lib/tevent/tevent_internal.h

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    generalised event loop handling
   5
   6    INTERNAL STRUCTS. THERE ARE NO API GUARANTEES.
   7    External users should only ever have to include this header when
   8    implementing new tevent backends.
   9
  10    Copyright (C) Stefan Metzmacher 2005-2009
  11
  12      ** NOTE! The following LGPL license applies to the tevent
  13      ** library. This does NOT imply that all of Samba is released
  14      ** under the LGPL
  15
  16    This library is free software; you can redistribute it and/or
  17    modify it under the terms of the GNU Lesser General Public
  18    License as published by the Free Software Foundation; either
  19    version 3 of the License, or (at your option) any later version.
  20
  21    This library is distributed in the hope that it will be useful,
  22    but WITHOUT ANY WARRANTY; without even the implied warranty of
  23    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  24    Lesser General Public License for more details.
  25
  26    You should have received a copy of the GNU Lesser General Public
  27    License along with this library; if not, see <http://www.gnu.org/licenses/>.
  28 */
  29
  30 struct tevent_req {
  31         /**
  32          * @brief What to do on completion
  33          *
  34          * This is used for the user of an async request, fn is called when
  35          * the request completes, either successfully or with an error.
  36          */
  37         struct {
  38                 /**
  39                  * @brief Completion function
  40                  * Completion function, to be filled by the API user
  41                  */
  42                 tevent_req_fn fn;
  43                 /**
  44                  * @brief Private data for the completion function
  45                  */
  46                 void *private_data;
  47         } async;
  48
  49         /**
  50          * @brief Private state pointer for the actual implementation
  51          *
  52          * The implementation doing the work for the async request needs to
  53          * keep around current data like for example a fd event. The user of
  54          * an async request should not touch this.
  55          */
  56         void *data;
  57
  58         /**
  59          * @brief A function to overwrite the default print function
  60          *
  61          * The implementation doing the work may want to implement a
  62          * custom function to print the text representation of the async
  63          * request.
  64          */
  65         tevent_req_print_fn private_print;
  66
  67         /**
  68          * @brief A function to cancel the request
  69          *
  70          * The implementation might want to set a function
  71          * that is called when the tevent_req_cancel() function
  72          * was called.
  73          */
  74         tevent_req_cancel_fn private_cancel;
  75
  76         /**
  77          * @brief A function to cleanup the request
  78          *
  79          * The implementation might want to set a function
  80          * that is called before the tevent_req_done() and tevent_req_error()
  81          * trigger the callers callback function.
  82          */
  83         struct {
  84                 tevent_req_cleanup_fn fn;
  85                 enum tevent_req_state state;
  86         } private_cleanup;
  87
  88         /**
  89          * @brief Internal state of the request
  90          *
  91          * Callers should only access this via functions and never directly.
  92          */
  93         struct {
  94                 /**
  95                  * @brief The talloc type of the data pointer
  96                  *
  97                  * This is filled by the tevent_req_create() macro.
  98                  *
  99                  * This for debugging only.
 100                  */
 101                 const char *private_type;
 102
 103                 /**
 104                  * @brief The location where the request was created
 105                  *
 106                  * This uses the __location__ macro via the tevent_req_create()
 107                  * macro.
 108                  *
 109                  * This for debugging only.
 110                  */
 111                 const char *create_location;
 112
 113                 /**
 114                  * @brief The location where the request was finished
 115                  *
 116                  * This uses the __location__ macro via the tevent_req_done(),
 117                  * tevent_req_error() or tevent_req_nomem() macro.
 118                  *
 119                  * This for debugging only.
 120                  */
 121                 const char *finish_location;
 122
 123                 /**
 124                  * @brief The location where the request was canceled
 125                  *
 126                  * This uses the __location__ macro via the
 127                  * tevent_req_cancel() macro.
 128                  *
 129                  * This for debugging only.
 130                  */
 131                 const char *cancel_location;
 132
 133                 /**
 134                  * @brief The external state - will be queried by the caller
 135                  *
 136                  * While the async request is being processed, state will remain in
 137                  * TEVENT_REQ_IN_PROGRESS. A request is finished if
 138                  * req->state>=TEVENT_REQ_DONE.
