static void Test()
{
ConcurrentExclusiveSchedulerPair pair = new ConcurrentExclusiveSchedulerPair();
readerAB1 = new ActionBlock<int>((i) =>
{
Console.WriteLine(i + " ReaderAB1 begin handing." + " Excute Time:" + DateTime.Now +
" currentThreadId : " + Thread.CurrentThread.ManagedThreadId);
Thread.Sleep(500);
}, new ExecutionDataflowBlockOptions() {TaskScheduler = pair.ConcurrentScheduler});
readerAB2 = new ActionBlock<int>((i) =>
{
Console.WriteLine(i + " ReaderAB2 begin handing." + " Excute Time:" + DateTime.Now +
" currentThreadId : " + Thread.CurrentThread.ManagedThreadId);
Thread.Sleep(500);
}, new ExecutionDataflowBlockOptions() {TaskScheduler = pair.ConcurrentScheduler});
readerAB3 = new ActionBlock<int>((i) =>
{
Console.WriteLine(i + " ReaderAB3 begin handing." + " Excute Time:" + DateTime.Now +
" currentThreadId : " + Thread.CurrentThread.ManagedThreadId);
Thread.Sleep(500);
}, new ExecutionDataflowBlockOptions() {TaskScheduler = pair.ConcurrentScheduler});
writeAB1 = new ActionBlock<int>((i) =>
{
Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine(i + " writeAB1 begin handing." + " Excute Time:" + DateTime.Now +
" currentThreadId : " + Thread.CurrentThread.ManagedThreadId);
Console.ResetColor();
Thread.Sleep(3000);
}, new ExecutionDataflowBlockOptions() {TaskScheduler = pair.ExclusiveScheduler});
bb.LinkTo(readerAB1);
bb.LinkTo(readerAB2);
bb.LinkTo(readerAB3);
var task1 = Task.Run(() =>
{
while (true)
{
bb.Post(1);
Thread.Sleep(1000);
}
});
var task2 = Task.Run(() =>
{
while (true)
{
writeAB1.Post(1);
Thread.Sleep(6000);
}
});
Task.WaitAll(task1, task2);
}
public void BasicConcurrentUsageTest()
{
schedPair = new ConcurrentExclusiveSchedulerPair(TaskScheduler.Default, 4);
factory = new TaskFactory(schedPair.ConcurrentScheduler);
bool launched = false;
factory.StartNew(() => launched = true);
Thread.Sleep(600);
Assert.IsTrue(launched);
}
public IEnumerable<IDocument> Execute(IReadOnlyList<IDocument> inputs, IExecutionContext context)
{
IRazorPageFactory pageFactory = new VirtualPathRazorPageFactory(context.InputFolder, context, _basePageType);
List<IDocument> validInputs = inputs
.Where(x => _ignorePrefix == null || !x.ContainsKey("SourceFileName") || !x.String("SourceFileName").StartsWith(_ignorePrefix))
.ToList();
// Compile the pages in parallel
ConcurrentDictionary<IDocument, Tuple<ViewContext, ViewEngineResult>> compilationResults
= new ConcurrentDictionary<IDocument, Tuple<ViewContext, ViewEngineResult>>();
Parallel.ForEach(validInputs, x =>
{
context.Trace.Verbose("Compiling Razor for {0}", x.Source);
IViewStartProvider viewStartProvider = new ViewStartProvider(pageFactory, _viewStartPath?.Invoke(x));
IRazorViewFactory viewFactory = new RazorViewFactory(viewStartProvider);
IRazorViewEngine viewEngine = new RazorViewEngine(pageFactory, viewFactory);
ViewContext viewContext = new ViewContext(null, new ViewDataDictionary(), null, x.Metadata, context, viewEngine);
ViewEngineResult viewEngineResult;
using (Stream stream = x.GetStream())
{
viewEngineResult = viewEngine.GetView(viewContext, GetRelativePath(x), stream).EnsureSuccessful();
}
compilationResults[x] = new Tuple<ViewContext, ViewEngineResult>(viewContext, viewEngineResult);
});
// Now evaluate them in sequence - have to do this because BufferedHtmlContent doesn't appear to work well in multi-threaded parallel execution
TaskScheduler exclusiveScheduler = new ConcurrentExclusiveSchedulerPair().ExclusiveScheduler;
CancellationToken cancellationToken = new CancellationToken();
return validInputs
.Select(x =>
{
using (context.Trace.WithIndent().Verbose("Processing Razor for {0}", x.Source))
{
Tuple<ViewContext, ViewEngineResult> compilationResult;
if (compilationResults.TryGetValue(x, out compilationResult))
{
using (StringWriter writer = new StringWriter())
{
compilationResult.Item1.View = compilationResult.Item2.View;
compilationResult.Item1.Writer = writer;
Task.Factory.StartNew(() => compilationResult.Item2.View.RenderAsync(compilationResult.Item1),
cancellationToken, TaskCreationOptions.None, exclusiveScheduler).Unwrap().GetAwaiter().GetResult();
return x.Clone(writer.ToString());
}
}
context.Trace.Warning("Could not find compilation result for {0}", x.Source);
return null;
}
});
}
public void ExclusiveUsageTest ()
{
schedPair = new ConcurrentExclusiveSchedulerPair (TaskScheduler.Default, 4);
factory = new TaskFactory (schedPair.ExclusiveScheduler);
int count = 0;
ManualResetEventSlim mreFinish = new ManualResetEventSlim (false);
ManualResetEventSlim mreStart = new ManualResetEventSlim (false);
factory.StartNew (() => {
mreStart.Set ();
Interlocked.Increment (ref count);
mreFinish.Wait ();
});
mreStart.Wait ();
factory.StartNew (() => Interlocked.Increment (ref count));
Thread.Sleep (100);
Assert.AreEqual (1, count);
mreFinish.Set ();
}
private static async Task Main(string[] args)
{
var inputBlock = new BroadcastBlock <int>(a => a);
var taskScheduler = new System.Threading.Tasks.ConcurrentExclusiveSchedulerPair();
Action <int> actionBlockFunction = (int a) =>
{
var counterValue = GetSharedObjectValue();
//very complexLogic
Task.Delay(_random.Next(300)).Wait();
Console.WriteLine($"The counter value I've read was {counterValue} " +
$"Now it is {_sharedCounter} " +
$"I will set it to {counterValue + 1}");
SetSharedObjectValue(counterValue + 1);
};
var incrementingBlock1 = new ActionBlock <int>(actionBlockFunction
, new ExecutionDataflowBlockOptions()
{
TaskScheduler = taskScheduler.ExclusiveScheduler
});
var incrementingBlock2 = new ActionBlock <int>(actionBlockFunction
