回调框架 不知道异步可以用不，在尝试

#include <iostream>using namespace std;class ITransaction{public:virtual ~ITransaction(){}};class Task{public:virtual int process(ITransaction *) = 0;virtual void doAfterSync(ITransaction *ctx){}void setCompleteListener(Task *l){mListener = l;}void complited(ITransaction *ctx){std::cout << "complited..." << std::endl;if (mListener) {mListener->doAfterSync(ctx);} else {std::cout << "mListener is null" << std::endl;}}private:Task *mListener;};enum {START = 0,A_START,A_COMPLETE,B_START,B_COMPLETE};std::string strStatus[] = {"start", "a_start", "a_complete", "b_start", "b_complete"};class Transaction : public ITransaction{public:Transaction():status(START){}int status;};class TaskA : public Task{public:TaskA(){}void setBTask(Task *taskB){taskB_ = taskB;}int process(ITransaction *ctx){ctx_ = dynamic_cast<Transaction *>(ctx);std::cout << "TaskA is running..., status is " << strStatus[ctx_->status] << std::endl;switch (ctx_->status){case START:ctx_->status = A_START;std::cout << "status is " << strStatus[ctx_->status] << std::endl;taskB_->setCompleteListener(this);taskB_->process(ctx_);return 1; // not finishedcase B_COMPLETE:complited(ctx_);return 0;}}void doAfterSync(ITransaction *ctx){std::cout << "TaskA::doAfterSync"<< std::endl;if (ctx_->status == B_COMPLETE) {process(ctx);}}private:Task *taskB_;Transaction *ctx_;};class TaskB : public Task{public:int process(ITransaction *ctx){std::cout << "TaskB is running..." << std::endl;ctx_ = dynamic_cast<Transaction *>(ctx);ctx_->status = B_COMPLETE;std::cout << "status is " << strStatus[ctx_->status] << std::endl;complited(ctx_);return 0;}private:Transaction *ctx_;};class Controller{public:Controller(TaskA *taskA, TaskB *taskB) : taskA_(taskA), taskB_(taskB){}void do_process(Transaction *ctx_){taskA_->process(ctx_);}TaskA *taskA_;TaskB *taskB_;};int main(){Transaction *ctx = new Transaction;TaskA *taskA = new TaskA();TaskB *taskB = new TaskB();taskA->setBTask(taskB);Controller *ctl = new Controller(taskA, taskB);ctl->do_process(ctx);return 0;}