public async Task CouldReadDataStreamWhileWritingFromManyThreads()
{
var map = new AppendSeries <int, int>();
var writeCount = 0L;
var count = 1000_000_000;
var rounds = 1;
var writeTask = Task.Run(async() =>
{
using (Benchmark.Run("Write", count * rounds, true))
{
for (int j = 0; j < rounds; j++)
{
var t1 = Task.Run(() =>
{
try
{
for (int i = j * count; i < (j + 1) * count; i++)
{
map.DangerousTryAppend(i, i);
// Thread.SpinWait(10);
// Thread.Yield();
Interlocked.Increment(ref writeCount);
}
}
catch (Exception e)
{
Console.WriteLine(e);
throw;
}
});
await t1;
}
}
});
AsyncCursor <int, int, SCursor <int, int> > cursor = null;
var cnt = 0L;
var readTask = Task.Run(async() =>
{
for (int r = 0; r < 1; r++)
{
using (cursor = new AsyncCursor <int, int, SCursor <int, int> >(map.GetCursor()))
{
using (Benchmark.Run("Read", count * rounds, true))
{
try
{
while (await cursor.MoveNextAsync())
{
Interlocked.Increment(ref cnt);
// Thread.Sleep(1);
}
}
catch (Exception e)
{
Console.WriteLine(e);
throw;
}
// Left from coreclr 19161 tests, TODO remove when everything works OK
// here is a strong reference to cursor with side effects of printing to console
// Console.WriteLine("Last value: " + cursor.Current.Key);
// another strong reference after while loop, we dereference it's value and return from task
// lastKey1 = cursor.CurrentKey;
}
}
}
});
var monitor = true;
var monitorTask = Task.Run(async() =>
{
try
{
var previousR = cursor?.CurrentKey;
var previousW = Volatile.Read(ref writeCount);
while (monitor)
{
await Task.Delay(1000);
var r = cursor.CurrentKey;
var w = Volatile.Read(ref writeCount);
Console.WriteLine($"R: {r:N0} - {((r - previousR) / 1000000.0):N2} Mops \t | W: {w:N0}- {((w - previousW) / 1000000.0):N2} Mops");
if (r == previousR)
{
Console.WriteLine($"IsAwaiting {cursor.IsTaskAwating} IsCompl {cursor.IsCompleted} Counter {cursor._counter}");
}
previousR = r;
previousW = w;
// cursor.TryComplete(false);
}
}
catch (Exception e)
{
Console.WriteLine(e);
throw;
}
});
await writeTask;
Console.WriteLine("COMPLETE");
map.MarkReadOnly();
map.NotifyUpdate();
Console.WriteLine("Read after map complete:" + Interlocked.Read(ref cnt));
await readTask;
Console.WriteLine("Read after finish:" + Interlocked.Read(ref cnt));
// Console.WriteLine("Last key: " + lastKey);
Benchmark.Dump();
GC.KeepAlive(cursor);
map.Dispose();
monitor = false;
}