, new ExecutionDataflowBlockOptions()
{
TaskScheduler = taskScheduler.ExclusiveScheduler
});
inputBlock.LinkToWithPropagation(incrementingBlock1);
inputBlock.LinkToWithPropagation(incrementingBlock2);
for (int i = 0; i < 10; i++)
{
inputBlock.Post(i);
}
inputBlock.Complete();
await incrementingBlock1.Completion;
await incrementingBlock2.Completion;
Console.WriteLine($"Current counter value {GetSharedObjectValue()}");
}
public void Run()
{
var propagateCompletion = new DataflowLinkOptions { PropagateCompletion = true };
var csep = new ConcurrentExclusiveSchedulerPair();
var concurrentOptions = new ExecutionDataflowBlockOptions
{
MaxDegreeOfParallelism = 2,
TaskScheduler = csep.ConcurrentScheduler
};
var exclusiveOptions = new ExecutionDataflowBlockOptions
{
TaskScheduler = csep.ExclusiveScheduler
};
var concurrent = new ActionBlock<int>(async i =>
{
Console.WriteLine("Concurent print value: {0}", i);
await Task.Delay(500);
}, concurrentOptions);
var exclusive = new ActionBlock<int>(i =>
{
Console.WriteLine("Exclusive print value: {0}", i);
Thread.Sleep(750);
}, exclusiveOptions);
var broadcaster = new BroadcastBlock<int>(i => i);
broadcaster.LinkTo(concurrent, propagateCompletion);
broadcaster.LinkTo(exclusive, propagateCompletion, i => i % 2 == 0);
Enumerable
.Range(1, 10)
.ToList()
.ForEach(i => broadcaster.Post(i));
broadcaster.Complete();
Task.WaitAll(concurrent.Completion, exclusive.Completion);
}
public static void TestConcurrentBlockage(bool useReader)
{
ConcurrentExclusiveSchedulerPair schedPair = new ConcurrentExclusiveSchedulerPair();
TaskFactory readers = new TaskFactory(schedPair.ConcurrentScheduler);
TaskFactory writers = new TaskFactory(schedPair.ExclusiveScheduler);
ManualResetEvent blockExclusiveTaskEvent = new ManualResetEvent(false);
ManualResetEvent blockMainThreadEvent = new ManualResetEvent(false);
ManualResetEvent blockMre = new ManualResetEvent(false);
//Schedule a concurrent task and ensure that it is executed, just for fun
Task<bool> conTask = readers.StartNew<bool>(() => { new ManualResetEvent(false).WaitOne(10); ; return true; });
conTask.Wait();
Assert.True(conTask.Result, "The concurrenttask when executed successfully should have returned true");
//Now scehdule a exclusive task that is blocked(thereby preventing other concurrent tasks to finish)
Task<bool> exclusiveTask = writers.StartNew<bool>(() => { blockMainThreadEvent.Set(); blockExclusiveTaskEvent.WaitOne(); return true; });
//With exclusive task in execution mode, schedule a number of concurrent tasks and ensure they are not executed
blockMainThreadEvent.WaitOne();
List<Task> taskList = new List<Task>();
for (int i = 0; i < 20; i++) taskList.Add(readers.StartNew<bool>(() => { blockMre.WaitOne(10); return true; }));
foreach (Task task in taskList)
{
bool wasTaskStarted = (task.Status != TaskStatus.Running) && (task.Status != TaskStatus.RanToCompletion);
Assert.True(wasTaskStarted, "Concurrent tasks should not be executed when a exclusive task is getting executed");
}
blockExclusiveTaskEvent.Set();
Task.WaitAll(taskList.ToArray());
}
public static void TestIntegration(String apiType, bool useReader)
{
Debug.WriteLine(string.Format(" Running apiType:{0} useReader:{1}", apiType, useReader));
int taskCount = Environment.ProcessorCount; //To get varying number of tasks as a function of cores
ConcurrentExclusiveSchedulerPair schedPair = new ConcurrentExclusiveSchedulerPair();
CountdownEvent cde = new CountdownEvent(taskCount); //Used to track how many tasks were executed
Action work = () => { cde.Signal(); }; //Work done by all APIs
//Choose the right scheduler to use based on input parameter
TaskScheduler scheduler = useReader ? schedPair.ConcurrentScheduler : schedPair.ExclusiveScheduler;
SelectAPI2Target(apiType, taskCount, scheduler, work);
cde.Wait(); //This will cause the test to block (and timeout) until all tasks are finished
}
public static void TestMaxItemsPerTask(int maxConcurrency, int maxItemsPerTask, bool completeBeforeTaskWait)
{
//Create a custom TaskScheduler with specified max concurrency (TrackingTaskScheduler is defined in Common\tools\CommonUtils\TPLTestSchedulers.cs)
TrackingTaskScheduler scheduler = new TrackingTaskScheduler(maxConcurrency);
//We need to use the custom scheduler to achieve the results. As a by-product, we test to ensure custom schedulers are supported
ConcurrentExclusiveSchedulerPair schedPair = new ConcurrentExclusiveSchedulerPair(scheduler, maxConcurrency, maxItemsPerTask);
TaskFactory readers = new TaskFactory(schedPair.ConcurrentScheduler); //get reader and writer schedulers
TaskFactory writers = new TaskFactory(schedPair.ExclusiveScheduler);
//These are threadlocals to ensure that no concurrency side effects occur
ThreadLocal<int> itemsExecutedCount = new ThreadLocal<int>(); //Track the items executed by CEScheduler Task
ThreadLocal<int> schedulerIDInsideTask = new ThreadLocal<int>(); //Used to store the Scheduler ID observed by a Task Executed by CEScheduler Task
//Work done by both reader and writer tasks
Action work = () =>
{
//Get the id of the parent Task (which is the task created by the scheduler). Each task run by the scheduler task should
//see the same SchedulerID value since they are run on the same thread
int id = ((TrackingTaskScheduler)scheduler).SchedulerID.Value;
if (id == schedulerIDInsideTask.Value)
{ //since ids match, this is one more Task being executed by the CEScheduler Task
itemsExecutedCount.Value = ++itemsExecutedCount.Value;
