static readonly System.Threading.Tasks.Schedulers.StaTaskScheduler _staTaskScheduler = new System.Threading.Tasks.Schedulers.StaTaskScheduler(4); //tested: without StaTaskScheduler would be 4 threads. With 3 the UI thread is slightly faster.
#else
async void _GetIconAsync(AsyncResult state)
{
var task = Task.Run(() =>
{
if (_canceled)
{
return;
}
//Thread.Sleep(500);
var k = state;
k.hIcon = GetFileIconHandle(k.file, _iconSize, _iconFlags);
});
await task;
//async continuation
if (_canceled)
{
Api.DestroyIcon(state.hIcon);
}
else
{
_callback(state, _objCommon); //even if hi == default, it can be useful
if (--_counter == 0)
{
if (_onFinished != null)
{
_onFinished(_objCommon);
}
_host._works.Remove(this);
_host = null;
}
}
}
void _GetIconAsync(Result state)
{
Util.ThreadPoolSTA_.SubmitCallback(state, d => { //this code runs in a thread pool thread
if (_canceled)
{
d.completionCallback = null;
return;
}
//Thread.Sleep(10);
var k = d.state as Result;
k.hIcon = AIcon.GetFileIconHandle(k.file, _iconSize, _iconFlags);
//var hi = GetFileIconHandle(k.file, _iconSize, _iconFlags);
//if(0!=(_iconFlags&IconGetFlags.NeedImage) && _nPending>20) { /*AOutput.Write(_nPending);*/ k.image = HandleToImage(hi); } else k.hIcon = hi;
//AOutput.Write("1");
//Prevent overflowing the message queue and the number of icon handles.
//Because bad things start when eg toolbar icon count is more than 3000 and they are extracted faster than consumed.
//But don't make the threshold too low, because then may need to wait unnecessarily, and it makes slower.
if (Interlocked.Increment(ref _nPending) >= 900)
{
//AOutput.Write(_nPending);
//var perf = APerf.Create();
Thread.Sleep(10);
//while(_nPending >= 900) Thread.Sleep(10);
//perf.NW();
}
}, o => { //this code runs in the caller's thread
Interlocked.Decrement(ref _nPending);
//AOutput.Write("2");
var k = o as Result;
if (_canceled)
{
Api.DestroyIcon(k.hIcon);
}
else
{
_callback(k, _objCommon, --_counter); //even if hIcon == default, it can be useful
if (_counter == 0)
{
_host._works.Remove(this);
_host = null;
Debug.Assert(_nPending == 0);
}
}
});
}
internal void GetAllAsync(IconsAsync_ host, Callback callback, int iconSize, IconGetFlags flags, object objCommon)
{
Debug.Assert(_callback == null); //must be called once
_host = host;
_callback = callback;
_iconSize = iconSize;
_iconFlags = flags;
_objCommon = objCommon;
_counter = _host._files.Count;
using (new Util.EnsureWindowsFormsSynchronizationContext_()) {
foreach (var v in _host._files)
{
if (!v.file.NE())
{
_GetIconAsync(new Result(v.file, v.obj));
}
}
}
}
