想要:对 x 求和并对 x*x 求和。其中 x = 行[i]。因为多个线程想要读/写“sumAll”和“sumAllQ”,所以我需要锁定其访问权限。问题是锁类型在这里序列化了事物。我需要将此操作拆分为 #"Environment.ProcessorCount" for 循环,每个循环对数组的一部分求和,最后对它们的结果求和。但我怎样才能以编程方式实现呢?
示例代码:
//line is a float[]
Parallel.For(0, line.Length,
new ParallelOptions { MaxDegreeOfParallelism = Environment.ProcessorCount },
i =>
{
x = (double)line[i];
lock (sumLocker)
{
sumAll += x;
sumAllQ += x * x;
}
});
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编辑 1:Matthew Watson 回答基准结果
在家里。CPU 核心 2 四核 Q9550 @ 2.83 GHz:
Result via Linq: SumAll=49999950000, SumAllQ=3,33332833333439E+15
Result via loop: SumAll=49999950000, SumAllQ=3,33332833333439E+15
Result via partition: SumAll=49999950000, SumAllQ=3,333328333335E+15
Via Linq took: 00:00:02.6983044
Via Loop took: 00:00:00.4811901
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