singrdk/base/Kernel/Singularity/Scheduling/Rialto/OneShotReservation.cs

788 lines
35 KiB
C#

////////////////////////////////////////////////////////////////////////////////
//
// Microsoft Research Singularity
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
// File: OneShotReservation.cs
//
// Note:
//
using System;
using System.Collections;
using System.Diagnostics;
using System.Threading;
using Microsoft.Singularity;
using Microsoft.Singularity.Scheduling;
namespace Microsoft.Singularity.Scheduling.Rialto
{
/// <summary>
/// OneShotReservations are created from tasks for the calling thread.
/// It has fields to track the thread calling and the thread waiting on,
/// the activity associated when it becomes an activity reservation, its
/// surrounding reservation, its place on the free reservation list,
/// general bookkeeping, bookkeeping for possible stolen time, and
/// references for the general reservation list.
/// </summary>
public class OneShotReservation : ISchedulerTask
{
static OneShotReservation guaranteedReservations = null;
public static OneShotReservation GuaranteedReservations
{
get { return guaranteedReservations; }
}
static OneShotReservation idleReservations = null;
public static OneShotReservation IdleReservations
{
get { return idleReservations; }
}
static OneShotReservation currentReservation = null;
public static OneShotReservation CurrentReservation
{
get { return currentReservation; }
//set { currentReservation = value; }
}
public Hashtable resourcesGranted = new Hashtable();
public override Hashtable ResourcesGranted
{
get {
resourcesGranted[CpuResource.Provider().ResourceString] = CpuResource.Provider().TimeToCpu(InitialEstimate);
return resourcesGranted;
}
}
private Task enclosingTask;
public override Task EnclosingTask
{
get { return enclosingTask; }
set { enclosingTask = value; }
}
public OneShotReservation SurroundingReservation;
public OneShotReservation FreeListNext;
public RialtoThread ReservTask;
TimeSpan constraintExecution;
public TimeSpan ConstraintExecution
{
get { return constraintExecution; }
}
TimeSpan initialThreadExecution;
public DateTime Start, Deadline;
public TimeSpan Estimate, RelativeDeadline;
public TimeSpan InitialEstimate; // test only
public QueueType MyQueueType;
public bool Guaranteed;
public bool Valid;
public bool Satisfied;
// Reservations can be made for Threads XOR Activities!.
public RialtoThread OriginalThread;
// always the constraint thread -- non-null until the reservation is complete
//public RialtoThread ActiveThread;
// the above, or the thread blocking it
//public int ActiveThreadEpoch;
public RialtoActivity AssociatedActivity; // the two fields above must be null!
public OneShotReservation Next;
public OneShotReservation Previous;
public TimeSpan InheritedEstimate; // Stolen => Inherited, no longer critical
public int ResolutionEpoch; // Stolen => Resolution, since not stealing.
public int ReferenceCount;
public OneShotReservation()
{
}
public void Clear()
{
//ActiveThread = null;
//ActiveThreadEpoch = 0;
constraintExecution = new TimeSpan(0); //Move to enclosing class
initialThreadExecution = new TimeSpan(0); //Move to enclosing class
Deadline = new DateTime(0);
RelativeDeadline = new TimeSpan(0);
Estimate = new TimeSpan(0);
FreeListNext = null;
Guaranteed = false;
InitialEstimate = new TimeSpan(0);
Next = null;
OriginalThread = null;
AssociatedActivity = null;
Previous = null;
MyQueueType = QueueType.NoQueue;
ReferenceCount = 0;
ReservTask = null;
Satisfied = false;
Start = new DateTime(0);
SurroundingReservation = null;
ResolutionEpoch = 0;
InheritedEstimate = new TimeSpan(0);
Valid = false;
if (enclosingTask != null) {
enclosingTask.ClearSchedulerTask();
enclosingTask = null;
}
}
// find the runnable thread of a reservation:
public RialtoThread GetRunnableThread()
{
// RialtoThread thread;
//
if (AssociatedActivity != null) {
// if an activity reservation
return AssociatedActivity.GetRunnableThread();
}
Debug.Assert(OriginalThread != null);
// if ((ActiveThread == OriginalThread) &&
// (ActiveThread.EnclosingThread.ThreadState == System.Threading.ThreadState.Running))
// return ActiveThread;
//
// thread = OriginalThread; // search for active thread starting w/ original thread
//
// if ((ActiveThread != null) &&
// (ActiveThread.Epoch == ActiveThreadEpoch)) {
// if (ActiveThread.EnclosingThread.ThreadState == System.Threading.ThreadState.Running) {
//#if DEBUG_MUTEX
// DebugStub.WriteLine("Mutex inheritance (Epoch ok): Orig {0} Active {1} GO ON",
// thread.Id, ActiveThread.Id);
//#endif
// return ActiveThread;
// }
// }
//CKillian -- can't do this because of the array of blockedOn.
