How to stack method calls?

Question

I have a WPF application that makes use of a resource. This resource can be used in two ways:

IU events. When the user clicks on different elements of the view, it writes a value.
On a background task. Periodically, readings of various values are made.

I have problems when a reading is in progress and the user has to do a writing. I want to stack the calls to the resource methods in order to execute them sequentially.

These are resource's methods:

async Task <bit []> ReadBitsAsync (byte id)
async Task <ushort []> ReadUshortsAsync (byte id)
async Task WriteBitAsync (byte id, ushort position, bool value)
async Task WriteUshortAsync (byte id, ushort position, ushort value)

I've tried doing it with the lock statement, but you can't await a task inside a lock statement.

Is there any way to stack these method calls with all parameter values?

@Servy This is not what I was asking, but it is what I wanted to do previously. Sorry for the duplicate. — Jon, Oct 31 '17 at 07:57

score 0 · Answer 1 · answered Oct 30 '17 at 15:19

0

Put all the commands/actions for a resource in a queue and have a single thread process this queue. If you want write/user actions to take precedence, do not use a queue but use a list instead and add these actions to the top.

answered Oct 30 '17 at 15:19

Emond

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score 0 · Answer 2 · answered Oct 30 '17 at 15:19

I've tried doing it with the lock statement, but you can't await a task inside a lock statement.

If you use a SemaphoreSlim, you could even "lock" asynchronously:

SemaphoreSlim semaphore = new SemaphoreSlim(1, 1);

await semaphore.WaitAsync(); //acquire "lock"
try
{
    //...
    await DoSomethingAsync();
}
finally
{
    semaphore.Release(); //release "lock"
}

How to stack method calls?

2 Answers2