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 Internal state of the request
  78          *
  79          * Callers should only access this via functions and never directly.
  80          */
  81         struct {
  82                 /**
  83                  * @brief The talloc type of the data pointer
  84                  *
  85                  * This is filled by the tevent_req_create() macro.
  86                  *
  87                  * This for debugging only.
  88                  */
  89                 const char *private_type;
  90
  91                 /**
  92                  * @brief The location where the request was created
  93                  *
  94                  * This uses the __location__ macro via the tevent_req_create()
  95                  * macro.
  96                  *
  97                  * This for debugging only.
  98                  */
  99                 const char *create_location;
 100
 101                 /**
 102                  * @brief The location where the request was finished
 103                  *
 104                  * This uses the __location__ macro via the tevent_req_done(),
 105                  * tevent_req_error() or tevent_req_nomem() macro.
 106                  *
 107                  * This for debugging only.
 108                  */
 109                 const char *finish_location;
 110
 111                 /**
 112                  * @brief The location where the request was canceled
 113                  *
 114                  * This uses the __location__ macro via the
 115                  * tevent_req_cancel() macro.
 116                  *
 117                  * This for debugging only.
 118                  */
 119                 const char *cancel_location;
 120
 121                 /**
 122                  * @brief The external state - will be queried by the caller
 123                  *
 124                  * While the async request is being processed, state will remain in
 125                  * TEVENT_REQ_IN_PROGRESS. A request is finished if
 126                  * req->state>=TEVENT_REQ_DONE.
 127                  */
 128                 enum tevent_req_state state;
 129
 130                 /**
 131                  * @brief status code when finished
 132                  *
 133                  * This status can be queried in the async completion function. It
 134                  * will be set to 0 when everything went fine.
 135                  */
 136                 uint64_t error;
 137
 138                 /**
 139                  * @brief the immediate event used by tevent_req_post
 140                  *
 141                  */
 142                 struct tevent_immediate *trigger;
 143
 144                 /**
 145                  * @brief the timer event if tevent_req_set_endtime was used
 146                  *
 147                  */
 148                 struct tevent_timer *timer;
 149         } internal;
 150 };
 151
 152 struct tevent_fd {
 153         struct tevent_fd *prev, *next;
 154         struct tevent_context *event_ctx;
 155         int fd;
 156         uint16_t flags; /* see TEVENT_FD_* flags */
 157         tevent_fd_handler_t handler;
 158         tevent_fd_close_fn_t close_fn;
 159         /* this is private for the specific handler */
 160         void *private_data;
 161         /* this is for debugging only! */
 162         const char *handler_name;
 163         const char *location;
 164         /* this is private for the events_ops implementation */
 165         uint16_t additional_flags;
 166         void *additional_data;
 167 };
 168
 169 struct tevent_timer {
 170         struct tevent_timer *prev, *next;
 171         struct tevent_context *event_ctx;
 172         struct timeval next_event;
 173         tevent_timer_handler_t handler;
 174         /* this is private for the specific handler */
 175         void *private_data;
 176         /* this is for debugging only! */
 177         const char *handler_name;
 178         const char *location;
 179         /* this is private for the events_ops implementation */
 180         void *additional_data;
 181 };
 182
 183 struct tevent_immediate {
 184         struct tevent_immediate *prev, *next;
 185         struct tevent_context *event_ctx;
 186         tevent_immediate_handler_t handler;
 187         /* this is private for the specific handler */
 188         void *private_data;
 189         /* this is for debugging only! */
 190         const char *handler_name;
 191         const char *create_location;
 192         const char *schedule_location;
 193         /* this is private for the events_ops implementation */
 194         void (*cancel_fn)(struct tevent_immediate *im);
 195         void *additional_data;
 196 };
 197
 198 struct tevent_signal {
 199         struct tevent_signal *prev, *next;
 200         struct tevent_context *event_ctx;
 201         int signum;
