如何设置Flask应用以支持多线程运行？

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在我之前，了解了flask如何支持多线程，主要通过两个类来实现，LocalStack和Local。在Local中，有两个属性：__storage__和__ident_func__。后者用来获取线程ID，从而区分不同线程发出的请求。这次要说的就是fl。

在我之前解释了flask如何支持多线程主要通过两个类来实现,LocalStack和Local,在Local中有两个属性,__storage__和__ident_func__,后者用来获取线程id,从而区分不同线程发来的请求

这次要说的是flask如何开启多线程

先从app.run()这个方法看起

def run(self, host=None, port=None, debug=None, **options): from werkzeug.serving import run_simple if host is None: host = '127.0.0.1' if port is None: server_name = self.config['SERVER_NAME'] if server_name and ':' in server_name: port = int(server_name.rsplit(':', 1)[1]) else: port = 5000 if debug is not None: self.debug = bool(debug) options.setdefault('use_reloader', self.debug) options.setdefault('use_debugger', self.debug) try: run_simple(host, port, self, **options) #会进入这个函数 finally: # reset the first request information if the development server # reset normally. This makes it possible to restart the server # without reloader and that stuff from an interactive shell. self._got_first_request = False

经过判断和设置后进入run_simple()这个函数,看下源码

def run_simple(hostname, port, application, use_reloader=False,

use_debugger=False, use_evalex=True, extra_files=None, reloader_interval=1, reloader_type='auto', threaded=False, processes=1, request_handler=None, static_files=None, passthrough_errors=False, ssl_context=None): """Start a WSGI application. Optional features include a reloader, multithreading and fork support. This function has a command-line interface too:: python -m werkzeug.serving --help .. versionadded:: 0.5 `static_files` was added to simplify serving of static files as well as `passthrough_errors`. .. versionadded:: 0.6 support for SSL was added. .. versionadded:: 0.8 Added support for automatically loading a SSL context from certificate file and private key. .. versionadded:: 0.9 Added command-line interface. .. versionadded:: 0.10 Improved the reloader and added support for changing the backend through the `reloader_type` parameter. See :ref:`reloader` for more information. :param hostname: The host for the application. eg: ``'localhost'`` :param port: The port for the server. eg: ``8080`` :param application: the WSGI application to execute :param use_reloader: should the server automatically restart the python process if modules were changed? :param use_debugger: should the werkzeug debugging system be used? :param use_evalex: should the exception evaluation feature be enabled? :param extra_files: a list of files the reloader should watch additionally to the modules. For example configuration files. :param reloader_interval: the interval for the reloader in seconds. :param reloader_type: the type of reloader to use. The default is auto detection. Valid values are ``'stat'`` and ``'watchdog'``. See :ref:`reloader` for more information. :param threaded: should the process handle each request in a separate thread? :param processes: if greater than 1 then handle each request in a new process up to this maximum number of concurrent processes. :param request_handler: optional parameter that can be used to replace the default one. You can use this to replace it with a different :class:`~BaseHTTPServer.BaseHTTPRequestHandler` subclass. :param static_files: a list or dict of paths for static files. This works exactly like :class:`SharedDataMiddleware`, it's actually just wrapping the application in that middleware before serving. :param passthrough_errors: set this to `True` to disable the error catching. This means that the server will die on errors but it can be useful to hook debuggers in (pdb etc.) :param ssl_context: an SSL context for the connection. Either an :class:`ssl.SSLContext`, a tuple in the form ``(cert_file, pkey_file)``, the string ``'adhoc'`` if the server should automatically create one, or ``None`` to disable SSL (which is the default). """ if not isinstance(port, int): raise TypeError('port must be an integer') if use_debugger: from werkzeug.debug import DebuggedApplication application = DebuggedApplication(application, use_evalex) if static_files: from werkzeug.wsgi import SharedDataMiddleware application = SharedDataMiddleware(application, static_files) def log_startup(sock): display_hostname = hostname not in ('', '*') and hostname or 'localhost' if ':' in display_hostname: display_hostname = '[%s]' % display_hostname quit_msg = '(Press CTRL+C to quit)' port = sock.getsockname()[1] _log('info', ' * Running on %s://%s:%d/ %s', ssl_context is None and '%s:%d/ %s', ssl_context is None and '127.0.0.1:5000/ (Press CTRL+C to quit)
139623180527360

第二种情况

Running on 127.0.0.1:5000/ (Press CTRL+C to quit)
140315469436672
140315477829376
140315486222080
140315316901632
140315105163008
140315096770304
140315088377600

结果显而易见

综上所述:flask支持多线程,但默认没开启,其次app.run()只适用于开发环境,生产环境下可以使用uWSGI,Gunicorn等web服务器

内容扩展：

flask开启多线程还是多进程

Flask 默认是单进程，单线程阻塞的任务模式，在项目上线的时候可以通过nginx+gunicorn 的方式部署flask任务。

但是在开发的过程中如果想通过延迟的方式测试高并发怎么实现呢，其实非常简单，

app.run()中可以接受两个参数，分别是threaded和processes，用于开启线程支持和进程支持。

1.threaded : 多线程支持，默认为False，即不开启多线程;

2.processes：进程数量，默认为1.

开启方式：

if __name__ == '__main__': app.run(threaded=True) # app.run(processes=4)

注意：多进程或多线程只能选择一个，不能同时开启。

以上就是flask开启多线程的具体方法的详细内容，更多关于flask如何开启多线程详解的资料请关注易盾网络其它相关文章！