Single entry tracking one in-flight backtest or live run.
Registered into the lookup map on activity start (e.g. INSTANCE_TASK_FN in
Backtest/Live, or per-strategy loop in WalkerLogicPrivateService) and
removed on completion or failure.
Used by Candle.spinLock to detect parallel workloads via LookupUtils.isParallel.
symbol: string
Trading pair symbol (e.g. "BTCUSDT").
context: { strategyName: string; exchangeName: string; frameName?: string; }
Execution context identifying the running strategy.
backtest: boolean
true for backtest activities, false for live activities.