 202         int sa_flags;
 203         tevent_signal_handler_t handler;
 204         /* this is private for the specific handler */
 205         void *private_data;
 206         /* this is for debugging only! */
 207         const char *handler_name;
 208         const char *location;
 209         /* this is private for the events_ops implementation */
 210         void *additional_data;
 211 };
 212
 213 struct tevent_debug_ops {
 214         void (*debug)(void *context, enum tevent_debug_level level,
 215                       const char *fmt, va_list ap) PRINTF_ATTRIBUTE(3,0);
 216         void *context;
 217 };
 218
 219 void tevent_debug(struct tevent_context *ev, enum tevent_debug_level level,
 220                   const char *fmt, ...) PRINTF_ATTRIBUTE(3,4);
 221
 222 struct tevent_context {
 223         /* the specific events implementation */
 224         const struct tevent_ops *ops;
 225
 226         /* list of fd events - used by common code */
 227         struct tevent_fd *fd_events;
 228
 229         /* list of timed events - used by common code */
 230         struct tevent_timer *timer_events;
 231
 232         /* list of immediate events - used by common code */
 233         struct tevent_immediate *immediate_events;
 234
 235         /* list of signal events - used by common code */
 236         struct tevent_signal *signal_events;
 237
 238         /* this is private for the events_ops implementation */
 239         void *additional_data;
 240
 241         /* pipe hack used with signal handlers */
 242         struct tevent_fd *pipe_fde;
 243         int pipe_fds[2];
 244
 245         /* debugging operations */
 246         struct tevent_debug_ops debug_ops;
 247
 248         /* info about the nesting status */
 249         struct {
 250                 bool allowed;
 251                 uint32_t level;
 252                 tevent_nesting_hook hook_fn;
 253                 void *hook_private;
 254         } nesting;
 255 };
 256
 257
 258 int tevent_common_context_destructor(struct tevent_context *ev);
 259 int tevent_common_loop_wait(struct tevent_context *ev,
 260                             const char *location);
 261
 262 int tevent_common_fd_destructor(struct tevent_fd *fde);
 263 struct tevent_fd *tevent_common_add_fd(struct tevent_context *ev,
 264                                        TALLOC_CTX *mem_ctx,
 265                                        int fd,
 266                                        uint16_t flags,
 267                                        tevent_fd_handler_t handler,
 268                                        void *private_data,
 269                                        const char *handler_name,
 270                                        const char *location);
 271 void tevent_common_fd_set_close_fn(struct tevent_fd *fde,
 272                                    tevent_fd_close_fn_t close_fn);
 273 uint16_t tevent_common_fd_get_flags(struct tevent_fd *fde);
 274 void tevent_common_fd_set_flags(struct tevent_fd *fde, uint16_t flags);
 275
 276 struct tevent_timer *tevent_common_add_timer(struct tevent_context *ev,
 277                                              TALLOC_CTX *mem_ctx,
 278                                              struct timeval next_event,
 279                                              tevent_timer_handler_t handler,
 280                                              void *private_data,
 281                                              const char *handler_name,
 282                                              const char *location);
 283 struct timeval tevent_common_loop_timer_delay(struct tevent_context *);
 284
 285 void tevent_common_schedule_immediate(struct tevent_immediate *im,
 286                                       struct tevent_context *ev,
 287                                       tevent_immediate_handler_t handler,
 288                                       void *private_data,
 289                                       const char *handler_name,
 290                                       const char *location);
 291 bool tevent_common_loop_immediate(struct tevent_context *ev);
 292
 293 struct tevent_signal *tevent_common_add_signal(struct tevent_context *ev,
 294                                                TALLOC_CTX *mem_ctx,
 295                                                int signum,
 296                                                int sa_flags,
 297                                                tevent_signal_handler_t handler,
 298                                                void *private_data,
 299                                                const char *handler_name,
 300                                                const char *location);
 301 int tevent_common_check_signal(struct tevent_context *ev);
 302
 303 bool tevent_standard_init(void);
 304 bool tevent_select_init(void);
 305 #ifdef HAVE_EPOLL
 306 bool tevent_epoll_init(void);
 307 #endif