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 #undef tevent_req_set_callback
  31
  32 char *tevent_req_default_print(struct tevent_req *req, TALLOC_CTX *mem_ctx)
  33 {
  34         return talloc_asprintf(mem_ctx,
  35                                "tevent_req[%p/%s]: state[%d] error[%lld (0x%llX)] "
  36                                " state[%s (%p)] timer[%p] finish[%s]",
  37                                req, req->internal.create_location,
  38                                req->internal.state,
  39                                (unsigned long long)req->internal.error,
  40                                (unsigned long long)req->internal.error,
  41                                req->internal.private_type,
  42                                req->data,
  43                                req->internal.timer,
  44                                req->internal.finish_location
  45                                );
  46 }
  47
  48 char *tevent_req_print(TALLOC_CTX *mem_ctx, struct tevent_req *req)
  49 {
  50         if (req == NULL) {
  51                 return talloc_strdup(mem_ctx, "tevent_req[NULL]");
  52         }
  53
  54         if (!req->private_print) {
  55                 return tevent_req_default_print(req, mem_ctx);
  56         }
  57
  58         return req->private_print(req, mem_ctx);
  59 }
  60
  61 static int tevent_req_destructor(struct tevent_req *req);
  62
  63 struct tevent_req *_tevent_req_create(TALLOC_CTX *mem_ctx,
  64                                     void *pdata,
  65                                     size_t data_size,
  66                                     const char *type,
  67                                     const char *location)
  68 {
  69         return __tevent_req_create(mem_ctx,
  70                                    pdata,
  71                                    data_size,
  72                                    type,
  73                                    NULL,
  74                                    location);
  75 }
  76
  77 struct tevent_req *__tevent_req_create(TALLOC_CTX *mem_ctx,
  78                                        void *pdata,
  79                                        size_t data_size,
  80                                        const char *type,
  81                                        const char *func,
  82                                        const char *location)
  83 {
  84         struct tevent_req *req;
  85         struct tevent_req *parent;
  86         void **ppdata = (void **)pdata;
  87         void *data;
  88         size_t payload;
  89
  90         payload = sizeof(struct tevent_immediate) + data_size;
  91         if (payload < sizeof(struct tevent_immediate)) {
  92                 /* overflow */
  93                 return NULL;
  94         }
  95
  96         req = talloc_pooled_object(
  97                 mem_ctx, struct tevent_req, 2,
  98                 sizeof(struct tevent_immediate) + data_size);
  99         if (req == NULL) {
 100                 return NULL;
 101         }
 102
 103         *req = (struct tevent_req) {
 104                 .internal = {
 105                         .private_type           = type,
 106                         .create_location        = location,
 107                         .state                  = TEVENT_REQ_IN_PROGRESS,
 108                         .trigger                = tevent_create_immediate(req),
 109                 },
 110         };
 111
 112         data = talloc_zero_size(req, data_size);
 113
 114         /*
 115          * No need to check for req->internal.trigger!=NULL or
 116          * data!=NULL, this can't fail: talloc_pooled_object has
 117          * already allocated sufficient memory.
 118          */
 119
 120         talloc_set_name_const(data, type);
 121
 122         req->data = data;
 123
 124         talloc_set_destructor(req, tevent_req_destructor);
 125
 126         parent = talloc_get_type(talloc_parent(mem_ctx), struct tevent_req);
 127         if ((parent != NULL) && (parent->internal.profile != NULL)) {
 128                 bool ok = tevent_req_set_profile(req);
 129
 130                 if (!ok) {
 131                         TALLOC_FREE(req);
 132                         return NULL;
 133                 }
 134                 req->internal.profile->parent = parent->internal.profile;
 135                 DLIST_ADD_END(parent->internal.profile->subprofiles,
 136                               req->internal.profile);
 137         }
 138
 139         *ppdata = data;
 140
 141         /* Initially, talloc_zero_size() sets internal.call_depth to 0 */
 142         if (parent != NULL && parent->internal.call_depth > 0) {
 143                 req->internal.call_depth = parent->internal.call_depth + 1;
 144                 tevent_thread_call_depth_set(req->internal.call_depth);
 145         }
 146
 147         return req;
 148 }
 149
 150 static int tevent_req_destructor(struct tevent_req *req)
 151 {
 152         tevent_req_received(req);
 153         return 0;
 154 }
 155
 156 void _tevent_req_notify_callback(struct tevent_req *req, const char *location)
 157 {
 158         req->internal.finish_location = location;
 159         if (req->internal.defer_callback_ev) {
 160                 (void)tevent_req_post(req, req->internal.defer_callback_ev);
 161                 req->internal.defer_callback_ev = NULL;
 162                 return;
 163         }
 164         if (req->async.fn != NULL) {
 165                 /* Calling back the parent code, decrement the call depth. */
 166                 tevent_thread_call_depth_set(req->internal.call_depth > 0 ?