// else if (ActiveThread.EnclosingThread.IsSleeping()) {
// // more efficient: search for active thread starting w/ current active thread
// thread = ActiveThread;
// }
// else {
// Debug.Assert(false);
// }
//}
Thread temp = /*Active*/OriginalThread.EnclosingThread.GetRunnableBeneficiary();
if (temp == null) {
return null;
}
else {
return (RialtoThread)temp.SchedulerThread;
}
}
public void StopThreadExecution(RialtoThread thread)
{
Debug.Assert(thread.ExecutionTime >= initialThreadExecution);
constraintExecution += thread.ExecutionTime - initialThreadExecution;
//Between two reservations which are atomically stopped/started, some
// time is charged against the default parent resource container. This
// is because I changed the way we account for tasks to do the general
// rule we wanted. In particular, I update the scheduling status just
// before resolving a new reservation. Not sure what the right fix is,
// so I'm leaving it. The assertion below will reveal the "error." The
// old code to track CPU usage is still active under constraintExecution,
// but isn't presently exposed to the applications. Currently UpdateSchedulingStatus()
// updates the CPU resources used for the whole task stack.
//Debug.Assert(CpuResource.Provider().TimeToCpu(constraintExecution).Cycles == ((CpuResourceAmount)enclosingTask.resourcesUsed[CpuResource.Provider().ResourceString]).Cycles);
//EnclosingTask.AddResourceAmountUsed(CpuResource.Provider().ResourceString, CpuResource.Provider().TimeToCpu(constraintExecution));
}
public void StartThreadExecution(RialtoThread thread)
{
initialThreadExecution = thread.ExecutionTime;
}
public void StartThreadExecution(RialtoThread thread, TimeSpan delta)
{
initialThreadExecution = thread.ExecutionTime + delta;
}
public static void BeginConstraintBeforeWait(RialtoThread thread,
bool endPrevious,
TimeConstraint timeConstraint,
DateTime timeNow)
{
OneShotReservation reservation;
Debug.Assert(thread == RialtoScheduler.GetCurrentThread());
Debug.Assert(!Processor.InterruptsDisabled());
if (endPrevious) {
bool iflag = Processor.DisableInterrupts();
EndPreviousConstraint(thread, timeNow);
Processor.RestoreInterrupts(iflag);
}
RialtoScheduler.UpdateSchedulingStatus();
reservation = thread.PendingReservation;
reservation.StartThreadExecution(thread, (timeNow - RialtoScheduler.SchedulingTime));
reservation.constraintExecution = new TimeSpan(0);
reservation.Start = timeConstraint.Start;
reservation.Deadline = timeConstraint.Deadline;
reservation.RelativeDeadline = timeConstraint.RelativeDeadline;
reservation.Estimate = timeConstraint.Estimate;
reservation.Valid = reservation.Guaranteed = true;
reservation.MyQueueType = QueueType.NoQueue;
reservation.ReservTask = thread;
reservation.OriginalThread = /*reservation.ActiveThread =*/ thread;
thread.AddRef();
//thread.AddRef();
//reservation.ActiveThreadEpoch = thread.Epoch;
reservation.AssociatedActivity = null;
reservation.Next = reservation.Previous = null;
}
// DI -- this is a new function used in both Begin and EndConstraint
public static bool EndPreviousConstraint(RialtoThread thread, DateTime timeNow)
{
OneShotReservation reservation;
OneShotReservation reservationNext;
bool success;
QueueType tempQueue; //Value assigned but never used.
