lib/events.c

説明を見る。

/*
   Unix SMB/CIFS implementation.
   Timed event library.
   Copyright (C) Andrew Tridgell 1992-1998
   Copyright (C) Volker Lendecke 2005

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program 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 General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "includes.h"

struct timed_event {
        struct timed_event *next, *prev;
        struct event_context *event_ctx;
        struct timeval when;
        const char *event_name;
        void (*handler)(struct event_context *event_ctx,
                        struct timed_event *te,
                        const struct timeval *now,
                        void *private_data);
        void *private_data;
};

struct fd_event {
        struct fd_event *prev, *next;
        struct event_context *event_ctx;
        int fd;
        uint16_t flags; /* see EVENT_FD_* flags */
        void (*handler)(struct event_context *event_ctx,
                        struct fd_event *event,
                        uint16 flags,
                        void *private_data);
        void *private_data;
};

#define EVENT_FD_WRITEABLE(fde) \
        event_set_fd_flags(fde, event_get_fd_flags(fde) | EVENT_FD_WRITE)
#define EVENT_FD_READABLE(fde) \
        event_set_fd_flags(fde, event_get_fd_flags(fde) | EVENT_FD_READ)

#define EVENT_FD_NOT_WRITEABLE(fde) \
        event_set_fd_flags(fde, event_get_fd_flags(fde) & ~EVENT_FD_WRITE)
#define EVENT_FD_NOT_READABLE(fde) \
        event_set_fd_flags(fde, event_get_fd_flags(fde) & ~EVENT_FD_READ)

struct event_context {
        struct timed_event *timed_events;
        struct fd_event *fd_events;
};

static int timed_event_destructor(struct timed_event *te)
{
        DEBUG(10, ("Destroying timed event %lx \"%s\"\n", (unsigned long)te,
                te->event_name));
        DLIST_REMOVE(te->event_ctx->timed_events, te);
        return 0;
}

/****************************************************************************
 Add te by time.
****************************************************************************/

static void add_event_by_time(struct timed_event *te)
{
        struct event_context *ctx = te->event_ctx;
        struct timed_event *last_te, *cur_te;

        /* Keep the list ordered by time. We must preserve this. */
        last_te = NULL;
        for (cur_te = ctx->timed_events; cur_te; cur_te = cur_te->next) {
                /* if the new event comes before the current one break */
                if (!timeval_is_zero(&cur_te->when) &&
                                timeval_compare(&te->when, &cur_te->when) < 0) {
                        break;
                }
                last_te = cur_te;
        }

        DLIST_ADD_AFTER(ctx->timed_events, te, last_te);
}

/****************************************************************************
 Schedule a function for future calling, cancel with TALLOC_FREE().
 It's the responsibility of the handler to call TALLOC_FREE() on the event
 handed to it.
****************************************************************************/

struct timed_event *event_add_timed(struct event_context *event_ctx,
                                TALLOC_CTX *mem_ctx,
                                struct timeval when,
                                const char *event_name,
                                void (*handler)(struct event_context *event_ctx,
                                                struct timed_event *te,
                                                const struct timeval *now,
                                                void *private_data),
                                void *private_data)
{
        struct timed_event *te;

        te = TALLOC_P(mem_ctx, struct timed_event);
        if (te == NULL) {
                DEBUG(0, ("talloc failed\n"));
                return NULL;
        }

        te->event_ctx = event_ctx;
        te->when = when;
        te->event_name = event_name;
        te->handler = handler;
        te->private_data = private_data;

        add_event_by_time(te);

        talloc_set_destructor(te, timed_event_destructor);

        DEBUG(10, ("Added timed event \"%s\": %lx\n", event_name,
                        (unsigned long)te));
        return te;
}

static int fd_event_destructor(struct fd_event *fde)
{
        struct event_context *event_ctx = fde->event_ctx;

        DLIST_REMOVE(event_ctx->fd_events, fde);
        return 0;
}

struct fd_event *event_add_fd(struct event_context *event_ctx,
                              TALLOC_CTX *mem_ctx,
                              int fd, uint16_t flags,
                              void (*handler)(struct event_context *event_ctx,
                                              struct fd_event *event,
                                              uint16 flags,
                                              void *private_data),
                              void *private_data)
{
        struct fd_event *fde;

        if (!(fde = TALLOC_P(mem_ctx, struct fd_event))) {
                return NULL;
        }

        fde->event_ctx = event_ctx;
        fde->fd = fd;
        fde->flags = flags;
        fde->handler = handler;
        fde->private_data = private_data;

