1 commit

Author	SHA1	Message	Date
Chris Guidry	d41bcb2c9e	Unify background task context forwarding, fix concurrent dependency bugs (#3710) ... * Unify background task context forwarding and fix concurrent dependency bugs We've been getting a steady trickle of edge-case reports around background tasks and contextual dependencies over the last few months (#3654, #3656, #3569). Each one pointed at a different symptom, but they all traced back to the same area: the way context is negotiated between the "frontend" server and Docket workers was grown piecemeal, with each new piece of context (access tokens, HTTP headers, origin request IDs) getting its own Redis key, its own restore function, and its own ContextVar. This made it hard to reason about what state was available where, and the shared-instance Dependency pattern made concurrent tasks stomp on each other's cleanup state. This takes a step back and reworks the whole thing as a single unified system: - Dependency subclasses (_CurrentContext, Progress, _CurrentAccessToken, etc.) are now stateless factories — __aenter__ returns a fresh per-invocation object, so concurrent tasks never share mutable state. Fixes #3654, #3656. - The three individual context-snapshot Redis keys (access_token, http_headers, origin_request_id) are collapsed into a single TaskContextSnapshot stored as one JSON key per task. The three _restore_task_* functions and two ContextVars they populated are gone. - Sync functions like get_http_request() and get_access_token() now find the snapshot transparently in background tasks via a 3-tier sync fallback: ContextVar (set by _CurrentContext for functions with deps) → in-memory dict (same-process workers) → sync Redis GET (out-of-process workers). No function wrapping needed. - The _wrap_for_task_http_headers hack is deleted. FunctionTool registers its raw function with Docket so Docket sees and resolves ALL dependencies, including Docket-native ones like Retry and Timeout. - ProxyTool.from_mcp_tool() now propagates execution.taskSupport metadata from remote tools. Fixes #3569. - Removed redundant _current_docket/_current_worker ContextVar management from Context.__aenter__/__aexit__ (they're only set in the lifespan now). Closes #3654 Closes #3656 Closes #3569 🤖 Generated with Claude Code Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * Address code review feedback - _OptionalCurrentContext: guard __aexit__ against cleaning up contexts it didn't create (check is_background_task before delegating) - Narrow except clauses in snapshot loading (OSError, JSONDecodeError, etc. instead of bare Exception) - Fix docstrings on register_with_docket for resources/prompts/templates - Simplify Progress: read ExecutionProgress directly from current_execution instead of creating and manually entering a DocketProgress wrapper 🤖 Generated with Claude Code Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * Use pop-on-access transfer buffer instead of bounded LRU cache for snapshots The in-memory snapshot dict is a transfer mechanism, not a cache. Entries go in at submission and come out at the worker's first access. Using pop instead of get means the dict only holds entries during the brief submission-to-execution window, bounded by task concurrency (~10) rather than a 10,000-entry LRU limit. 🤖 Generated with Claude Code Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * Drop in-memory transfer buffer, use sync Redis for all backends Instead of maintaining an in-memory dict to bridge the async/sync gap, use a sync Redis client directly. For memory:// backends (fakeredis), shares the same FakeServer instance via docket._redis.get_memory_server() so data written by the async Docket client is visible to sync reads. For real Redis, creates a standard sync connection. No in-process state to manage at all. 🤖 Generated with Claude Code Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * Move snapshot operations to TaskContextSnapshot methods capture(), from_json(), to_json(), save() are now classmethod/instance methods on the dataclass instead of free functions. Deduplicates JSON parsing that was copy-pasted between the async and sync load paths. 🤖 Generated with Claude Code Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * Trim implementation details from register_with_docket docstrings 🤖 Generated with Claude Code Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * Clarify docket lookup comment in submit_to_docket 🤖 Generated with Claude Code Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * Restore docket/worker ContextVar bridge in Context.__aenter__ Servers that own the Docket (the parent) re-set _current_docket/_current_worker from their instance attributes when entering a Context. Mounted children skip this (their _docket is None), so they inherit the parent's value. This is needed for ASGI deployments where ContextVars set during the lifespan don't propagate to request handlers. 🤖 Generated with Claude Code Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * Key snapshot cache by task_id to prevent cross-task context leakage Docket workers may reuse the same asyncio context for sequential tasks. The ContextVar cache now stores (task_id, snapshot) tuples so stale entries from previous tasks are automatically ignored. 🤖 Generated with Claude Code Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>	2026-04-03 10:48:27 -04:00