Debug.Assert(Processor.InterruptsDisabled());
reservation = thread.ReservationStack;
success = (timeNow <= reservation.Deadline);
RialtoScheduler.UpdateSchedulingStatus();
reservation.StopThreadExecution(thread);
Debug.Assert(reservation.ConstraintExecution.Ticks >= 0);
// if (timeTaken.Ticks != 0) {
// timeTaken = reservation.ConstraintExecution;
// Debug.Assert(timeTaken.Ticks >= 0); //CK: Added = because VPC returns 0 sometimes.
// }
thread.ReservationStack = reservation.SurroundingReservation;
reservation.SurroundingReservation = null;
if (currentReservation == reservation) {
// note that it might be the case that
// a reservation for the task id exist on the guaranteed Q but the
// the actual (executed) constraint is in the UnfinishedQ
currentReservation = null; // ????????????
RialtoScheduler.Reschedule();
}
Debug.Assert(reservation.OriginalThread == thread);
Debug.Assert(reservation.Start <= timeNow);
if (thread.ReservationStack == null) {
if (reservation.Estimate >= RialtoScheduler.MinSlice) {
// the constraint used less than estimated:
Debug.Assert(reservation.MyQueueType == QueueType.GuaranteedQueue);
//Debug.Assert((reservation.ActiveThread == null) ||
// (reservation.ActiveThread.Epoch != reservation.ActiveThreadEpoch) ||
// (reservation.ActiveThread == reservation.OriginalThread));
// reservation.ActiveThread.ReleaseProtected();
reservation.OriginalThread.ReleaseProtected();
reservation.AssociatedActivity = reservation.OriginalThread.AssociatedActivity; // and make it an activity reserv
reservation.OriginalThread = null;
//reservation.ActiveThread = null;
reservation.ReservTask = null;
RialtoScheduler.ActivityObjAddRef(reservation.AssociatedActivity);
// leave it on whatever Q it happens to be on
}
else {
reservation.DequeueReservation(); // from whatever Q it happens to be on
}
}
else {
tempQueue = reservation.MyQueueType;
reservationNext = thread.ReservationStack;
reservationNext.Estimate += reservation.Estimate;
reservationNext.constraintExecution += reservation.constraintExecution;
reservationNext.StartThreadExecution(thread);
Debug.Assert(((reservation.MyQueueType == QueueType.GuaranteedQueue) &&
(reservationNext.MyQueueType == QueueType.NoQueue)) ||
((reservation.MyQueueType == QueueType.UnfinishedQueue) &&
((reservationNext.Estimate.Ticks <= 0) || (reservationNext.MyQueueType != QueueType.UnfinishedQueue))));
reservation.Estimate = new TimeSpan(0);
Debug.Assert(reservation.Next != null);
reservation.DequeueReservation();
ReplaceOnEarliestDeadlineFirst(reservationNext, timeNow);
}
// fprintf(stdout,"EndPrevConstr 0x%x %d\n", reservation, reservation.ReferenceCount);
reservation.ReleaseReservationProtected();
Scheduler.LogEndConstraint();
if (success == false) {
Scheduler.LogSchedulerLate();
}
// DebugStub.WriteLine("EndPreviousConstraint() {0} constraintExecution: {1}", success?"SUCCESS":"FAILURE", reservation.constraintExecution.Ticks);
return success;
}
public static bool ResolveConstraint(RialtoThread thread)
{
TimeSpan timeLeft, ownNodesTimeToSteal = new TimeSpan(1);
DateTime start, deadline;
TimeSpan timeInherited;
OneShotReservation pendingReservation = thread.PendingReservation;
OneShotReservation reservationPrevious;
DateTime timeNow = SystemClock.GetKernelTime();
bool ok = false;
Debug.Assert(Processor.InterruptsDisabled());
Debug.Assert(pendingReservation != null);
Scheduler.LogResolveConstraint();
thread.PendingReservation = null; // just clean the place
Debug.Assert(pendingReservation.Start.Ticks >= 0);
start = pendingReservation.Start;
if (start < timeNow) {
start = timeNow;
}
Debug.Assert(pendingReservation.Deadline.Ticks >= 0);
deadline = pendingReservation.Deadline;
if (deadline.Ticks == 0) {
deadline = timeNow + pendingReservation.RelativeDeadline;
}
if (thread.ReservationStack != null) {
OneShotReservation reservation = thread.ReservationStack;
while (!reservation.Valid && ((reservation = reservation.SurroundingReservation)!= null)) {
// no body.
