mirror of
https://github.com/mangosfour/server.git
synced 2025-12-12 10:37:03 +00:00
382 lines
11 KiB
C++
382 lines
11 KiB
C++
/*
|
|
* Copyright (c) 2005, Eric Crahen
|
|
*
|
|
* 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 __ZTTHREADLOCAL_H__
|
|
#define __ZTTHREADLOCAL_H__
|
|
|
|
#include "zthread/ThreadLocalImpl.h"
|
|
|
|
namespace ZThread {
|
|
|
|
/**
|
|
* @class ThreadLocal
|
|
*
|
|
* @author Eric Crahen <http://www.code-foo.com>
|
|
* @date <2003-07-27T11:18:21-0400>
|
|
* @version 2.3.0
|
|
*
|
|
* Provides access to store and retrieve value types to and from a thread local
|
|
* storage context. A thread local storage context consists of the calling thread
|
|
* a specific ThreadLocal object. Since this context is specific to each thread
|
|
* whenever a value is stored in a ThreadLocal that is accessible from multiple
|
|
* threads, it can only be retrieved by the thread that stored it.
|
|
*
|
|
* The first time a thread accesses the value associated with a thread local storage
|
|
* context, a value is created. That value is either an initial value (determined by
|
|
* InitialValueT) or an inherited value (determined by ChildValueT).
|
|
*
|
|
* - If a threads parent had no value associated with a ThreadLocal when the thread was created,
|
|
* then the InitialValueT functor is used to create an initial value.
|
|
*
|
|
* - If a threads parent did have a value associated with a ThreadLocal when the thread was
|
|
* created, then the childValueT functor is used to create an initial value.
|
|
*
|
|
* Not all ThreadLocal's support the inheritance of values from parent threads. The default
|
|
* behavoir is to create values through the InitialValueT functor for all thread when
|
|
* they first access a thread local storage context.
|
|
*
|
|
* - Inheritance is enabled automatically when a user supplies a ChildValueT functor other
|
|
* than the default one supplied.
|
|
*
|
|
* - Inheritance can be controlled explicitly by the user through a third functor,
|
|
* InheritableValueT.
|
|
*
|
|
* <h2>Examples</h2>
|
|
*
|
|
* - <a href="#ex1">Default initial value</a>
|
|
* - <a href="#ex2">User-specified initial value</a>
|
|
* - <a href="#ex3">User-specified inherited value</a>
|
|
*
|
|
* <h2><a name="ex1">Default initial value</a></h2>
|
|
* A ThreadLocal that does not inherit, and uses the default value
|
|
* for an int as its initial value.
|
|
*
|
|
* @code
|
|
*
|
|
* #include "zthread/ThreadLocal.h"
|
|
* #include "zthread/Thread.h"
|
|
* #include <iostream>
|
|
*
|
|
* using namespace ZThread;
|
|
*
|
|
* class aRunnable : public Runnable {
|
|
* ThreadLocal<int> localValue;
|
|
* public:
|
|
* void run() {
|
|
* std::cout << localValue.get() << std::endl;
|
|
* }
|
|
* };
|
|
*
|
|
* int main() {
|
|
*
|
|
* // Create a shared task to display ThreadLocal values
|
|
* Task task(new aRunnable);
|
|
*
|
|
* Thread t0(task); t0.wait();
|
|
* Thread t1(task); t1.wait();
|
|
* Thread t2(task); t2.wait();
|
|
*
|
|
* // Output:
|
|
*
|
|
* // 0
|
|
* // 0
|
|
* // 0
|
|
*
|
|
* return 0;
|
|
*
|
|
* }
|
|
*
|
|
* @endcode
|
|
*
|
|
* <h2><a name="ex2">User-specified initial value</a></h2>
|
|
* A ThreadLocal that does not inherit, and uses a custom initial value.
