Simplify reloader and remove --workers (#141)

* Simplify reloader and remove --workers * Remove commented-out code
encode · Jul 20, 2018 · 63e3a17 · 63e3a17
1 parent 84ecdbd
commit 63e3a17
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Showing 4 changed files with 91 additions and 128 deletions.
diff --git a/uvicorn/debug.py b/uvicorn/debug.py
@@ -80,7 +80,10 @@ async def __call__(self, receive, send):
             accept = get_accept_header(self.scope)
             if "text/html" in accept:
                 exc_html = html.escape(traceback.format_exc())
-                content = "<html><body><h1>500 Server Error</h1><pre>%s</pre></body></html>" % exc_html
+                content = (
+                    "<html><body><h1>500 Server Error</h1><pre>%s</pre></body></html>"
+                    % exc_html
+                )
                 response = HTMLResponse(content, status_code=500)
             else:
                 content = traceback.format_exc()

diff --git a/uvicorn/main.py b/uvicorn/main.py
@@ -1,6 +1,5 @@
 from uvicorn.debug import DebugMiddleware
 from uvicorn.importer import import_from_string, ImportFromStringError
-from uvicorn.reloaders.noreload import NoReload
 from uvicorn.reloaders.statreload import StatReload
 import asyncio
 import click
@@ -45,7 +44,6 @@ def get_socket(host, port):
     sock = socket.socket()
     sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
     sock.bind((host, port))
-    sock.set_inheritable(True)
     return sock
 
 
@@ -61,21 +59,9 @@ def get_logger(log_level):
 @click.option("--port", type=int, default=8000, help="Port")
 @click.option("--loop", type=LOOP_CHOICES, default="auto", help="Event loop")
 @click.option("--http", type=HTTP_CHOICES, default="auto", help="HTTP Handler")
-@click.option("--workers", type=int, default=1, help="Number of worker processes")
-@click.option(
-    "--debug", type=bool, is_flag=True, default=False, help="Enable debug mode"
-)
+@click.option("--debug", is_flag=True, default=False, help="Enable debug mode")
 @click.option("--log-level", type=LEVEL_CHOICES, default="info", help="Log level")
-def main(
-    app,
-    host: str,
-    port: int,
-    loop: str,
-    http: str,
-    workers: int,
-    debug: bool,
-    log_level: str,
-):
+def main(app, host: str, port: int, loop: str, http: str, debug: bool, log_level: str):
     sys.path.insert(0, ".")
 
     kwargs = {
@@ -85,10 +71,15 @@ def main(
         "loop": loop,
         "http": http,
         "log_level": log_level,
-        "workers": workers,
         "debug": debug,
     }
-    run(**kwargs)
+
+    if debug:
+        logger = get_logger(log_level)
+        reloader = StatReload(logger)
+        reloader.run(run, kwargs)
+    else:
+        run(**kwargs)
 
 
 def run(
@@ -98,74 +89,8 @@ def run(
     loop="auto",
     http="auto",
     log_level="info",
-    workers=1,
     debug=False,
 ):
-    sock = get_socket(host, port)
-    logger = get_logger(log_level)
-    pid = os.getpid()
-
-    message = "* Uvicorn running on http://%s:%d 🦄 (Press CTRL+C to quit)"
-    click.echo(message % (host, port))
-    logger.info("Started parent [{}]".format(pid))
-
-    processes = []
-    seen_shutdown = False
-    seen_restart = False
-
-    if debug:
-        reloader = StatReload(logger)
-    else:
-        reloader = NoReload()
-
-    def shutdown(sig, frame):
-        nonlocal seen_shutdown
-
-        seen_shutdown = True
-
-        logger.warning("Got signal %s. Shutting down.", signal.Signals(sig).name)
-
-        for process, event in processes:
-            event.set()
-
-    for sig in HANDLED_SIGNALS:
-        signal.signal(sig, shutdown)
-
-    while not seen_shutdown:
-        for _ in range(workers):
-            event = multiprocessing.Event()
-            kwargs = {
-                "app": app,
-                "sock": sock,
-                "event": event,
-                "logger": logger,
-                "loop": loop,
-                "http": http,
-                "debug": debug,
-            }
-            process = multiprocessing.Process(target=run_one, kwargs=kwargs)
-            process.start()
-            processes.append((process, event))
-
-        while not (seen_shutdown or seen_restart):
-            if not any([process.is_alive() for process, event in processes]):
-                seen_shutdown = True
-            time.sleep(0.2)
-            seen_restart = reloader.should_restart()
-
-        if seen_restart:
-            for process, event in processes:
-                event.set()
-            seen_restart = False
-            reloader.clear()
-
-        for process, event in processes:
-            process.join()
-
-    logger.info("Stopping parent [{}]".format(pid))
-
-
-def run_one(app, sock, event, logger, debug=False, loop="auto", http="auto"):
     try:
         app = import_from_string(app)
     except ImportFromStringError as exc:
@@ -175,61 +100,69 @@ def run_one(app, sock, event, logger, debug=False, loop="auto", http="auto"):
     if debug:
         app = DebugMiddleware(app)
 
+    logger = get_logger(log_level)
     loop_setup = import_from_string(LOOP_SETUPS[loop])
     protocol_class = import_from_string(HTTP_PROTOCOLS[http])
 
     loop = loop_setup()
 