}
if (reservation!= null) {
deadline = RialtoScheduler.minTime(deadline, reservation.Deadline);
}
}
// update data ure
pendingReservation.Start = start;
pendingReservation.Deadline = deadline;
//TODO: Should be for SIM ONLY!
Scheduler.LogReservationId(pendingReservation); // SIM only
if (start + pendingReservation.Estimate > deadline) {
// DebugStub.WriteLine("RialtoScheduler::ResolveConstraint FAIL - start({0}) + pendingReservation.Estimate({1}) > deadline({2})", start.Ticks, pendingReservation.Estimate.Ticks, deadline.Ticks);
ok = false;
goto Failure;
}
timeInherited = new TimeSpan(0);
RialtoScheduler.ResolutionAttempt++; // mark a new resolution epoch
RecurringReservation recurringReservation = thread.AssociatedActivity.MyRecurringCpuReservation;
RialtoScheduler.ReserveSlices(start, deadline, pendingReservation.Estimate,
thread, out timeLeft, ref timeInherited,
pendingReservation, (recurringReservation != null?recurringReservation.AssignedNodes:null), timeNow);
if (timeLeft.Ticks == 0) {
// Success:
goto Success;
}
RialtoScheduler.ReserveSlices(start, deadline, timeLeft,
thread, out timeLeft, ref timeInherited,
pendingReservation, RialtoScheduler.FreeNodes, timeNow);
if (timeLeft.Ticks <= 0) {
// Success:
goto Success;
}
// DebugStub.WriteLine("RialtoScheduler::ResolveConstraint FAIL - couldn't find time in schedule");
Failure:
// Failure:
pendingReservation.Valid = false;
pendingReservation.Start = timeNow; // no waiting if failed
pendingReservation.Estimate = new TimeSpan(0);
goto Exit;
Success:
// DebugStub.WriteLine("RialtoScheduler::ResolveConstraint SUCCESS");
InheritAndReplaceOnEarliestDeadlineFirst(thread.ReservationStack, timeInherited, timeNow);
ok = true;
Exit:
pendingReservation.InitialEstimate = pendingReservation.Estimate;
reservationPrevious = thread.ReservationStack;
pendingReservation.SurroundingReservation= thread.ReservationStack;
thread.ReservationStack = pendingReservation;
RialtoScheduler.AddRefReservation(pendingReservation);
if (reservationPrevious != null) {
reservationPrevious.constraintExecution += pendingReservation.initialThreadExecution -
reservationPrevious.initialThreadExecution;
}
//
// Reschedule() called if currently we are executing on a pendingReservation
// and the EarliestDeadlineFirst top changed
// or the current pendingReservation goes into the idle list
// solve in SetStateWaiting
//
pendingReservation.EnqueueReservation(timeNow);
RialtoScheduler.DirectSwitchOnConstraint();
#if DEBUG_RESERV
PrintReservations(pendingReservation, sc, timeNow);
#endif
return ok;
}
void EnqueueReservation(DateTime timeNow)
{
OneShotReservation temp;
Debug.Assert((AssociatedActivity != null) ||
(OriginalThread != null));
// Infeasible or (Estimate == 0) Reservations:
if (Estimate <= RialtoScheduler.AFewSlice) {
RialtoActivity activity;
Debug.Assert(OriginalThread != null);
Debug.Assert(AssociatedActivity == null);
activity = OriginalThread.AssociatedActivity;
MyQueueType = QueueType.UnfinishedQueue;
if (activity.UnfinishedConstraints == null) {
Next = Previous = this;
activity.UnfinishedConstraints = this;
}
else {
// no order enforced
Next = activity.UnfinishedConstraints;
Previous = activity.UnfinishedConstraints.Previous;
activity.UnfinishedConstraints.Previous.Next = this;
