source: vendor/current/lib/tevent/tevent_req.c

/*
   Unix SMB/CIFS implementation.
   Infrastructure for async requests
   Copyright (C) Volker Lendecke 2008
   Copyright (C) Stefan Metzmacher 2009

     ** NOTE! The following LGPL license applies to the tevent
     ** library. This does NOT imply that all of Samba is released
     ** under the LGPL

   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; either
   version 3 of the License, or (at your option) any later version.

   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, see <http://www.gnu.org/licenses/>.
*/

#include "replace.h"
#include "tevent.h"
#include "tevent_internal.h"
#include "tevent_util.h"

char *tevent_req_default_print(struct tevent_req *req, TALLOC_CTX *mem_ctx)
{
        return talloc_asprintf(mem_ctx,
                               "tevent_req[%p/%s]: state[%d] error[%lld (0x%llX)] "
                               " state[%s (%p)] timer[%p]",
                               req, req->internal.create_location,
                               req->internal.state,
                               (unsigned long long)req->internal.error,
                               (unsigned long long)req->internal.error,
                               talloc_get_name(req->data),
                               req->data,
                               req->internal.timer
                               );
}

char *tevent_req_print(TALLOC_CTX *mem_ctx, struct tevent_req *req)
{
        if (!req->private_print) {
                return tevent_req_default_print(req, mem_ctx);
        }

        return req->private_print(req, mem_ctx);
}

static int tevent_req_destructor(struct tevent_req *req);

struct tevent_req *_tevent_req_create(TALLOC_CTX *mem_ctx,
                                    void *pdata,
                                    size_t data_size,
                                    const char *type,
                                    const char *location)
{
        struct tevent_req *req;
        void **ppdata = (void **)pdata;
        void *data;

        req = talloc_pooled_object(
                mem_ctx, struct tevent_req, 2,
                sizeof(struct tevent_immediate) + data_size);
        if (req == NULL) {
                return NULL;
        }
        ZERO_STRUCTP(req);
        req->internal.private_type      = type;
        req->internal.create_location   = location;
        req->internal.state             = TEVENT_REQ_IN_PROGRESS;
        req->internal.trigger           = tevent_create_immediate(req);
        if (!req->internal.trigger) {
                talloc_free(req);
                return NULL;
        }

        data = talloc_zero_size(req, data_size);
        if (data == NULL) {
                talloc_free(req);
                return NULL;
        }
        talloc_set_name_const(data, type);

        req->data = data;

        talloc_set_destructor(req, tevent_req_destructor);

        *ppdata = data;
        return req;
}

static int tevent_req_destructor(struct tevent_req *req)
{
        tevent_req_received(req);
        return 0;
}

void _tevent_req_notify_callback(struct tevent_req *req, const char *location)
{
        req->internal.finish_location = location;
        if (req->internal.defer_callback_ev) {
                (void)tevent_req_post(req, req->internal.defer_callback_ev);
                req->internal.defer_callback_ev = NULL;
                return;
        }
        if (req->async.fn != NULL) {
                req->async.fn(req);
        }
}

static void tevent_req_cleanup(struct tevent_req *req)
{
        if (req->private_cleanup.fn == NULL) {
                return;
        }

        if (req->private_cleanup.state >= req->internal.state) {
                /*
                 * Don't call the cleanup_function multiple times for the same
                 * state recursively
                 */
                return;
        }

        req->private_cleanup.state = req->internal.state;
        req->private_cleanup.fn(req, req->internal.state);
}

static void tevent_req_finish(struct tevent_req *req,
                              enum tevent_req_state state,
                              const char *location)
{
        /*
         * make sure we do not timeout after
         * the request was already finished
         */
        TALLOC_FREE(req->internal.timer);

        req->internal.state = state;
        req->internal.finish_location = location;

        tevent_req_cleanup(req);

        _tevent_req_notify_callback(req, location);
}

void _tevent_req_done(struct tevent_req *req,
                      const char *location)
{
        tevent_req_finish(req, TEVENT_REQ_DONE, location);
}

bool _tevent_req_error(struct tevent_req *req,
                       uint64_t error,
                       const char *location)
{
        if (error == 0) {
                return false;
        }

        req->internal.error = error;
        tevent_req_finish(req, TEVENT_REQ_USER_ERROR, location);
        return true;
}

void _tevent_req_oom(struct tevent_req *req, const char *location)
{
        tevent_req_finish(req, TEVENT_REQ_NO_MEMORY, location);
}

bool _tevent_req_nomem(const void *p,
                       struct tevent_req *req,
                       const char *location)
{
        if (p != NULL) {
                return false;
        }
        _tevent_req_oom(req, location);
        return true;
}