//This does not need to be thread safe since we are looking to ensure that only n number of tasks were executed and not the order
//in which they were executed. Also asserting inside the thread is fine since we just want the test to be marked as failure
Assert.True(itemsExecutedCount.Value <= maxItemsPerTask, string.Format("itemsExecutedCount={0} cant be greater than maxValue={1}. Parent TaskID={2}",
itemsExecutedCount, maxItemsPerTask, id));
}
else
{ //Since ids dont match, this is the first Task being executed in the CEScheduler Task
schedulerIDInsideTask.Value = id; //cache the scheduler ID seen by the thread, so other tasks running in same thread can see this
itemsExecutedCount.Value = 1;
}
//Give enough time for a Task to stay around, so that other tasks will be executed by the same CEScheduler Task
//or else the CESchedulerTask will die and each Task might get executed by a different CEScheduler Task. This does not affect the
//verifications, but its increases the chance of finding a bug if the maxItemPerTask is not respected
new ManualResetEvent(false).WaitOne(20);
};
List<Task> taskList = new List<Task>();
int maxConcurrentTasks = maxConcurrency * maxItemsPerTask * 5;
int maxExclusiveTasks = maxConcurrency * maxItemsPerTask * 2;
// Schedule Tasks in both concurrent and exclusive mode
for (int i = 0; i < maxConcurrentTasks; i++)
taskList.Add(readers.StartNew(work));
for (int i = 0; i < maxExclusiveTasks; i++)
taskList.Add(writers.StartNew(work));
if (completeBeforeTaskWait)
{
schedPair.Complete();
schedPair.Completion.Wait();
Assert.True(taskList.TrueForAll(t => t.IsCompleted), "All tasks should have completed for scheduler to complete");
}
//finally wait for all of the tasks, to ensure they all executed properly
Task.WaitAll(taskList.ToArray());
if (!completeBeforeTaskWait)
{
schedPair.Complete();
schedPair.Completion.Wait();
Assert.True(taskList.TrueForAll(t => t.IsCompleted), "All tasks should have completed for scheduler to complete");
}
}
public static void TestLowerConcurrencyLevel()
{
//a custom scheduler with maxConcurrencyLevel of one
int customSchedulerConcurrency = 1;
TrackingTaskScheduler scheduler = new TrackingTaskScheduler(customSchedulerConcurrency);
// specify a maxConcurrencyLevel > TaskScheduler's maxconcurrencyLevel to ensure the pair takes the min of the two
ConcurrentExclusiveSchedulerPair schedPair = new ConcurrentExclusiveSchedulerPair(scheduler, Int32.MaxValue);
Assert.Equal(scheduler.MaximumConcurrencyLevel, schedPair.ConcurrentScheduler.MaximumConcurrencyLevel);
//Now schedule a reader task that would block and verify that more reader tasks scheduled are not executed
//(as long as the first task is blocked)
TaskFactory readers = new TaskFactory(schedPair.ConcurrentScheduler);
ManualResetEvent blockReaderTaskEvent = new ManualResetEvent(false);
ManualResetEvent blockMainThreadEvent = new ManualResetEvent(false);
//Add a reader tasks that would block
readers.StartNew(() => { blockMainThreadEvent.Set(); blockReaderTaskEvent.WaitOne(); });
blockMainThreadEvent.WaitOne(); // wait for the blockedTask to start execution
//Now add more reader tasks
int maxConcurrentTasks = Environment.ProcessorCount;
List<Task> taskList = new List<Task>();
for (int i = 0; i < maxConcurrentTasks; i++)
taskList.Add(readers.StartNew(() => { })); //schedule some dummy reader tasks
foreach (Task task in taskList)
{
bool wasTaskStarted = (task.Status != TaskStatus.Running) && (task.Status != TaskStatus.RanToCompletion);
Assert.True(wasTaskStarted, string.Format("Additional reader tasks should not start when scheduler concurrency is {0} and a reader task is blocked", customSchedulerConcurrency));
}
//finally unblock the blocjedTask and wait for all of the tasks, to ensure they all executed properly
blockReaderTaskEvent.Set();
Task.WaitAll(taskList.ToArray());
}
public void ExclusiveUsageWithConcurrentExecutingTest()
{
schedPair = new ConcurrentExclusiveSchedulerPair(TaskScheduler.Default, 4);
TaskFactory exclFact = new TaskFactory(schedPair.ExclusiveScheduler);
TaskFactory concFact = new TaskFactory(schedPair.ConcurrentScheduler);
int count = 0;
bool started = false;
ManualResetEventSlim mreStart = new ManualResetEventSlim(false);
ManualResetEventSlim mreFinish = new ManualResetEventSlim(false);
concFact.StartNew(() =>
{
started = true;
mreStart.Set();
mreFinish.Wait();
started = false;
});
mreStart.Wait();
exclFact.StartNew(() => Interlocked.Increment(ref count));
Thread.Sleep(100);
Assert.IsTrue(started);
Assert.AreEqual(0, count);
mreFinish.Set();
}
/// <summary>Initializes the debug view.</summary>
/// <param name="pair">The pair being debugged.</param>
public DebugView(ConcurrentExclusiveSchedulerPair pair)
{
Debug.Assert(pair != null, "Need a pair with which to construct the debug view.");
m_pair = pair;
}
public void ConcurrentUsageTest()
{
schedPair = new ConcurrentExclusiveSchedulerPair(TaskScheduler.Default, 4);
factory = new TaskFactory(schedPair.ConcurrentScheduler);
int count = 0;
ManualResetEventSlim mreFinish = new ManualResetEventSlim(false);
CountdownEvent cntd = new CountdownEvent(2);
factory.StartNew(() =>
{
Interlocked.Increment(ref count);
cntd.Signal();
mreFinish.Wait();
});
factory.StartNew(() =>
{
Interlocked.Increment(ref count);
cntd.Signal();
mreFinish.Wait();
});
cntd.Wait();
Assert.AreEqual(2, count);
mreFinish.Set();
}
public static void TestConcurrentExclusiveChain(bool syncContinuations)
{
var scheduler = new TrackingTaskScheduler(Environment.ProcessorCount);
var cesp = new ConcurrentExclusiveSchedulerPair(scheduler);
// continuations
{
var starter = new Task(() => { });
