/// <inheritdoc />
public override SystemState NextState(SystemState start)
{
var result = SystemState.Copy(ref start);
switch (start.Phase)
{
case Phase.REST:
result.Phase = Phase.PREP_INDEX_CHECKPOINT;
break;
case Phase.PREP_INDEX_CHECKPOINT:
result.Phase = Phase.WAIT_INDEX_ONLY_CHECKPOINT;
break;
case Phase.WAIT_INDEX_ONLY_CHECKPOINT:
result.Phase = Phase.REST;
break;
default:
throw new FasterException("Invalid Enum Argument");
}
return(result);
}
/// <inheritdoc />
public override SystemState NextState(SystemState start)
{
var nextState = SystemState.Copy(ref start);
switch (start.phase)
{
case Phase.REST:
nextState.phase = Phase.PREPARE_GROW;
break;
case Phase.PREPARE_GROW:
nextState.phase = Phase.IN_PROGRESS_GROW;
break;
case Phase.IN_PROGRESS_GROW:
nextState.phase = Phase.REST;
break;
default:
throw new FasterException("Invalid Enum Argument");
}
return(nextState);
}
private void HandleCheckpointingPhases()
{
var previousState = SystemState.Make(threadCtx.phase, threadCtx.version);
var finalState = SystemState.Copy(ref _systemState);
// Don't play around when system state is being changed
if (finalState.phase == Phase.INTERMEDIATE)
{
return;
}
// We need to move from previousState to finalState one step at a time
do
{
var currentState = default(SystemState);
if (previousState.word == finalState.word)
{
currentState.word = previousState.word;
}
else
{
currentState = GetNextState(previousState, _checkpointType);
}
switch (currentState.phase)
{
case Phase.PREP_INDEX_CHECKPOINT:
{
if (!threadCtx.markers[EpochPhaseIdx.PrepareForIndexCheckpt])
{
if (epoch.MarkAndCheckIsComplete(EpochPhaseIdx.PrepareForIndexCheckpt, threadCtx.version))
{
GlobalMoveToNextCheckpointState(currentState);
}
threadCtx.markers[EpochPhaseIdx.PrepareForIndexCheckpt] = true;
}
break;
}
case Phase.INDEX_CHECKPOINT:
{
if (_checkpointType == CheckpointType.INDEX_ONLY)
{
// Reseting the marker for a potential FULL or INDEX_ONLY checkpoint in the future
threadCtx.markers[EpochPhaseIdx.PrepareForIndexCheckpt] = false;
}
if (IsIndexFuzzyCheckpointCompleted())
{
GlobalMoveToNextCheckpointState(currentState);
}
break;
}
case Phase.PREPARE:
{
if (!threadCtx.markers[EpochPhaseIdx.Prepare])
{
// Thread local action
AcquireSharedLatchesForAllPendingRequests();
var idx = Interlocked.Increment(ref _hybridLogCheckpoint.info.numThreads);
idx -= 1;
_hybridLogCheckpoint.info.guids[idx] = threadCtx.guid;
if (epoch.MarkAndCheckIsComplete(EpochPhaseIdx.Prepare, threadCtx.version))
{
GlobalMoveToNextCheckpointState(currentState);
}
threadCtx.markers[EpochPhaseIdx.Prepare] = true;
}
break;
}
case Phase.IN_PROGRESS:
{
// Need to be very careful here as threadCtx is changing
FasterExecutionContext ctx;
if (previousState.phase == Phase.PREPARE)
{
ctx = threadCtx;
}
else
{
ctx = prevThreadCtx;
}
if (!ctx.markers[EpochPhaseIdx.InProgress])
{
prevThreadCtx = threadCtx;
InitLocalContext(ref threadCtx, prevThreadCtx.guid);
if (epoch.MarkAndCheckIsComplete(EpochPhaseIdx.InProgress, ctx.version))
{
GlobalMoveToNextCheckpointState(currentState);
}
prevThreadCtx.markers[EpochPhaseIdx.InProgress] = true;
}
break;
}
case Phase.WAIT_PENDING:
{
if (!prevThreadCtx.markers[EpochPhaseIdx.WaitPending])
{
var notify = (prevThreadCtx.ioPendingRequests.Count == 0);
notify = notify && (prevThreadCtx.retryRequests.Count == 0);
if (notify)
{
if (epoch.MarkAndCheckIsComplete(EpochPhaseIdx.WaitPending, threadCtx.version))
{
GlobalMoveToNextCheckpointState(currentState);
}
prevThreadCtx.markers[EpochPhaseIdx.WaitPending] = true;
}
}
break;
}
case Phase.WAIT_FLUSH:
{
