lib/tevent/tevent_internal.h

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    generalised event loop handling
   5
   6    Internal structs
   7
   8    Copyright (C) Stefan Metzmacher 2005-2009
   9
  10      ** NOTE! The following LGPL license applies to the tevent
  11      ** library. This does NOT imply that all of Samba is released
  12      ** under the LGPL
  13
  14    This library is free software; you can redistribute it and/or
  15    modify it under the terms of the GNU Lesser General Public
  16    License as published by the Free Software Foundation; either
  17    version 3 of the License, or (at your option) any later version.
  18
  19    This library is distributed in the hope that it will be useful,
  20    but WITHOUT ANY WARRANTY; without even the implied warranty of
  21    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  22    Lesser General Public License for more details.
  23
  24    You should have received a copy of the GNU Lesser General Public
  25    License along with this library; if not, see <http://www.gnu.org/licenses/>.
  26 */
  27
  28 struct tevent_req {
  29         /**
  30          * @brief What to do on completion
  31          *
  32          * This is used for the user of an async request, fn is called when
  33          * the request completes, either successfully or with an error.
  34          */
  35         struct {
  36                 /**
  37                  * @brief Completion function
  38                  * Completion function, to be filled by the API user
  39                  */
  40                 tevent_req_fn fn;
  41                 /**
  42                  * @brief Private data for the completion function
  43                  */
  44                 void *private_data;
  45         } async;
  46
  47         /**
  48          * @brief Private state pointer for the actual implementation
  49          *
  50          * The implementation doing the work for the async request needs to
  51          * keep around current data like for example a fd event. The user of
  52          * an async request should not touch this.
  53          */
  54         void *data;
  55
  56         /**
  57          * @brief A function to overwrite the default print function
  58          *
  59          * The implementation doing the work may want to implement a
  60          * custom function to print the text representation of the async
  61          * request.
  62          */
  63         tevent_req_print_fn private_print;
  64
  65         /**
  66          * @brief Internal state of the request
  67          *
  68          * Callers should only access this via functions and never directly.
  69          */
  70         struct {
  71                 /**
  72                  * @brief The talloc type of the data pointer
  73                  *
  74                  * This is filled by the tevent_req_create() macro.
  75                  *
  76                  * This for debugging only.
  77                  */
  78                 const char *private_type;
  79
  80                 /**
  81                  * @brief The location where the request was created
  82                  *
  83                  * This uses the __location__ macro via the tevent_req_create()
  84                  * macro.
  85                  *
  86                  * This for debugging only.
  87                  */
  88                 const char *location;
  89
  90                 /**
  91                  * @brief The external state - will be queried by the caller
  92                  *
  93                  * While the async request is being processed, state will remain in
  94                  * TEVENT_REQ_IN_PROGRESS. A request is finished if
  95                  * req->state>=TEVENT_REQ_DONE.
  96                  */
  97                 enum tevent_req_state state;
  98
  99                 /**
 100                  * @brief status code when finished
 101                  *
 102                  * This status can be queried in the async completion function. It
 103                  * will be set to 0 when everything went fine.
 104                  */
 105                 uint64_t error;
 106
 107                 /**
 108                  * @brief the timer event if tevent_req_post was used
 109                  *
 110                  */
 111                 struct tevent_timer *trigger;
 112
 113                 /**
 114                  * @brief the timer event if tevent_req_set_timeout was used
 115                  *
 116                  */
 117                 struct tevent_timer *timer;
 118         } internal;
 119 };
 120
 121 struct tevent_ops {
 122         /* conntext init */
 123         int (*context_init)(struct tevent_context *ev);
 124
 125         /* fd_event functions */
 126         struct tevent_fd *(*add_fd)(struct tevent_context *ev,
 127                                     TALLOC_CTX *mem_ctx,
 128                                     int fd, uint16_t flags,
 129                                     tevent_fd_handler_t handler,
 130                                     void *private_data,
 131                                     const char *handler_name,
 132                                     const char *location);
 133         void (*set_fd_close_fn)(struct tevent_fd *fde,
 134                                 tevent_fd_close_fn_t close_fn);
 135         uint16_t (*get_fd_flags)(struct tevent_fd *fde);
 136         void (*set_fd_flags)(struct tevent_fd *fde, uint16_t flags);
 137
 138         /* timed_event functions */
 139         struct tevent_timer *(*add_timer)(struct tevent_context *ev,
 140                                           TALLOC_CTX *mem_ctx,
 141                                           struct timeval next_event,
 142                                           tevent_timer_handler_t handler,
 143                                           void *private_data,
 144                                           const char *handler_name,
 145                                           const char *location);
