/// <summary>
/// Execute one iteration of time-granting loop.
/// </summary>
/// <remarks>
/// The steps are as follows:
/// (1) remove and forget all slave handles that requested detaching
/// (2) check if there are any blocked slaves; if so DO NOT grant a time interval
/// (2.1) if there are no blocked slaves grant a new time interval to every slave
/// (3) wait for all slaves that are relevant in this execution (it can be either all slaves or just blocked ones) until they report back
/// (4) (optional) sleep if the virtual time passed faster than a real one; this step is executed if <see cref="AdvanceImmediately"> is not set and <see cref="Performance"> is low enough
/// (5) update elapsed virtual time
/// (6) execute sync hook and delayed actions if any
/// </remarks>
/// <param name="virtualTimeElapsed">Contains the amount of virtual time that passed during execution of this method. It is the minimal value reported by a slave (i.e, some slaves can report higher/lower values).</param>
/// <returns>
/// True if sync point has just been reached or False if the execution has been blocked.
/// </returns>
protected bool InnerExecute(out TimeInterval virtualTimeElapsed)
{
DebugHelper.Assert(NearestSyncPoint.Ticks >= ElapsedVirtualTime.Ticks, "Nearest sync point set in the past");
isBlocked = false;
var quantum = NearestSyncPoint - ElapsedVirtualTime;
this.Trace($"Starting a loop with #{quantum.Ticks} ticks");
virtualTimeElapsed = TimeInterval.Empty;
State = TimeSourceState.ReportingElapsedTime;
using (sync.LowPriority)
{
if ((isPaused || !isStarted) && recentlyUnblockedSlaves.Count == 0)
{
// the time source is not started and it has not acknowledged any unblocks - it means no one is currently working
DebugHelper.Assert(handles.All.All(x => !x.SourceSideActive), "No source side active slaves were expected at this point.");
State = TimeSourceState.Idle;
EnterBlockedState();
return(false);
}
handles.LatchAllAndCollectGarbage();
var shouldGrantTime = handles.AreAllReadyForNewGrant;
this.Trace($"Iteration start: slaves left {handles.ActiveCount}; will we try to grant time? {shouldGrantTime}");
elapsedAtLastGrant = stopwatch.Elapsed;
if (handles.ActiveCount > 0)
{
if (shouldGrantTime && quantum != TimeInterval.Empty)
{
this.Trace($"Granting {quantum.Ticks} ticks");
// inform all slaves about elapsed time
foreach (var slave in handles)
{
slave.GrantTimeInterval(quantum);
}
}
// in case we did not grant any time due to quantum being empty, we must not call wait as well
if (!(shouldGrantTime && quantum == TimeInterval.Empty))
{
this.Trace("Waiting for slaves");
// wait for everyone to report back
State = TimeSourceState.WaitingForReportBack;
TimeInterval?minInterval = null;
foreach (var slave in handles.WithLinkedListNode)
{
var result = slave.Value.WaitUntilDone(out var usedInterval);
if (!result.IsDone)
{
EnterBlockedState();
}
handles.UpdateHandle(slave);
if (result.IsUnblockedRecently)
{
Antmicro.Renode.Debugging.DebugHelper.Assert(recentlyUnblockedSlaves.Contains(slave.Value), $"Expected slave to be in {nameof(recentlyUnblockedSlaves)} collection.");
recentlyUnblockedSlaves.Remove(slave.Value);
this.Trace($"Number of unblocked slaves set to {recentlyUnblockedSlaves.Count}");
if (recentlyUnblockedSlaves.Count == 0)
{
sync.Pulse();
}
}
if (minInterval == null || minInterval > slave.Value.TotalElapsedTime)
{
minInterval = slave.Value.TotalElapsedTime;
}
}
if (minInterval != null)
{
virtualTimeElapsed = minInterval.Value - ElapsedVirtualTime;
}
}
}
else
{
this.Trace($"There are no slaves, updating VTE by {quantum.Ticks}");
// if there are no slaves just make the time pass
virtualTimeElapsed = quantum;
TimePassed?.Invoke(quantum);
}
handles.UnlatchAll();
State = TimeSourceState.Sleeping;
var elapsedThisTime = stopwatch.Elapsed - elapsedAtLastGrant;
if (!AdvanceImmediately)
{
var scaledVirtualTicksElapsed = virtualTimeElapsed.WithScaledTicks(1 / Performance).ToTimeSpan() - elapsedThisTime;
sleeper.Sleep(scaledVirtualTicksElapsed);
}
lock (hostTicksElapsed)
{
this.Trace($"Updating virtual time by {virtualTimeElapsed.InMicroseconds} us");
this.virtualTicksElapsed.Update(virtualTimeElapsed.InMicroseconds);
this.hostTicksElapsed.Update(elapsedThisTime.InMicroseconds());
}
}
if (!isBlocked)
{
ExecuteSyncPhase();
}
else
{
BlockHook?.Invoke();
}
State = TimeSourceState.Idle;
this.Trace($"The end of {nameof(InnerExecute)} with result={!isBlocked}");
return(!isBlocked);
}
/// <summary>
/// Execute one iteration of time-granting loop.
