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         if (!req->internal.trigger) {
  81                 talloc_free(req);
  82                 return NULL;
  83         }
  84
  85         data = talloc_zero_size(req, data_size);
  86         if (data == NULL) {
  87                 talloc_free(req);
  88                 return NULL;
  89         }
  90         talloc_set_name_const(data, type);
  91
  92         req->data = data;
  93
  94         talloc_set_destructor(req, tevent_req_destructor);
  95
  96         *ppdata = data;
  97         return req;
  98 }
  99
 100 static int tevent_req_destructor(struct tevent_req *req)
 101 {
 102         tevent_req_received(req);
 103         return 0;
 104 }
 105
 106 void _tevent_req_notify_callback(struct tevent_req *req, const char *location)
 107 {
 108         req->internal.finish_location = location;
 109         if (req->internal.defer_callback_ev) {
 110                 (void)tevent_req_post(req, req->internal.defer_callback_ev);
 111                 req->internal.defer_callback_ev = NULL;
 112                 return;
 113         }
 114         if (req->async.fn != NULL) {
 115                 req->async.fn(req);
 116         }
 117 }
 118
 119 static void tevent_req_cleanup(struct tevent_req *req)
 120 {
 121         if (req->private_cleanup.fn == NULL) {
 122                 return;
 123         }
 124
 125         if (req->private_cleanup.state >= req->internal.state) {
 126                 /*
 127                  * Don't call the cleanup_function multiple times for the same
 128                  * state recursively
 129                  */
 130                 return;
 131         }
 132
 133         req->private_cleanup.state = req->internal.state;
 134         req->private_cleanup.fn(req, req->internal.state);
 135 }
 136
 137 static void tevent_req_finish(struct tevent_req *req,
 138                               enum tevent_req_state state,
 139                               const char *location)
 140 {
 141         /*
 142          * make sure we do not timeout after
 143          * the request was already finished
 144          */
 145         TALLOC_FREE(req->internal.timer);
 146
 147         req->internal.state = state;
 148         req->internal.finish_location = location;
 149
 150         tevent_req_cleanup(req);
 151
 152         _tevent_req_notify_callback(req, location);
 153 }
 154
 155 void _tevent_req_done(struct tevent_req *req,
 156                       const char *location)
 157 {
 158         tevent_req_finish(req, TEVENT_REQ_DONE, location);
 159 }
 160
 161 bool _tevent_req_error(struct tevent_req *req,
 162                        uint64_t error,
 163                        const char *location)
 164 {
 165         if (error == 0) {
 166                 return false;
 167         }
 168
 169         req->internal.error = error;
 170         tevent_req_finish(req, TEVENT_REQ_USER_ERROR, location);
 171         return true;
 172 }
 173
 174 void _tevent_req_oom(struct tevent_req *req, const char *location)
 175 {
 176         tevent_req_finish(req, TEVENT_REQ_NO_MEMORY, location);
 177 }
 178
 179 bool _tevent_req_nomem(const void *p,
 180                        struct tevent_req *req,
 181                        const char *location)
 182 {
 183         if (p != NULL) {
 184                 return false;
 185         }
 186         _tevent_req_oom(req, location);
 187         return true;
 188 }
 189
 190 /**
 191  * @internal
 192  *
 193  * @brief Immediate event callback.
 194  *
 195  * @param[in]  ev       The event context to use.
 196  *
 197  * @param[in]  im       The immediate event.
 198  *
 199  * @param[in]  priv     The async request to be finished.