 139                  */
 140                 enum tevent_req_state state;
 141
 142                 /**
 143                  * @brief status code when finished
 144                  *
 145                  * This status can be queried in the async completion function. It
 146                  * will be set to 0 when everything went fine.
 147                  */
 148                 uint64_t error;
 149
 150                 /**
 151                  * @brief the immediate event used by tevent_req_post
 152                  *
 153                  */
 154                 struct tevent_immediate *trigger;
 155
 156                 /**
 157                  * @brief An event context which will be used to
 158                  *        defer the _tevent_req_notify_callback().
 159                  */
 160                 struct tevent_context *defer_callback_ev;
 161
 162                 /**
 163                  * @brief the timer event if tevent_req_set_endtime was used
 164                  *
 165                  */
 166                 struct tevent_timer *timer;
 167         } internal;
 168 };
 169
 170 struct tevent_fd {
 171         struct tevent_fd *prev, *next;
 172         struct tevent_context *event_ctx;
 173         int fd;
 174         uint16_t flags; /* see TEVENT_FD_* flags */
 175         tevent_fd_handler_t handler;
 176         tevent_fd_close_fn_t close_fn;
 177         /* this is private for the specific handler */
 178         void *private_data;
 179         /* this is for debugging only! */
 180         const char *handler_name;
 181         const char *location;
 182         /* this is private for the events_ops implementation */
 183         uint64_t additional_flags;
 184         void *additional_data;
 185 };
 186
 187 struct tevent_timer {
 188         struct tevent_timer *prev, *next;
 189         struct tevent_context *event_ctx;
 190         struct timeval next_event;
 191         tevent_timer_handler_t handler;
 192         /* this is private for the specific handler */
 193         void *private_data;
 194         /* this is for debugging only! */
 195         const char *handler_name;
 196         const char *location;
 197         /* this is private for the events_ops implementation */
 198         void *additional_data;
 199 };
 200
 201 struct tevent_immediate {
 202         struct tevent_immediate *prev, *next;
 203         struct tevent_context *event_ctx;
 204         tevent_immediate_handler_t handler;
 205         /* this is private for the specific handler */
 206         void *private_data;
 207         /* this is for debugging only! */
 208         const char *handler_name;
 209         const char *create_location;
 210         const char *schedule_location;
 211         /* this is private for the events_ops implementation */
 212         void (*cancel_fn)(struct tevent_immediate *im);
 213         void *additional_data;
 214 };
 215
 216 struct tevent_signal {
 217         struct tevent_signal *prev, *next;
 218         struct tevent_context *event_ctx;
 219         int signum;
 220         int sa_flags;
 221         tevent_signal_handler_t handler;
 222         /* this is private for the specific handler */
 223         void *private_data;
 224         /* this is for debugging only! */
 225         const char *handler_name;
 226         const char *location;
 227         /* this is private for the events_ops implementation */
 228         void *additional_data;
 229 };
 230
 231 struct tevent_debug_ops {
 232         void (*debug)(void *context, enum tevent_debug_level level,
 233                       const char *fmt, va_list ap) PRINTF_ATTRIBUTE(3,0);
 234         void *context;
 235 };
 236
 237 void tevent_debug(struct tevent_context *ev, enum tevent_debug_level level,
 238                   const char *fmt, ...) PRINTF_ATTRIBUTE(3,4);
 239
 240 struct tevent_context {
 241         /* the specific events implementation */
 242         const struct tevent_ops *ops;
 243
 244         /* list of fd events - used by common code */
 245         struct tevent_fd *fd_events;
 246
 247         /* list of timed events - used by common code */
 248         struct tevent_timer *timer_events;
 249
 250         /* list of immediate events - used by common code */
 251         struct tevent_immediate *immediate_events;
 252
 253         /* list of signal events - used by common code */
 254         struct tevent_signal *signal_events;
 255
 256         /* this is private for the events_ops implementation */
 257         void *additional_data;
 258
 259         /* pipe hack used with signal handlers */
 260         struct tevent_fd *pipe_fde;
 261         int pipe_fds[2];
 262
 263         /* debugging operations */
 264         struct tevent_debug_ops debug_ops;
 265
 266         /* info about the nesting status */
