lib/tevent/tevent_req.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Infrastructure for async requests
   4    Copyright (C) Volker Lendecke 2008
   5    Copyright (C) Stefan Metzmacher 2009
   6
   7      ** NOTE! The following LGPL license applies to the tevent
   8      ** library. This does NOT imply that all of Samba is released
   9      ** under the LGPL
  10
  11    This library is free software; you can redistribute it and/or
  12    modify it under the terms of the GNU Lesser General Public
  13    License as published by the Free Software Foundation; either
  14    version 3 of the License, or (at your option) any later version.
  15
  16    This library is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19    Lesser General Public License for more details.
  20
  21    You should have received a copy of the GNU Lesser General Public
  22    License along with this library; if not, see <http://www.gnu.org/licenses/>.
  23 */
  24
  25 #include "replace.h"
  26 #include "tevent.h"
  27 #include "tevent_internal.h"
  28 #include "tevent_util.h"
  29
  30 char *tevent_req_default_print(struct tevent_req *req, TALLOC_CTX *mem_ctx)
  31 {
  32         return talloc_asprintf(mem_ctx,
  33                                "tevent_req[%p/%s]: state[%d] error[%lld (0x%llX)] "
  34                                " state[%s (%p)] timer[%p]",
  35                                req, req->internal.create_location,
  36                                req->internal.state,
  37                                (unsigned long long)req->internal.error,
  38                                (unsigned long long)req->internal.error,
  39                                talloc_get_name(req->data),
  40                                req->data,
  41                                req->internal.timer
  42                                );
  43 }
  44
  45 char *tevent_req_print(TALLOC_CTX *mem_ctx, struct tevent_req *req)
  46 {
  47         if (!req->private_print) {
  48                 return tevent_req_default_print(req, mem_ctx);
  49         }
  50
  51         return req->private_print(req, mem_ctx);
  52 }
  53
  54 static int tevent_req_destructor(struct tevent_req *req);
  55
  56 struct tevent_req *_tevent_req_create(TALLOC_CTX *mem_ctx,
  57                                     void *pdata,
  58                                     size_t data_size,
  59                                     const char *type,
  60                                     const char *location)
  61 {
  62         struct tevent_req *req;
  63         void **ppdata = (void **)pdata;
  64         void *data;
  65
  66         req = talloc_pooled_object(
  67                 mem_ctx, struct tevent_req, 2,
  68                 sizeof(struct tevent_immediate) + data_size);
  69         if (req == NULL) {
  70                 return NULL;
  71         }
  72
  73         *req = (struct tevent_req) {
  74                 .internal.private_type          = type,
  75                 .internal.create_location       = location,
  76                 .internal.state                 = TEVENT_REQ_IN_PROGRESS,
  77                 .internal.trigger               = tevent_create_immediate(req)
  78         };
  79
  80         data = talloc_zero_size(req, data_size);
  81
  82         /*
  83          * No need to check for req->internal.trigger!=NULL or
  84          * data!=NULL, this can't fail: talloc_pooled_object has
  85          * already allocated sufficient memory.
  86          */
  87
  88         talloc_set_name_const(data, type);
  89
  90         req->data = data;
  91
  92         talloc_set_destructor(req, tevent_req_destructor);
  93
  94         *ppdata = data;
  95         return req;
  96 }
  97
  98 static int tevent_req_destructor(struct tevent_req *req)
  99 {
 100         tevent_req_received(req);
 101         return 0;
 102 }
 103
 104 void _tevent_req_notify_callback(struct tevent_req *req, const char *location)
 105 {
 106         req->internal.finish_location = location;
 107         if (req->internal.defer_callback_ev) {
 108                 (void)tevent_req_post(req, req->internal.defer_callback_ev);
 109                 req->internal.defer_callback_ev = NULL;
 110                 return;
 111         }
 112         if (req->async.fn != NULL) {
 113                 req->async.fn(req);
 114         }
 115 }
 116
 117 static void tevent_req_cleanup(struct tevent_req *req)
 118 {
 119         if (req->private_cleanup.fn == NULL) {
 120                 return;
 121         }
 122
 123         if (req->private_cleanup.state >= req->internal.state) {
 124                 /*
 125                  * Don't call the cleanup_function multiple times for the same
 126                  * state recursively
 127                  */
 128                 return;
 129         }
 130
 131         req->private_cleanup.state = req->internal.state;
 132         req->private_cleanup.fn(req, req->internal.state);
 133 }
 134
 135 static void tevent_req_finish(struct tevent_req *req,
 136                               enum tevent_req_state state,
 137                               const char *location)
 138 {
 139         /*
 140          * make sure we do not timeout after
 141          * the request was already finished
 142          */
 143         TALLOC_FREE(req->internal.timer);
 144
 145         req->internal.state = state;
 146         req->internal.finish_location = location;
 147
 148         tevent_req_cleanup(req);
 149
 150         _tevent_req_notify_callback(req, location);
 151 }
 152
 153 void _tevent_req_done(struct tevent_req *req,
 154                       const char *location)
 155 {
 156         tevent_req_finish(req, TEVENT_REQ_DONE, location);
 157 }
 158
 159 bool _tevent_req_error(struct tevent_req *req,
 160                        uint64_t error,
 161                        const char *location)
 162 {
 163         if (error == 0) {
 164                 return false;
 165         }
 166
 167         req->internal.error = error;
 168         tevent_req_finish(req, TEVENT_REQ_USER_ERROR, location);
 169         return true;
 170 }
 171
 172 void _tevent_req_oom(struct tevent_req *req, const char *location)
 173 {
 174         tevent_req_finish(req, TEVENT_REQ_NO_MEMORY, location);
 175 }
 176
 177 bool _tevent_req_nomem(const void *p,
 178                        struct tevent_req *req,
 179                        const char *location)
 180 {
 181         if (p != NULL) {
 182                 return false;
 183         }
 184         _tevent_req_oom(req, location);
 185         return true;
 186 }
 187
 188 /**
 189  * @internal
 190  *
 191  * @brief Immediate event callback.
