preen

esphome/core/scheduler.cpp

@@ -14,7 +14,18 @@ namespace esphome {
 
 static const char *const TAG = "scheduler";
 
+// Memory pool configuration constants
+// Pool size of 10 is a balance between memory usage and performance:
+// - Small enough to not waste memory on simple configs (1-2 timers)
+// - Large enough to handle complex setups with multiple sensors/components
+// - Prevents system-wide stalls from heap allocation/deallocation that can
+//   disrupt task synchronization and cause dropped events
+static constexpr size_t MAX_POOL_SIZE = 10;
+// Maximum number of cancelled items to keep in the heap before forcing a cleanup.
+// Set to 6 to trigger cleanup relatively frequently, ensuring cancelled items are
+// recycled to the pool in a timely manner to maintain pool efficiency.
 static const uint32_t MAX_LOGICALLY_DELETED_ITEMS = 6;
+
 // Half the 32-bit range - used to detect rollovers vs normal time progression
 static constexpr uint32_t HALF_MAX_UINT32 = std::numeric_limits<uint32_t>::max() / 2;
 // max delay to start an interval sequence
@@ -765,12 +776,6 @@ void Scheduler::recycle_item_(std::unique_ptr<SchedulerItem> item) {
   if (!item)
     return;
 
-  // Pool size of 10 is a balance between memory usage and performance:
-  // - Small enough to not waste memory on simple configs (1-2 timers)
-  // - Large enough to handle complex setups with multiple sensors/components
-  // - Prevents system-wide stalls from heap allocation/deallocation that can
-  //   disrupt task synchronization and cause dropped events
-  static constexpr size_t MAX_POOL_SIZE = 10;
   if (this->scheduler_item_pool_.size() < MAX_POOL_SIZE) {
     // Clear callback to release captured resources
     item->callback = nullptr;

tests/integration/test_scheduler_pool.py

@@ -47,6 +47,7 @@ async def test_scheduler_pool(
         3: loop.create_future(),
         4: loop.create_future(),
         5: loop.create_future(),
+        6: loop.create_future(),
     }
 
     def check_output(line: str) -> None:
@@ -68,7 +69,7 @@ async def test_scheduler_pool(
             new_alloc_count += 1
 
         # Track phase completion
-        for phase_num in range(1, 6):
+        for phase_num in range(1, 7):
             if (
                 f"Phase {phase_num} complete" in line
                 and not phase_futures[phase_num].done()
@@ -100,6 +101,7 @@ async def test_scheduler_pool(
             "run_phase_3",
             "run_phase_4",
             "run_phase_5",
+            "run_phase_6",
             "run_complete",
         }
         assert expected_services.issubset(service_names), (
@@ -109,7 +111,7 @@ async def test_scheduler_pool(
         # Get service objects
         phase_services = {
             num: next(s for s in services if s.name == f"run_phase_{num}")
-            for num in range(1, 6)
+            for num in range(1, 7)
         }
         complete_service = next(s for s in services if s.name == "run_complete")
 
@@ -137,7 +139,12 @@ async def test_scheduler_pool(
             # Phase 5: Pool reuse verification
             client.execute_service(phase_services[5], {})
             await asyncio.wait_for(phase_futures[5], timeout=3.0)
-            await asyncio.sleep(0.5)  # Let reuse tests complete
+            await asyncio.sleep(1.0)  # Let Phase 5 timeouts complete and recycle
+
+            # Phase 6: Full pool reuse verification
+            client.execute_service(phase_services[6], {})
+            await asyncio.wait_for(phase_futures[6], timeout=3.0)
+            await asyncio.sleep(1.0)  # Let Phase 6 timeouts complete
 
             # Complete test
             client.execute_service(complete_service, {})
@@ -159,7 +166,7 @@ async def test_scheduler_pool(
             )
 
     # Verify all test phases ran
-    for phase_num in range(1, 6):
+    for phase_num in range(1, 7):
         assert phase_futures[phase_num].done(), f"Phase {phase_num} did not complete"
 
     # Verify pool behavior