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 struct tevent_req *_tevent_req_create(TALLOC_CTX *mem_ctx,
  55                                     void *pdata,
  56                                     size_t data_size,
  57                                     const char *type,
  58                                     const char *location)
  59 {
  60         struct tevent_req *req;
  61         void **ppdata = (void **)pdata;
  62         void *data;
  63
  64         req = talloc_pooled_object(
  65                 mem_ctx, struct tevent_req, 2,
  66                 sizeof(struct tevent_immediate) + data_size);
  67         if (req == NULL) {
  68                 return NULL;
  69         }
  70         ZERO_STRUCTP(req);
  71         req->internal.private_type      = type;
  72         req->internal.create_location   = location;
  73         req->internal.state             = TEVENT_REQ_IN_PROGRESS;
  74         req->internal.trigger           = tevent_create_immediate(req);
  75         if (!req->internal.trigger) {
  76                 talloc_free(req);
  77                 return NULL;
  78         }
  79
  80         data = talloc_zero_size(req, data_size);
  81         if (data == NULL) {
  82                 talloc_free(req);
  83                 return NULL;
  84         }
  85         talloc_set_name_const(data, type);
  86
  87         req->data = data;
  88
  89         *ppdata = data;
  90         return req;
  91 }
  92
  93 void _tevent_req_notify_callback(struct tevent_req *req, const char *location)
  94 {
  95         req->internal.finish_location = location;
  96         if (req->internal.defer_callback_ev) {
  97                 (void)tevent_req_post(req, req->internal.defer_callback_ev);
  98                 req->internal.defer_callback_ev = NULL;
  99                 return;
 100         }
 101         if (req->async.fn != NULL) {
 102                 req->async.fn(req);
 103         }
 104 }
 105
 106 static void tevent_req_finish(struct tevent_req *req,
 107                               enum tevent_req_state state,
 108                               const char *location)
 109 {
 110         /*
 111          * make sure we do not timeout after
 112          * the request was already finished
 113          */
 114         TALLOC_FREE(req->internal.timer);
 115
 116         req->internal.state = state;
 117         _tevent_req_notify_callback(req, location);
 118 }
 119
 120 void _tevent_req_done(struct tevent_req *req,
 121                       const char *location)
 122 {
 123         tevent_req_finish(req, TEVENT_REQ_DONE, location);
 124 }
 125
 126 bool _tevent_req_error(struct tevent_req *req,
 127                        uint64_t error,
 128                        const char *location)
 129 {
 130         if (error == 0) {
 131                 return false;
 132         }
 133
 134         req->internal.error = error;
 135         tevent_req_finish(req, TEVENT_REQ_USER_ERROR, location);
 136         return true;
 137 }
 138
 139 void _tevent_req_oom(struct tevent_req *req, const char *location)
 140 {
 141         tevent_req_finish(req, TEVENT_REQ_NO_MEMORY, location);
 142 }
 143
 144 bool _tevent_req_nomem(const void *p,
 145                        struct tevent_req *req,
 146                        const char *location)
 147 {
 148         if (p != NULL) {
 149                 return false;
 150         }
 151         _tevent_req_oom(req, location);
 152         return true;
 153 }
 154
 155 /**
 156  * @internal
 157  *
 158  * @brief Immediate event callback.
 159  *
 160  * @param[in]  ev       The event context to use.
 161  *
 162  * @param[in]  im       The immediate event.
 163  *
 164  * @param[in]  priv     The async request to be finished.
