|
static private SetCurrentScheduler ( |
||
| scheduler | ||
| internalInvoke | bool | |
| return | void | |
/// <summary>
/// Executes the fiber until it ends or yields.
/// </summary>
/// <returns>
/// A fiber instruction to be processed by the scheduler.
/// </returns>
internal FiberInstruction Execute()
{
// Sanity check the scheduler. Since this is a scheduler
// only issue, this test happens first before execution
// and before allowing an exception handler to take over.
if (FiberState == FiberState.Stopped)
{
throw new InvalidOperationException("An attempt was made to execute a stopped Fiber. This indicates a logic error in the scheduler.");
}
// Setup thread globals with this scheduler as the owner.
// The sync context is also setup when the scheduler changes.
// Setting the sync context isn't a simple assign in .NET
// so don't do this until needed.
//
// Doing this setup in Execute() frees derived schedulers from the
// burden of setting up the sync context or scheduler. It also allows the
// current scheduler to change on demand when there is more than one
// scheduler running per thread.
//
// For example, each MonoBehaviour in Unity is assigned its own
// scheduler since the behavior determines the lifetime of tasks.
// The active scheduler then can vary depending on which behavior is
// currently executing tasks. Unity will decide outside of this framework
// which behaviour to execute in which order and therefore which
// scheduler is active. The active scheduler in this case can
// only be determined at the time of fiber execution.
//
// Unlike CurrentFiber below, this does not need to be stacked
// once set because the scheduler will never change during fiber
// execution. Only something outside of the scheduler would
// change the scheduler.
if (FiberScheduler.Current != scheduler)
{
FiberScheduler.SetCurrentScheduler(scheduler, true);
}
// Push the current fiber onto the stack and pop it in finally.
// This must be stacked because the fiber may spawn another
// fiber which the scheduler may choose to inline which would result
// in a new fiber temporarily taking its place as current.
var lastFiber = Fiber.CurrentFiber;
Fiber.CurrentFiber = this;
try
{
// Process an abort if pending
if (FiberState == FiberState.AbortRequested)
{
throw new FiberAbortException();
}
object result;
// Execute the coroutine or action
if (coroutine != null)
{
// Execute coroutine
if (coroutine.MoveNext())
{
// Get result of execution
result = coroutine.Current;
}
else
{
// Coroutine finished executing
result = Stop();
}
}
else if (action != null)
{
// Execute action
action();
// Action finished executing
result = Stop();
}
else if (actionObject != null)
{
// Execute action
actionObject(objectState);
// Action finished executing
result = Stop();
}
else if (func != null)
{
result = func();
func = null;
}
else if (funcObject != null)
{
result = funcObject(objectState);
funcObject = null;
}
else
{
// Func execution nulls out the function
// so the scheduler will return to here
// when complete and then stop.
result = Stop();
}
// Treat null as a special case
if (result == null)
{
return(FiberInstruction.YieldToAnyFiber);
}
// Return instructions or throw if invalid
var instruction = result as FiberInstruction;
if (instruction == null)
{
return(new ObjectInstruction(result));
}
else
{
// Verify same scheduler
if (instruction is YieldUntilComplete && ((YieldUntilComplete)instruction).Fiber.Scheduler != FiberScheduler.Current)
{
throw new InvalidOperationException("Currently only fibers belonging to the same scheduler may be yielded to. FiberScheduler.Current = "
+ (FiberScheduler.Current == null ? "null" : FiberScheduler.Current.ToString())
+ ", Fiber.Scheduler = " + (((YieldUntilComplete)instruction).Fiber.Scheduler == null ? "null" : ((YieldUntilComplete)instruction).Fiber.Scheduler.ToString()));
}
var yieldToFiberInstruction = instruction as YieldToFiber;
if (yieldToFiberInstruction != null)
{
// Start fibers yielded to that aren't running yet
var originalState = (FiberState)Interlocked.CompareExchange(ref yieldToFiberInstruction.Fiber.fiberState, (int)FiberState.Running, (int)FiberState.Unstarted);
if (originalState == FiberState.Unstarted)
{
yieldToFiberInstruction.Fiber.scheduler = scheduler;
}
// Can't switch to stopped fibers
if (yieldToFiberInstruction.Fiber.FiberState == FiberState.Stopped)
{
throw new InvalidOperationException("An attempt was made to yield to a stopped fiber.");
}
// Verify scheduler
if (yieldToFiberInstruction.Fiber.Scheduler != FiberScheduler.Current)
{
throw new InvalidOperationException("Currently only fibers belonging to the same scheduler may be yielded to. FiberScheduler.Current = "
+ (FiberScheduler.Current == null ? "null" : FiberScheduler.Current.ToString())
+ ", Fiber.Scheduler = " + (yieldToFiberInstruction.Fiber.Scheduler == null ? "null" : yieldToFiberInstruction.Fiber.Scheduler.ToString()));
}
}
return(instruction);
}
}
catch (Exception fiberException)
{
// If an exception occurs allow the handler to run.
