Optimize scheduler string storage to eliminate heap allocations (#9251)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

tests/integration/test_scheduler_string_test.py

@@ -0,0 +1,166 @@
+"""Test scheduler string optimization with static and dynamic strings."""
+
+import asyncio
+import re
+
+import pytest
+
+from .types import APIClientConnectedFactory, RunCompiledFunction
+
+
+@pytest.mark.asyncio
+async def test_scheduler_string_test(
+    yaml_config: str,
+    run_compiled: RunCompiledFunction,
+    api_client_connected: APIClientConnectedFactory,
+) -> None:
+    """Test that scheduler handles both static and dynamic strings correctly."""
+    # Track counts
+    timeout_count = 0
+    interval_count = 0
+
+    # Events for each test completion
+    static_timeout_1_fired = asyncio.Event()
+    static_timeout_2_fired = asyncio.Event()
+    static_interval_fired = asyncio.Event()
+    static_interval_cancelled = asyncio.Event()
+    empty_string_timeout_fired = asyncio.Event()
+    static_timeout_cancelled = asyncio.Event()
+    dynamic_timeout_fired = asyncio.Event()
+    dynamic_interval_fired = asyncio.Event()
+    cancel_test_done = asyncio.Event()
+    final_results_logged = asyncio.Event()
+
+    # Track interval counts
+    static_interval_count = 0
+    dynamic_interval_count = 0
+
+    def on_log_line(line: str) -> None:
+        nonlocal \
+            timeout_count, \
+            interval_count, \
+            static_interval_count, \
+            dynamic_interval_count
+
+        # Strip ANSI color codes
+        clean_line = re.sub(r"\x1b\[[0-9;]*m", "", line)
+
+        # Check for static timeout completions
+        if "Static timeout 1 fired" in clean_line:
+            static_timeout_1_fired.set()
+            timeout_count += 1
+
+        elif "Static timeout 2 fired" in clean_line:
+            static_timeout_2_fired.set()
+            timeout_count += 1
+
+        # Check for static interval
+        elif "Static interval 1 fired" in clean_line:
+            match = re.search(r"count: (\d+)", clean_line)
+            if match:
+                static_interval_count = int(match.group(1))
+                static_interval_fired.set()
+
+        elif "Cancelled static interval 1" in clean_line:
+            static_interval_cancelled.set()
+
+        # Check for empty string timeout
+        elif "Empty string timeout fired" in clean_line:
+            empty_string_timeout_fired.set()
+
+        # Check for static timeout cancellation
+        elif "Cancelled static timeout using const char*" in clean_line:
+            static_timeout_cancelled.set()
+
+        # Check for dynamic string tests
+        elif "Dynamic timeout fired" in clean_line:
+            dynamic_timeout_fired.set()
+            timeout_count += 1
+
+        elif "Dynamic interval fired" in clean_line:
+            dynamic_interval_count += 1
+            dynamic_interval_fired.set()
+
+        # Check for cancel test
+        elif "Cancelled timeout using different string object" in clean_line:
+            cancel_test_done.set()
+
+        # Check for final results
+        elif "Final results" in clean_line:
+            match = re.search(r"Timeouts: (\d+), Intervals: (\d+)", clean_line)
+            if match:
+                timeout_count = int(match.group(1))
+                interval_count = int(match.group(2))
+                final_results_logged.set()
+
+    async with (
+        run_compiled(yaml_config, line_callback=on_log_line),
+        api_client_connected() as client,
+    ):
+        # Verify we can connect
+        device_info = await client.device_info()
+        assert device_info is not None
+        assert device_info.name == "scheduler-string-test"
+
+        # Wait for static string tests
+        try:
+            await asyncio.wait_for(static_timeout_1_fired.wait(), timeout=0.5)
+        except asyncio.TimeoutError:
+            pytest.fail("Static timeout 1 did not fire within 0.5 seconds")
+
+        try:
+            await asyncio.wait_for(static_timeout_2_fired.wait(), timeout=0.5)
+        except asyncio.TimeoutError:
+            pytest.fail("Static timeout 2 did not fire within 0.5 seconds")
+
+        try:
+            await asyncio.wait_for(static_interval_fired.wait(), timeout=1.0)
+        except asyncio.TimeoutError:
+            pytest.fail("Static interval did not fire within 1 second")
+
+        try:
+            await asyncio.wait_for(static_interval_cancelled.wait(), timeout=2.0)
+        except asyncio.TimeoutError:
+            pytest.fail("Static interval was not cancelled within 2 seconds")
+
+        # Verify static interval ran at least 3 times
+        assert static_interval_count >= 2, (
+            f"Expected static interval to run at least 3 times, got {static_interval_count + 1}"
+        )
+
+        # Verify static timeout was cancelled
+        assert static_timeout_cancelled.is_set(), (
+            "Static timeout should have been cancelled"
+        )
+
+        # Wait for dynamic string tests
+        try:
+            await asyncio.wait_for(dynamic_timeout_fired.wait(), timeout=1.0)
+        except asyncio.TimeoutError:
+            pytest.fail("Dynamic timeout did not fire within 1 second")
+
+        try:
+            await asyncio.wait_for(dynamic_interval_fired.wait(), timeout=1.5)
+        except asyncio.TimeoutError:
+            pytest.fail("Dynamic interval did not fire within 1.5 seconds")
+
+        # Wait for cancel test
+        try:
+            await asyncio.wait_for(cancel_test_done.wait(), timeout=1.0)
+        except asyncio.TimeoutError:
+            pytest.fail("Cancel test did not complete within 1 second")
+
+        # Wait for final results
+        try:
+            await asyncio.wait_for(final_results_logged.wait(), timeout=4.0)
+        except asyncio.TimeoutError:
+            pytest.fail("Final results were not logged within 4 seconds")
+
+        # Verify results
+        assert timeout_count >= 3, f"Expected at least 3 timeouts, got {timeout_count}"
+        assert interval_count >= 3, (
+            f"Expected at least 3 interval fires, got {interval_count}"
+        )
+
+        # Empty string timeout DOES fire (scheduler accepts empty names)
+        assert empty_string_timeout_fired.is_set(), "Empty string timeout should fire"