var t = starter;
for (int i = 0; i < 10; i++)
{
t = t.ContinueWith(delegate { }, CancellationToken.None, syncContinuations ? TaskContinuationOptions.ExecuteSynchronously : TaskContinuationOptions.None, cesp.ConcurrentScheduler);
t = t.ContinueWith(delegate { }, CancellationToken.None, syncContinuations ? TaskContinuationOptions.ExecuteSynchronously : TaskContinuationOptions.None, cesp.ExclusiveScheduler);
}
starter.Start(cesp.ExclusiveScheduler);
t.Wait();
}
// parent/child
{
var errorString = "hello faulty world";
var root = Task.Factory.StartNew(() =>
{
Task.Factory.StartNew(() =>
{
Task.Factory.StartNew(() =>
{
Task.Factory.StartNew(() =>
{
Task.Factory.StartNew(() =>
{
Task.Factory.StartNew(() =>
{
Task.Factory.StartNew(() =>
{
throw new InvalidOperationException(errorString);
}, CancellationToken.None, TaskCreationOptions.AttachedToParent, cesp.ExclusiveScheduler).Wait();
}, CancellationToken.None, TaskCreationOptions.AttachedToParent, cesp.ExclusiveScheduler);
}, CancellationToken.None, TaskCreationOptions.AttachedToParent, cesp.ConcurrentScheduler);
}, CancellationToken.None, TaskCreationOptions.AttachedToParent, cesp.ExclusiveScheduler);
}, CancellationToken.None, TaskCreationOptions.AttachedToParent, cesp.ConcurrentScheduler);
}, CancellationToken.None, TaskCreationOptions.AttachedToParent, cesp.ExclusiveScheduler);
}, CancellationToken.None, TaskCreationOptions.None, cesp.ConcurrentScheduler);
((IAsyncResult)root).AsyncWaitHandle.WaitOne();
Assert.True(root.IsFaulted, "Root should have been faulted by child's error");
var ae = root.Exception.Flatten();
Assert.True(ae.InnerException is InvalidOperationException && ae.InnerException.Message == errorString,
"Child's exception should have propagated to the root.");
}
}
public void Synchronous_client_call_from_async_context_using_exclusive_scheduler_is_not_deadlocked()
{
// Note that this will probably leave a hanging worker thread if failing :/
// Not sure how to clean that up properly, might have to implement a custom TaskScheduler to do that
var ccsp = new ConcurrentExclusiveSchedulerPair(TaskScheduler.Default, 1);
var tf = new TaskFactory(CancellationToken.None, TaskCreationOptions.DenyChildAttach, TaskContinuationOptions.None,
ccsp.ExclusiveScheduler);
// Should have good time to complete in 10seconds, on any computer
var hasCompleted = tf.StartNew(async () =>
{
// Just do some random sync client call
Client.Critters.Post(new CritterForm() { Name = "hi" });
await Task.Yield();
Client.Critters.Post(new CritterForm() { Name = "again" });
}).Wait(10000);
Assert.That(hasCompleted, Is.True, "Task never completed, which means it's probably deadlocked.");
}
/// <summary>
/// Initializes a new instance of the <see cref="AsyncReaderWriterLock"/> class.
/// </summary>
public AsyncReaderWriterLock()
{
// Built upon ConcurrentExclusiveSchedulerPair is a .Net TPL construct that provides exactly what we need
// - reader/writer orchestration
ConcurrentExclusiveSchedulerPair = new ConcurrentExclusiveSchedulerPair();
ConcurrentNonExclusiveTaskFactory = new TaskFactory(this.ConcurrentExclusiveSchedulerPair.ConcurrentScheduler);
ExclusiveTaskFactory = new TaskFactory(this.ConcurrentExclusiveSchedulerPair.ExclusiveScheduler);
}
public InnerTaskScheduler(ConcurrentExclusiveSchedulerPair scheduler,
ConcurrentQueue <Task> queue)
{
this.scheduler = scheduler;
this.queue = queue;
}
public void RunConcurrentExclusiveSchedulerPairRWTests()
{
// Validate reader tasks get scheduled concurrently
{
bool localPassed = true;
foreach (var cesp in new[] { new ConcurrentExclusiveSchedulerPair(), new ConcurrentExclusiveSchedulerPair(TaskScheduler.Default, -1) })
{
try
{
int numToSchedule = Environment.ProcessorCount; // doesn't validate much on a single core, but that's ok
Barrier b = new Barrier(numToSchedule);
var tasks = new Task[numToSchedule];
for (int i = 0; i < numToSchedule; i++)
{
tasks[i] = Task.Factory.StartNew(() =>
{
localPassed &= b.SignalAndWait(1000);
}, CancellationToken.None, TaskCreationOptions.None, cesp.ConcurrentScheduler);
}
Task.WaitAll(tasks);
}
finally { cesp.Complete(); }
}
Assert.True(localPassed, string.Format("{0}: Test concurrent readers", localPassed ? "Success" : "Failure"));
}
// Validate reader tasks don't go above max concurrency level
{
bool localPassed = true;
int mcl = 2;
var cesp = new ConcurrentExclusiveSchedulerPair(TaskScheduler.Default, mcl);
try
{
int numToSchedule = 2;
int concurrentTasks = 0;
var tasks = new Task[numToSchedule];
for (int i = 0; i < numToSchedule; i++)
{
tasks[i] = Task.Factory.StartNew(() =>
{
Interlocked.Increment(ref concurrentTasks);
Task.Delay(1).Wait();
if (concurrentTasks > mcl) localPassed = false;
Task.Delay(1).Wait();
Interlocked.Decrement(ref concurrentTasks);
}, CancellationToken.None, TaskCreationOptions.None, cesp.ConcurrentScheduler);
}
Task.WaitAll(tasks);
}
finally { cesp.Complete(); }
Assert.True(localPassed, string.Format("{0}: Test concurrent readers stay below maximum", localPassed ? "Success" : "Failure"));
}
// Validate writers tasks don't run concurrently with each other
{
bool localPassed = true;
var cesp = new ConcurrentExclusiveSchedulerPair(TaskScheduler.Default);
try
{
int numToSchedule = 2;
int concurrentTasks = 0;
var tasks = new Task[numToSchedule];
for (int i = 0; i < numToSchedule; i++)
{
tasks[i] = Task.Factory.StartNew(() =>
{
Interlocked.Increment(ref concurrentTasks);
Task.Delay(100).Wait();
if (concurrentTasks > 1) localPassed &= false;
Task.Delay(100).Wait();
Interlocked.Decrement(ref concurrentTasks);
