virtualx-engine/thirdparty/libwebsockets/include/libwebsockets/lws-service.h
2019-03-06 02:02:52 +01:00

215 lines
8 KiB
C++

/*
* libwebsockets - small server side websockets and web server implementation
*
* Copyright (C) 2010-2018 Andy Green <andy@warmcat.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation:
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301 USA
*
* included from libwebsockets.h
*/
/** \defgroup service Built-in service loop entry
*
* ##Built-in service loop entry
*
* If you're not using libev / libuv, these apis are needed to enter the poll()
* wait in lws and service any connections with pending events.
*/
///@{
/**
* lws_service() - Service any pending websocket activity
* \param context: Websocket context
* \param timeout_ms: Timeout for poll; 0 means return immediately if nothing needed
* service otherwise block and service immediately, returning
* after the timeout if nothing needed service.
*
* This function deals with any pending websocket traffic, for three
* kinds of event. It handles these events on both server and client
* types of connection the same.
*
* 1) Accept new connections to our context's server
*
* 2) Call the receive callback for incoming frame data received by
* server or client connections.
*
* You need to call this service function periodically to all the above
* functions to happen; if your application is single-threaded you can
* just call it in your main event loop.
*
* Alternatively you can fork a new process that asynchronously handles
* calling this service in a loop. In that case you are happy if this
* call blocks your thread until it needs to take care of something and
* would call it with a large nonzero timeout. Your loop then takes no
* CPU while there is nothing happening.
*
* If you are calling it in a single-threaded app, you don't want it to
* wait around blocking other things in your loop from happening, so you
* would call it with a timeout_ms of 0, so it returns immediately if
* nothing is pending, or as soon as it services whatever was pending.
*/
LWS_VISIBLE LWS_EXTERN int
lws_service(struct lws_context *context, int timeout_ms);
/**
* lws_service_tsi() - Service any pending websocket activity
*
* \param context: Websocket context
* \param timeout_ms: Timeout for poll; 0 means return immediately if nothing needed
* service otherwise block and service immediately, returning
* after the timeout if nothing needed service.
* \param tsi: Thread service index, starting at 0
*
* Same as lws_service(), but for a specific thread service index. Only needed
* if you are spawning multiple service threads.
*/
LWS_VISIBLE LWS_EXTERN int
lws_service_tsi(struct lws_context *context, int timeout_ms, int tsi);
/**
* lws_cancel_service_pt() - Cancel servicing of pending socket activity
* on one thread
* \param wsi: Cancel service on the thread this wsi is serviced by
*
* Same as lws_cancel_service(), but targets a single service thread, the one
* the wsi belongs to. You probably want to use lws_cancel_service() instead.
*/
LWS_VISIBLE LWS_EXTERN void
lws_cancel_service_pt(struct lws *wsi);
/**
* lws_cancel_service() - Cancel wait for new pending socket activity
* \param context: Websocket context
*
* This function creates an immediate "synchronous interrupt" to the lws poll()
* wait or event loop. As soon as possible in the serialzed service sequencing,
* a LWS_CALLBACK_EVENT_WAIT_CANCELLED callback is sent to every protocol on
* every vhost.
*
* lws_cancel_service() may be called from another thread while the context
* exists, and its effect will be immediately serialized.
*/
LWS_VISIBLE LWS_EXTERN void
lws_cancel_service(struct lws_context *context);
/**
* lws_service_fd() - Service polled socket with something waiting
* \param context: Websocket context
* \param pollfd: The pollfd entry describing the socket fd and which events
* happened, or NULL to tell lws to do only timeout servicing.
*
* This function takes a pollfd that has POLLIN or POLLOUT activity and
* services it according to the state of the associated
* struct lws.
*
* The one call deals with all "service" that might happen on a socket
* including listen accepts, http files as well as websocket protocol.
*
* If a pollfd says it has something, you can just pass it to
* lws_service_fd() whether it is a socket handled by lws or not.
* If it sees it is a lws socket, the traffic will be handled and
* pollfd->revents will be zeroed now.
*
* If the socket is foreign to lws, it leaves revents alone. So you can
* see if you should service yourself by checking the pollfd revents
* after letting lws try to service it.
*
* You should also call this with pollfd = NULL to just allow the
* once-per-second global timeout checks; if less than a second since the last
* check it returns immediately then.
*/
LWS_VISIBLE LWS_EXTERN int
lws_service_fd(struct lws_context *context, struct lws_pollfd *pollfd);
/**
* lws_service_fd_tsi() - Service polled socket in specific service thread
* \param context: Websocket context
* \param pollfd: The pollfd entry describing the socket fd and which events
* happened.
* \param tsi: thread service index
*
* Same as lws_service_fd() but used with multiple service threads
*/
LWS_VISIBLE LWS_EXTERN int
lws_service_fd_tsi(struct lws_context *context, struct lws_pollfd *pollfd,
int tsi);
/**
* lws_service_adjust_timeout() - Check for any connection needing forced service
* \param context: Websocket context
* \param timeout_ms: The original poll timeout value. You can just set this
* to 1 if you don't really have a poll timeout.
* \param tsi: thread service index
*
* Under some conditions connections may need service even though there is no
* pending network action on them, this is "forced service". For default
* poll() and libuv / libev, the library takes care of calling this and
* dealing with it for you. But for external poll() integration, you need
* access to the apis.
*
* If anybody needs "forced service", returned timeout is zero. In that case,
* you can call lws_service_tsi() with a timeout of -1 to only service
* guys who need forced service.
*/
LWS_VISIBLE LWS_EXTERN int
lws_service_adjust_timeout(struct lws_context *context, int timeout_ms, int tsi);
/* Backwards compatibility */
#define lws_plat_service_tsi lws_service_tsi
LWS_VISIBLE LWS_EXTERN int
lws_handle_POLLOUT_event(struct lws *wsi, struct lws_pollfd *pollfd);
///@}
/*! \defgroup uv libuv helpers
*
* ##libuv helpers
*
* APIs specific to libuv event loop itegration
*/
///@{
#ifdef LWS_WITH_LIBUV
/*
* Any direct libuv allocations in lws protocol handlers must participate in the
* lws reference counting scheme. Two apis are provided:
*
* - lws_libuv_static_refcount_add(handle, context) to mark the handle with
* a pointer to the context and increment the global uv object counter
*
* - lws_libuv_static_refcount_del() which should be used as the close callback
* for your own libuv objects declared in the protocol scope.
*
* Using the apis allows lws to detach itself from a libuv loop completely
* cleanly and at the moment all of its libuv objects have completed close.
*/
LWS_VISIBLE LWS_EXTERN uv_loop_t *
lws_uv_getloop(struct lws_context *context, int tsi);
LWS_VISIBLE LWS_EXTERN void
lws_libuv_static_refcount_add(uv_handle_t *, struct lws_context *context);
LWS_VISIBLE LWS_EXTERN void
lws_libuv_static_refcount_del(uv_handle_t *);
#endif /* LWS_WITH_LIBUV */
#if defined(LWS_WITH_ESP32)
#define lws_libuv_static_refcount_add(_a, _b)
#define lws_libuv_static_refcount_del NULL
#endif
///@}