activity.UnfinishedConstraints.Previous = this;
activity.UnfinishedConstraints = this; // optional
}
// DebugStub.WriteLine("Add: EnqueueReserve 1 0x{0:x} {1}", this, ReferenceCount);
RialtoScheduler.AddRefReservation(this);
return;
}
// Debug.Assert(Valid);
// Idle Reservations:
if (Start > timeNow + RialtoScheduler.AFewSlice) {
// take thread off activity RoundRobin queue and simulate a sleep
// i.e. don't set a timer interrupt
OriginalThread.InternalSetStateWaiting(DateTime.MaxValue);
#if DEBUG_START_RESERV
DebugStub.WriteLine("Put reservation {0}:{1} in IdleQueue\n", OriginalThread,
ReservationId);
#endif
Debug.Assert(OriginalThread != null);
MyQueueType = QueueType.IdleQueue;
if (idleReservations == null) {
Next = Previous = this;
idleReservations = this;
}
else {
temp = idleReservations;
if (Start < temp.Start) {
idleReservations = this;
}
else {
do {
temp = temp.Next;
} while (temp != idleReservations &&
Start >= temp.Start); // >= is compulsory to keep it 'FIFO'
} // insert before 'temp'
Next = temp;
Previous = temp.Previous;
temp.Previous.Next = this;
temp.Previous = this;
}
// fprintf(stdout,"Add: EnqueueReserve 2 0x%x %d\n", this, ReferenceCount);
RialtoScheduler.AddRefReservation(this);
return;
}
// Guaranteed OneShotReservation:
MyQueueType = QueueType.GuaranteedQueue;
if (GuaranteedReservations == null) {
Next = Previous = this;
guaranteedReservations = this;
}
else {
temp = GuaranteedReservations;
if (Deadline < GuaranteedReservations.Deadline) {
guaranteedReservations = this;
}
else {
do {
temp = temp.Next;
} while (temp != guaranteedReservations &&
Deadline > temp.Deadline); // > is compulsory to keep it 'FIFO'
} // insert before 'temp'
Next = temp;
Previous = temp.Previous;
temp.Previous.Next = this;
temp.Previous = this;
}
RialtoScheduler.AddRefReservation(this);
#if DEBUG_RESERV
PrintQueueReserv(guaranteedReservations, timeNow); //TODO: PrintQueueReserv
#endif
return;
}
static void ReplaceOnEarliestDeadlineFirst(OneShotReservation reservation, DateTime timeNow)
{
while (reservation != null) {
if (reservation.Estimate.Ticks > 0) {
if (reservation.MyQueueType == QueueType.NoQueue) {
reservation.EnqueueReservation(timeNow);
}
else {
Debug.Assert(reservation.MyQueueType == QueueType.GuaranteedQueue);
}
break;
}
if (reservation.MyQueueType == QueueType.NoQueue) {
reservation.EnqueueReservation(timeNow);
}
else {
Debug.Assert(reservation.MyQueueType == QueueType.UnfinishedQueue);
}
reservation = reservation.SurroundingReservation;
}
}
public static bool SatisfyAcceptedConstraint(DateTime timeNow)
{
OneShotReservation reservation;
if (currentReservation != null) {
currentReservation.Estimate -= timeNow - RialtoScheduler.SchedulingTime;
if (currentReservation.Estimate.Ticks <= 0) {
RialtoThread tempThread = currentReservation.OriginalThread;
currentReservation.DequeueReservation();
if (tempThread != null) {
// activity reservations vanish here
//Debug.Assert(currentReservation.ActiveThread == RialtoScheduler.GetCurrentThread()); // only thread reserv are added to
currentReservation.EnqueueReservation(RialtoScheduler.SchedulingTime); // the UnfinishedConstraints list of the OriginalThread's Activ
OneShotReservation.ReplaceOnEarliestDeadlineFirst(currentReservation.SurroundingReservation, RialtoScheduler.SchedulingTime);
