Sleep in Reloader loop to conserve CPU resources

sanic/cli/app.py

@@ -181,6 +181,7 @@ def _build_run_kwargs(self):
 
         kwargs = {
             "access_log": self.args.access_log,
+            "auto_reload_interval": self.args.auto_reload_interval,
             "coffee": self.args.coffee,
             "debug": self.args.debug,
             "fast": self.args.fast,

sanic/cli/arguments.py

@@ -277,6 +277,14 @@ def attach(self):
                 "changes"
             ),
         )
+        self.container.add_argument(
+            "-i",
+            "--interval",
+            "--auto-reload-interval",
+            dest="auto_reload_interval",
+            type=float,
+            help="Interval in seconds to check for file changes [default 1.0]",
+        )
         self.container.add_argument(
             "-R",
             "--reload-dir",

sanic/config.py

@@ -38,6 +38,7 @@
     "ACCESS_LOG": False,
     "AUTO_EXTEND": True,
     "AUTO_RELOAD": False,
+    "AUTO_RELOAD_INTERVAL": 1.0,
     "EVENT_AUTOREGISTER": False,
     "DEPRECATION_FILTER": "once",
     "FORWARDED_FOR_HEADER": "X-Forwarded-For",
@@ -85,6 +86,7 @@ class Config(dict, metaclass=DescriptorMeta):
     ACCESS_LOG: bool
     AUTO_EXTEND: bool
     AUTO_RELOAD: bool
+    AUTO_RELOAD_INTERVAL: Union[int, float]
     EVENT_AUTOREGISTER: bool
     DEPRECATION_FILTER: FilterWarningType
     FORWARDED_FOR_HEADER: str

sanic/mixins/startup.py

@@ -114,6 +114,7 @@ def run(
         dev: bool = False,
         debug: bool = False,
         auto_reload: Optional[bool] = None,
+        auto_reload_interval: Optional[Union[int, float]] = None,
         version: HTTPVersion = HTTP.VERSION_1,
         ssl: Union[None, SSLContext, dict, str, list, tuple] = None,
         sock: Optional[socket] = None,
@@ -176,6 +177,7 @@ def run(
             dev=dev,
             debug=debug,
             auto_reload=auto_reload,
+            auto_reload_interval=auto_reload_interval,
             version=version,
             ssl=ssl,
             sock=sock,
@@ -213,6 +215,7 @@ def prepare(
         dev: bool = False,
         debug: bool = False,
         auto_reload: Optional[bool] = None,
+        auto_reload_interval: Optional[Union[int, float]] = None,
         version: HTTPVersion = HTTP.VERSION_1,
         ssl: Union[None, SSLContext, dict, str, list, tuple] = None,
         sock: Optional[socket] = None,
@@ -305,6 +308,7 @@ def prepare(
         for attribute, value in {
             "ACCESS_LOG": access_log,
             "AUTO_RELOAD": auto_reload,
+            "AUTO_RELOAD_INTERVAL": auto_reload_interval,
             "MOTD": motd,
             "NOISY_EXCEPTIONS": noisy_exceptions,
         }.items():
@@ -608,6 +612,12 @@ def get_motd_data(
         extra = {}
         if self.config.AUTO_RELOAD:
             reload_display = "enabled"
+
+            if self.config.AUTO_RELOAD_INTERVAL:
+                reload_display += " [{:.1f}s]".format(
+                    self.config.AUTO_RELOAD_INTERVAL
+                )
+
             if self.state.reload_dirs:
                 reload_display += ", ".join(
                     [
@@ -618,6 +628,7 @@ def get_motd_data(
                         ),
                     ]
                 )
+
             display["auto-reload"] = reload_display
 
         packages = []
@@ -817,7 +828,12 @@ def serve(
                 reload_dirs: Set[Path] = primary.state.reload_dirs.union(
                     *(app.state.reload_dirs for app in apps)
                 )
-                reloader = Reloader(monitor_pub, 1.0, reload_dirs, app_loader)
+                reloader = Reloader(
+                    monitor_pub,
+                    primary.config.AUTO_RELOAD_INTERVAL,
+                    reload_dirs,
+                    app_loader,
+                )
                 manager.manage("Reloader", reloader, {}, transient=False)
 