 267         struct {
 268                 bool allowed;
 269                 uint32_t level;
 270                 tevent_nesting_hook hook_fn;
 271                 void *hook_private;
 272         } nesting;
 273
 274         struct {
 275                 tevent_trace_callback_t callback;
 276                 void *private_data;
 277         } tracing;
 278
 279         /*
 280          * an optimization pointer into timer_events
 281          * used by used by common code via
 282          * tevent_common_add_timer_v2()
 283          */
 284         struct tevent_timer *last_zero_timer;
 285 };
 286
 287 const struct tevent_ops *tevent_find_ops_byname(const char *name);
 288
 289 int tevent_common_context_destructor(struct tevent_context *ev);
 290 int tevent_common_loop_wait(struct tevent_context *ev,
 291                             const char *location);
 292
 293 int tevent_common_fd_destructor(struct tevent_fd *fde);
 294 struct tevent_fd *tevent_common_add_fd(struct tevent_context *ev,
 295                                        TALLOC_CTX *mem_ctx,
 296                                        int fd,
 297                                        uint16_t flags,
 298                                        tevent_fd_handler_t handler,
 299                                        void *private_data,
 300                                        const char *handler_name,
 301                                        const char *location);
 302 void tevent_common_fd_set_close_fn(struct tevent_fd *fde,
 303                                    tevent_fd_close_fn_t close_fn);
 304 uint16_t tevent_common_fd_get_flags(struct tevent_fd *fde);
 305 void tevent_common_fd_set_flags(struct tevent_fd *fde, uint16_t flags);
 306
 307 struct tevent_timer *tevent_common_add_timer(struct tevent_context *ev,
 308                                              TALLOC_CTX *mem_ctx,
 309                                              struct timeval next_event,
 310                                              tevent_timer_handler_t handler,
 311                                              void *private_data,
 312                                              const char *handler_name,
 313                                              const char *location);
 314 struct tevent_timer *tevent_common_add_timer_v2(struct tevent_context *ev,
 315                                                 TALLOC_CTX *mem_ctx,
 316                                                 struct timeval next_event,
 317                                                 tevent_timer_handler_t handler,
 318                                                 void *private_data,
 319                                                 const char *handler_name,
 320                                                 const char *location);
 321 struct timeval tevent_common_loop_timer_delay(struct tevent_context *);
 322
 323 void tevent_common_schedule_immediate(struct tevent_immediate *im,
 324                                       struct tevent_context *ev,
 325                                       tevent_immediate_handler_t handler,
 326                                       void *private_data,
 327                                       const char *handler_name,
 328                                       const char *location);
 329 bool tevent_common_loop_immediate(struct tevent_context *ev);
 330
 331 struct tevent_signal *tevent_common_add_signal(struct tevent_context *ev,
 332                                                TALLOC_CTX *mem_ctx,
 333                                                int signum,
 334                                                int sa_flags,
 335                                                tevent_signal_handler_t handler,
 336                                                void *private_data,
 337                                                const char *handler_name,
 338                                                const char *location);
 339 int tevent_common_check_signal(struct tevent_context *ev);
 340 void tevent_cleanup_pending_signal_handlers(struct tevent_signal *se);
 341
 342 bool tevent_standard_init(void);
 343 bool tevent_select_init(void);
 344 bool tevent_poll_init(void);
 345 void tevent_poll_event_add_fd_internal(struct tevent_context *ev,
 346                                        struct tevent_fd *fde);
 347 bool tevent_poll_mt_init(void);
 348 #ifdef HAVE_EPOLL
 349 bool tevent_epoll_init(void);
 350 void tevent_epoll_set_panic_fallback(struct tevent_context *ev,
 351                         bool (*panic_fallback)(struct tevent_context *ev,
 352                                                bool replay));
 353 #endif
 354
 355
 356 void tevent_trace_point_callback(struct tevent_context *ev,
 357                                  enum tevent_trace_point);