/**
 * @internal
 *
 * @brief Immediate event callback.
 *
 * @param[in]  ev       The event context to use.
 *
 * @param[in]  im       The immediate event.
 *
 * @param[in]  priv     The async request to be finished.
 */
static void tevent_req_trigger(struct tevent_context *ev,
                               struct tevent_immediate *im,
                               void *private_data)
{
        struct tevent_req *req =
                talloc_get_type_abort(private_data,
                struct tevent_req);

        tevent_req_finish(req, req->internal.state,
                          req->internal.finish_location);
}

struct tevent_req *tevent_req_post(struct tevent_req *req,
                                   struct tevent_context *ev)
{
        tevent_schedule_immediate(req->internal.trigger,
                                  ev, tevent_req_trigger, req);
        return req;
}

void tevent_req_defer_callback(struct tevent_req *req,
                               struct tevent_context *ev)
{
        req->internal.defer_callback_ev = ev;
}

bool tevent_req_is_in_progress(struct tevent_req *req)
{
        if (req->internal.state == TEVENT_REQ_IN_PROGRESS) {
                return true;
        }

        return false;
}

void tevent_req_received(struct tevent_req *req)
{
        talloc_set_destructor(req, NULL);

        req->private_print = NULL;
        req->private_cancel = NULL;

        TALLOC_FREE(req->internal.trigger);
        TALLOC_FREE(req->internal.timer);

        req->internal.state = TEVENT_REQ_RECEIVED;

        tevent_req_cleanup(req);

        TALLOC_FREE(req->data);
}

bool tevent_req_poll(struct tevent_req *req,
                     struct tevent_context *ev)
{
        while (tevent_req_is_in_progress(req)) {
                int ret;

                ret = tevent_loop_once(ev);
                if (ret != 0) {
                        return false;
                }
        }

        return true;
}

bool tevent_req_is_error(struct tevent_req *req, enum tevent_req_state *state,
                        uint64_t *error)
{
        if (req->internal.state == TEVENT_REQ_DONE) {
                return false;
        }
        if (req->internal.state == TEVENT_REQ_USER_ERROR) {
                *error = req->internal.error;
        }
        *state = req->internal.state;
        return true;
}

static void tevent_req_timedout(struct tevent_context *ev,
                               struct tevent_timer *te,
                               struct timeval now,
                               void *private_data)
{
        struct tevent_req *req =
                talloc_get_type_abort(private_data,
                struct tevent_req);

        TALLOC_FREE(req->internal.timer);

        tevent_req_finish(req, TEVENT_REQ_TIMED_OUT, __FUNCTION__);
}

bool tevent_req_set_endtime(struct tevent_req *req,
                            struct tevent_context *ev,
                            struct timeval endtime)
{
        TALLOC_FREE(req->internal.timer);

        req->internal.timer = tevent_add_timer(ev, req, endtime,
                                               tevent_req_timedout,
                                               req);
        if (tevent_req_nomem(req->internal.timer, req)) {
                return false;
        }

        return true;
}

void tevent_req_set_callback(struct tevent_req *req, tevent_req_fn fn, void *pvt)
{
        req->async.fn = fn;
        req->async.private_data = pvt;
}

void *_tevent_req_callback_data(struct tevent_req *req)
{
        return req->async.private_data;
}

void *_tevent_req_data(struct tevent_req *req)
{
        return req->data;
}

void tevent_req_set_print_fn(struct tevent_req *req, tevent_req_print_fn fn)
{
        req->private_print = fn;
}

void tevent_req_set_cancel_fn(struct tevent_req *req, tevent_req_cancel_fn fn)
{
        req->private_cancel = fn;
}

bool _tevent_req_cancel(struct tevent_req *req, const char *location)
{
        if (req->private_cancel == NULL) {
                return false;
        }

        return req->private_cancel(req);
}

void tevent_req_set_cleanup_fn(struct tevent_req *req, tevent_req_cleanup_fn fn)
{
        req->private_cleanup.state = req->internal.state;
        req->private_cleanup.fn = fn;
}