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         size_t payload;
  66
  67         payload = sizeof(struct tevent_immediate) + data_size;
  68         if (payload < sizeof(struct tevent_immediate)) {
  69                 /* overflow */
  70                 return NULL;
  71         }
  72
  73         req = talloc_pooled_object(
  74                 mem_ctx, struct tevent_req, 2,
  75                 sizeof(struct tevent_immediate) + data_size);
  76         if (req == NULL) {
  77                 return NULL;
  78         }
  79
  80         *req = (struct tevent_req) {
  81                 .internal.private_type          = type,
  82                 .internal.create_location       = location,
  83                 .internal.state                 = TEVENT_REQ_IN_PROGRESS,
  84                 .internal.trigger               = tevent_create_immediate(req)
  85         };
  86
  87         data = talloc_zero_size(req, data_size);
  88
  89         /*
  90          * No need to check for req->internal.trigger!=NULL or
  91          * data!=NULL, this can't fail: talloc_pooled_object has
  92          * already allocated sufficient memory.
  93          */
  94
  95         talloc_set_name_const(data, type);
  96
  97         req->data = data;
  98
  99         talloc_set_destructor(req, tevent_req_destructor);
 100
 101         *ppdata = data;
 102         return req;
 103 }
 104
 105 static int tevent_req_destructor(struct tevent_req *req)
 106 {
 107         tevent_req_received(req);
 108         return 0;
 109 }
 110
 111 void _tevent_req_notify_callback(struct tevent_req *req, const char *location)
 112 {
 113         req->internal.finish_location = location;
 114         if (req->internal.defer_callback_ev) {
 115                 (void)tevent_req_post(req, req->internal.defer_callback_ev);
 116                 req->internal.defer_callback_ev = NULL;
 117                 return;
 118         }
 119         if (req->async.fn != NULL) {
 120                 req->async.fn(req);
 121         }
 122 }
 123
 124 static void tevent_req_cleanup(struct tevent_req *req)
 125 {
 126         if (req->private_cleanup.fn == NULL) {
 127                 return;
 128         }
 129
 130         if (req->private_cleanup.state >= req->internal.state) {
 131                 /*
 132                  * Don't call the cleanup_function multiple times for the same
 133                  * state recursively
 134                  */
 135                 return;
 136         }
 137
 138         req->private_cleanup.state = req->internal.state;
 139         req->private_cleanup.fn(req, req->internal.state);
 140 }
 141
 142 static void tevent_req_finish(struct tevent_req *req,
 143                               enum tevent_req_state state,
 144                               const char *location)
 145 {
 146         /*
 147          * make sure we do not timeout after
 148          * the request was already finished
 149          */
 150         TALLOC_FREE(req->internal.timer);
 151
 152         req->internal.state = state;
 153         req->internal.finish_location = location;
 154
 155         tevent_req_cleanup(req);
 156
 157         _tevent_req_notify_callback(req, location);
 158 }
 159
 160 void _tevent_req_done(struct tevent_req *req,
 161                       const char *location)
 162 {
 163         tevent_req_finish(req, TEVENT_REQ_DONE, location);
 164 }
 165
 166 bool _tevent_req_error(struct tevent_req *req,
 167                        uint64_t error,
 168                        const char *location)
 169 {
 170         if (error == 0) {
 171                 return false;
 172         }
 173
 174         req->internal.error = error;
 175         tevent_req_finish(req, TEVENT_REQ_USER_ERROR, location);
 176         return true;
 177 }
 178
 179 void _tevent_req_oom(struct tevent_req *req, const char *location)
 180 {
 181         tevent_req_finish(req, TEVENT_REQ_NO_MEMORY, location);
 182 }
 183
 184 bool _tevent_req_nomem(const void *p,
 185                        struct tevent_req *req,
 186                        const char *location)
 187 {
 188         if (p != NULL) {
 189                 return false;
 190         }
 191         _tevent_req_oom(req, location);
 192         return true;
 193 }
 194
 195 /**
 196  * @internal
 197  *
 198  * @brief Immediate event callback.
 199  *
 200  * @param[in]  ev       The event context to use.
 201  *
 202  * @param[in]  im       The immediate event.
 203  *
 204  * @param[in]  priv     The async request to be finished.