             inspector = None

sanic/worker/reloader.py

@@ -9,7 +9,8 @@
 from pathlib import Path
 from signal import SIGINT, SIGTERM
 from signal import signal as signal_func
-from typing import Dict, Set
+from threading import Event
+from typing import Dict, Optional, Set, Union
 
 from sanic.server.events import trigger_events
 from sanic.worker.loader import AppLoader
@@ -19,14 +20,14 @@ class Reloader:
     def __init__(
         self,
         publisher: Connection,
-        interval: float,
+        interval: Union[int, float],
         reload_dirs: Set[Path],
         app_loader: AppLoader,
     ):
+        self._stop: Optional[Event] = None
         self._publisher = publisher
-        self.interval = interval
+        self.interval = float(interval)
         self.reload_dirs = reload_dirs
-        self.run = True
         self.app_loader = app_loader
 
     def __call__(self) -> None:
@@ -40,10 +41,11 @@ def __call__(self) -> None:
         before_trigger = app.listeners.get("before_reload_trigger")
         after_trigger = app.listeners.get("after_reload_trigger")
         loop = new_event_loop()
+        self._stop = Event()
         if reloader_start:
             trigger_events(reloader_start, loop, app)
 
-        while self.run:
+        while not self._stop.is_set():
             changed = set()
             for filename in self.files():
                 try:
@@ -62,12 +64,13 @@ def __call__(self) -> None:
                 self.reload(",".join(changed) if changed else "unknown")
                 if after_trigger:
                     trigger_events(after_trigger, loop, app)
+            self._stop.wait(self.interval)
         else:
             if reloader_stop:
                 trigger_events(reloader_stop, loop, app)
 
     def stop(self, *_):
-        self.run = False
+        self._stop.set()
 
     def reload(self, reloaded_files):
         message = f"__ALL_PROCESSES__:{reloaded_files}"

tests/fake/server.py

@@ -23,6 +23,7 @@ async def app_info_dump(app: Sanic, _):
     app_data = {
         "access_log": app.config.ACCESS_LOG,
         "auto_reload": app.auto_reload,
+        "auto_reload_interval": app.config.AUTO_RELOAD_INTERVAL,
         "debug": app.debug,
         "noisy_exceptions": app.config.NOISY_EXCEPTIONS,
     }

tests/test_cli.py

@@ -245,6 +245,18 @@ def test_auto_reload(cmd: str, caplog):
     assert info["auto_reload"] is True
 
 
+@pytest.mark.parametrize(
+    "cmd",
+    (("--auto-reload-interval=5.0",), ("--interval=5.0",), ("-i", "5.0")),
+)
+def test_auto_reload_interval(cmd: str, caplog):
+    command = ["fake.server.app", *cmd]
+    lines = capture(command, caplog)
+    info = read_app_info(lines)
+
+    assert info["auto_reload_interval"] == 5.0
+
+
 @pytest.mark.parametrize(
     "cmd,expected",
     (

tests/test_motd.py

@@ -79,5 +79,20 @@ def test_reload_dirs(app):
             reload_dir="./", auto_reload=True, motd_display={"foo": "bar"}
         )
     mock.assert_called()
-    assert mock.call_args.args[2]["auto-reload"] == f"enabled, {os.getcwd()}"
+    assert (
+        mock.call_args.args[2]["auto-reload"]
+        == f"enabled [1.0s], {os.getcwd()}"
+    )
     assert mock.call_args.args[3] == {"foo": "bar"}
+
+
+def test_reload_interval(app):
+    app.config.LOGO = None
+    app.config.MOTD = True
+    app.config.AUTO_RELOAD = True
+    app.config.AUTO_RELOAD_INTERVAL = 5.0
+
+    with patch.object(MOTD, "output") as mock:
+        app.prepare()
+    mock.assert_called()
+    assert mock.call_args.args[2]["auto-reload"] == "enabled [5.0s]"