⚡ Bolt: Eliminate LINQ Count() enumerator allocation in hot path#41
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⚡ Bolt: Eliminate LINQ Count() enumerator allocation in hot path#41lordhippo wants to merge 4 commits into
lordhippo wants to merge 4 commits into
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- **What:** Replaced the `Context.OwnRobots.Count(robot => robot.Seen)` LINQ method call in `Knowledge.Update()` with an explicit `foreach` loop and counter. - **Why:** The `Knowledge.Update()` method is part of the AI hot path, running every frame (~100Hz). Using the LINQ `Count(predicate)` method on collections forces a cast to `IEnumerable<T>`, which boxes the underlying struct enumerator, causing a heap allocation on every frame. - **Impact:** Eliminates 1 enumerator boxing allocation per frame per team. At 100Hz with two teams, this saves ~200 allocs/sec from the Gen 0 heap, reducing GC pressure and potential latency spikes in the real-time loop. - **Verification:** Run `dotnet-counters monitor --counters System.Runtime[gen-0-gc-count,alloc-rate]` to observe reduced allocation rates during gameplay. Co-authored-by: lordhippo <5122916+lordhippo@users.noreply.github.com>
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- **What:** Replaced the `Context.OwnRobots.Count(robot => robot.Seen)` LINQ method call in `Knowledge.Update()` with an explicit `foreach` loop and counter. - **Why:** The `Knowledge.Update()` method is part of the AI hot path, running every frame (~100Hz). Using the LINQ `Count(predicate)` method on collections forces a cast to `IEnumerable<T>`, which boxes the underlying struct enumerator, causing a heap allocation on every frame. - **Impact:** Eliminates 1 enumerator boxing allocation per frame per team. At 100Hz with two teams, this saves ~200 allocs/sec from the Gen 0 heap, reducing GC pressure and potential latency spikes in the real-time loop. - **Verification:** Run `dotnet-counters monitor --counters System.Runtime[gen-0-gc-count,alloc-rate]` to observe reduced allocation rates during gameplay. - Also fixed several build warnings (unused fields and possible null dereferences in BallPlacement and OurFreekick). Co-authored-by: lordhippo <5122916+lordhippo@users.noreply.github.com>
- **What:** Replaced the `Context.OwnRobots.Count(robot => robot.Seen)` LINQ method call in `Knowledge.Update()` with an explicit `foreach` loop and counter. - **Why:** The `Knowledge.Update()` method is part of the AI hot path, running every frame (~100Hz). Using the LINQ `Count(predicate)` method on collections forces a cast to `IEnumerable<T>`, which boxes the underlying struct enumerator, causing a heap allocation on every frame. - **Impact:** Eliminates 1 enumerator boxing allocation per frame per team. At 100Hz with two teams, this saves ~200 allocs/sec from the Gen 0 heap, reducing GC pressure and potential latency spikes in the real-time loop. - **Verification:** Run `dotnet-counters monitor --counters System.Runtime[gen-0-gc-count,alloc-rate]` to observe reduced allocation rates during gameplay. Co-authored-by: lordhippo <5122916+lordhippo@users.noreply.github.com>
- **What:** Replaced the `Context.OwnRobots.Count(robot => robot.Seen)` LINQ method call in `Knowledge.Update()` with an explicit `foreach` loop and counter. - **Why:** The `Knowledge.Update()` method is part of the AI hot path, running every frame (~100Hz). Using the LINQ `Count(predicate)` method on collections forces a cast to `IEnumerable<T>`, which boxes the underlying struct enumerator, causing a heap allocation on every frame. - **Impact:** Eliminates 1 enumerator boxing allocation per frame per team. At 100Hz with two teams, this saves ~200 allocs/sec from the Gen 0 heap, reducing GC pressure and potential latency spikes in the real-time loop. - **Verification:** Run `dotnet-counters monitor --counters System.Runtime[gen-0-gc-count,alloc-rate]` to observe reduced allocation rates during gameplay. - Also fixed several build warnings (unused fields and possible null dereferences in BallPlacement and OurFreekick). Co-authored-by: lordhippo <5122916+lordhippo@users.noreply.github.com>
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💡 What: Replaced the
Context.OwnRobots.Count(robot => robot.Seen)LINQ method call inKnowledge.Update()with an explicitforeachloop and counter. Also documented the learning in.jules/bolt.md.🎯 Why: The
Knowledge.Update()method is part of the AI hot path, running every frame (~100Hz). Using the LINQCount(predicate)method on collections forces a cast toIEnumerable<T>, which boxes the underlying struct enumerator, causing a heap allocation on every single frame. GC pauses are the primary enemy in this real-time loop.📊 Impact: Eliminates 1 enumerator boxing allocation per frame per team. At 100Hz with two teams, this saves ~200 allocs/sec from the Gen 0 heap, reducing GC pressure and potential latency spikes.
🔬 Measurement: Use
dotnet-counters monitor --counters System.Runtime[gen-0-gc-count,alloc-rate]to observe reduced allocation rates during gameplay.PR created automatically by Jules for task 3894145543788865041 started by @lordhippo