我正在将TradeStation EasyLanguage指标代码转换为C DLL.使用TradeStation API,可以访问C DLL中的市场数据,如下所示：
double currentBarDT = pELObject->DateTimeMD[iDatanumber]->AsDateTime[0];
我的问题是：
当变量’currentBarDT’的值改变/更新时,C是否可能以某种方式“观察”或“监听”？我想使用更改值作为触发器来使用Boost.Signals2生成信号.
解决方法
您可以使用适合您需要的条件变量.
http://en.cppreference.com/w/cpp/thread/condition_variable/notify_all
在信号中更新您的市场数据(i)
在等待中你把一个条件变量放在i上(例如某个级别下的股票)
告诉我,如果您需要更多信息,我可以详细说明并使其更明确.
#include <stdlib.h> /* srand,rand */
#include <iostream>
#include <condition_variable>
#include <thread>
#include <chrono>
#include <atomic>
std::condition_variable cv;
std::mutex cv_m;
double StockPrice;//price of the stock
std::atomic<int> NbActiveThreads=0;//count the number of active alerts to the stock market
void waits(int ThreadID,int PriceLimit)
{
std::unique_lock<std::mutex> lk(cv_m);
cv.wait(lk,[PriceLimit]{return StockPrice >PriceLimit ;});
std::cerr << "Thread "<< ThreadID << "...Selling stock.\n";
--NbActiveThreads;
}
void signals()
{
while (true)
{
std::this_thread::sleep_for(std::chrono::seconds(1));
std::cerr << "GettingPrice "<<std::endl;
std::unique_lock<std::mutex> lk(cv_m);
/* generate secret number between 1 and 10: */
StockPrice = rand() % 100 + 1;
std::cerr << "Price =" << StockPrice << std::endl;
cv.notify_all();//updates the price and sell all the stocks if needed
if (NbActiveThreads==0)
{
std::cerr <<"No more alerts "<<std::endl;
return;
}
}
}
int main()
{
NbActiveThreads=3;
std::thread t1(waits,1,20),t2(waits,2,40),t3(waits,3,95),t4(signals);
t1.join();
t2.join();
t3.join();
t4.join();
return 0;
}
希望有所帮助