if (!prevThreadCtx.markers[EpochPhaseIdx.WaitFlush])
{
var notify = false;
if (FoldOverSnapshot)
{
notify = (hlog.FlushedUntilAddress >= _hybridLogCheckpoint.info.finalLogicalAddress);
}
else
{
notify = (_hybridLogCheckpoint.flushed != null) && _hybridLogCheckpoint.flushed.IsSet;
}
if (_checkpointType == CheckpointType.FULL)
{
notify = notify && IsIndexFuzzyCheckpointCompleted();
}
if (notify)
{
WriteHybridLogContextInfo();
if (epoch.MarkAndCheckIsComplete(EpochPhaseIdx.WaitFlush, prevThreadCtx.version))
{
GlobalMoveToNextCheckpointState(currentState);
}
prevThreadCtx.markers[EpochPhaseIdx.WaitFlush] = true;
}
}
break;
}
case Phase.PERSISTENCE_CALLBACK:
{
if (!prevThreadCtx.markers[EpochPhaseIdx.CheckpointCompletionCallback])
{
// Thread local action
functions.CheckpointCompletionCallback(threadCtx.guid, prevThreadCtx.serialNum);
if (epoch.MarkAndCheckIsComplete(EpochPhaseIdx.CheckpointCompletionCallback, prevThreadCtx.version))
{
GlobalMoveToNextCheckpointState(currentState);
}
prevThreadCtx.markers[EpochPhaseIdx.CheckpointCompletionCallback] = true;
}
break;
}
case Phase.REST:
{
break;
}
default:
Debug.WriteLine("Error!");
break;
}
// update thread local variables
threadCtx.phase = currentState.phase;
threadCtx.version = currentState.version;
previousState.word = currentState.word;
} while (previousState.word != finalState.word);
}
private async ValueTask HandleCheckpointingPhasesAsync(FasterExecutionContext ctx, ClientSession <Key, Value, Input, Output, Context, Functions> clientSession, bool async = true, CancellationToken token = default)
{
if (async)
{
clientSession?.UnsafeResumeThread();
}
var finalState = SystemState.Copy(ref _systemState);
while (finalState.phase == Phase.INTERMEDIATE)
{
finalState = SystemState.Copy(ref _systemState);
}
var previousState = ctx != null?SystemState.Make(ctx.phase, ctx.version) : finalState;
// We need to move from previousState to finalState one step at a time
var currentState = previousState;
SystemState startState = GetStartState(finalState);
if ((currentState.version < startState.version) ||
(currentState.version == startState.version && currentState.phase < startState.phase))
{
// Fast-forward to beginning of current checkpoint cycle
currentState = startState;
}
do
{
switch (currentState.phase)
{
case Phase.PREP_INDEX_CHECKPOINT:
{
if (ctx != null)
{
if (!ctx.markers[EpochPhaseIdx.PrepareForIndexCheckpt])
{
ctx.markers[EpochPhaseIdx.PrepareForIndexCheckpt] = true;
}
epoch.Mark(EpochPhaseIdx.PrepareForIndexCheckpt, currentState.version);
}
if (epoch.CheckIsComplete(EpochPhaseIdx.PrepareForIndexCheckpt, currentState.version))
{
GlobalMoveToNextCheckpointState(currentState);
}
break;
}
case Phase.INDEX_CHECKPOINT:
{
if (_checkpointType == CheckpointType.INDEX_ONLY && ctx != null)
{
// Reseting the marker for a potential FULL or INDEX_ONLY checkpoint in the future
ctx.markers[EpochPhaseIdx.PrepareForIndexCheckpt] = false;
}
if (async && !IsIndexFuzzyCheckpointCompleted())
{
clientSession?.UnsafeSuspendThread();
await IsIndexFuzzyCheckpointCompletedAsync(token);
clientSession?.UnsafeResumeThread();
}
GlobalMoveToNextCheckpointState(currentState);
break;
}
case Phase.PREPARE:
{
if (ctx != null)
{
if (!ctx.markers[EpochPhaseIdx.Prepare])
{
if (!RelaxedCPR)
{
AcquireSharedLatchesForAllPendingRequests(ctx);
}
ctx.markers[EpochPhaseIdx.Prepare] = true;
}
epoch.Mark(EpochPhaseIdx.Prepare, currentState.version);
}
if (epoch.CheckIsComplete(EpochPhaseIdx.Prepare, currentState.version))
{
GlobalMoveToNextCheckpointState(currentState);
}
break;
}
case Phase.IN_PROGRESS:
{
if (ctx != null)