 205  */
 206 static void tevent_req_trigger(struct tevent_context *ev,
 207                                struct tevent_immediate *im,
 208                                void *private_data)
 209 {
 210         struct tevent_req *req =
 211                 talloc_get_type_abort(private_data,
 212                 struct tevent_req);
 213
 214         tevent_req_finish(req, req->internal.state,
 215                           req->internal.finish_location);
 216 }
 217
 218 struct tevent_req *tevent_req_post(struct tevent_req *req,
 219                                    struct tevent_context *ev)
 220 {
 221         tevent_schedule_immediate(req->internal.trigger,
 222                                   ev, tevent_req_trigger, req);
 223         return req;
 224 }
 225
 226 void tevent_req_defer_callback(struct tevent_req *req,
 227                                struct tevent_context *ev)
 228 {
 229         req->internal.defer_callback_ev = ev;
 230 }
 231
 232 bool tevent_req_is_in_progress(struct tevent_req *req)
 233 {
 234         if (req->internal.state == TEVENT_REQ_IN_PROGRESS) {
 235                 return true;
 236         }
 237
 238         return false;
 239 }
 240
 241 void tevent_req_received(struct tevent_req *req)
 242 {
 243         talloc_set_destructor(req, NULL);
 244
 245         req->private_print = NULL;
 246         req->private_cancel = NULL;
 247
 248         TALLOC_FREE(req->internal.trigger);
 249         TALLOC_FREE(req->internal.timer);
 250
 251         req->internal.state = TEVENT_REQ_RECEIVED;
 252
 253         tevent_req_cleanup(req);
 254
 255         TALLOC_FREE(req->data);
 256 }
 257
 258 bool tevent_req_poll(struct tevent_req *req,
 259                      struct tevent_context *ev)
 260 {
 261         while (tevent_req_is_in_progress(req)) {
 262                 int ret;
 263
 264                 ret = tevent_loop_once(ev);
 265                 if (ret != 0) {
 266                         return false;
 267                 }
 268         }
 269
 270         return true;
 271 }
 272
 273 bool tevent_req_is_error(struct tevent_req *req, enum tevent_req_state *state,
 274                         uint64_t *error)
 275 {
 276         if (req->internal.state == TEVENT_REQ_DONE) {
 277                 return false;
 278         }
 279         if (req->internal.state == TEVENT_REQ_USER_ERROR) {
 280                 *error = req->internal.error;
 281         }
 282         *state = req->internal.state;
 283         return true;
 284 }
 285
 286 static void tevent_req_timedout(struct tevent_context *ev,
 287                                struct tevent_timer *te,
 288                                struct timeval now,
 289                                void *private_data)
 290 {
 291         struct tevent_req *req =
 292                 talloc_get_type_abort(private_data,
 293                 struct tevent_req);
 294
 295         TALLOC_FREE(req->internal.timer);
 296
 297         tevent_req_finish(req, TEVENT_REQ_TIMED_OUT, __FUNCTION__);
 298 }
 299
 300 bool tevent_req_set_endtime(struct tevent_req *req,
 301                             struct tevent_context *ev,
 302                             struct timeval endtime)
 303 {
 304         TALLOC_FREE(req->internal.timer);
 305
 306         req->internal.timer = tevent_add_timer(ev, req, endtime,
 307                                                tevent_req_timedout,
 308                                                req);
 309         if (tevent_req_nomem(req->internal.timer, req)) {
 310                 return false;
 311         }
 312
 313         return true;
 314 }
 315
 316 void tevent_req_reset_endtime(struct tevent_req *req)
 317 {
 318         TALLOC_FREE(req->internal.timer);
 319 }
 320
 321 void tevent_req_set_callback(struct tevent_req *req, tevent_req_fn fn, void *pvt)
 322 {
 323         req->async.fn = fn;
 324         req->async.private_data = pvt;
 325 }
 326
 327 void *_tevent_req_callback_data(struct tevent_req *req)
 328 {
 329         return req->async.private_data;
 330 }
 331
 332 void *_tevent_req_data(struct tevent_req *req)
 333 {
 334         return req->data;
 335 }
 336
 337 void tevent_req_set_print_fn(struct tevent_req *req, tevent_req_print_fn fn)
 338 {
 339         req->private_print = fn;
 340 }
 341
 342 void tevent_req_set_cancel_fn(struct tevent_req *req, tevent_req_cancel_fn fn)
 343 {
 344         req->private_cancel = fn;
 345 }
 346
 347 bool _tevent_req_cancel(struct tevent_req *req, const char *location)
 348 {
 349         if (req->private_cancel == NULL) {
 350                 return false;
 351         }
 352
 353         return req->private_cancel(req);
 354 }
 355
 356 void tevent_req_set_cleanup_fn(struct tevent_req *req, tevent_req_cleanup_fn fn)
 357 {
 358         req->private_cleanup.state = req->internal.state;
 359         req->private_cleanup.fn = fn;
 360 }