支持多線程的單例類

singleton.h:

#ifndef _SINGLETON_H

#define _SINGLETON_H

#include "lock.h"

template<class type>

class Singleton : public NonCopy

{

public:

Singleton() : instance_(NULL) {

}

~Singleton() {

if (instance_ != NULL) {

delete instance_;

instance_ = NULL;

}

}

type *Get() {

if (instance_ == NULL) {

ScopeLock scope_lock(&lock_);

if (instance_ == NULL) {

type *temp = new type;

instance_ = temp;

}

}

return instance_;

}

type &operator*() {

return *Get();

}

type *operator->() {

return Get();

}

private:

SpinLock lock_;

type *volatile instance_;

};

#endif // _SINGLETON_H

singleton.cpp

#include "singleton.h"

class Test{

public: void print() {

cout << "test" << endl;

}

static Test* GetInstance() {

static Singleton<Test>?test;

return test.Get();

}

};

int main()

{

Test::GetInstance()->print();

return 0;

}

編譯:g++ -o singleton singleton.cpp lock.cpp -lpthread