 192  *
 193  * @param[in]  ev       The event context to use.
 194  *
 195  * @param[in]  im       The immediate event.
 196  *
 197  * @param[in]  priv     The async request to be finished.
 198  */
 199 static void tevent_req_trigger(struct tevent_context *ev,
 200                                struct tevent_immediate *im,
 201                                void *private_data)
 202 {
 203         struct tevent_req *req =
 204                 talloc_get_type_abort(private_data,
 205                 struct tevent_req);
 206
 207         tevent_req_finish(req, req->internal.state,
 208                           req->internal.finish_location);
 209 }
 210
 211 struct tevent_req *tevent_req_post(struct tevent_req *req,
 212                                    struct tevent_context *ev)
 213 {
 214         tevent_schedule_immediate(req->internal.trigger,
 215                                   ev, tevent_req_trigger, req);
 216         return req;
 217 }
 218
 219 void tevent_req_defer_callback(struct tevent_req *req,
 220                                struct tevent_context *ev)
 221 {
 222         req->internal.defer_callback_ev = ev;
 223 }
 224
 225 bool tevent_req_is_in_progress(struct tevent_req *req)
 226 {
 227         if (req->internal.state == TEVENT_REQ_IN_PROGRESS) {
 228                 return true;
 229         }
 230
 231         return false;
 232 }
 233
 234 void tevent_req_received(struct tevent_req *req)
 235 {
 236         talloc_set_destructor(req, NULL);
 237
 238         req->private_print = NULL;
 239         req->private_cancel = NULL;
 240
 241         TALLOC_FREE(req->internal.trigger);
 242         TALLOC_FREE(req->internal.timer);
 243
 244         req->internal.state = TEVENT_REQ_RECEIVED;
 245
 246         tevent_req_cleanup(req);
 247
 248         TALLOC_FREE(req->data);
 249 }
 250
 251 bool tevent_req_poll(struct tevent_req *req,
 252                      struct tevent_context *ev)
 253 {
 254         while (tevent_req_is_in_progress(req)) {
 255                 int ret;
 256
 257                 ret = tevent_loop_once(ev);
 258                 if (ret != 0) {
 259                         return false;
 260                 }
 261         }
 262
 263         return true;
 264 }
 265
 266 bool tevent_req_is_error(struct tevent_req *req, enum tevent_req_state *state,
 267                         uint64_t *error)
 268 {
 269         if (req->internal.state == TEVENT_REQ_DONE) {
 270                 return false;
 271         }
 272         if (req->internal.state == TEVENT_REQ_USER_ERROR) {
 273                 *error = req->internal.error;
 274         }
 275         *state = req->internal.state;
 276         return true;
 277 }
 278
 279 static void tevent_req_timedout(struct tevent_context *ev,
 280                                struct tevent_timer *te,
 281                                struct timeval now,
 282                                void *private_data)
 283 {
 284         struct tevent_req *req =
 285                 talloc_get_type_abort(private_data,
 286                 struct tevent_req);
 287
 288         TALLOC_FREE(req->internal.timer);
 289
 290         tevent_req_finish(req, TEVENT_REQ_TIMED_OUT, __FUNCTION__);
 291 }
 292
 293 bool tevent_req_set_endtime(struct tevent_req *req,
 294                             struct tevent_context *ev,
 295                             struct timeval endtime)
 296 {
 297         TALLOC_FREE(req->internal.timer);
 298
 299         req->internal.timer = tevent_add_timer(ev, req, endtime,
 300                                                tevent_req_timedout,
 301                                                req);
 302         if (tevent_req_nomem(req->internal.timer, req)) {
 303                 return false;
 304         }
 305
 306         return true;
 307 }
 308
 309 void tevent_req_set_callback(struct tevent_req *req, tevent_req_fn fn, void *pvt)
 310 {
 311         req->async.fn = fn;
 312         req->async.private_data = pvt;
 313 }
 314
 315 void *_tevent_req_callback_data(struct tevent_req *req)
 316 {
 317         return req->async.private_data;
 318 }
 319
 320 void *_tevent_req_data(struct tevent_req *req)
 321 {
 322         return req->data;
 323 }
 324
 325 void tevent_req_set_print_fn(struct tevent_req *req, tevent_req_print_fn fn)
 326 {
 327         req->private_print = fn;
 328 }
 329
 330 void tevent_req_set_cancel_fn(struct tevent_req *req, tevent_req_cancel_fn fn)
 331 {
 332         req->private_cancel = fn;
 333 }
 334
 335 bool _tevent_req_cancel(struct tevent_req *req, const char *location)
 336 {
 337         if (req->private_cancel == NULL) {
 338                 return false;
 339         }
 340
 341         return req->private_cancel(req);
 342 }
 343
 344 void tevent_req_set_cleanup_fn(struct tevent_req *req, tevent_req_cleanup_fn fn)
 345 {
 346         req->private_cleanup.state = req->internal.state;
 347         req->private_cleanup.fn = fn;
 348 }