// Fiber execution will terminate even with a handler
// because it's not possible to resume an action or a
// coroutine that throws an exception.
//
// The only exception that could result in a contiunation
// is FiberAbortException. Handlers may choose to deny
// the abort by calling Fiber.ResetAbort().
try
{
// Invoke the exception handler (which could throw)
var unhandledException = this.unhandledException;
var eventArgs = new FiberUnhandledExceptionEventArgs(this, fiberException);
if (unhandledException != null)
{
foreach (var subscriber in unhandledException.GetInvocationList())
{
subscriber.DynamicInvoke(this, eventArgs);
if (eventArgs.Handled)
{
break;
}
}
}
// See if an abort was requested. The flag is thread safe because
// it is only ever touched by the scheduler thread.
if (resetAbortRequested)
{
resetAbortRequested = false;
fiberState = (int)FiberState.Running;
return(FiberInstruction.YieldToAnyFiber); // signal the scheduler to continue
}
else
{
if (!eventArgs.Handled)
{
throw fiberException;
}
else
{
return(Stop());
}
}
}
catch (Exception fiberOrHandlerException)
{
// The exception wasn't from an abort or it wasn't reset
// and so the exception needs to happen.
// Clear reset requests (if any). This is needed here in case
// the exceptionHandler above threw after ResetAbort() was
// called.
//
// The flag is thread safe because
// it is only ever touched by the scheduler thread.
resetAbortRequested = false;
// Stop the fiber. This will invoke completion handlers
// but they won't know this fiber failed due to an exception
// unless they handled the exception above or wait for
// the scheduler to do something after the throw below.
Stop();
// Throw the exception back to the scheduler.
throw fiberOrHandlerException;
}
}
finally
{
// Pop the current fiber
Fiber.CurrentFiber = lastFiber;
}
}
/// <summary>
/// Executes the fiber until it ends or yields.
/// </summary>
/// <returns>
/// A fiber instruction to be processed by the scheduler.
/// </returns>
internal FiberInstruction Execute()
{
//Console.WriteLine ("Fiber {0}:{1} start executing", Id, Status);
// Sanity check the scheduler. Since this is a scheduler
// only issue, this test happens first before execution
// and before allowing an exception handler to take over.
if (IsCompleted)
{
throw new InvalidOperationException("An attempt was made to execute a completed Fiber. This indicates a logic error in the scheduler.");
}
// Setup thread globals with this scheduler as the owner.
// The sync context is also setup when the scheduler changes.
// Setting the sync context isn't a simple assign in .NET
// so don't do this until needed.
//
// Doing this setup in Execute() frees derived schedulers from the
// burden of setting up the sync context or scheduler. It also allows the
// current scheduler to change on demand when there is more than one
// scheduler running per thread.
//
// For example, each MonoBehaviour in Unity is assigned its own
// scheduler since the behavior determines the lifetime of tasks.
// The active scheduler then can vary depending on which behavior is
// currently executing tasks. Unity will decide outside of this framework
// which behaviour to execute in which order and therefore which
// scheduler is active. The active scheduler in this case can
// only be determined at the time of fiber execution.
//
// Unlike CurrentFiber below, this does not need to be stacked
// once set because the scheduler will never change during fiber
// execution. Only something outside of the scheduler would
// change the scheduler.
if (FiberScheduler.Current != scheduler)
{
FiberScheduler.SetCurrentScheduler(scheduler, true);
}
// Push the current fiber onto the stack and pop it in finally.
// This must be stacked because the fiber may spawn another
// fiber which the scheduler may choose to inline which would result
// in a new fiber temporarily taking its place as current.
