The Android Open Source Project | 845e012 | 2009-03-03 19:31:34 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Event loop |
| 3 | * Copyright (c) 2002-2006, Jouni Malinen <j@w1.fi> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License version 2 as |
| 7 | * published by the Free Software Foundation. |
| 8 | * |
| 9 | * Alternatively, this software may be distributed under the terms of BSD |
| 10 | * license. |
| 11 | * |
| 12 | * See README and COPYING for more details. |
| 13 | * |
| 14 | * This file defines an event loop interface that supports processing events |
| 15 | * from registered timeouts (i.e., do something after N seconds), sockets |
| 16 | * (e.g., a new packet available for reading), and signals. eloop.c is an |
| 17 | * implementation of this interface using select() and sockets. This is |
| 18 | * suitable for most UNIX/POSIX systems. When porting to other operating |
| 19 | * systems, it may be necessary to replace that implementation with OS specific |
| 20 | * mechanisms. |
| 21 | */ |
| 22 | |
| 23 | #ifndef ELOOP_H |
| 24 | #define ELOOP_H |
| 25 | |
| 26 | /** |
| 27 | * ELOOP_ALL_CTX - eloop_cancel_timeout() magic number to match all timeouts |
| 28 | */ |
| 29 | #define ELOOP_ALL_CTX (void *) -1 |
| 30 | |
| 31 | /** |
| 32 | * eloop_event_type - eloop socket event type for eloop_register_sock() |
| 33 | * @EVENT_TYPE_READ: Socket has data available for reading |
| 34 | * @EVENT_TYPE_WRITE: Socket has room for new data to be written |
| 35 | * @EVENT_TYPE_EXCEPTION: An exception has been reported |
| 36 | */ |
| 37 | typedef enum { |
| 38 | EVENT_TYPE_READ = 0, |
| 39 | EVENT_TYPE_WRITE, |
| 40 | EVENT_TYPE_EXCEPTION |
| 41 | } eloop_event_type; |
| 42 | |
| 43 | /** |
| 44 | * eloop_sock_handler - eloop socket event callback type |
| 45 | * @sock: File descriptor number for the socket |
| 46 | * @eloop_ctx: Registered callback context data (eloop_data) |
| 47 | * @sock_ctx: Registered callback context data (user_data) |
| 48 | */ |
| 49 | typedef void (*eloop_sock_handler)(int sock, void *eloop_ctx, void *sock_ctx); |
| 50 | |
| 51 | /** |
| 52 | * eloop_event_handler - eloop generic event callback type |
| 53 | * @eloop_ctx: Registered callback context data (eloop_data) |
| 54 | * @sock_ctx: Registered callback context data (user_data) |
| 55 | */ |
| 56 | typedef void (*eloop_event_handler)(void *eloop_data, void *user_ctx); |
| 57 | |
| 58 | /** |
| 59 | * eloop_timeout_handler - eloop timeout event callback type |
| 60 | * @eloop_ctx: Registered callback context data (eloop_data) |
| 61 | * @sock_ctx: Registered callback context data (user_data) |
| 62 | */ |
| 63 | typedef void (*eloop_timeout_handler)(void *eloop_data, void *user_ctx); |
| 64 | |
| 65 | /** |
| 66 | * eloop_signal_handler - eloop signal event callback type |
| 67 | * @sig: Signal number |
| 68 | * @eloop_ctx: Registered callback context data (global user_data from |
| 69 | * eloop_init() call) |
| 70 | * @signal_ctx: Registered callback context data (user_data from |
| 71 | * eloop_register_signal(), eloop_register_signal_terminate(), or |
| 72 | * eloop_register_signal_reconfig() call) |
| 73 | */ |
| 74 | typedef void (*eloop_signal_handler)(int sig, void *eloop_ctx, |
| 75 | void *signal_ctx); |
| 76 | |
| 77 | /** |
| 78 | * eloop_init() - Initialize global event loop data |
| 79 | * @user_data: Pointer to global data passed as eloop_ctx to signal handlers |
| 80 | * Returns: 0 on success, -1 on failure |
| 81 | * |
| 82 | * This function must be called before any other eloop_* function. user_data |
| 83 | * can be used to configure a global (to the process) pointer that will be |
| 84 | * passed as eloop_ctx parameter to signal handlers. |
| 85 | */ |
| 86 | int eloop_init(void *user_data); |
| 87 | |
| 88 | /** |
| 89 | * eloop_register_read_sock - Register handler for read events |
| 90 | * @sock: File descriptor number for the socket |
| 91 | * @handler: Callback function to be called when data is available for reading |
| 92 | * @eloop_data: Callback context data (eloop_ctx) |
| 93 | * @user_data: Callback context data (sock_ctx) |
| 94 | * Returns: 0 on success, -1 on failure |
| 95 | * |
| 96 | * Register a read socket notifier for the given file descriptor. The handler |
| 97 | * function will be called whenever data is available for reading from the |
| 98 | * socket. The handler function is responsible for clearing the event after |
| 99 | * having processed it in order to avoid eloop from calling the handler again |
| 100 | * for the same event. |
| 101 | */ |
| 102 | int eloop_register_read_sock(int sock, eloop_sock_handler handler, |
| 103 | void *eloop_data, void *user_data); |
| 104 | |
| 105 | /** |
| 106 | * eloop_unregister_read_sock - Unregister handler for read events |
| 107 | * @sock: File descriptor number for the socket |
| 108 | * |
