Parallel in C#

https://docs.microsoft.com/en-us/dotnet/standard/parallel-programming/how-to-write-a-simple-parallel-foreach-loop

 

 [Test]
        public void ParallelTets()
        {
            int processCount = Environment.ProcessorCount;
            Console.WriteLine($@"{nameof(Environment.ProcessorCount)} = {processCount}");

            DataTable dataTable=new DataTable();
            dataTable.Columns.Add("Id");
            for (int i = 0; i < processCount * 10; i++)
            {
                DataRow dataRow = dataTable.NewRow();
                dataRow["Id"] = i + 1;
                dataTable.Rows.Add(dataRow);
            }


            Stopwatch stopwatch = new Stopwatch();
            stopwatch.Start();
            foreach (DataRow row in dataTable.Rows)
            {
                Thread.Sleep(10);
                Console.Write($@"{row["Id"]},");
            }
            Console.WriteLine();
            stopwatch.Stop();
            Console.WriteLine($@"No parallel takes {stopwatch.ElapsedMilliseconds} ms");

            Console.WriteLine();

            stopwatch.Reset();
            stopwatch.Start();
            Parallel.ForEach(dataTable.Rows.Cast<DataRow>(), row =>
            {
                Thread.Sleep(10);
                Console.Write($@"{row["Id"]},");
            });
            Console.WriteLine();
            stopwatch.Stop();
            Console.WriteLine($@"With parallel takes {stopwatch.ElapsedMilliseconds} ms");
        }

 

使用并行可能存在的问题，很重要

Potential Pitfalls in Data and Task Parallelism

 

作者:Chuck Lu    GitHub