|
|
*
|
|
* @code
|
|
*
|
|
* #include "zthread/ThreadLocal.h"
|
|
* #include "zthread/Thread.h"
|
|
* #include <iostream>
|
|
*
|
|
* using namespace ZThread;
|
|
*
|
|
* struct anInitialValueFn {
|
|
* int operator()() {
|
|
* static int next = 100;
|
|
* int val = next; next += 100;
|
|
* return val;
|
|
* }
|
|
* };
|
|
*
|
|
* class aRunnable : public Runnable {
|
|
* ThreadLocal<int, anInitialValueFn> localValue;
|
|
* public:
|
|
* void run() {
|
|
* std::cout << localValue.get() << std::endl;
|
|
* }
|
|
* };
|
|
*
|
|
* int main() {
|
|
*
|
|
* // Create a shared task to display ThreadLocal values
|
|
* Task task(new aRunnable);
|
|
*
|
|
* Thread t0(task); t0.wait();
|
|
* Thread t1(task); t1.wait();
|
|
* Thread t2(task); t2.wait();
|
|
*
|
|
* // Output:
|
|
*
|
|
* // 100
|
|
* // 200
|
|
* // 300
|
|
*
|
|
* return 0;
|
|
*
|
|
* }
|
|
*
|
|
* @endcode
|
|
*
|
|
* <h2><a name="ex3">User-specified inherited value</a></h2>
|
|
* A ThreadLocal that does inherit and modify child values.
|
|
* (The default initial value functor is used)
|
|
*
|
|
* @code
|
|
*
|
|
* #include "zthread/ThreadLocal.h"
|
|
* #include "zthread/Thread.h"
|
|
* #include <iostream>
|
|
*
|
|
* using namespace ZThread;
|
|
*
|
|
* struct anInheritedValueFn {
|
|
* int operator()(int val) {
|
|
* return val + 100;
|
|
* }
|
|
* };
|
|
*
|
|
* // This Runnable associates no ThreadLocal value in the main thread; so
|
|
* // none of the child threads have anything to inherit.
|
|
* class aRunnable : public Runnable {
|
|
* ThreadLocal<int, ThreadLocalImpl::InitialValueFn<int>, anInheritedValueFn> localValue;
|
|
* public:
|
|
* void run() {
|
|
* std::cout << localValue.get() << std::endl;
|
|
* }
|
|
* };
|
|
*
|
|
* // This Runnable associates a ThreadLocal value in the main thread which
|
|
* // is inherited when the child threads are created.
|
|
* class anotherRunnable : public Runnable {
|
|
* ThreadLocal<int, ThreadLocalImpl::InitialValueFn<int>, anInheritedValueFn> localValue;
|
|
* public:
|
|
* anotherRunnable() {
|
|
* localValue.set(100);
|
|
* }
|
|
* void run() {
|
|
* std::cout << localValue.get() << std::endl;
|
|
* }
|
|
* };
|
|
*
|
|
* int main() {
|
|
*
|
|
* // Create a shared task to display ThreadLocal values
|
|
* Task task(new aRunnable);
|
|
*
|
|
* Thread t0(task); t0.wait();
|
|
* Thread t1(task); t1.wait();
|
|
* Thread t2(task); t2.wait();
|
|
*
|
|
* // Output:
|
|
*
|
|
* // 0
|
|
* // 0
|
|
* // 0
|
|
*
|
|
* task = Task(new anotherRunnable);
|
|
*
|
|
* Thread t10(task); t10.wait();
|
|
* Thread t11(task); t11.wait();
|
|
* Thread t12(task); t12.wait();
|
|
*
|
|
* // Output:
|
|
*
|
|
* // 200
|
|
* // 200
|
|
* // 200
|
|
*
|
|
* return 0;
|
|
*
|
|
* }
|
|
*
|
|
* @endcode
|
|
*
|
|
* <h2>Parameters</h2>
|
|
*
|
|
* <em>InitialValueT</em>
|
|
*
|
|
* This template parameter should indicate the functor used to set
|
|
* the initial value. It should support the following operator:
|
|
*
|
|
* <code>
|
|
* // required operator
|
|
* T operator()
|
|
*
|
|
* // supported expression
|
|
* InitialValueT()()
|
|
* </code>
|
|
*
|
|
*
|
|
* <em>ChildValueT</em>
|
|
*
|
|
* This template parameter should indicate the functor used to set
|
|
* the value that will be inherited by thread whose parent have associated
|
|
* a value with the ThreadLocal's context at the time they are created.
