CODEWITHSUNDEEP
c#.net-coreasync-awaittask-parallel-librarythreadpool
wezhuan
wezhuan

Reputation: 33

How can I limit the maximum number of threads when using Task.Run()?

I want to limit the maximum number of threads. How can I do it? I know I could use something like SetMaximum...if I were using the ThreadPool.

public async Task ProcessAsync()
{
    while (true)
    {
        Task.Run(Work);
    }
}

async Task Work()
{
    // some time-consuming job
}

Upvotes: 1

Views: 1576

Answers (1)

Phillip Ngan
Phillip Ngan

Reputation: 16126

You can use a SemaphoreSlim to limit the number of concurrent threads. For example to limit the execution to 3 threads at a time:

async Task  Main()
{
    SemaphoreSlim semaphore = new SemaphoreSlim(3); // Limit to 3 threads
    while (true)
    {
        await semaphore.WaitAsync(); // Wait when more than 3 threads are running
        Task.Run(() =>
        {
            Work();
            semaphore.Release(); // Work is done, signal to semaphore that more work is possible
        });
    }

}

void Work()
{
    Console.WriteLine(DateTime.Now);
    Thread.Sleep(3000);
}

Semaphores can be used to limit the consumption of many types of resources, but in this example the resource is a thread from the thread pool.

Upvotes: 3

Related Questions