}
}
}
reservation = guaranteedReservations;
while (reservation != null) {
if (!RialtoScheduler.CheckReservation(reservation, timeNow)) {
return false;
}
reservation = reservation.Next;
if (reservation == guaranteedReservations) {
break;
}
}
reservation = idleReservations;
while (reservation != null) {
if (!RialtoScheduler.CheckReservation(reservation, timeNow)) {
return false;
}
reservation = reservation.Next;
if (reservation == idleReservations) {
break;
}
}
return true;
}
public static void UpdateCurrentReservation()
{
if ((currentReservation != null) &&
(currentReservation.Estimate <= RialtoScheduler.AFewSlice)) {
// slice used for a reservation (CK: & estimate now empty)
RialtoThread tempThread = currentReservation.OriginalThread;
currentReservation.DequeueReservation();
if (tempThread != null) {
// activity reservations vanish here
currentReservation.EnqueueReservation(RialtoScheduler.SchedulingTime); // the UnfinishedConstraints list of the OriginalThread's Activ
ReplaceOnEarliestDeadlineFirst(currentReservation.SurroundingReservation, RialtoScheduler.SchedulingTime);
}
}
}
public static void FreshenReservationQueues()
{
OneShotReservation tempReservation;
// Move 'idle' reservations to the 'active' reservations list, if necessary.
// A reservation is 'idle' until its Start time is reached.
// The 'active' reservation list is ordered 'Earliest Deadline Firts'.
// The 'idle' queue is ordered Earliest Start First.
while ((tempReservation = IdleReservations) != null) {
if (RialtoScheduler.SchedulingTime + RialtoScheduler.AFewSlice < tempReservation.Start) {
break;
}
tempReservation.DequeueReservation(); // Remove OneShotReservation from the Idle Queue
tempReservation.EnqueueReservation(RialtoScheduler.SchedulingTime); // Earliest Deadline First in the (Non)Guaranteed Queue
RialtoScheduler.EnqueueRunThread(tempReservation.OriginalThread);
#if DEBUG_START_RESERV
DebugStub.WriteLine("Get reservation {0}:{1} from IdleQueue", tempReservation.OriginalThread,
tempReservation.ReservationId);
#endif
}
// Remove the active reservations from the guaranteed and nonguaranteed queues
// if their Deadline is <= CurrentTime.
while ((tempReservation = guaranteedReservations) != null) {
if (RialtoScheduler.SchedulingTime + RialtoScheduler.AFewSlice < tempReservation.Deadline) {
break;
}
// fprintf(stdout,"Add: Reschedule Guaranteed Deadline 0x%x %d\n", tempReservation, tempReservation.ReferenceCount);
RialtoScheduler.AddRefReservation(tempReservation);
tempReservation.DequeueReservation(); // Remove OneShotReservation from the Guaranteed Queue
if ((tempReservation.OriginalThread != null) && // if a thread reservation
(tempReservation.OriginalThread.AssociatedActivity != null)) {
// if a thread reservation
tempReservation.Estimate = new TimeSpan(0);
tempReservation.EnqueueReservation(RialtoScheduler.SchedulingTime); // add it to the Pending End Constraint List
}
// fprintf(stdout,"Reschedule Guaranteed Deadline off 0x%x %d\n", tempReservation, tempReservation.ReferenceCount);
tempReservation.ReleaseReservationProtected();
}
}
int ReleaseReservationProtected()
{
return RialtoScheduler.ReleaseReservationProtected(this);
}
public void DequeueReservation() //TODO: Should this be a resource container function?
