreadLocalPtr() : id_(threadlocal_detail::StaticMeta<Tag>::create()) { }
+ constexpr ThreadLocalPtr() : id_() {}
- ThreadLocalPtr(ThreadLocalPtr&& other) : id_(other.id_) {
- other.id_ = 0;
+ ThreadLocalPtr(ThreadLocalPtr&& other) noexcept :
+ id_(std::move(other.id_)) {
}
ThreadLocalPtr& operator=(ThreadLocalPtr&& other) {
assert(this != &other);
destroy();
- id_ = other.id_;
- other.id_ = 0;
+ id_ = std::move(other.id_);
return *this;
}
}
T* get() const {
- return static_cast<T*>(threadlocal_detail::StaticMeta<Tag>::get(id_).ptr);
+ threadlocal_detail::ElementWrapper& w = StaticMeta::get(&id_);
+ return static_cast<T*>(w.ptr);
}
T* operator->() const {
return *get();
}
+ T* release() {
+ threadlocal_detail::ElementWrapper& w = StaticMeta::get(&id_);
+
+ return static_cast<T*>(w.release());
+ }
+
void reset(T* newPtr = nullptr) {
- threadlocal_detail::ElementWrapper& w =
- threadlocal_detail::StaticMeta<Tag>::get(id_);
+ threadlocal_detail::ElementWrapper& w = StaticMeta::get(&id_);
+
if (w.ptr != newPtr) {
w.dispose(TLPDestructionMode::THIS_THREAD);
w.set(newPtr);
*/
template <class Deleter>
void reset(T* newPtr, Deleter deleter) {
- threadlocal_detail::ElementWrapper& w =
- threadlocal_detail::StaticMeta<Tag>::get(id_);
+ threadlocal_detail::ElementWrapper& w = StaticMeta::get(&id_);
if (w.ptr != newPtr) {
w.dispose(TLPDestructionMode::THIS_THREAD);
w.set(newPtr, deleter);
friend class ThreadLocalPtr<T,Tag>;
threadlocal_detail::StaticMeta<Tag>& meta_;
- boost::mutex* lock_;
- int id_;
+ std::mutex* lock_;
+ uint32_t id_;
public:
class Iterator;
Accessor(const Accessor&) = delete;
Accessor& operator=(const Accessor&) = delete;
- Accessor(Accessor&& other) FOLLY_NOEXCEPT
+ Accessor(Accessor&& other) noexcept
: meta_(other.meta_),
lock_(other.lock_),
id_(other.id_) {
other.lock_ = nullptr;
}
- Accessor& operator=(Accessor&& other) FOLLY_NOEXCEPT {
+ Accessor& operator=(Accessor&& other) noexcept {
// Each Tag has its own unique meta, and accessors with different Tags
// have different types. So either *this is empty, or this and other
// have the same tag. But if they have the same tag, they have the same
}
private:
- explicit Accessor(int id)
+ explicit Accessor(uint32_t id)
: meta_(threadlocal_detail::StaticMeta<Tag>::instance()),
lock_(&meta_.lock_) {
lock_->lock();
// accessor allows a client to iterate through all thread local child
// elements of this ThreadLocal instance. Holds a global lock for each <Tag>
Accessor accessAllThreads() const {
- FOLLY_ASSERT(static_assert(!std::is_same<Tag, void>::value,
- "Must use a unique Tag to use the accessAllThreads feature"));
- return Accessor(id_);
+ static_assert(!std::is_same<Tag, void>::value,
+ "Must use a unique Tag to use the accessAllThreads feature");
+ return Accessor(id_.getOrAllocate());
}
private:
void destroy() {
- if (id_) {
- threadlocal_detail::StaticMeta<Tag>::destroy(id_);
- }
+ StaticMeta::destroy(&id_);
}
// non-copyable
ThreadLocalPtr(const ThreadLocalPtr&) = delete;
ThreadLocalPtr& operator=(const ThreadLocalPtr&) = delete;
- int id_; // every instantiation has a unique id
+ mutable typename StaticMeta::EntryID id_;
};
-#undef FOLLY_NOEXCEPT
-
} // namespace folly
#endif /* FOLLY_THREADLOCAL_H_ */
projects / folly.git / blobdiff