/// </summary>
/// <remarks>
/// The steps are as follows:
/// (1) remove and forget all slave handles that requested detaching
/// (2) check if there are any blocked slaves; if so DO NOT grant a time interval
/// (2.1) if there are no blocked slaves grant a new time interval to every slave
/// (3) wait for all slaves that are relevant in this execution (it can be either all slaves or just blocked ones) until they report back
/// (4) (optional) sleep if the virtual time passed faster than a real one; this step is executed if <see cref="AdvanceImmediately"> is not set and <see cref="Performance"> is low enough
/// (5) update elapsed virtual time
/// (6) execute sync hook and delayed actions if any
/// </remarks>
/// <param name="virtualTimeElapsed">Contains the amount of virtual time that passed during execution of this method. It is the minimal value reported by a slave (i.e, some slaves can report higher/lower values).</param>
/// <param name="timeLimit">Maximum amount of virtual time that can pass during the execution of this method. If not set, current <see cref="Quantum"> is used.</param>
/// <returns>
/// True if sync point has just been reached or False if the execution has been blocked.
/// </returns>
protected bool InnerExecute(out TimeInterval virtualTimeElapsed, TimeInterval?timeLimit = null)
{
if (updateNearestSyncPoint)
{
NearestSyncPoint += timeLimit.HasValue ? TimeInterval.Min(timeLimit.Value, Quantum) : Quantum;
updateNearestSyncPoint = false;
this.Trace($"Updated NearestSyncPoint to: {NearestSyncPoint}");
}
DebugHelper.Assert(NearestSyncPoint.Ticks >= ElapsedVirtualTime.Ticks, $"Nearest sync point set in the past: EVT={ElapsedVirtualTime} NSP={NearestSyncPoint}");
isBlocked = false;
var quantum = NearestSyncPoint - ElapsedVirtualTime;
this.Trace($"Starting a loop with #{quantum.Ticks} ticks");
virtualTimeElapsed = TimeInterval.Empty;
using (sync.LowPriority)
{
handles.LatchAllAndCollectGarbage();
var shouldGrantTime = handles.AreAllReadyForNewGrant;
this.Trace($"Iteration start: slaves left {handles.ActiveCount}; will we try to grant time? {shouldGrantTime}");
elapsedAtLastGrant = stopwatch.Elapsed;
if (handles.ActiveCount > 0)
{
var executor = new PhaseExecutor <LinkedListNode <TimeHandle> >();
if (!shouldGrantTime)
{
executor.RegisterPhase(ExecuteUnblockPhase);
executor.RegisterPhase(ExecuteWaitPhase);
}
else if (quantum != TimeInterval.Empty)
{
executor.RegisterPhase(s => ExecuteGrantPhase(s, quantum));
executor.RegisterPhase(ExecuteWaitPhase);
}
if (ExecuteInSerial)
{
executor.ExecuteInSerial(handles.WithLinkedListNode);
}
else
{
executor.ExecuteInParallel(handles.WithLinkedListNode);
}
var commonElapsedTime = handles.CommonElapsedTime;
DebugHelper.Assert(commonElapsedTime >= ElapsedVirtualTime, $"A slave reports time from the past! The current virtual time is {ElapsedVirtualTime}, but {commonElapsedTime} has been reported");
virtualTimeElapsed = commonElapsedTime - ElapsedVirtualTime;
}
else
{
this.Trace($"There are no slaves, updating VTE by {quantum.Ticks}");
// if there are no slaves just make the time pass
virtualTimeElapsed = quantum;
// here we must trigger `TimePassed` manually as no handles has been updated so they won't reflect the passed time
TimePassed?.Invoke(quantum);
}
handles.UnlatchAll();
State = TimeSourceState.Sleeping;
var elapsedThisTime = stopwatch.Elapsed - elapsedAtLastGrant;
if (!AdvanceImmediately)
{
var scaledVirtualTicksElapsed = virtualTimeElapsed.WithScaledTicks(1 / Performance).ToTimeSpan() - elapsedThisTime;
sleeper.Sleep(scaledVirtualTicksElapsed);
}
lock (hostTicksElapsed)
{
this.Trace($"Updating virtual time by {virtualTimeElapsed.InMicroseconds} us");
this.virtualTicksElapsed.Update(virtualTimeElapsed.Ticks);
this.hostTicksElapsed.Update(TimeInterval.FromTimeSpan(elapsedThisTime).Ticks);
}
}
if (!isBlocked)
{
ExecuteSyncPhase();
updateNearestSyncPoint = true;
}
else
{
BlockHook?.Invoke();
}
State = TimeSourceState.Idle;
this.Trace($"The end of {nameof(InnerExecute)} with result={!isBlocked}");
return(!isBlocked);
}