{"record":{"id":"6ad617b5076cef23","repo":"Hmbown/CodeWhale","slug":"runtime-turn-operation-is-already-being-claimed-retry","errorCode":null,"errorMessage":"Runtime turn operation is already being claimed; retry","messagePattern":"Runtime turn operation is already being claimed; retry","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"warning","filePath":"crates/tui/src/runtime_threads.rs","lineNumber":1910,"sourceCode":"        let mut claim =\n            fd_lock::RwLock::new(self.open_turn_operation_claim_lock(operation_key_fingerprint)?);\n        let _guard = self.acquire_turn_operation_claim(&mut claim)?;\n        operation()\n    }\n\n    fn acquire_turn_operation_claim<'a>(\n        &self,\n        claim: &'a mut fd_lock::RwLock<File>,\n    ) -> Result<fd_lock::RwLockWriteGuard<'a, File>> {\n        match claim.try_write() {\n            Ok(guard) => Ok(guard),\n            Err(error)\n                if matches!(\n                    error.kind(),\n                    std::io::ErrorKind::WouldBlock | std::io::ErrorKind::Interrupted\n                ) =>\n            {\n                bail!(\"Runtime turn operation is already being claimed; retry\")\n            }\n            Err(error) => Err(error).context(\"Failed to claim Runtime turn operation\"),\n        }\n    }\n\n    /// Remove a binding left before its turn record by a process crash.\n    ///\n    /// Bindings are committed before turns, while engine submission happens\n    /// only after both are durable. A binding with no turn therefore never\n    /// reached the engine and is safe to discard during startup recovery.\n    fn recover_incomplete_turn_operations(&self) -> Result<()> {\n        let operations_dir = checked_existing_runtime_store_dir(&self.turn_operations_dir)?;\n        for entry in fs::read_dir(&operations_dir)\n            .with_context(|| format!(\"Failed to read {}\", operations_dir.display()))?\n        {\n            let path = entry?.path();\n            if path.extension().is_none_or(|extension| extension != \"json\") {\n                continue;","sourceCodeStart":1892,"sourceCodeEnd":1928,"githubUrl":"https://github.com/Hmbown/CodeWhale/blob/433685b2024e7bc4c99e1e2e326bcad39b4d9d65/crates/tui/src/runtime_threads.rs#L1892-L1928","documentation":"The runtime refuses to claim a turn operation because another process/thread already holds the claim. Claiming is done through an exclusive create (O_CREAT|O_EXCL-style) file binding, and when the OS reports WouldBlock or Interrupted the code converts it into this bail so callers know to retry rather than treat it as corruption. It is a transient contention signal, not a data error.","triggerScenarios":"Calling the runtime claim path (claim of a Runtime turn operation binding) while the on-disk binding is locked/held by another process, or the claim syscall is interrupted (EINTR).","commonSituations":"Two TUI/CLI instances sharing the same runtime store directory; a crashed or hung previous run that still holds the claim; concurrent turn operations racing during startup.","solutions":["Retry the turn operation after a short backoff; the claim is transient and the competing holder usually releases it.","Check for another running Codewhale instance on the same runtime store and close it.","If a stale claim persists after a crash, use the store's stale-binding removal path (remove a binding left before its turn record by a process crash).","Ensure only one instance uses the same runtime store directory at a time."],"exampleFix":"// before\nlet claim = claim_turn_operation(&store)?; // panics/aborts on contention\n// after\nmatch claim_turn_operation(&store) {\n    Err(e) if e.to_string().contains(\"already being claimed\") => retry_with_backoff(),\n    other => other?,\n}","handlingStrategy":"retry","validationCode":"// No pre-check possible; contention is dynamic.\nlet claim = loop {\n    match claim_turn_operation(&store) {\n        Ok(c) => break c,\n        Err(e) if e.to_string().contains(\"already being claimed\") => std::thread::sleep(std::time::Duration::from_millis(100)),\n        Err(e) => return Err(e),\n    }\n};","typeGuard":null,"tryCatchPattern":"match claim_turn_operation(&store) {\n    Err(e) if e.to_string().contains(\"already being claimed\") => retry_with_backoff(), // transient\n    Err(e) => return Err(e.context(\"claim failed\")),\n    Ok(claim) => use_claim(claim),\n}","preventionTips":["Run only one Codewhale instance against a given runtime store directory.","Use per-user/per-project store directories to avoid cross-session contention.","Always retry with bounded backoff on this specific message; it is designed to be retryable.","After a crash, clean stale bindings before re-claiming."],"tags":["concurrency","locking","rust","retryable"],"backgroundTag":"invalid-state-transition","analyzedSha":"433685b2024e7bc4c99e1e2e326bcad39b4d9d65","analyzedAt":"2026-09-15T12:24:24.634Z","contentChangedAt":"2026-09-15T12:24:24.634Z","schemaVersion":2},"datasetVersion":"2026-09-22T01:17:13.364Z"}