Struct UnitOfWorkContext

Namespace

Typhon.Engine

Assembly

Typhon.Engine.dll

A 24-byte execution context that flows through all operations inside a Unit of Work (or standalone transaction). Embeds a WaitContext (deadline + cancellation) and adds UoW identity and holdoff state. Lock sites can use ref ctx.WaitContext directly — zero construction cost.

public struct UnitOfWorkContext

Inherited Members

ValueType.Equals(object)

ValueType.GetHashCode()

ValueType.ToString()

object.GetType()

object.Equals(object, object)

object.ReferenceEquals(object, object)

Remarks

default(UnitOfWorkContext) is already expired (fail-safe) — the embedded deadline is expired and ThrowIfCancelled() will throw immediately. Use None for unbounded operations (infinite deadline, no cancellation).

This is a value type passed by ref through synchronous call chains. The CancellationTokenSource that generates the token is owned externally — by the future UnitOfWork class (Tier 3) or by Typhon.Engine.Internals.DeadlineWatchdog.

Constructors

UnitOfWorkContext(Deadline, CancellationToken, ushort)

Primary constructor — deadline + cancellation token.

public UnitOfWorkContext(Deadline deadline, CancellationToken token, ushort uowId = 0)

Parameters

deadline Deadline

token CancellationToken

uowId ushort

UnitOfWorkContext(WaitContext, ushort)

Primary constructor — WaitContext + UoW ID.

public UnitOfWorkContext(WaitContext waitContext, ushort uowId = 0)

Parameters

waitContext WaitContext

uowId ushort

Fields

UowId

UoW identifier for revision stamping and crash recovery. Distinct from EpochManager.GlobalEpoch (EBRM resource lifecycle).

public readonly ushort UowId

Field Value

ushort

WaitContext

Embedded wait context carrying deadline + cancellation token. Lock call sites can use ref ctx.WaitContext directly. Non-readonly to allow ref passing to lock primitives.

public WaitContext WaitContext

Field Value

WaitContext

Properties

Deadline

The embedded deadline.

public Deadline Deadline { get; }

Property Value

Deadline

IsCancellationRequested

True if the cancellation token has been triggered.

public bool IsCancellationRequested { get; }

Property Value

bool

IsExpired

True if the deadline has expired.

public bool IsExpired { get; }

Property Value

bool

IsInHoldoff

True if currently inside a holdoff region.

public bool IsInHoldoff { get; }

Property Value

bool

None

Unbounded context: infinite deadline, no cancellation. For internal operations that should not be subject to timeout (e.g., cleanup, rollback).

public static UnitOfWorkContext None { get; }

Property Value

UnitOfWorkContext

Remaining

Remaining time until deadline expires.

public TimeSpan Remaining { get; }

Property Value

TimeSpan

Token

The embedded cancellation token.

public CancellationToken Token { get; }

Property Value

CancellationToken

Methods

BeginHoldoff()

Increment holdoff counter (prefer Typhon.Engine.UnitOfWorkContext.EnterHoldoff for RAII safety).

public void BeginHoldoff()

EndHoldoff()

Decrement holdoff counter.

public void EndHoldoff()

FromTimeout(TimeSpan)

Create from a relative timeout (no cancellation, no UoW ID).

public static UnitOfWorkContext FromTimeout(TimeSpan timeout)

Parameters

timeout TimeSpan

Returns

UnitOfWorkContext

FromTimeout(TimeSpan, CancellationToken)

Create from a relative timeout + cancellation token.

public static UnitOfWorkContext FromTimeout(TimeSpan timeout, CancellationToken token)

Parameters

timeout TimeSpan

token CancellationToken

Returns

UnitOfWorkContext

ThrowIfCancelled()

Cooperative cancellation check. Call at yield points (safe locations where aborting won't leave data structures in an inconsistent state).

public void ThrowIfCancelled()

Remarks

If Typhon.Engine.UnitOfWorkContext._holdoffCount > 0 (inside a holdoff region), this is a no-op. Cancellation is deferred until the holdoff exits.

Checks deadline first (cheaper than token check on most paths), then cancellation token. Accesses fields through embedded WaitContext — the JIT resolves struct field offsets at compile time, producing identical code to direct field access.

Exceptions

TyphonTimeoutException

Deadline has expired (outside holdoff).

OperationCanceledException

Token was canceled (outside holdoff).