var lastFiber = Fiber.CurrentFiber;
Fiber.CurrentFiber = this;
// Start the fiber if not started
Interlocked.CompareExchange(ref status, (int)FiberStatus.WaitingToRun, (int)FiberStatus.Created);
Interlocked.CompareExchange(ref status, (int)FiberStatus.Running, (int)FiberStatus.WaitingToRun);
try {
object result = null;
// Execute the coroutine or action
if (coroutine != null)
{
//Console.WriteLine ("Fiber {0}:{1} start executing coroutine", Id, Status);
// Execute coroutine
if (coroutine.MoveNext())
{
// Get result of execution
result = coroutine.Current;
// If the coroutine returned a stop directly
// the fiber still needs to process it
if (result is StopInstruction)
{
Stop(FiberStatus.RanToCompletion);
}
}
else
{
// Coroutine finished executing
result = Stop(FiberStatus.RanToCompletion);
}
//Console.WriteLine ("Fiber {0}:{1} end executing coroutine", Id, Status);
}
else if (action != null)
{
// Execute action
action();
// Action finished executing
result = Stop(FiberStatus.RanToCompletion);
}
else if (actionObject != null)
{
// Execute action
actionObject(objectState);
// Action finished executing
result = Stop(FiberStatus.RanToCompletion);
}
else if (func != null)
{
result = func();
func = null;
if (result is StopInstruction)
{
Stop(FiberStatus.RanToCompletion);
}
}
else if (funcObject != null)
{
result = funcObject(objectState);
funcObject = null;
if (result is StopInstruction)
{
Stop(FiberStatus.RanToCompletion);
}
}
else
{
// Func execution nulls out the function
// so the scheduler will return to here
// when complete and then stop.
result = Stop(FiberStatus.RanToCompletion);
}
// Treat null as a special case
if (result == null)
{
return(FiberInstruction.YieldToAnyFiber);
}
// Return instructions or throw if invalid
var instruction = result as FiberInstruction;
if (instruction == null)
{
// If the result was an enumerator there is a nested coroutine to execute
if (result is IEnumerator)
{
instruction = new YieldUntilComplete(Fiber.Factory.StartNew(result as IEnumerator, cancelToken, scheduler));
}
else if (result is Fiber)
{
// Convert fibers into yield instructions
instruction = new YieldUntilComplete(result as Fiber);
}
else
{
// Pass through other values
return(new ObjectInstruction(result));
}
}
if (instruction is FiberResult)
{
ResultAsObject = ((FiberResult)instruction).Result;
result = Stop(FiberStatus.RanToCompletion);
}
// Verify same scheduler
if (instruction is YieldUntilComplete && ((YieldUntilComplete)instruction).Fiber.Scheduler != FiberScheduler.Current)
{
throw new InvalidOperationException("Currently only fibers belonging to the same scheduler may be yielded to. FiberScheduler.Current = "
+ (FiberScheduler.Current == null ? "null" : FiberScheduler.Current.ToString())
+ ", Fiber.Scheduler = " + (((YieldUntilComplete)instruction).Fiber.Scheduler == null ? "null" : ((YieldUntilComplete)instruction).Fiber.Scheduler.ToString()));
}
var yieldToFiberInstruction = instruction as YieldToFiber;
if (yieldToFiberInstruction != null)
{
// Start fibers yielded to that aren't running yet
Interlocked.CompareExchange(ref yieldToFiberInstruction.Fiber.status, (int)FiberStatus.WaitingToRun, (int)FiberStatus.Created);
var originalState = (FiberStatus)Interlocked.CompareExchange(ref yieldToFiberInstruction.Fiber.status, (int)FiberStatus.Running, (int)FiberStatus.WaitingToRun);
if (originalState == FiberStatus.WaitingToRun)
{
yieldToFiberInstruction.Fiber.scheduler = scheduler;
}
// Can't switch to completed fibers
if (yieldToFiberInstruction.Fiber.IsCompleted)
{
throw new InvalidOperationException("An attempt was made to yield to a completed fiber.");
}
// Verify scheduler
if (yieldToFiberInstruction.Fiber.Scheduler != FiberScheduler.Current)
{
throw new InvalidOperationException("Currently only fibers belonging to the same scheduler may be yielded to. FiberScheduler.Current = "
+ (FiberScheduler.Current == null ? "null" : FiberScheduler.Current.ToString())
+ ", Fiber.Scheduler = " + (yieldToFiberInstruction.Fiber.Scheduler == null ? "null" : yieldToFiberInstruction.Fiber.Scheduler.ToString()));
}
}
//Console.WriteLine ("Fiber {0}:{1} returning {2}", Id, Status, instruction);
return(instruction);
} catch (System.Threading.OperationCanceledException cancelException) {
// Handle as proper cancellation only if the token matches.
// Otherwise treat it as a fault.
if (cancelException.CancellationToken == cancelToken)
{
this.Exception = null;
return(Stop(FiberStatus.Canceled));
}
else
{
this.Exception = cancelException;
return(Stop(FiberStatus.Faulted));
}
} catch (Exception fiberException) {
this.Exception = fiberException;
return(Stop(FiberStatus.Faulted));
} finally {
// Pop the current fiber
Fiber.CurrentFiber = lastFiber;
//Console.WriteLine ("Fiber {0}:{1} end executing", Id, Status);
}
}