}, CancellationToken.None, TaskCreationOptions.None, cesp.ExclusiveScheduler);
}
Task.WaitAll(tasks);
}
finally { cesp.Complete(); }
Assert.True(localPassed, string.Format("{0}: Test writers don't run concurrently with each other", localPassed ? "Success" : "Failure"));
}
// Validate writers tasks don't run concurrently with readers or writers
{
bool localPassed = true;
var cesp = new ConcurrentExclusiveSchedulerPair(TaskScheduler.Default);
int numWritersToSchedule = 2;
int numReadersToSchedule = 3;
int runningTasks = 0;
var readerTasks = new Task[numReadersToSchedule];
for (int i = 0; i < numReadersToSchedule; i++)
{
readerTasks[i] = Task.Factory.StartNew(() =>
{
Interlocked.Increment(ref runningTasks);
Task.Delay(1).Wait();
Interlocked.Decrement(ref runningTasks);
}, CancellationToken.None, TaskCreationOptions.None, cesp.ConcurrentScheduler);
}
var writerTasks = new Task[numWritersToSchedule];
for (int i = 0; i < numWritersToSchedule; i++)
{
writerTasks[i] = Task.Factory.StartNew(() =>
{
Interlocked.Increment(ref runningTasks);
Task.Delay(100).Wait();
if (runningTasks > 1) localPassed &= false;
Task.Delay(100).Wait();
Interlocked.Decrement(ref runningTasks);
}, CancellationToken.None, TaskCreationOptions.None, cesp.ExclusiveScheduler);
}
Task.WaitAll(writerTasks);
Task.WaitAll(readerTasks);
// not completing the cesp here, just so that some of our tests don't
// and so that we don't hide any issues by always completing
Assert.True(localPassed, string.Format("{0}: Test writers don't run concurrently with anything", localPassed ? "Success" : "Failure"));
}
}
public void RunConcurrentExclusiveSchedulerPairTests()
{
// Validate invalid arguments
{
Assert.Throws<ArgumentNullException>(() => new ConcurrentExclusiveSchedulerPair(null));
Assert.Throws<ArgumentOutOfRangeException>(() => new ConcurrentExclusiveSchedulerPair(TaskScheduler.Default, -2));
Assert.Throws<ArgumentOutOfRangeException>(() => new ConcurrentExclusiveSchedulerPair(TaskScheduler.Default, 0));
Assert.Throws<ArgumentOutOfRangeException>(() => new ConcurrentExclusiveSchedulerPair(TaskScheduler.Default, 1, -2));
Assert.Throws<ArgumentOutOfRangeException>(() => new ConcurrentExclusiveSchedulerPair(TaskScheduler.Default, 1, 0));
}
// Validate completion prevents more tasks
{
bool localPassed = true;
ConcurrentExclusiveSchedulerPair cesp = new ConcurrentExclusiveSchedulerPair();
cesp.Complete();
Assert.Throws<TaskSchedulerException>(() => Task.Factory.StartNew(() => { }, CancellationToken.None, TaskCreationOptions.None, cesp.ConcurrentScheduler).Wait());
Assert.Throws<TaskSchedulerException>(() => Task.Factory.StartNew(() => { }, CancellationToken.None, TaskCreationOptions.None, cesp.ExclusiveScheduler).Wait());
Assert.True(localPassed, string.Format("{0}: Completion prevents more tasks", localPassed ? "Success" : "Failure"));
}
// Validate completion allows existing scheduled tasks to complete
{
bool localPassed = true;
ConcurrentExclusiveSchedulerPair cesp = new ConcurrentExclusiveSchedulerPair();
int tasksToSchedule = 2;
int count = 0;
var tasks = new Task[tasksToSchedule];
using (var mres = new ManualResetEventSlim())
{
for (int i = 0; i < tasksToSchedule; i++)
{
tasks[i] = Task.Factory.StartNew(() =>
{
mres.Wait();
Interlocked.Increment(ref count);
}, CancellationToken.None, TaskCreationOptions.None, cesp.ExclusiveScheduler);
}
cesp.Complete();
Assert.True(count == 0, "No tasks should have completed yet");
mres.Set();
Task.WaitAll(tasks);
Assert.True(count == tasksToSchedule, "All of the tasks should have executed");
cesp.Completion.Wait();
}
Assert.True(localPassed, string.Format("{0}: Completion allows existing tasks to complete", localPassed ? "Success" : "Failure"));
}
// Validate MCL handling
{
bool localPassed = true;
{
var cesp = new ConcurrentExclusiveSchedulerPair(new ControllableMclTaskScheduler(4), 8);
localPassed &= cesp.ConcurrentScheduler.MaximumConcurrencyLevel == 4;
localPassed &= cesp.ExclusiveScheduler.MaximumConcurrencyLevel == 1;
}
{
var cesp = new ConcurrentExclusiveSchedulerPair(new ControllableMclTaskScheduler(8), 4);
localPassed &= cesp.ConcurrentScheduler.MaximumConcurrencyLevel == 4;
localPassed &= cesp.ExclusiveScheduler.MaximumConcurrencyLevel == 1;
}
{
var cesp = new ConcurrentExclusiveSchedulerPair(TaskScheduler.Default, -1);
localPassed &= cesp.ConcurrentScheduler.MaximumConcurrencyLevel == Int32.MaxValue;
localPassed &= cesp.ExclusiveScheduler.MaximumConcurrencyLevel == 1;
}
{
var cesp = new ConcurrentExclusiveSchedulerPair(new ControllableMclTaskScheduler(-2), -1);
localPassed &= cesp.ConcurrentScheduler.MaximumConcurrencyLevel == Int32.MaxValue;
localPassed &= cesp.ExclusiveScheduler.MaximumConcurrencyLevel == 1;
}
{
var cesp = new ConcurrentExclusiveSchedulerPair(new ControllableMclTaskScheduler(-2), 1);
localPassed &= cesp.ConcurrentScheduler.MaximumConcurrencyLevel == 1;
localPassed &= cesp.ExclusiveScheduler.MaximumConcurrencyLevel == 1;
}
Assert.True(localPassed, string.Format("{0}: Max Concurrency Level corner cases handling correctly", localPassed ? "Success" : "Failure"));
}
// Validate queueing when layering on a faulty scheduler
{
bool localPassed = true;
var ts = new ControllableTaskScheduler();
// NOTE: We're using new pair instances on each iteration to avoid code paths
// where a replica task gets queued up in the scheduler. If that happens while the underlying
// scheduler is FailQueueing==true, the task used internally by CESP will fault
// and will go unobserved. This is by design and we don't want it bringing down the tests.