 200  */
 201 static void tevent_req_trigger(struct tevent_context *ev,
 202                                struct tevent_immediate *im,
 203                                void *private_data)
 204 {
 205         struct tevent_req *req =
 206                 talloc_get_type_abort(private_data,
 207                 struct tevent_req);
 208
 209         tevent_req_finish(req, req->internal.state,
 210                           req->internal.finish_location);
 211 }
 212
 213 struct tevent_req *tevent_req_post(struct tevent_req *req,
 214                                    struct tevent_context *ev)
 215 {
 216         tevent_schedule_immediate(req->internal.trigger,
 217                                   ev, tevent_req_trigger, req);
 218         return req;
 219 }
 220
 221 void tevent_req_defer_callback(struct tevent_req *req,
 222                                struct tevent_context *ev)
 223 {
 224         req->internal.defer_callback_ev = ev;
 225 }
 226
 227 bool tevent_req_is_in_progress(struct tevent_req *req)
 228 {
 229         if (req->internal.state == TEVENT_REQ_IN_PROGRESS) {
 230                 return true;
 231         }
 232
 233         return false;
 234 }
 235
 236 void tevent_req_received(struct tevent_req *req)
 237 {
 238         talloc_set_destructor(req, NULL);
 239
 240         req->private_print = NULL;
 241         req->private_cancel = NULL;
 242
 243         TALLOC_FREE(req->internal.trigger);
 244         TALLOC_FREE(req->internal.timer);
 245
 246         req->internal.state = TEVENT_REQ_RECEIVED;
 247
 248         tevent_req_cleanup(req);
 249
 250         TALLOC_FREE(req->data);
 251 }
 252
 253 bool tevent_req_poll(struct tevent_req *req,
 254                      struct tevent_context *ev)
 255 {
 256         while (tevent_req_is_in_progress(req)) {
 257                 int ret;
 258
 259                 ret = tevent_loop_once(ev);
 260                 if (ret != 0) {
 261                         return false;
 262                 }
 263         }
 264
 265         return true;
 266 }
 267
 268 bool tevent_req_is_error(struct tevent_req *req, enum tevent_req_state *state,
 269                         uint64_t *error)
 270 {
 271         if (req->internal.state == TEVENT_REQ_DONE) {
 272                 return false;
 273         }
 274         if (req->internal.state == TEVENT_REQ_USER_ERROR) {
 275                 *error = req->internal.error;
 276         }
 277         *state = req->internal.state;
 278         return true;
 279 }
 280
 281 static void tevent_req_timedout(struct tevent_context *ev,
 282                                struct tevent_timer *te,
 283                                struct timeval now,
 284                                void *private_data)
 285 {
 286         struct tevent_req *req =
 287                 talloc_get_type_abort(private_data,
 288                 struct tevent_req);
 289
 290         TALLOC_FREE(req->internal.timer);
 291
 292         tevent_req_finish(req, TEVENT_REQ_TIMED_OUT, __FUNCTION__);
 293 }
 294
 295 bool tevent_req_set_endtime(struct tevent_req *req,
 296                             struct tevent_context *ev,
 297                             struct timeval endtime)
 298 {
 299         TALLOC_FREE(req->internal.timer);
 300
 301         req->internal.timer = tevent_add_timer(ev, req, endtime,
 302                                                tevent_req_timedout,
 303                                                req);
 304         if (tevent_req_nomem(req->internal.timer, req)) {
 305                 return false;
 306         }
 307
 308         return true;
 309 }
 310
 311 void tevent_req_set_callback(struct tevent_req *req, tevent_req_fn fn, void *pvt)
 312 {
 313         req->async.fn = fn;
 314         req->async.private_data = pvt;
 315 }
 316
 317 void *_tevent_req_callback_data(struct tevent_req *req)
 318 {
 319         return req->async.private_data;
 320 }
 321
 322 void *_tevent_req_data(struct tevent_req *req)
 323 {
 324         return req->data;
 325 }
 326
 327 void tevent_req_set_print_fn(struct tevent_req *req, tevent_req_print_fn fn)
 328 {
 329         req->private_print = fn;
 330 }
 331
 332 void tevent_req_set_cancel_fn(struct tevent_req *req, tevent_req_cancel_fn fn)
 333 {
 334         req->private_cancel = fn;
 335 }
 336
 337 bool _tevent_req_cancel(struct tevent_req *req, const char *location)
 338 {
 339         if (req->private_cancel == NULL) {
 340                 return false;
 341         }
 342
 343         return req->private_cancel(req);
 344 }
 345
 346 void tevent_req_set_cleanup_fn(struct tevent_req *req, tevent_req_cleanup_fn fn)
 347 {
 348         req->private_cleanup.state = req->internal.state;
 349         req->private_cleanup.fn = fn;
 350 }