 167                                              req->internal.call_depth - 1 : 0);
 168                 req->async.fn(req);
 169         }
 170 }
 171
 172 static void tevent_req_cleanup(struct tevent_req *req)
 173 {
 174         if (req->private_cleanup.fn == NULL) {
 175                 return;
 176         }
 177
 178         if (req->private_cleanup.state >= req->internal.state) {
 179                 /*
 180                  * Don't call the cleanup_function multiple times for the same
 181                  * state recursively
 182                  */
 183                 return;
 184         }
 185
 186         req->private_cleanup.state = req->internal.state;
 187         req->private_cleanup.fn(req, req->internal.state);
 188 }
 189
 190 static void tevent_req_finish(struct tevent_req *req,
 191                               enum tevent_req_state state,
 192                               const char *location)
 193 {
 194         struct tevent_req_profile *p;
 195         /*
 196          * make sure we do not timeout after
 197          * the request was already finished
 198          */
 199         TALLOC_FREE(req->internal.timer);
 200
 201         req->internal.state = state;
 202         req->internal.finish_location = location;
 203
 204         tevent_req_cleanup(req);
 205
 206         p = req->internal.profile;
 207
 208         if (p != NULL) {
 209                 p->stop_location = location;
 210                 p->stop_time = tevent_timeval_current();
 211                 p->state = state;
 212                 p->user_error = req->internal.error;
 213
 214                 if (p->parent != NULL) {
 215                         talloc_steal(p->parent, p);
 216                         req->internal.profile = NULL;
 217                 }
 218         }
 219
 220         _tevent_req_notify_callback(req, location);
 221 }
 222
 223 void _tevent_req_done(struct tevent_req *req,
 224                       const char *location)
 225 {
 226         tevent_req_finish(req, TEVENT_REQ_DONE, location);
 227 }
 228
 229 bool _tevent_req_error(struct tevent_req *req,
 230                        uint64_t error,
 231                        const char *location)
 232 {
 233         if (error == 0) {
 234                 return false;
 235         }
 236
 237         req->internal.error = error;
 238         tevent_req_finish(req, TEVENT_REQ_USER_ERROR, location);
 239         return true;
 240 }
 241
 242 void _tevent_req_oom(struct tevent_req *req, const char *location)
 243 {
 244         tevent_req_finish(req, TEVENT_REQ_NO_MEMORY, location);
 245 }
 246
 247 bool _tevent_req_nomem(const void *p,
 248                        struct tevent_req *req,
 249                        const char *location)
 250 {
 251         if (p != NULL) {
 252                 return false;
 253         }
 254         _tevent_req_oom(req, location);
 255         return true;
 256 }
 257
 258 /**
 259  * @internal
 260  *
 261  * @brief Immediate event callback.
 262  *
 263  * @param[in]  ev       The event context to use.
 264  *
 265  * @param[in]  im       The immediate event.
 266  *
 267  * @param[in]  priv     The async request to be finished.
 268  */
 269 static void tevent_req_trigger(struct tevent_context *ev,
 270                                struct tevent_immediate *im,
 271                                void *private_data)
 272 {
 273         struct tevent_req *req =
 274                 talloc_get_type_abort(private_data,
 275                 struct tevent_req);
 276
 277         tevent_req_finish(req, req->internal.state,
 278                           req->internal.finish_location);
 279 }
 280
 281 struct tevent_req *tevent_req_post(struct tevent_req *req,
 282                                    struct tevent_context *ev)
 283 {
 284         tevent_schedule_immediate(req->internal.trigger,
 285                                   ev, tevent_req_trigger, req);
 286         return req;
 287 }
 288
 289 void tevent_req_defer_callback(struct tevent_req *req,
 290                                struct tevent_context *ev)
 291 {
 292         req->internal.defer_callback_ev = ev;
 293 }
 294
 295 bool tevent_req_is_in_progress(struct tevent_req *req)
 296 {
 297         if (req->internal.state == TEVENT_REQ_IN_PROGRESS) {
 298                 return true;
 299         }
 300
 301         return false;
 302 }
 303
 304 void tevent_req_received(struct tevent_req *req)
 305 {
 306         talloc_set_destructor(req, NULL);
 307
 308         req->private_print = NULL;
 309         req->private_cancel = NULL;
 310
 311         TALLOC_FREE(req->internal.trigger);
 312         TALLOC_FREE(req->internal.timer);
 313
 314         req->internal.state = TEVENT_REQ_RECEIVED;
 315
 316         tevent_req_cleanup(req);
 317
 318         TALLOC_FREE(req->data);