|
|
* It should support the following operator:
|
|
*
|
|
* <code>
|
|
* // required operator
|
|
* T operator(const T& parentValue)
|
|
*
|
|
* // supported expression
|
|
* ChildValueT()(parentValue)
|
|
* </code>
|
|
*
|
|
*
|
|
* <em>InheritableValueT</em>
|
|
*
|
|
* This template parameter should indicate the functor, used to determine
|
|
* wheather or not this ThreadLocal will allow values from a parent threads
|
|
* context to be inherited by child threads when they are created.
|
|
* It should support the following operator:
|
|
*
|
|
* <code>
|
|
* // required operator
|
|
* bool operator(const T& childValueFunctor)
|
|
*
|
|
* // supported expression
|
|
* InheritableValueT()( ChildValueT() )
|
|
* </code>
|
|
*
|
|
*/
|
|
template <
|
|
typename T,
|
|
typename InitialValueT = ThreadLocalImpl::InitialValueFn<T>,
|
|
typename ChildValueT = ThreadLocalImpl::UniqueChildValueFn,
|
|
typename InheritableValueT = ThreadLocalImpl::InheritableValueFn
|
|
>
|
|
class ThreadLocal : private ThreadLocalImpl {
|
|
|
|
typedef ThreadLocalImpl::ValuePtr ValuePtr;
|
|
|
|
class Value : public ThreadLocalImpl::Value {
|
|
|
|
T value;
|
|
|
|
public:
|
|
|
|
Value() : value( InitialValueT()() ) { }
|
|
|
|
Value(const Value& v) : value( ChildValueT()(v.value) ) { }
|
|
|
|
virtual ~Value() { }
|
|
|
|
operator T() { return value; }
|
|
|
|
const Value& operator=(const T& v) { value = v; }
|
|
|
|
virtual bool isInheritable() const {
|
|
return InheritableValueT()( ChildValueT() );
|
|
}
|
|
|
|
virtual ValuePtr clone() const {
|
|
return ValuePtr( new Value(*this) );
|
|
}
|
|
|
|
};
|
|
|
|
static ValuePtr createValue() {
|
|
return ValuePtr( new Value );
|
|
}
|
|
|
|
public:
|
|
|
|
/**
|
|
* Get the value associated with the context (this ThreadLocal and
|
|
* the calling thread) of the invoker. If no value is currently
|
|
* associated, then an intial value is created and associated; that value
|
|
* is returned.
|
|
*
|
|
* @return <em>T</em> associated value.
|
|
*
|
|
* @post If no value has been associated with the invoking context
|
|
* then an inital value will be associated. That value is
|
|
* created by the <em>InitialValueT</em> functor.
|
|
*/
|
|
T get() const {
|
|
return (T)reinterpret_cast<Value&>( *value(&createValue) );
|
|
}
|
|
|
|
/**
|
|
* Replace the value associated with the context (this ThreadLocal and
|
|
* the calling thread) of the invoker. If no value is currently
|
|
* associated, then an intial value is first created and subsequently
|
|
* replaced by the new value.
|
|
*
|
|
* @param v value of type <em>T</em> to associate.
|
|
*
|
|
* @post If no value has been associated with the invoking context
|
|
* then an inital value will first be associated. That value is
|
|
* created by the <em>InitialValueT</em> functor and then
|
|
* replaced with the new value.
|
|
*/
|
|
void set(T v) const {
|
|
reinterpret_cast<Value&>( *value(&createValue) ) = v;
|
|
}
|
|
|
|
/**
|
|
* Remove any value current associated with this ThreadLocal.
|
|
*
|
|
* @post Upon thier next invocation the get() and set() functions will behave as
|
|
* if no value has been associated with this ThreadLocal and an
|
|
* initial value will be generated.
|
|
*/
|
|
void clear() const {
|
|
ThreadLocalImpl::clear();
|
|
}
|
|
|
|
/**
|
|
* Remove any value current associated with <em>any</em> ThreadLocal.
|
|
*
|
|
* @post Upon thier next invocation the get() and set() functions will behave as
|
|
* if no value has been associated with <em>any</em> ThreadLocal and new
|
|
* initial values will be generated.
|
|
*/
|
|
static void clearAll() {
|
|
ThreadLocalImpl::clearAll();
|
|
}
|
|
|
|
};
|
|
|
|
|
|
} // namespace ZThread
|
|
|
|
#endif // __ZTTHREADLOCAL_H__
|