var cesp1 = new ConcurrentExclusiveSchedulerPair(ts);
var cesp2 = new ConcurrentExclusiveSchedulerPair(ts);
foreach (var cesp in new[] { cesp1, cesp2 })
{
var scheduler = cesp == cesp1 ? cesp1.ConcurrentScheduler : cesp2.ExclusiveScheduler;
// Queue a task that will cause the CESP to fail queueing to its underlying scheduler
ts.FailQueueing = true;
Task.Factory.StartNew(() => { }, CancellationToken.None, TaskCreationOptions.None, scheduler);
try
{
Task.Factory.StartNew(() => { }, CancellationToken.None, TaskCreationOptions.None, scheduler);
localPassed = false;
}
catch (Exception exc)
{
Assert.True(
exc is TaskSchedulerException && ((TaskSchedulerException)exc).InnerException is InvalidOperationException,
"Expected a TaskSchedulerException containing an InvalidOperationException");
}
Assert.True(SpinWait.SpinUntil(() => cesp.Completion.IsCompleted, 1), "Excepted CESP to complete in allotted time");
Assert.True(cesp.Completion.Exception != null, "Excepted CESP task to have exceptions");
}
Assert.True(localPassed, string.Format("{0}: Test queueing layering on faulty scheduler", localPassed ? "Success" : "Failure"));
}
// Validate inlining when layering on a faulty scheduler
{
bool localPassed = true;
var ts = new ControllableTaskScheduler();
// NOTE: We're using new pair instances on each iteration to avoid code paths
// where a replica task gets queued up in the scheduler. If that happens while the underlying
// scheduler is FailQueueing==true, the task used internally by CESP will fault
// and will go unobserved. This is by design and we don't want it bringing down the tests.
var cesp1 = new ConcurrentExclusiveSchedulerPair(ts);
var cesp2 = new ConcurrentExclusiveSchedulerPair(ts);
foreach (var cesp in new[] { cesp1, cesp2 })
{
var scheduler = cesp == cesp1 ? cesp1.ConcurrentScheduler : cesp2.ExclusiveScheduler;
// Inline a task that will cause the CESP to fail queueing to its underlying scheduler
ts.FailQueueing = false;
Task.Factory.StartNew(() =>
{
ts.FailQueueing = true;
Task t = new Task(() => { });
try
{
t.RunSynchronously(scheduler);
localPassed = false;
}
catch (Exception exc)
{
Assert.True(
exc is TaskSchedulerException && ((TaskSchedulerException)exc).InnerException is TaskSchedulerException,
"Excepted a TaskSchedulerException to contain another TaskSchedulerException");
}
Assert.True(t.IsCompleted, "Expected the queued task to be completed");
Assert.True(t.Exception != null, "Expected the queued task to be faulted");
}, CancellationToken.None, TaskCreationOptions.None, scheduler).Wait();
ts.FailQueueing = false;
Task.Factory.StartNew(() => { }, CancellationToken.None, TaskCreationOptions.None, scheduler).Wait();
cesp.Complete();
Assert.True(SpinWait.SpinUntil(() => cesp.Completion.IsCompleted, 1), "Expected the CESP to complete in the allotted time");
Assert.True(cesp.Completion.Exception == null, "Expected the task to not be faulted and have no exceptions");
}
Assert.True(localPassed, string.Format("{0}: Test inlining layering on faulty scheduler", localPassed ? "Success" : "Failure"));
}
// Validate tasks on the same scheduler waiting on each other
{
bool localPassed = true;
foreach (var underlyingScheduler in new[] { TaskScheduler.Default, new ControllableTaskScheduler() { FailQueueing = false } })
{
var cesp = new ConcurrentExclusiveSchedulerPair(underlyingScheduler);
TaskRecursion(2, new ParallelOptions { TaskScheduler = cesp.ExclusiveScheduler });
cesp.Complete();
cesp = new ConcurrentExclusiveSchedulerPair(underlyingScheduler);
TaskRecursion(2, new ParallelOptions { TaskScheduler = cesp.ConcurrentScheduler });
cesp.Complete();
}
Assert.True(localPassed, string.Format("{0}: Recursively waiting on same scheduler", localPassed ? "Success" : "Failure"));
}
// Exercise additional inlining code paths
{
bool localPassed = true;
foreach (var underlyingScheduler in new[] { TaskScheduler.Default, new ControllableTaskScheduler() { FailQueueing = false } })
{
var cesp = new ConcurrentExclusiveSchedulerPair(underlyingScheduler);
Task.Factory.StartNew(() => { }).ContinueWith(_ => { }, CancellationToken.None, TaskContinuationOptions.ExecuteSynchronously, cesp.ExclusiveScheduler).Wait();
Task.Factory.StartNew(() => { }).ContinueWith(_ => { }, CancellationToken.None, TaskContinuationOptions.ExecuteSynchronously, cesp.ConcurrentScheduler).Wait();
var t = new Task(() => { });
t.RunSynchronously(cesp.ConcurrentScheduler);
t.Wait();
t = new Task(() => { });
t.RunSynchronously(cesp.ExclusiveScheduler);
t.Wait();
Task.Factory.StartNew(() =>
{
new Task(() => { }, TaskCreationOptions.AttachedToParent).RunSynchronously(cesp.ConcurrentScheduler);
}, CancellationToken.None, TaskCreationOptions.None, cesp.ConcurrentScheduler).Wait();
Task.Factory.StartNew(() =>
{
new Task(() => { }, TaskCreationOptions.AttachedToParent).RunSynchronously(cesp.ExclusiveScheduler);
}, CancellationToken.None, TaskCreationOptions.None, cesp.ExclusiveScheduler).Wait();
}
Assert.True(localPassed, string.Format("{0}: Additional inlining code paths", localPassed ? "Success" : "Failure"));
}
}
public static void TestCompletionTask()
{
// Completion tasks is valid after initialization
{
var cesp = new ConcurrentExclusiveSchedulerPair();
Assert.True(cesp.Completion != null, "CompletionTask should never be null (after initialization)");
Assert.True(!cesp.Completion.IsCompleted, "CompletionTask should not have completed");
}
// Completion task is valid after complete is called
{
var cesp = new ConcurrentExclusiveSchedulerPair();
cesp.Complete();
Assert.True(cesp.Completion != null, "CompletionTask should never be null (after complete)");
cesp.Completion.Wait();
}
// Complete method may be called multiple times, and CompletionTask still completes
{
var cesp = new ConcurrentExclusiveSchedulerPair();
for (int i = 0; i < 20; i++) cesp.Complete(); // ensure multiple calls to Complete succeed
