Question

I'm creating a indicator that recognizes candlestick shapes.

To do that I created a separate class Candlestick that I include to the indicator file.

The problem is that I suffer from memory leaks.

I'm new to pointers and after reading / watching a lot, I still seem to miss something here.

This is the Indicator class. The content of the Candlestick class is irrelevant so I leave that out.

Candlestick *candles[]; 

void OnDeinit(const int reason)
{
    for(int i = 0; i < ArraySize(candles); i++ ){
      delete(candles[i]);
    }
}

int OnCalculate(args here)
{
    ArrayResize(candles, Bars);

    for(int i = MathMax(Bars-2-IndicatorCounted(), 1); i >= 0; i--)
    {            
        candles[i] = new Candlestick();

        // Do stuff with this candle (and other candles) here e.g.
        if(candles[i+1].type == BULLISH) Print("Last candle was Bullish");
    }
}

When I do this I get memory leak errors. It seems that I need to delete the pointers to the candles in that dynamic array. The problem is, when and where? Because I need them in the next iteration of the for(){...} loop. So I can't delete it there.

When I delete it in the OnDeinit() function there are still candles out there and I still get the leak error.

How come?

Answer 1

首先，尼克，欢迎来到{strong> MQL4

的世界

您可能已经意识到， MQL4 代码不是 C 。

在许多重要的差异中，关键在于代码执行平台（ MetaTrader Terminal 4 ）在什么时候做什么。

OnCalculate() 是一个类似僵尸的过程，被多次调用，但无论如何，绝对不在您的控制之下

接下来，OnCalculate()副设计并不意味着新的Bar。

如何？

MQL4概念上源于几天，当时计算资源的许多订单更小，而且在代码执行阶段的时间共享CPU-MUX方面要贵得多。

因此，MQL4 - 用户域语言保留了一些无法直接访问的隐藏宝石的好处。其中之一是非常有效的基于寄存器的更新处理，并在miminum上保持动态资源分配，因为它们对实时执行可预测性具有破坏性的不利影响。

这将有助于您了解如何设计＆amp;通过模仿 ＆＃34;石器时代＆＃34; - 但非常高效行为（时间和记忆）来处理您的概念对象更聪明-wise），而不是在每次调用OnCalulate()时使用无限量的非托管实例充斥你的内存池，这些实例会消耗无数的 new Candlestick(); // *--> candles[]

最好的下一步：

如果有疑问，只需在平台localhost-help / documentation中阅读 ArrayResize() 的最佳实践，开始实现这些内容，即引入开销（如果不是块）域名，nano$econd$计数＆amp;在专业软件设计中受到伤害。

Why memory leaks with a dynamic array of a custom class?

1 个答案:

如何？

最好的下一步：