 319 }
 320
 321 bool tevent_req_poll(struct tevent_req *req,
 322                      struct tevent_context *ev)
 323 {
 324         while (tevent_req_is_in_progress(req)) {
 325                 int ret;
 326
 327                 ret = tevent_loop_once(ev);
 328                 if (ret != 0) {
 329                         return false;
 330                 }
 331         }
 332
 333         return true;
 334 }
 335
 336 bool tevent_req_is_error(struct tevent_req *req, enum tevent_req_state *state,
 337                         uint64_t *error)
 338 {
 339         if (req->internal.state == TEVENT_REQ_DONE) {
 340                 return false;
 341         }
 342         if (req->internal.state == TEVENT_REQ_USER_ERROR) {
 343                 *error = req->internal.error;
 344         }
 345         *state = req->internal.state;
 346         return true;
 347 }
 348
 349 static void tevent_req_timedout(struct tevent_context *ev,
 350                                struct tevent_timer *te,
 351                                struct timeval now,
 352                                void *private_data)
 353 {
 354         struct tevent_req *req =
 355                 talloc_get_type_abort(private_data,
 356                 struct tevent_req);
 357
 358         TALLOC_FREE(req->internal.timer);
 359
 360         tevent_req_finish(req, TEVENT_REQ_TIMED_OUT, __FUNCTION__);
 361 }
 362
 363 bool tevent_req_set_endtime(struct tevent_req *req,
 364                             struct tevent_context *ev,
 365                             struct timeval endtime)
 366 {
 367         TALLOC_FREE(req->internal.timer);
 368
 369         req->internal.timer = tevent_add_timer(ev, req, endtime,
 370                                                tevent_req_timedout,
 371                                                req);
 372         if (tevent_req_nomem(req->internal.timer, req)) {
 373                 return false;
 374         }
 375
 376         return true;
 377 }
 378
 379 void tevent_req_reset_endtime(struct tevent_req *req)
 380 {
 381         TALLOC_FREE(req->internal.timer);
 382 }
 383
 384 void tevent_req_set_callback(struct tevent_req *req, tevent_req_fn fn, void *pvt)
 385 {
 386         return _tevent_req_set_callback(req, fn, NULL, pvt);
 387 }
 388
 389 void _tevent_req_set_callback(struct tevent_req *req,
 390                               tevent_req_fn fn,
 391                               const char *fn_name,
 392                               void *pvt)
 393 {
 394         req->async.fn = fn;
 395         req->async.fn_name = fn_name;
 396         req->async.private_data = pvt;
 397 }
 398
 399 void *_tevent_req_callback_data(struct tevent_req *req)
 400 {
 401         return req->async.private_data;
 402 }
 403
 404 void *_tevent_req_data(struct tevent_req *req)
 405 {
 406         return req->data;
 407 }
 408
 409 void tevent_req_set_print_fn(struct tevent_req *req, tevent_req_print_fn fn)
 410 {
 411         req->private_print = fn;
 412 }
 413
 414 void tevent_req_set_cancel_fn(struct tevent_req *req, tevent_req_cancel_fn fn)
 415 {
 416         req->private_cancel = fn;
 417 }
 418
 419 bool _tevent_req_cancel(struct tevent_req *req, const char *location)
 420 {
 421         if (req->private_cancel == NULL) {
 422                 return false;
 423         }
 424
 425         return req->private_cancel(req);
 426 }
 427
 428 void tevent_req_set_cleanup_fn(struct tevent_req *req, tevent_req_cleanup_fn fn)
 429 {
 430         req->private_cleanup.state = req->internal.state;
 431         req->private_cleanup.fn = fn;
 432 }
 433
 434 static int tevent_req_profile_destructor(struct tevent_req_profile *p);
 435
 436 bool tevent_req_set_profile(struct tevent_req *req)
 437 {
 438         struct tevent_req_profile *p;
 439
 440         if (req->internal.profile != NULL) {
 441                 tevent_req_error(req, EINVAL);
 442                 return false;
 443         }
 444
 445         p = tevent_req_profile_create(req);
 446
 447         if (tevent_req_nomem(p, req)) {
 448                 return false;
 449         }
 450
 451         p->req_name = talloc_get_name(req->data);
 452         p->start_location = req->internal.create_location;
 453         p->start_time = tevent_timeval_current();
 454
 455         req->internal.profile = p;
 456
 457         return true;
 458 }
 459
 460 static int tevent_req_profile_destructor(struct tevent_req_profile *p)
 461 {
 462         if (p->parent != NULL) {
 463                 DLIST_REMOVE(p->parent->subprofiles, p);
 464                 p->parent = NULL;
 465         }
 466
 467         while (p->subprofiles != NULL) {
 468                 p->subprofiles->parent = NULL;
 469                 DLIST_REMOVE(p->subprofiles, p->subprofiles);
 470         }
 471
 472         return 0;
 473 }
