增加并行运行线程的数量.For [英] Increase Number of running thread in Parallel.For
问题描述
我刚刚使用此链接 如下:
Console.WriteLine("Number of Threads: {0}", System.Diagnostics.Process.GetCurrentProcess().Threads.Count);
int count = 0;
Parallel.For(0, 50000, options,(i, state) =>
{
count++;
});
Console.WriteLine("Number of Threads: {0}", System.Diagnostics.Process.GetCurrentProcess().Threads.Count);
Console.ReadKey();
它在 Parellel.For 之前为我提供了 15 个线程，在它仅提供了 17 个线程之后.所以只有 2 个线程被 Parellel.For 占用.
It gives me 15 thread before Parellel.For and after it gives me 17 thread only. So only 2 thread is occupy with Parellel.For.
然后我使用此链接创建了另一个示例代码，如下所示:
Then I have created a another sample code using This Link like below:
var options = new ParallelOptions { MaxDegreeOfParallelism = Environment.ProcessorCount * 10 };
Console.WriteLine("MaxDegreeOfParallelism : {0}", Environment.ProcessorCount * 10);
Console.WriteLine("Number of Threads: {0}", System.Diagnostics.Process.GetCurrentProcess().Threads.Count);
int count = 0;
Parallel.For(0, 50000, options,(i, state) =>
{
count++;
});
Console.WriteLine("Number of Threads: {0}", System.Diagnostics.Process.GetCurrentProcess().Threads.Count);
Console.ReadKey();
在上面的代码中，我将 MaxDegreeOfParallelism 设置为 40，但仍然为 Parallel.For 使用相同的线程.
In above code, I have set MaxDegreeOfParallelism where it sets 40 but is still taking same threads for Parallel.For.
那么如何增加Parallel.For的运行线程?
So how can I increase running thread for Parallel.For?
推荐答案
并行循环使用硬件 CPU 内核.如果您的 CPU 有 2 个内核，则这是您的机器可以达到的最大并行度.
Parallel loops use hardware CPU cores. If your CPU has 2 cores, this is the maximum degree of paralellism that you can get in your machine.
默认情况下，并行度(即在硬件中同时运行多少次迭代)取决于可用内核数.在典型场景中，您的核心数越多有，你的循环执行得越快，直到你到达阿姆达尔定律预测的收益递减.多快取决于您的循环所做的工作类型.
What to Expect
By default, the degree of parallelism (that is, how many iterations run at the same time in hardware) depends on the number of available cores. In typical scenarios, the more cores you have, the faster your loop executes, until you reach the point of diminishing returns that Amdahl's Law predicts. How much faster depends on the kind of work your loop does.
进一步阅读:
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