{
// Need to be very careful here as threadCtx is changing
FasterExecutionContext _ctx;
if (previousState.phase == Phase.IN_PROGRESS)
{
_ctx = ctx.prevCtx;
}
else
{
_ctx = ctx;
}
if (!_ctx.markers[EpochPhaseIdx.InProgress])
{
AtomicSwitch(ctx, ctx.prevCtx, _ctx.version);
InitContext(ctx, ctx.prevCtx.guid, ctx.prevCtx.serialNum);
// Has to be prevCtx, not ctx
ctx.prevCtx.markers[EpochPhaseIdx.InProgress] = true;
}
epoch.Mark(EpochPhaseIdx.InProgress, currentState.version);
}
// Has to be prevCtx, not ctx
if (epoch.CheckIsComplete(EpochPhaseIdx.InProgress, currentState.version))
{
GlobalMoveToNextCheckpointState(currentState);
}
break;
}
case Phase.WAIT_PENDING:
{
if (ctx != null)
{
if (!ctx.prevCtx.markers[EpochPhaseIdx.WaitPending])
{
var notify = (ctx.prevCtx.ioPendingRequests.Count == 0);
notify = notify && (ctx.prevCtx.retryRequests.Count == 0);
if (notify)
{
ctx.prevCtx.markers[EpochPhaseIdx.WaitPending] = true;
}
else
{
break;
}
}
epoch.Mark(EpochPhaseIdx.WaitPending, currentState.version);
}
if (epoch.CheckIsComplete(EpochPhaseIdx.WaitPending, currentState.version))
{
GlobalMoveToNextCheckpointState(currentState);
}
break;
}
case Phase.WAIT_FLUSH:
{
if (ctx == null || !ctx.prevCtx.markers[EpochPhaseIdx.WaitFlush])
{
bool notify;
if (FoldOverSnapshot)
{
notify = (hlog.FlushedUntilAddress >= _hybridLogCheckpoint.info.finalLogicalAddress);
}
else
{
notify = (_hybridLogCheckpoint.flushedSemaphore != null) && _hybridLogCheckpoint.flushedSemaphore.CurrentCount > 0;
}
if (async && !notify)
{
Debug.Assert(_hybridLogCheckpoint.flushedSemaphore != null);
clientSession?.UnsafeSuspendThread();
await _hybridLogCheckpoint.flushedSemaphore.WaitAsync(token);
clientSession?.UnsafeResumeThread();
_hybridLogCheckpoint.flushedSemaphore.Release();
notify = true;
}
if (_checkpointType == CheckpointType.FULL)
{
notify = notify && IsIndexFuzzyCheckpointCompleted();
if (async && !notify)
{
clientSession?.UnsafeSuspendThread();
await IsIndexFuzzyCheckpointCompletedAsync(token);
clientSession?.UnsafeResumeThread();
notify = true;
}
}
if (notify)
{
if (ctx != null)
{
ctx.prevCtx.markers[EpochPhaseIdx.WaitFlush] = true;
}
}
else
{
break;
}
}
if (ctx != null)
{
epoch.Mark(EpochPhaseIdx.WaitFlush, currentState.version);
}
if (epoch.CheckIsComplete(EpochPhaseIdx.WaitFlush, currentState.version))
{
GlobalMoveToNextCheckpointState(currentState);
}
break;
}
case Phase.PERSISTENCE_CALLBACK:
{
if (ctx != null)
{
if (!ctx.prevCtx.markers[EpochPhaseIdx.CheckpointCompletionCallback])
{
if (ctx.prevCtx.serialNum != -1)
{
var commitPoint = new CommitPoint
{
UntilSerialNo = ctx.prevCtx.serialNum,
ExcludedSerialNos = ctx.prevCtx.excludedSerialNos
};
// Thread local action
functions.CheckpointCompletionCallback(ctx.guid, commitPoint);
if (clientSession != null)
{
clientSession.LatestCommitPoint = commitPoint;
}
}
ctx.prevCtx.markers[EpochPhaseIdx.CheckpointCompletionCallback] = true;
}
epoch.Mark(EpochPhaseIdx.CheckpointCompletionCallback, currentState.version);
}
if (epoch.CheckIsComplete(EpochPhaseIdx.CheckpointCompletionCallback, currentState.version))
{
GlobalMoveToNextCheckpointState(currentState);
}
break;
}
case Phase.REST:
{
break;
}
default:
throw new FasterException("Invalid state found during checkpointing");
}
if (ctx != null)
{
// update thread local variables
ctx.phase = currentState.phase;
ctx.version = currentState.version;
}
previousState.word = currentState.word;
currentState = GetNextState(currentState, _checkpointType);
} while (previousState.word != finalState.word);
if (async)
{
clientSession?.UnsafeSuspendThread();
}
}