 474
 475 struct tevent_req_profile *tevent_req_move_profile(struct tevent_req *req,
 476                                                    TALLOC_CTX *mem_ctx)
 477 {
 478         return talloc_move(mem_ctx, &req->internal.profile);
 479 }
 480
 481 const struct tevent_req_profile *tevent_req_get_profile(
 482         struct tevent_req *req)
 483 {
 484         return req->internal.profile;
 485 }
 486
 487 void tevent_req_profile_get_name(const struct tevent_req_profile *profile,
 488                                  const char **req_name)
 489 {
 490         if (req_name != NULL) {
 491                 *req_name = profile->req_name;
 492         }
 493 }
 494
 495 void tevent_req_profile_get_start(const struct tevent_req_profile *profile,
 496                                   const char **start_location,
 497                                   struct timeval *start_time)
 498 {
 499         if (start_location != NULL) {
 500                 *start_location = profile->start_location;
 501         }
 502         if (start_time != NULL) {
 503                 *start_time = profile->start_time;
 504         }
 505 }
 506
 507 void tevent_req_profile_get_stop(const struct tevent_req_profile *profile,
 508                                  const char **stop_location,
 509                                  struct timeval *stop_time)
 510 {
 511         if (stop_location != NULL) {
 512                 *stop_location = profile->stop_location;
 513         }
 514         if (stop_time != NULL) {
 515                 *stop_time = profile->stop_time;
 516         }
 517 }
 518
 519 void tevent_req_profile_get_status(const struct tevent_req_profile *profile,
 520                                    pid_t *pid,
 521                                    enum tevent_req_state *state,
 522                                    uint64_t *user_error)
 523 {
 524         if (pid != NULL) {
 525                 *pid = profile->pid;
 526         }
 527         if (state != NULL) {
 528                 *state = profile->state;
 529         }
 530         if (user_error != NULL) {
 531                 *user_error = profile->user_error;
 532         }
 533 }
 534
 535 const struct tevent_req_profile *tevent_req_profile_get_subprofiles(
 536         const struct tevent_req_profile *profile)
 537 {
 538         return profile->subprofiles;
 539 }
 540
 541 const struct tevent_req_profile *tevent_req_profile_next(
 542         const struct tevent_req_profile *profile)
 543 {
 544         return profile->next;
 545 }
 546
 547 struct tevent_req_profile *tevent_req_profile_create(TALLOC_CTX *mem_ctx)
 548 {
 549         struct tevent_req_profile *result;
 550
 551         result = talloc_zero(mem_ctx, struct tevent_req_profile);
 552         if (result == NULL) {
 553                 return NULL;
 554         }
 555         talloc_set_destructor(result, tevent_req_profile_destructor);
 556
 557         return result;
 558 }
 559
 560 bool tevent_req_profile_set_name(struct tevent_req_profile *profile,
 561                                  const char *req_name)
 562 {
 563         profile->req_name = talloc_strdup(profile, req_name);
 564         return (profile->req_name != NULL);
 565 }
 566
 567 bool tevent_req_profile_set_start(struct tevent_req_profile *profile,
 568                                   const char *start_location,
 569                                   struct timeval start_time)
 570 {
 571         profile->start_time = start_time;
 572
 573         profile->start_location = talloc_strdup(profile, start_location);
 574         return (profile->start_location != NULL);
 575 }
 576
 577 bool tevent_req_profile_set_stop(struct tevent_req_profile *profile,
 578                                  const char *stop_location,
 579                                  struct timeval stop_time)
 580 {
 581         profile->stop_time = stop_time;
 582
 583         profile->stop_location = talloc_strdup(profile, stop_location);
 584         return (profile->stop_location != NULL);
 585 }
 586
 587 void tevent_req_profile_set_status(struct tevent_req_profile *profile,
 588                                    pid_t pid,
 589                                    enum tevent_req_state state,
 590                                    uint64_t user_error)
 591 {
 592         profile->pid = pid;
 593         profile->state = state;
 594         profile->user_error = user_error;
 595 }
 596
 597 void tevent_req_profile_append_sub(struct tevent_req_profile *parent_profile,
 598                                    struct tevent_req_profile **sub_profile)
 599 {
 600         struct tevent_req_profile *sub;
 601
 602         sub = talloc_move(parent_profile, sub_profile);
 603
 604         sub->parent = parent_profile;
 605         DLIST_ADD_END(parent_profile->subprofiles, sub);
 606 }