[core] Add memory pool to scheduler to reduce heap fragmentation (#10536)

tests/integration/test_scheduler_pool.py

@@ -0,0 +1,209 @@
+"""Integration test for scheduler memory pool functionality."""
+
+from __future__ import annotations
+
+import asyncio
+import re
+
+import pytest
+
+from .types import APIClientConnectedFactory, RunCompiledFunction
+
+
+@pytest.mark.asyncio
+async def test_scheduler_pool(
+    yaml_config: str,
+    run_compiled: RunCompiledFunction,
+    api_client_connected: APIClientConnectedFactory,
+) -> None:
+    """Test that the scheduler memory pool is working correctly with realistic usage.
+
+    This test simulates real-world scheduler usage patterns and verifies that:
+    1. Items are recycled to the pool when timeouts complete naturally
+    2. Items are recycled when intervals/timeouts are cancelled
+    3. Items are reused from the pool for new scheduler operations
+    4. The pool grows gradually based on actual usage patterns
+    5. Pool operations are logged correctly with debug scheduler enabled
+    """
+    # Track log messages to verify pool behavior
+    log_lines: list[str] = []
+    pool_reuse_count = 0
+    pool_recycle_count = 0
+    pool_full_count = 0
+    new_alloc_count = 0
+
+    # Patterns to match pool operations
+    reuse_pattern = re.compile(r"Reused item from pool \(pool size now: (\d+)\)")
+    recycle_pattern = re.compile(r"Recycled item to pool \(pool size now: (\d+)\)")
+    pool_full_pattern = re.compile(r"Pool full \(size: (\d+)\), deleting item")
+    new_alloc_pattern = re.compile(r"Allocated new item \(pool empty\)")
+
+    # Futures to track when test phases complete
+    loop = asyncio.get_running_loop()
+    test_complete_future: asyncio.Future[bool] = loop.create_future()
+    phase_futures = {
+        1: loop.create_future(),
+        2: loop.create_future(),
+        3: loop.create_future(),
+        4: loop.create_future(),
+        5: loop.create_future(),
+        6: loop.create_future(),
+        7: loop.create_future(),
+    }
+
+    def check_output(line: str) -> None:
+        """Check log output for pool operations and phase completion."""
+        nonlocal pool_reuse_count, pool_recycle_count, pool_full_count, new_alloc_count
+        log_lines.append(line)
+
+        # Track pool operations
+        if reuse_pattern.search(line):
+            pool_reuse_count += 1
+
+        elif recycle_pattern.search(line):
+            pool_recycle_count += 1
+
+        elif pool_full_pattern.search(line):
+            pool_full_count += 1
+
+        elif new_alloc_pattern.search(line):
+            new_alloc_count += 1
+
+        # Track phase completion
+        for phase_num in range(1, 8):
+            if (
+                f"Phase {phase_num} complete" in line
+                and phase_num in phase_futures
+                and not phase_futures[phase_num].done()
+            ):
+                phase_futures[phase_num].set_result(True)
+
+        # Check for test completion
+        if "Pool recycling test complete" in line and not test_complete_future.done():
+            test_complete_future.set_result(True)
+
+    # Run the test with log monitoring
+    async with (
+        run_compiled(yaml_config, line_callback=check_output),
+        api_client_connected() as client,
+    ):
+        # Verify device is running
+        device_info = await client.device_info()
+        assert device_info is not None
+        assert device_info.name == "scheduler-pool-test"
+
+        # Get list of services
+        entities, services = await client.list_entities_services()
+        service_names = {s.name for s in services}
+
+        # Verify all test services are available
+        expected_services = {
+            "run_phase_1",
+            "run_phase_2",
+            "run_phase_3",
+            "run_phase_4",
+            "run_phase_5",
+            "run_phase_6",
+            "run_phase_7",
+            "run_complete",
+        }
+        assert expected_services.issubset(service_names), (
+            f"Missing services: {expected_services - service_names}"
