Question

when parent thread sleep does sub threads also sleep ?

Now main thread is UI
I create 20 sub threads inside main thread with task factory (lets call threads 2)
Inside of this 20 sub threads i create another 10 sub threads again with sub factory (lets call threads 3)

Now inside of this threads 2 i have infinite loop. Inside of infinite loop checking whether threads 3 completed or not. If completed dispose completed thread and start another thread. I am using 250 ms sleep for each checking inside infinite while loop. So when threads 2 in sleep does also threads 3 sleep or they are independent. Here the code you can see.

while (true)
{
    int irActiveThreadCount = 0;
    int irFinishedLast = -1;

    for (int i = 0; i < irPerMainSiteThreadCount; i++)
    {
        if (MainSitesTaskList[irWhichMainTask, i] == null)
        {
            irFinishedLast = i;
            break;
        }
        if (MainSitesTaskList[irWhichMainTask, i].IsCompleted == true)
        {
            irFinishedLast = i;
            break;
        }
    }

    for (int i = 0; i < irPerMainSiteThreadCount; i++)
    {
        if (MainSitesTaskList[irWhichMainTask, i] != null)
            if (MainSitesTaskList[irWhichMainTask, i].IsCompleted == false)
            {
                irActiveThreadCount++;
            }
    }

    if (irFinishedLast > -1)
    {
        var newTask = Task.Factory.StartNew(() =>
        {
            fcStartSubPageCrawl(srMainSiteURL, srMainSiteId, irWhichMainTask);
        });
        lock (lockerMainSitesArray)
        {
            if (MainSitesTaskList[irWhichMainTask, irFinishedLast] != null)
                MainSitesTaskList[irWhichMainTask, irFinishedLast].Dispose();
            MainSitesTaskList[irWhichMainTask, irFinishedLast] = newTask;
        }
    }

    Thread.Sleep(250);

    srQuery = "myquery";
    using (DataSet dsTemp = DbConnection.db_Select_Query(srQuery))
    {
        if (dsTemp != null)
            if (dsTemp.Tables.Count > 0)
                if (dsTemp.Tables[0].Rows.Count == 0)
                {
                    break;
                }
    }
}

Answer 1

There’s no such thing as a “parent” thread really. One thread starts another, but then there’s no particular relationship between them. For example, the starting thread can terminate without any of the new threads dying.

The starting thread sleeping definitely doesn’t affect any other thread.