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         ZERO_STRUCTP(req);
  73         req->internal.private_type      = type;
  74         req->internal.create_location   = location;
  75         req->internal.state             = TEVENT_REQ_IN_PROGRESS;
  76         req->internal.trigger           = tevent_create_immediate(req);
  77         if (!req->internal.trigger) {
  78                 talloc_free(req);
  79                 return NULL;
  80         }
  81
  82         data = talloc_zero_size(req, data_size);
  83         if (data == NULL) {
  84                 talloc_free(req);
  85                 return NULL;
  86         }
  87         talloc_set_name_const(data, type);
  88
  89         req->data = data;
  90
  91         talloc_set_destructor(req, tevent_req_destructor);
  92
  93         *ppdata = data;
  94         return req;
  95 }
  96
  97 static int tevent_req_destructor(struct tevent_req *req)
  98 {
  99         tevent_req_received(req);
 100         return 0;
 101 }
 102
 103 void _tevent_req_notify_callback(struct tevent_req *req, const char *location)
 104 {
 105         req->internal.finish_location = location;
 106         if (req->internal.defer_callback_ev) {
 107                 (void)tevent_req_post(req, req->internal.defer_callback_ev);
 108                 req->internal.defer_callback_ev = NULL;
 109                 return;
 110         }
 111         if (req->async.fn != NULL) {
 112                 req->async.fn(req);
 113         }
 114 }
 115
 116 static void tevent_req_cleanup(struct tevent_req *req)
 117 {
 118         if (req->private_cleanup.fn == NULL) {
 119                 return;
 120         }
 121
 122         if (req->private_cleanup.state >= req->internal.state) {
 123                 /*
 124                  * Don't call the cleanup_function multiple times for the same
 125                  * state recursively
 126                  */
 127                 return;
 128         }
 129
 130         req->private_cleanup.state = req->internal.state;
 131         req->private_cleanup.fn(req, req->internal.state);
 132 }
 133
 134 static void tevent_req_finish(struct tevent_req *req,
 135                               enum tevent_req_state state,
 136                               const char *location)
 137 {
 138         /*
 139          * make sure we do not timeout after
 140          * the request was already finished
 141          */
 142         TALLOC_FREE(req->internal.timer);
 143
 144         req->internal.state = state;
 145         req->internal.finish_location = location;
 146
 147         tevent_req_cleanup(req);
 148
 149         _tevent_req_notify_callback(req, location);
 150 }
 151
 152 void _tevent_req_done(struct tevent_req *req,
 153                       const char *location)
 154 {
 155         tevent_req_finish(req, TEVENT_REQ_DONE, location);
 156 }
 157
 158 bool _tevent_req_error(struct tevent_req *req,
 159                        uint64_t error,
 160                        const char *location)
 161 {
 162         if (error == 0) {
 163                 return false;
 164         }
 165
 166         req->internal.error = error;
 167         tevent_req_finish(req, TEVENT_REQ_USER_ERROR, location);
 168         return true;
 169 }
 170
 171 void _tevent_req_oom(struct tevent_req *req, const char *location)
 172 {
 173         tevent_req_finish(req, TEVENT_REQ_NO_MEMORY, location);
 174 }
 175
 176 bool _tevent_req_nomem(const void *p,
 177                        struct tevent_req *req,
 178                        const char *location)
 179 {
 180         if (p != NULL) {
 181                 return false;
 182         }
 183         _tevent_req_oom(req, location);
 184         return true;
 185 }
 186
 187 /**
 188  * @internal
 189  *
 190  * @brief Immediate event callback.
 191  *
 192  * @param[in]  ev       The event context to use.
 193  *
 194  * @param[in]  im       The immediate event.
 195  *
 196  * @param[in]  priv     The async request to be finished.