+        )
+
+        # Get service objects
+        phase_services = {
+            num: next(s for s in services if s.name == f"run_phase_{num}")
+            for num in range(1, 8)
+        }
+        complete_service = next(s for s in services if s.name == "run_complete")
+
+        try:
+            # Phase 1: Component lifecycle
+            client.execute_service(phase_services[1], {})
+            await asyncio.wait_for(phase_futures[1], timeout=1.0)
+            await asyncio.sleep(0.05)  # Let timeouts complete
+
+            # Phase 2: Sensor polling
+            client.execute_service(phase_services[2], {})
+            await asyncio.wait_for(phase_futures[2], timeout=1.0)
+            await asyncio.sleep(0.1)  # Let intervals run a bit
+
+            # Phase 3: Communication patterns
+            client.execute_service(phase_services[3], {})
+            await asyncio.wait_for(phase_futures[3], timeout=1.0)
+            await asyncio.sleep(0.1)  # Let heartbeat run
+
+            # Phase 4: Defer patterns
+            client.execute_service(phase_services[4], {})
+            await asyncio.wait_for(phase_futures[4], timeout=1.0)
+            await asyncio.sleep(0.2)  # Let everything settle and recycle
+
+            # Phase 5: Pool reuse verification
+            client.execute_service(phase_services[5], {})
+            await asyncio.wait_for(phase_futures[5], timeout=1.0)
+            await asyncio.sleep(0.1)  # 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=1.0)
+            await asyncio.sleep(0.1)  # Let Phase 6 timeouts complete
+
+            # Phase 7: Same-named defer optimization
+            client.execute_service(phase_services[7], {})
+            await asyncio.wait_for(phase_futures[7], timeout=1.0)
+            await asyncio.sleep(0.05)  # Let the single defer execute
+
+            # Complete test
+            client.execute_service(complete_service, {})
+            await asyncio.wait_for(test_complete_future, timeout=0.5)
+
+        except TimeoutError as e:
+            # Print debug info if test times out
+            recent_logs = "\n".join(log_lines[-30:])
+            phases_completed = [num for num, fut in phase_futures.items() if fut.done()]
+            pytest.fail(
+                f"Test timed out waiting for phase/completion. Error: {e}\n"
+                f"  Phases completed: {phases_completed}\n"
+                f"  Pool stats:\n"
+                f"    Reuse count: {pool_reuse_count}\n"
+                f"    Recycle count: {pool_recycle_count}\n"
+                f"    Pool full count: {pool_full_count}\n"
+                f"    New alloc count: {new_alloc_count}\n"
+                f"Recent logs:\n{recent_logs}"
+            )
+
+    # Verify all test phases ran
+    for phase_num in range(1, 8):
+        assert phase_futures[phase_num].done(), f"Phase {phase_num} did not complete"
+
+    # Verify pool behavior
+    assert pool_recycle_count > 0, "Should have recycled items to pool"
+
+    # Check pool metrics
+    if pool_recycle_count > 0:
+        max_pool_size = 0
+        for line in log_lines:
+            if match := recycle_pattern.search(line):
+                size = int(match.group(1))
+                max_pool_size = max(max_pool_size, size)
+
+        # Pool can grow up to its maximum of 5
+        assert max_pool_size <= 5, f"Pool grew beyond maximum ({max_pool_size})"
+
+    # Log summary for debugging
+    print("\nScheduler Pool Test Summary (Python Orchestrated):")
+    print(f"  Items recycled to pool: {pool_recycle_count}")
+    print(f"  Items reused from pool: {pool_reuse_count}")
+    print(f"  Pool full events: {pool_full_count}")
+    print(f"  New allocations: {new_alloc_count}")
+    print("  All phases completed successfully")
+
+    # Verify reuse happened
+    if pool_reuse_count == 0 and pool_recycle_count > 3:
+        pytest.fail("Pool had items recycled but none were reused")
+
+    # Success - pool is working
+    assert pool_recycle_count > 0 or new_alloc_count < 15, (
+        "Pool should either recycle items or limit new allocations"
+    )