        DLIST_ADD(event_ctx->fd_events, fde);

        talloc_set_destructor(fde, fd_event_destructor);
        return fde;
}

void event_fd_set_writeable(struct fd_event *fde)
{
        fde->flags |= EVENT_FD_WRITE;
}

void event_fd_set_not_writeable(struct fd_event *fde)
{
        fde->flags &= ~EVENT_FD_WRITE;
}

void event_fd_set_readable(struct fd_event *fde)
{
        fde->flags |= EVENT_FD_READ;
}

void event_fd_set_not_readable(struct fd_event *fde)
{
        fde->flags &= ~EVENT_FD_READ;
}

void event_add_to_select_args(struct event_context *event_ctx,
                              const struct timeval *now,
                              fd_set *read_fds, fd_set *write_fds,
                              struct timeval *timeout, int *maxfd)
{
        struct fd_event *fde;
        struct timeval diff;

        for (fde = event_ctx->fd_events; fde; fde = fde->next) {
                if (fde->flags & EVENT_FD_READ) {
                        FD_SET(fde->fd, read_fds);
                }
                if (fde->flags & EVENT_FD_WRITE) {
                        FD_SET(fde->fd, write_fds);
                }

                if ((fde->flags & (EVENT_FD_READ|EVENT_FD_WRITE))
                    && (fde->fd > *maxfd)) {
                        *maxfd = fde->fd;
                }
        }

        if (event_ctx->timed_events == NULL) {
                return;
        }

        diff = timeval_until(now, &event_ctx->timed_events->when);
        *timeout = timeval_min(timeout, &diff);
}

BOOL run_events(struct event_context *event_ctx,
                int selrtn, fd_set *read_fds, fd_set *write_fds)
{
        BOOL fired = False;
        struct fd_event *fde, *next;

        /* Run all events that are pending, not just one (as we
           did previously. */

        while (event_ctx->timed_events) {
                struct timeval now;
                GetTimeOfDay(&now);

                if (timeval_compare(
                            &now, &event_ctx->timed_events->when) < 0) {
                        /* Nothing to do yet */
                        DEBUG(11, ("run_events: Nothing to do\n"));
                        break;
                }

                DEBUG(10, ("Running event \"%s\" %lx\n",
                           event_ctx->timed_events->event_name,
                           (unsigned long)event_ctx->timed_events));

                event_ctx->timed_events->handler(
                        event_ctx,
                        event_ctx->timed_events, &now,
                        event_ctx->timed_events->private_data);

                fired = True;
        }

        if (fired) {
                /*
                 * We might have changed the socket status during the timed
                 * events, return to run select again.
                 */
                return True;
        }

        if (selrtn == 0) {
                /*
                 * No fd ready
                 */
                return fired;
        }

        for (fde = event_ctx->fd_events; fde; fde = next) {
                uint16 flags = 0;

                next = fde->next;
                if (FD_ISSET(fde->fd, read_fds)) flags |= EVENT_FD_READ;
                if (FD_ISSET(fde->fd, write_fds)) flags |= EVENT_FD_WRITE;

                if (flags) {
                        fde->handler(event_ctx, fde, flags, fde->private_data);
                        fired = True;
                }
        }

        return fired;
}


struct timeval *get_timed_events_timeout(struct event_context *event_ctx,
                                         struct timeval *to_ret)
{
        struct timeval now;

        if (event_ctx->timed_events == NULL) {
                return NULL;
        }

        now = timeval_current();
        *to_ret = timeval_until(&now, &event_ctx->timed_events->when);

        DEBUG(10, ("timed_events_timeout: %d/%d\n", (int)to_ret->tv_sec,
                (int)to_ret->tv_usec));

        return to_ret;
}

struct event_context *event_context_init(TALLOC_CTX *mem_ctx)
{
        return TALLOC_ZERO_P(NULL, struct event_context);
}

int set_event_dispatch_time(struct event_context *event_ctx,
                            const char *event_name, struct timeval when)
{
        struct timed_event *te;

        for (te = event_ctx->timed_events; te; te = te->next) {
                if (strcmp(event_name, te->event_name) == 0) {
                        DLIST_REMOVE(event_ctx->timed_events, te);
                        te->when = when;
                        add_event_by_time(te);
                        return 1;
                }
        }
        return 0;
}

/* Returns 1 if event was found and cancelled, 0 otherwise. */

int cancel_named_event(struct event_context *event_ctx,
                       const char *event_name)
{
        struct timed_event *te;

        for (te = event_ctx->timed_events; te; te = te->next) {
                if (strcmp(event_name, te->event_name) == 0) {
                        TALLOC_FREE(te);
                        return 1;
                }
        }
        return 0;
}

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