在工廠中會有產線的流程，而當中就會有生者者，與消費者的角色問題
然而產線可以有一條多條，一個生產者多個生產者，一個消費者多個消費者，而本次關心的是，這個產線的效能
選手一 BlockingCollection
- .NET Framework 4.0 開始引入的物件
- 在MSDN上的說明為: 提供安全執行緒集合適用的封鎖和界限容量
選手二Channel
- .Net Core 2.1 開始引入的物件
- 在MSDN上的說明為: 提供一組同步資料結構，用來在生產者和消費者之間以非同步方式傳遞資料
實驗步驟
設計一個生產者，一個消費者，觀察兩者之間的產生效能速度
程式碼部分為
var channel = Channel.CreateUnbounded<string>();
var producer1 = new Producer(channel.Writer, 1, 0);
var consumer1 = new Consumer(channel.Reader, 1, 0);
Task consumerTask1 = consumer1.ConsumeData();
Task producerTask1 = producer1.BeginProducing();
await producerTask1.ContinueWith(_ => channel.Writer.Complete());
await consumerTask1;
var blockQueue = new BlockingCollection<string>();
var producer1 = new Producer2(blockQueue, 1, 0);
var consumer1 = new Consumer2(blockQueue, 1, 0);
Task.Run(consumer1.ConsumeData);
Task.Run(producer1.BeginProducing);編寫的物件
public class Producer
{
private readonly ChannelWriter<string> _writer;
private readonly int _identifier;
private readonly int _delay;
public Producer(ChannelWriter<string> writer, int identifier, int delay)
{
_writer = writer;
_identifier = identifier;
_delay = delay;
}
public async Task BeginProducing()
{
Console.WriteLine($"PRODUCER ({_identifier}): Starting");
for (var i = 0; i < 10; i++)
{
await Task.Delay(_delay);
var msg = $"P{_identifier} - {DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.ffff")}";
Console.WriteLine($"PRODUCER ({_identifier}): Creating {msg}");
await _writer.WriteAsync(msg);
}
Console.WriteLine($"PRODUCER ({_identifier}): Completed");
}
}
public class Consumer
{
private readonly ChannelReader<string> _reader;
private readonly int _identifier;
private readonly int _delay;
public Consumer(ChannelReader<string> reader, int identifier, int delay)
{
_reader = reader;
_identifier = identifier;
_delay = delay;
}
public async Task ConsumeData()
{
Console.WriteLine($"CONSUMER ({_identifier}): Starting");
while (await _reader.WaitToReadAsync())
{
if (_reader.TryRead(out var timeString))
{
await Task.Delay(_delay);
Console.WriteLine($"CONSUMER ({_identifier}): Consuming {timeString}- {DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.ffff")}");
}
}
Console.WriteLine($"CONSUMER ({_identifier}): Completed");
}
}
public class Producer2
{
private readonly BlockingCollection<string> _writer;
private readonly int _identifier;
private readonly int _delay;
public Producer2(BlockingCollection<string> writer, int identifier, int delay)
{
_writer = writer;
_identifier = identifier;
_delay = delay;
}
public void BeginProducing()
{
Console.WriteLine($"PRODUCER ({_identifier}): Starting");
for (var i = 0; i < 10; i++)
{
Thread.Sleep(_delay);
var msg = $"P{_identifier} - {DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.ffff")}";
Console.WriteLine($"PRODUCER ({_identifier}): Creating {msg}");
_writer.Add(msg);
}
Console.WriteLine($"PRODUCER ({_identifier}): Completed");
}
}
public class Consumer2
{
private readonly BlockingCollection<string> _reader;
private readonly int _identifier;
private readonly int _delay;
public Consumer2(BlockingCollection<string> reader, int identifier, int delay)
{
_reader = reader;
_identifier = identifier;
_delay = delay;
}
public void ConsumeData()
{
Console.WriteLine($"CONSUMER ({_identifier}): Starting");
foreach (var timeString in _reader.GetConsumingEnumerable())
{
Thread.Sleep(_delay);
Console.WriteLine($"CONSUMER ({_identifier}): Consuming {timeString}- {DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.ffff")}");
}
Console.WriteLine($"CONSUMER ({_identifier}): Completed");
}
}
結論
- Channel較優，實際上差異極小，以 async/await 寫法來看，Thread之間的時間差，造成效能上的差異最明顯
- BlockingCollection如果沒資料則會Block直到有資料才可拿取，Channel如果沒資料則不會Block，而進行結束，得再自行通知
- Channel在生產者第一次時需要0.01秒左右(第一次跟第二次的間隔)，後續的每次生產都只需要0.0001~0.0002秒左右
- Channel在消費者第一次時需要0.001秒左右(第一次跟第二次的間隔)，後續的每次消費都只需要0.0001~0.0004秒左右
- BlockingCollection在生者者第一次時需要0.001秒左右(第一次跟第二次的間隔)後續的每次生產都只需要0.0003~0.027秒左右
- BlockingCollection在消費者第一次時需要0.0018秒左右(第一次跟第二次的間隔)，後續的每次消費都只需要0.0009~0.0018秒左右
資料參考來源