eventloop_posix.h

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 *    Copyright 2021 (c) Fraunhofer IOSB (Author: Julius Pfrommer)
 *    Copyright 2021 (c) Fraunhofer IOSB (Author: Jan Hermes)
 */

#ifndef UA_EVENTLOOP_POSIX_H_
#define UA_EVENTLOOP_POSIX_H_

#include <open62541/config.h>
#include <open62541/plugin/eventloop.h>

#if defined(UA_ARCHITECTURE_POSIX) || defined(UA_ARCHITECTURE_WIN32)

#include "common/ua_timer.h"
#include "open62541_queue.h"

/* epoll_pwait returns bogus data with the tc compiler */
#if defined(__linux__) && !defined(__TINYC__)
# define UA_HAVE_EPOLL
# include <sys/epoll.h>
#endif

_UA_BEGIN_DECLS

/* POSIX events are based on sockets / file descriptors. The EventSources can
 * register their fd in the EventLoop so that they are considered by the
 * EventLoop dropping into "poll" to wait for events. */

/* TODO: Move the macro-forest from /arch/<arch>/ua_architecture.h */

#define UA_FD UA_SOCKET
#define UA_INVALID_FD UA_INVALID_SOCKET

struct UA_RegisteredFD;
typedef struct UA_RegisteredFD UA_RegisteredFD;

/* Bitmask to be used for the UA_FDCallback event argument */
#define UA_FDEVENT_IN 1
#define UA_FDEVENT_OUT 2
#define UA_FDEVENT_ERR 4

typedef void (*UA_FDCallback)(UA_EventSource *es, UA_RegisteredFD *rfd, short event);

struct UA_RegisteredFD {
    UA_DelayedCallback dc; /* Used for async closing. Must be the first member
                            * because the rfd is freed by the delayed callback
                            * mechanism. */

    LIST_ENTRY(UA_RegisteredFD) es_pointers; /* Register FD in the EventSource */
    UA_FD fd;
    short listenEvents; /* UA_FDEVENT_IN | UA_FDEVENT_OUT*/

    UA_EventSource *es; /* Backpointer to the EventSource */
    UA_FDCallback callback;
    void *application;
    void *context;
};

typedef struct {
    UA_EventLoop eventLoop;

    /* Timer */
    UA_Timer timer;

    /* Linked List of Delayed Callbacks */
    UA_DelayedCallback *delayedCallbacks;

    /* Flag determining whether the eventloop is currently within the
     * "run" method */
    UA_Boolean executing;

#if defined(UA_HAVE_EPOLL)
    UA_FD epollfd;
#else
    /* Explicit list of file descriptors */
    size_t fdsSize;
    UA_RegisteredFD **fds;
#endif

#if UA_MULTITHREADING >= 100
    UA_Lock elMutex;
#endif
} UA_EventLoopPOSIX;

/* The following functions differ between epoll and normal select */

/* Register to start receiving events */
UA_StatusCode
UA_EventLoopPOSIX_registerFD(UA_EventLoopPOSIX *el, UA_RegisteredFD *rfd);

/* Modify the events that the fd listens on */
UA_StatusCode
UA_EventLoopPOSIX_modifyFD(UA_EventLoopPOSIX *el, UA_RegisteredFD *rfd);

/* Deregister but do not close the fd. No further events are received. */
void
UA_EventLoopPOSIX_deregisterFD(UA_EventLoopPOSIX *el, UA_RegisteredFD *rfd);

UA_StatusCode
UA_EventLoopPOSIX_pollFDs(UA_EventLoopPOSIX *el, UA_DateTime listenTimeout);

_UA_END_DECLS

#endif /* defined(UA_ARCHITECTURE_POSIX) || defined(UA_ARCHITECTURE_WIN32) */

#endif /* UA_EVENTLOOP_POSIX_H_ */