Assert.True(cesp.Completion != null, "CompletionTask should never be null (after multiple completes)");
cesp.Completion.Wait();
}
// Can create a bunch of schedulers, do work on them all, complete them all, and they all complete
{
var cesps = new ConcurrentExclusiveSchedulerPair[100];
for (int i = 0; i < cesps.Length; i++)
{
cesps[i] = new ConcurrentExclusiveSchedulerPair();
}
for (int i = 0; i < cesps.Length; i++)
{
Action work = () => new ManualResetEvent(false).WaitOne(2); ;
Task.Factory.StartNew(work, CancellationToken.None, TaskCreationOptions.None, cesps[i].ConcurrentScheduler);
Task.Factory.StartNew(work, CancellationToken.None, TaskCreationOptions.None, cesps[i].ExclusiveScheduler);
}
for (int i = 0; i < cesps.Length; i++)
{
cesps[i].Complete();
cesps[i].Completion.Wait();
}
}
// Validate that CESP does not implement IDisposable
Assert.Equal(null, new ConcurrentExclusiveSchedulerPair() as IDisposable);
}
public void ReaderWriterLockUsage()
{
// для секций с известной операцией доступа (чтение или запись) можно использовать
// ReaderWriterLockSlim (ReaderWriterLock не рекомендуется)
ReaderWriterLockSlim rwLock = new ReaderWriterLockSlim();
rwLock.EnterReadLock();
// критическая секция с чтением данных
rwLock.ExitReadLock();
rwLock.EnterWriteLock();
// критическая секция с изменением данных
rwLock.ExitWriteLock();
// также существует класс ConcurrentExclusiveSchedulerPair,
// который содержит 2 менеджера заданий
// все задания в ExclusiveScheduler выполняются по одному,
// если не выполняется ни одно задание в ConcurrentScheduler
// все задания в ConcurrentScheduler выполняются одновременно,
// если не выполняется ни одно задание в ExclusiveScheduler
ConcurrentExclusiveSchedulerPair schedulerPair = new ConcurrentExclusiveSchedulerPair();
TaskFactory exclusiveFactory = new TaskFactory(schedulerPair.ExclusiveScheduler);
exclusiveFactory.StartNew(() => Console.WriteLine(DateTime.Now.ToLongTimeString()));
// класс, который блокирует поток, пока внутренний счётчик не достигнет нуля
CountdownEvent countdownEvent = new CountdownEvent(5);
countdownEvent.Wait();
// критическая секция
countdownEvent.Signal(2); // блокировка не снята
countdownEvent.Signal(3); // блокировка снята
// класс Barrier предоставляет возможность совокупности потоков проходить
// через определённые шаги исполнения одновременно
}
public static void TestSchedulerNesting()
{
// Create a hierarchical set of scheduler pairs
var cespParent = new ConcurrentExclusiveSchedulerPair();
var cespChild1 = new ConcurrentExclusiveSchedulerPair(cespParent.ConcurrentScheduler);
var cespChild1Child1 = new ConcurrentExclusiveSchedulerPair(cespChild1.ConcurrentScheduler);
var cespChild1Child2 = new ConcurrentExclusiveSchedulerPair(cespChild1.ExclusiveScheduler);
var cespChild2 = new ConcurrentExclusiveSchedulerPair(cespParent.ExclusiveScheduler);
var cespChild2Child1 = new ConcurrentExclusiveSchedulerPair(cespChild2.ConcurrentScheduler);
var cespChild2Child2 = new ConcurrentExclusiveSchedulerPair(cespChild2.ExclusiveScheduler);
// these are ordered such that we will complete the child schedulers before we complete their parents. That way
// we don't complete a parent that's still in use.
var cesps = new[] {
cespChild1Child1,
cespChild1Child2,
cespChild1,
cespChild2Child1,
cespChild2Child2,
cespChild2,
cespParent,
};
// Get the schedulers from all of the pairs
List<TaskScheduler> schedulers = new List<TaskScheduler>();
foreach (var s in cesps)
{
schedulers.Add(s.ConcurrentScheduler);
schedulers.Add(s.ExclusiveScheduler);
}
// Keep track of all created tasks
var tasks = new List<Task>();
// Queue lots of work to each scheduler
foreach (var scheduler in schedulers)
{
// Create a function that schedules and inlines recursively queued tasks
Action<int> recursiveWork = null;
recursiveWork = depth =>
{
if (depth > 0)
{
Action work = () =>
{
new ManualResetEvent(false).WaitOne(1);
recursiveWork(depth - 1);
};
TaskFactory factory = new TaskFactory(scheduler);
Debug.WriteLine(string.Format("Start tasks in scheduler {0}", scheduler.Id));
Task t1 = factory.StartNew(work); Task t2 = factory.StartNew(work); Task t3 = factory.StartNew(work);
Task.WaitAll(t1, t2, t3);
}
};
for (int i = 0; i < 2; i++)
{
tasks.Add(Task.Factory.StartNew(() => recursiveWork(2), CancellationToken.None, TaskCreationOptions.None, scheduler));
}
}
// Wait for all tasks to complete, then complete the schedulers
Task.WaitAll(tasks.ToArray());
foreach (var cesp in cesps)
{
cesp.Complete();
cesp.Completion.Wait();
}
}
public InnerTaskScheduler (ConcurrentExclusiveSchedulerPair scheduler,
ConcurrentQueue<Task> queue)
{
this.scheduler = scheduler;
this.queue = queue;
}
public static void TestCreationOptions(String ctorType)
{
ConcurrentExclusiveSchedulerPair schedPair = null;
//Need to define the default values since these values are passed to the verification methods
TaskScheduler scheduler = TaskScheduler.Default;
int maxConcurrentLevel = Environment.ProcessorCount;
//Based on input args, use one of the ctor overloads
switch (ctorType.ToLower())
{
case "default":
schedPair = new ConcurrentExclusiveSchedulerPair();
break;
case "scheduler":
schedPair = new ConcurrentExclusiveSchedulerPair(scheduler);
break;
case "maxconcurrent":
maxConcurrentLevel = 2;
schedPair = new ConcurrentExclusiveSchedulerPair(scheduler, maxConcurrentLevel);
break;
case "all":
maxConcurrentLevel = Int32.MaxValue;
schedPair = new ConcurrentExclusiveSchedulerPair(scheduler, -1/*MaxConcurrentLevel*/, -1/*MaxItemsPerTask*/); //-1 gets converted to Int32.MaxValue
break;
default:
throw new NotImplementedException(String.Format("The option specified {0} to create the ConcurrentExclusiveSchedulerPair is invalid", ctorType));
}
//Create the factories that use the exclusive scheduler and the concurrent scheduler. We test to ensure
//that the ConcurrentExclusiveSchedulerPair created are valid by scheduling work on them.