{
Debug.Assert(Processor.InterruptsDisabled());
OneShotReservation next;
// OneShotReservation pSurrounding = null;
Debug.Assert((AssociatedActivity != null) ||
(OriginalThread != null));
if (Next != this) {
//If there's another reservation, remove us from the queue
Next.Previous = Previous;
Previous.Next = Next;
next = Next;
Debug.Assert(next.Deadline.Ticks > 0);
}
else {
//Otherwise we are only reservation.
Debug.Assert(Previous == this);
next = null;
}
if (this == GuaranteedReservations) {
//Take care when we're the head of the list.
guaranteedReservations = next;
#if DEBUG_RESERV
DebugStub.WriteLine("Dequeue {0}: {1}", ReservationId, Estimate);
// Debug.Assert(Criticality != CRITICAL || !Valid || Estimate ==0);
PrintQueueReserv(GuaranteedReservations, SystemClock.GetKernelTime());
#endif
}
else if (this == IdleReservations) {
//Or maybe we're the head of this list (but definitely not both).
idleReservations = next;
}
else if ((OriginalThread != null) &&
(this == OriginalThread.AssociatedActivity.UnfinishedConstraints)) {
//Or else we might be the head of the unfinished constraints list for the activity associated with our original thread.
OriginalThread.AssociatedActivity.UnfinishedConstraints = next;
} // else { we're OK! }
Next = Previous = null;
// DebugStub.WriteLine("DequeueReservation 0x{0:x} {1}", this, ReferenceCount);
MyQueueType = QueueType.NoQueue;
ReleaseReservationProtected();
}
public static void FindRunnableReservation(ref RialtoThread currentThread)
{
currentReservation = guaranteedReservations;
while (currentReservation != null) {
if ((currentThread = currentReservation.GetRunnableThread()) != null) {
break;
}
currentReservation = currentReservation.Next;
if (currentReservation == guaranteedReservations) {
break;
}
}
}
static void InheritAndReplaceOnEarliestDeadlineFirst(OneShotReservation reservation,
TimeSpan timeInherited,
DateTime timeNow)
{
OneShotReservation current = null;
while (reservation != null) {
if (reservation.Estimate.Ticks > 0) {
if (current == null) {
Debug.Assert(reservation.MyQueueType != QueueType.NoQueue);
current = reservation;
}
else {
Debug.Assert(reservation.MyQueueType == QueueType.NoQueue);
}
}
else if (reservation.MyQueueType != QueueType.NoQueue) {
Debug.Assert (current != null || reservation.MyQueueType == QueueType.UnfinishedQueue);
reservation.DequeueReservation();
}
if (reservation.ResolutionEpoch == RialtoScheduler.ResolutionAttempt) {
Debug.Assert(timeInherited >= reservation.InheritedEstimate);
timeInherited -= reservation.InheritedEstimate;
Debug.Assert(reservation.Estimate >= reservation.InheritedEstimate);
reservation.Estimate -= reservation.InheritedEstimate;
}
reservation = reservation.SurroundingReservation;
}
if (current != null) {
if (current == CurrentReservation) {
current.Estimate -= timeNow - RialtoScheduler.SchedulingTime;
currentReservation = null;
RialtoScheduler.Reschedule();
}
current.DequeueReservation();
}
}
public static void InheritOnEarliestDeadlineFirst(OneShotReservation reservation,
TimeSpan timeToInherit)
{
while (reservation != null && timeToInherit.Ticks > 0) {
if (reservation.ResolutionEpoch == RialtoScheduler.ResolutionAttempt) {
Debug.Assert(timeToInherit >= reservation.InheritedEstimate);
reservation.Estimate -= reservation.InheritedEstimate;
timeToInherit -= reservation.InheritedEstimate;
}
reservation = reservation.SurroundingReservation;
}
}
public static void ClearCurrentReservation() {
currentReservation = null;
}
}
}