 197  */
 198 static void tevent_req_trigger(struct tevent_context *ev,
 199                                struct tevent_immediate *im,
 200                                void *private_data)
 201 {
 202         struct tevent_req *req =
 203                 talloc_get_type_abort(private_data,
 204                 struct tevent_req);
 205
 206         tevent_req_finish(req, req->internal.state,
 207                           req->internal.finish_location);
 208 }
 209
 210 struct tevent_req *tevent_req_post(struct tevent_req *req,
 211                                    struct tevent_context *ev)
 212 {
 213         tevent_schedule_immediate(req->internal.trigger,
 214                                   ev, tevent_req_trigger, req);
 215         return req;
 216 }
 217
 218 void tevent_req_defer_callback(struct tevent_req *req,
 219                                struct tevent_context *ev)
 220 {
 221         req->internal.defer_callback_ev = ev;
 222 }
 223
 224 bool tevent_req_is_in_progress(struct tevent_req *req)
 225 {
 226         if (req->internal.state == TEVENT_REQ_IN_PROGRESS) {
 227                 return true;
 228         }
 229
 230         return false;
 231 }
 232
 233 void tevent_req_received(struct tevent_req *req)
 234 {
 235         talloc_set_destructor(req, NULL);
 236
 237         req->private_print = NULL;
 238         req->private_cancel = NULL;
 239
 240         TALLOC_FREE(req->internal.trigger);
 241         TALLOC_FREE(req->internal.timer);
 242
 243         req->internal.state = TEVENT_REQ_RECEIVED;
 244
 245         tevent_req_cleanup(req);
 246
 247         TALLOC_FREE(req->data);
 248 }
 249
 250 bool tevent_req_poll(struct tevent_req *req,
 251                      struct tevent_context *ev)
 252 {
 253         while (tevent_req_is_in_progress(req)) {
 254                 int ret;
 255
 256                 ret = tevent_loop_once(ev);
 257                 if (ret != 0) {
 258                         return false;
 259                 }
 260         }
 261
 262         return true;
 263 }
 264
 265 bool tevent_req_is_error(struct tevent_req *req, enum tevent_req_state *state,
 266                         uint64_t *error)
 267 {
 268         if (req->internal.state == TEVENT_REQ_DONE) {
 269                 return false;
 270         }
 271         if (req->internal.state == TEVENT_REQ_USER_ERROR) {
 272                 *error = req->internal.error;
 273         }
 274         *state = req->internal.state;
 275         return true;
 276 }
 277
 278 static void tevent_req_timedout(struct tevent_context *ev,
 279                                struct tevent_timer *te,
 280                                struct timeval now,
 281                                void *private_data)
 282 {
 283         struct tevent_req *req =
 284                 talloc_get_type_abort(private_data,
 285                 struct tevent_req);
 286
 287         TALLOC_FREE(req->internal.timer);
 288
 289         tevent_req_finish(req, TEVENT_REQ_TIMED_OUT, __FUNCTION__);
 290 }
 291
 292 bool tevent_req_set_endtime(struct tevent_req *req,
 293                             struct tevent_context *ev,
 294                             struct timeval endtime)
 295 {
 296         TALLOC_FREE(req->internal.timer);
 297
 298         req->internal.timer = tevent_add_timer(ev, req, endtime,
 299                                                tevent_req_timedout,
 300                                                req);
 301         if (tevent_req_nomem(req->internal.timer, req)) {
 302                 return false;
 303         }
 304
 305         return true;
 306 }
 307
 308 void tevent_req_set_callback(struct tevent_req *req, tevent_req_fn fn, void *pvt)
 309 {
 310         req->async.fn = fn;
 311         req->async.private_data = pvt;
 312 }
 313
 314 void *_tevent_req_callback_data(struct tevent_req *req)
 315 {
 316         return req->async.private_data;
 317 }
 318
 319 void *_tevent_req_data(struct tevent_req *req)
 320 {
 321         return req->data;
 322 }
 323
 324 void tevent_req_set_print_fn(struct tevent_req *req, tevent_req_print_fn fn)
 325 {
 326         req->private_print = fn;
 327 }
 328
 329 void tevent_req_set_cancel_fn(struct tevent_req *req, tevent_req_cancel_fn fn)
 330 {
 331         req->private_cancel = fn;
 332 }
 333
 334 bool _tevent_req_cancel(struct tevent_req *req, const char *location)
 335 {
 336         if (req->private_cancel == NULL) {
 337                 return false;
 338         }
 339
 340         return req->private_cancel(req);
 341 }
 342
 343 void tevent_req_set_cleanup_fn(struct tevent_req *req, tevent_req_cleanup_fn fn)
 344 {
 345         req->private_cleanup.state = req->internal.state;
 346         req->private_cleanup.fn = fn;
 347 }