 146         /* signal functions */
 147         struct tevent_signal *(*add_signal)(struct tevent_context *ev,
 148                                             TALLOC_CTX *mem_ctx,
 149                                             int signum, int sa_flags,
 150                                             tevent_signal_handler_t handler,
 151                                             void *private_data,
 152                                             const char *handler_name,
 153                                             const char *location);
 154
 155         /* loop functions */
 156         int (*loop_once)(struct tevent_context *ev);
 157         int (*loop_wait)(struct tevent_context *ev);
 158 };
 159
 160 struct tevent_fd {
 161         struct tevent_fd *prev, *next;
 162         struct tevent_context *event_ctx;
 163         int fd;
 164         uint16_t flags; /* see TEVENT_FD_* flags */
 165         tevent_fd_handler_t handler;
 166         tevent_fd_close_fn_t close_fn;
 167         /* this is private for the specific handler */
 168         void *private_data;
 169         /* this is for debugging only! */
 170         const char *handler_name;
 171         const char *location;
 172         /* this is private for the events_ops implementation */
 173         uint16_t additional_flags;
 174         void *additional_data;
 175 };
 176
 177 struct tevent_timer {
 178         struct tevent_timer *prev, *next;
 179         struct tevent_context *event_ctx;
 180         struct timeval next_event;
 181         tevent_timer_handler_t handler;
 182         /* this is private for the specific handler */
 183         void *private_data;
 184         /* this is for debugging only! */
 185         const char *handler_name;
 186         const char *location;
 187         /* this is private for the events_ops implementation */
 188         void *additional_data;
 189 };
 190
 191 struct tevent_signal {
 192         struct tevent_signal *prev, *next;
 193         struct tevent_context *event_ctx;
 194         int signum;
 195         int sa_flags;
 196         tevent_signal_handler_t handler;
 197         /* this is private for the specific handler */
 198         void *private_data;
 199         /* this is for debugging only! */
 200         const char *handler_name;
 201         const char *location;
 202         /* this is private for the events_ops implementation */
 203         void *additional_data;
 204 };
 205
 206 struct tevent_debug_ops {
 207         void (*debug)(void *context, enum tevent_debug_level level,
 208                       const char *fmt, va_list ap) PRINTF_ATTRIBUTE(3,0);
 209         void *context;
 210 };
 211
 212 void tevent_debug(struct tevent_context *ev, enum tevent_debug_level level,
 213                   const char *fmt, ...) PRINTF_ATTRIBUTE(3,4);
 214
 215 struct tevent_context {
 216         /* the specific events implementation */
 217         const struct tevent_ops *ops;
 218
 219         /* list of fd events - used by common code */
 220         struct tevent_fd *fd_events;
 221
 222         /* list of timed events - used by common code */
 223         struct tevent_timer *timer_events;
 224
 225         /* list of signal events - used by common code */
 226         struct tevent_signal *signal_events;
 227
 228         /* this is private for the events_ops implementation */
 229         void *additional_data;
 230
 231         /* pipe hack used with signal handlers */
 232         struct tevent_fd *pipe_fde;
 233
 234         /* debugging operations */
 235         struct tevent_debug_ops debug_ops;
 236 };
 237
 238
 239 bool tevent_register_backend(const char *name, const struct tevent_ops *ops);
 240
 241 int tevent_common_context_destructor(struct tevent_context *ev);
 242
 243 int tevent_common_fd_destructor(struct tevent_fd *fde);
 244 struct tevent_fd *tevent_common_add_fd(struct tevent_context *ev,
 245                                        TALLOC_CTX *mem_ctx,
 246                                        int fd,
 247                                        uint16_t flags,
 248                                        tevent_fd_handler_t handler,
 249                                        void *private_data,
 250                                        const char *handler_name,
 251                                        const char *location);
 252 void tevent_common_fd_set_close_fn(struct tevent_fd *fde,
 253                                    tevent_fd_close_fn_t close_fn);
 254 uint16_t tevent_common_fd_get_flags(struct tevent_fd *fde);
 255 void tevent_common_fd_set_flags(struct tevent_fd *fde, uint16_t flags);
 256
 257 struct tevent_timer *tevent_common_add_timer(struct tevent_context *ev,
 258                                              TALLOC_CTX *mem_ctx,
 259                                              struct timeval next_event,
 260                                              tevent_timer_handler_t handler,
 261                                              void *private_data,
 262                                              const char *handler_name,
 263                                              const char *location);
 264 struct timeval tevent_common_loop_timer_delay(struct tevent_context *);
 265
 266 struct tevent_signal *tevent_common_add_signal(struct tevent_context *ev,
 267                                                TALLOC_CTX *mem_ctx,
 268                                                int signum,
 269                                                int sa_flags,
 270                                                tevent_signal_handler_t handler,
 271                                                void *private_data,
 272                                                const char *handler_name,
 273                                                const char *location);
 274 int tevent_common_check_signal(struct tevent_context *ev);
 275
 276 bool tevent_standard_init(void);
 277 bool tevent_select_init(void);
 278 #ifdef HAVE_EPOLL
 279 bool tevent_epoll_init(void);
 280 #endif