fix(graph): only evaluate outbound edges from completed nodes#1846
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giulio-leone wants to merge 1 commit intostrands-agents:mainfrom
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fix(graph): only evaluate outbound edges from completed nodes#1846giulio-leone wants to merge 1 commit intostrands-agents:mainfrom
giulio-leone wants to merge 1 commit intostrands-agents:mainfrom
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_find_newly_ready_nodes iterated over ALL nodes in the graph after each batch completion, checking every node for readiness. This caused O(all_edges) evaluation instead of O(outbound_edges) and could fire nodes whose actual dependencies had not completed. Now collects candidate nodes from outbound edges of the completed batch only, preventing incorrect out-of-order execution. Fixes strands-agents#685 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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Bug
After any node completes, the graph evaluates ALL edges in the entire graph instead of only outbound edges from the completed nodes. This causes
O(all_edges)evaluation instead ofO(outbound_edges)and can fire nodes whose actual dependencies haven't completed yet.Reported in: #685
Root cause
_find_newly_ready_nodes()iterates overself.nodes.items()(ALL nodes in the graph) and checks each one against the completed batch. Nodes connected to irrelevant edges could pass the readiness check if their incoming edges happened to match the completed batch.Fix
Replace the all-nodes iteration with a targeted lookup:
This changes the evaluation from
O(all_nodes × incoming_edges)toO(outbound_edges × incoming_edges), and prevents false-positive readiness detection.Testing
test_find_newly_ready_nodes_only_evaluates_outbound_edges: builds a graph with two independent chains (A→B→C, D→E), verifies completing A only readies B (not E), and completing D only readies E (not B or C)Fixes #685