-    # Ignore signals, instead allowing the parent process to handle them.
-    # Communication with subprocesses is via the 'multiprocessing.Event' instance.
-    def ignore(sig, frame):
-        pass
-
-    for sig in HANDLED_SIGNALS:
-        signal.signal(sig, ignore)
-
-    server = Server(app, sock, event, logger, loop, protocol_class)
+    server = Server(
+        app=app,
+        host=host,
+        port=port,
+        logger=logger,
+        loop=loop,
+        protocol_class=protocol_class,
+    )
     server.run()
 
 
 class Server:
-    def __init__(self, app, sock, event, logger, loop, protocol_class):
+    def __init__(self, app, host, port, logger, loop, protocol_class):
         self.app = app
-        self.sock = sock
-        self.event = event
+        self.host = host
+        self.port = port
         self.logger = logger
         self.loop = loop
         self.protocol_class = protocol_class
+        self.should_exit = False
         self.pid = os.getpid()
 
+    def set_signal_handlers(self):
+        try:
+            for sig in HANDLED_SIGNALS:
+                self.loop.add_signal_handler(sig, self.handle_exit, sig, None)
+        except NotImplementedError:
+            # Windows
+            for sig in HANDLED_SIGNALS:
+                signal.signal(sig, self.handle_exit)
+
+    def handle_exit(self, sig, frame):
+        self.should_exit = True
+
     def run(self):
-        self.logger.info("Started worker [{}]".format(self.pid))
+        self.logger.info("Started server process [{}]".format(self.pid))
+        self.set_signal_handlers()
         self.loop.run_until_complete(self.create_server())
         self.loop.create_task(self.tick())
         self.loop.run_forever()
 
     def create_protocol(self):
-        try:
-            return self.protocol_class(app=self.app, loop=self.loop, logger=self.logger)
-        except Exception as exc:
-            self.logger.error(exc)
-            self.event.set()
+        return self.protocol_class(app=self.app, loop=self.loop, logger=self.logger)
 
     async def create_server(self):
-        try:
-            self.server = await self.loop.create_server(
-                self.create_protocol, sock=self.sock
-            )
-        except Exception as exc:
-            self.logger.error(exc)
-            self.event.set()
+        self.server = await self.loop.create_server(
+            self.create_protocol, self.host, self.port
+        )
+        message = "* Uvicorn running on http://%s:%d 🦄 (Press CTRL+C to quit)"
+        click.echo(message % (self.host, self.port))
 
     async def tick(self):
-        while not self.event.is_set():
+        while not self.should_exit:
             self.protocol_class.tick()
             await asyncio.sleep(1)
 
-        self.logger.info("Stopping worker [{}]".format(self.pid))
+        self.logger.info("Stopping server process [{}]".format(self.pid))
         self.server.close()
         await self.server.wait_closed()
         self.loop.stop()

diff --git a/uvicorn/reloaders/noreload.py b/uvicorn/reloaders/noreload.py
diff --git a/uvicorn/reloaders/statreload.py b/uvicorn/reloaders/statreload.py
@@ -1,25 +1,54 @@
 import os
+import signal
 import sys
+import time
+import multiprocessing
 
 
-def _iter_py_files():
-    for subdir, dirs, files in os.walk("."):
-        for file in files:
-            filepath = subdir + os.sep + file
-            if filepath.endswith(".py"):
-                yield filepath
+HANDLED_SIGNALS = (
+    signal.SIGINT,  # Unix signal 2. Sent by Ctrl+C.
+    signal.SIGTERM,  # Unix signal 15. Sent by `kill <pid>`.
+)
 
 
 class StatReload:
     def __init__(self, logger):
         self.logger = logger
+        self.should_exit = False
         self.mtimes = {}
 
+    def handle_exit(self, sig, frame):
+        self.should_exit = True
+
+    def run(self, target, kwargs):
+        pid = os.getpid()
+
+        self.logger.info("Started reloader process [{}]".format(pid))
+
+        for sig in HANDLED_SIGNALS:
+            signal.signal(sig, self.handle_exit)
+
+        process = multiprocessing.Process(target=target, kwargs=kwargs)
+        process.start()
+
+        while process.is_alive() and not self.should_exit:
+            time.sleep(0.2)
+            if self.should_restart():
+                self.clear()
+                os.kill(process.pid, signal.SIGTERM)
+                process.join()
+                process = multiprocessing.Process(target=target, kwargs=kwargs)
+                process.start()
+
+        self.logger.info("Stopping reloader process [{}]".format(pid))
+
+        sys.exit(process.exitcode)
+
     def clear(self):
         self.mtimes = {}
 
     def should_restart(self):
-        for filename in _iter_py_files():
+        for filename in self.iter_py_files():
             try:
                 mtime = os.stat(filename).st_mtime
             except OSError:
@@ -34,3 +63,10 @@ def should_restart(self):
                 self.logger.warning(message, filename)
                 return True
         return False
+
+    def iter_py_files(self):
+        for subdir, dirs, files in os.walk("."):
+            for file in files:
+                filepath = subdir + os.sep + file
+                if filepath.endswith(".py"):
+                    yield filepath