TaskFactory writers = new TaskFactory(schedPair.ExclusiveScheduler);
TaskFactory readers = new TaskFactory(schedPair.ConcurrentScheduler);
List<Task> taskList = new List<Task>(); //Store all tasks created, to enable wait until all of them are finished
// Schedule some dummy work that should be run with as much parallelism as possible
for (int i = 0; i < 50; i++)
{
//In the current design, when there are no more tasks to execute, the Task used by concurrentexclusive scheduler dies
//by sleeping we simulate some non trival work that takes time and causes the concurrentexclusive scheduler Task
//to stay around for addition work.
taskList.Add(readers.StartNew(() => { new ManualResetEvent(false).WaitOne(10); }));
}
// Schedule work where each item must be run when no other items are running
for (int i = 0; i < 10; i++) taskList.Add(writers.StartNew(() => { new ManualResetEvent(false).WaitOne(5); }));
//Wait on the tasks to finish to ensure that the ConcurrentExclusiveSchedulerPair created can schedule and execute tasks without issues
foreach (var item in taskList)
{
item.Wait();
}
//verify that maxconcurrency was respected.
if (ctorType == "maxconcurrent")
{
Assert.Equal(maxConcurrentLevel, schedPair.ConcurrentScheduler.MaximumConcurrencyLevel);
}
Assert.Equal(1, schedPair.ExclusiveScheduler.MaximumConcurrencyLevel);
//verify that the schedulers have not completed
Assert.False(schedPair.Completion.IsCompleted, "The schedulers should not have completed as a completion request was not issued.");
//complete the scheduler and make sure it shuts down successfully
schedPair.Complete();
schedPair.Completion.Wait();
//make sure no additional work may be scheduled
foreach (var schedPairScheduler in new TaskScheduler[] { schedPair.ConcurrentScheduler, schedPair.ExclusiveScheduler })
{
Exception caughtException = null;
try
{
Task.Factory.StartNew(() => { }, CancellationToken.None, TaskCreationOptions.None, schedPairScheduler);
}
catch (Exception exc)
{
caughtException = exc;
}
Assert.True(
caughtException is TaskSchedulerException && caughtException.InnerException is InvalidOperationException,
"Queueing after completion should fail");
}
}
public SchedulerDebuggerView(ConcurrentExclusiveSchedulerPair owner)
{
this.owner = owner;
}
public SchedulerDebuggerView (ConcurrentExclusiveSchedulerPair owner)
{
this.owner = owner;
}
/// <summary>Initializes the debug view.</summary>
/// <param name="pair">The pair being debugged.</param>
public DebugView(ConcurrentExclusiveSchedulerPair pair)
{
Contract.Requires(pair != null, "Need a pair with which to construct the debug view.");
m_pair = pair;
}
public static void TaskContinuation()
{
int taskCount = Environment.ProcessorCount;
int maxDOP = Int32.MaxValue;
int maxNumberExecutionsPerTask = 1;
int data = 0;
Task[] allTasks = new Task[taskCount + 1];
CancellationTokenSource[] cts = new CancellationTokenSource[taskCount + 1];
for (int i = 0; i <= taskCount; i++)
{
cts[i] = new CancellationTokenSource();
}
CancellationTokenSource cts2 = new CancellationTokenSource();
ConcurrentExclusiveSchedulerPair scheduler = new ConcurrentExclusiveSchedulerPair(TaskScheduler.Default, maxDOP, maxNumberExecutionsPerTask);
for (int i = 0; i <= taskCount; i++)
{
int j = i;
allTasks[i] = new Task(() =>
{
new TaskFactory(TaskScheduler.Current).StartNew(() => { }).
ContinueWith((task, o) =>
{
int d = (int)o;
Interlocked.Add(ref data, d);
}, j).
ContinueWith((task, o) =>
{
int d = (int)o;
Interlocked.Add(ref data, d);
cts[d].Cancel();
if (d <= taskCount)
{
throw new OperationCanceledException(cts[d].Token);
}
return "Done";
}, j, cts[j].Token).
ContinueWith((task, o) =>
{
int d = (int)o;
Interlocked.Add(ref data, d);
}, j, CancellationToken.None, TaskContinuationOptions.OnlyOnCanceled, TaskScheduler.Default).Wait(Int32.MaxValue - 1, cts2.Token);
});
allTasks[i].Start(scheduler.ConcurrentScheduler);
}
Task.WaitAll(allTasks, int.MaxValue - 1, CancellationToken.None);
Debug.WriteLine("Tasks ended: result {0}", data);
Task completion = scheduler.Completion;
scheduler.Complete();
completion.Wait();
int expectedResult = 3 * taskCount * (taskCount + 1) / 2;
Assert.Equal(expectedResult, data);
Assert.NotEqual(TaskScheduler.Default.Id, scheduler.ConcurrentScheduler.Id);
Assert.NotEqual(TaskScheduler.Default.Id, scheduler.ExclusiveScheduler.Id);
}
// Token: 0x06006EED RID: 28397 RVA: 0x0017DDB5 File Offset: 0x0017BFB5
public DebugView(ConcurrentExclusiveSchedulerPair pair)
{
this.m_pair = pair;
}