 165  */
 166 static void tevent_req_trigger(struct tevent_context *ev,
 167                                struct tevent_immediate *im,
 168                                void *private_data)
 169 {
 170         struct tevent_req *req =
 171                 talloc_get_type_abort(private_data,
 172                 struct tevent_req);
 173
 174         tevent_req_finish(req, req->internal.state,
 175                           req->internal.finish_location);
 176 }
 177
 178 struct tevent_req *tevent_req_post(struct tevent_req *req,
 179                                    struct tevent_context *ev)
 180 {
 181         tevent_schedule_immediate(req->internal.trigger,
 182                                   ev, tevent_req_trigger, req);
 183         return req;
 184 }
 185
 186 void tevent_req_defer_callback(struct tevent_req *req,
 187                                struct tevent_context *ev)
 188 {
 189         req->internal.defer_callback_ev = ev;
 190 }
 191
 192 bool tevent_req_is_in_progress(struct tevent_req *req)
 193 {
 194         if (req->internal.state == TEVENT_REQ_IN_PROGRESS) {
 195                 return true;
 196         }
 197
 198         return false;
 199 }
 200
 201 void tevent_req_received(struct tevent_req *req)
 202 {
 203         TALLOC_FREE(req->data);
 204         req->private_print = NULL;
 205         req->private_cancel = NULL;
 206
 207         TALLOC_FREE(req->internal.trigger);
 208         TALLOC_FREE(req->internal.timer);
 209
 210         req->internal.state = TEVENT_REQ_RECEIVED;
 211 }
 212
 213 bool tevent_req_poll(struct tevent_req *req,
 214                      struct tevent_context *ev)
 215 {
 216         while (tevent_req_is_in_progress(req)) {
 217                 int ret;
 218
 219                 ret = tevent_loop_once(ev);
 220                 if (ret != 0) {
 221                         return false;
 222                 }
 223         }
 224
 225         return true;
 226 }
 227
 228 bool tevent_req_is_error(struct tevent_req *req, enum tevent_req_state *state,
 229                         uint64_t *error)
 230 {
 231         if (req->internal.state == TEVENT_REQ_DONE) {
 232                 return false;
 233         }
 234         if (req->internal.state == TEVENT_REQ_USER_ERROR) {
 235                 *error = req->internal.error;
 236         }
 237         *state = req->internal.state;
 238         return true;
 239 }
 240
 241 static void tevent_req_timedout(struct tevent_context *ev,
 242                                struct tevent_timer *te,
 243                                struct timeval now,
 244                                void *private_data)
 245 {
 246         struct tevent_req *req =
 247                 talloc_get_type_abort(private_data,
 248                 struct tevent_req);
 249
 250         TALLOC_FREE(req->internal.timer);
 251
 252         tevent_req_finish(req, TEVENT_REQ_TIMED_OUT, __FUNCTION__);
 253 }
 254
 255 bool tevent_req_set_endtime(struct tevent_req *req,
 256                             struct tevent_context *ev,
 257                             struct timeval endtime)
 258 {
 259         TALLOC_FREE(req->internal.timer);
 260
 261         req->internal.timer = tevent_add_timer(ev, req, endtime,
 262                                                tevent_req_timedout,
 263                                                req);
 264         if (tevent_req_nomem(req->internal.timer, req)) {
 265                 return false;
 266         }
 267
 268         return true;
 269 }
 270
 271 void tevent_req_set_callback(struct tevent_req *req, tevent_req_fn fn, void *pvt)
 272 {
 273         req->async.fn = fn;
 274         req->async.private_data = pvt;
 275 }
 276
 277 void *_tevent_req_callback_data(struct tevent_req *req)
 278 {
 279         return req->async.private_data;
 280 }
 281
 282 void *_tevent_req_data(struct tevent_req *req)
 283 {
 284         return req->data;
 285 }
 286
 287 void tevent_req_set_print_fn(struct tevent_req *req, tevent_req_print_fn fn)
 288 {
 289         req->private_print = fn;
 290 }
 291
 292 void tevent_req_set_cancel_fn(struct tevent_req *req, tevent_req_cancel_fn fn)
 293 {
 294         req->private_cancel = fn;
 295 }
 296
 297 bool _tevent_req_cancel(struct tevent_req *req, const char *location)
 298 {
 299         if (req->private_cancel == NULL) {
 300                 return false;
 301         }
 302
 303         return req->private_cancel(req);
 304 }