| 109 | * Unregister a read socket notifier that was previously registered with |
| 110 | * eloop_register_read_sock(). |
| 111 | */ |
| 112 | void eloop_unregister_read_sock(int sock); |
| 113 | |
| 114 | /** |
| 115 | * eloop_register_sock - Register handler for socket events |
| 116 | * @sock: File descriptor number for the socket |
| 117 | * @type: Type of event to wait for |
| 118 | * @handler: Callback function to be called when the event is triggered |
| 119 | * @eloop_data: Callback context data (eloop_ctx) |
| 120 | * @user_data: Callback context data (sock_ctx) |
| 121 | * Returns: 0 on success, -1 on failure |
| 122 | * |
| 123 | * Register an event notifier for the given socket's file descriptor. The |
| 124 | * handler function will be called whenever the that event is triggered for the |
| 125 | * socket. The handler function is responsible for clearing the event after |
| 126 | * having processed it in order to avoid eloop from calling the handler again |
| 127 | * for the same event. |
| 128 | */ |
| 129 | int eloop_register_sock(int sock, eloop_event_type type, |
| 130 | eloop_sock_handler handler, |
| 131 | void *eloop_data, void *user_data); |
| 132 | |
| 133 | /** |
| 134 | * eloop_unregister_sock - Unregister handler for socket events |
| 135 | * @sock: File descriptor number for the socket |
| 136 | * @type: Type of event for which sock was registered |
| 137 | * |
| 138 | * Unregister a socket event notifier that was previously registered with |
| 139 | * eloop_register_sock(). |
| 140 | */ |
| 141 | void eloop_unregister_sock(int sock, eloop_event_type type); |
| 142 | |
| 143 | /** |
| 144 | * eloop_register_event - Register handler for generic events |
| 145 | * @event: Event to wait (eloop implementation specific) |
| 146 | * @event_size: Size of event data |
| 147 | * @handler: Callback function to be called when event is triggered |
| 148 | * @eloop_data: Callback context data (eloop_data) |
| 149 | * @user_data: Callback context data (user_data) |
| 150 | * Returns: 0 on success, -1 on failure |
| 151 | * |
| 152 | * Register an event handler for the given event. This function is used to |
| 153 | * register eloop implementation specific events which are mainly targetted for |
| 154 | * operating system specific code (driver interface and l2_packet) since the |
| 155 | * portable code will not be able to use such an OS-specific call. The handler |
| 156 | * function will be called whenever the event is triggered. The handler |
| 157 | * function is responsible for clearing the event after having processed it in |
| 158 | * order to avoid eloop from calling the handler again for the same event. |
| 159 | * |
| 160 | * In case of Windows implementation (eloop_win.c), event pointer is of HANDLE |
| 161 | * type, i.e., void*. The callers are likely to have 'HANDLE h' type variable, |
| 162 | * and they would call this function with eloop_register_event(h, sizeof(h), |
| 163 | * ...). |
| 164 | */ |
| 165 | int eloop_register_event(void *event, size_t event_size, |
| 166 | eloop_event_handler handler, |
| 167 | void *eloop_data, void *user_data); |
| 168 | |
| 169 | /** |
| 170 | * eloop_unregister_event - Unregister handler for a generic event |
| 171 | * @event: Event to cancel (eloop implementation specific) |
| 172 | * @event_size: Size of event data |
| 173 | * |
| 174 | * Unregister a generic event notifier that was previously registered with |
| 175 | * eloop_register_event(). |
| 176 | */ |
| 177 | void eloop_unregister_event(void *event, size_t event_size); |
| 178 | |
| 179 | /** |
| 180 | * eloop_register_timeout - Register timeout |
| 181 | * @secs: Number of seconds to the timeout |
| 182 | * @usecs: Number of microseconds to the timeout |
| 183 | * @handler: Callback function to be called when timeout occurs |
| 184 | * @eloop_data: Callback context data (eloop_ctx) |
| 185 | * @user_data: Callback context data (sock_ctx) |
| 186 | * Returns: 0 on success, -1 on failure |
| 187 | * |
| 188 | * Register a timeout that will cause the handler function to be called after |
| 189 | * given time. |
| 190 | */ |
| 191 | int eloop_register_timeout(unsigned int secs, unsigned int usecs, |
| 192 | eloop_timeout_handler handler, |
| 193 | void *eloop_data, void *user_data); |
| 194 | |
| 195 | /** |
| 196 | * eloop_cancel_timeout - Cancel timeouts |
| 197 | * @handler: Matching callback function |
| 198 | * @eloop_data: Matching eloop_data or %ELOOP_ALL_CTX to match all |
| 199 | * @user_data: Matching user_data or %ELOOP_ALL_CTX to match all |
| 200 | * Returns: Number of cancelled timeouts |
| 201 | * |
| 202 | * Cancel matching <handler,eloop_data,user_data> timeouts registered with |
| 203 | * eloop_register_timeout(). ELOOP_ALL_CTX can be used as a wildcard for |
| 204 | * cancelling all timeouts regardless of eloop_data/user_data. |
| 205 | */ |
| 206 | int eloop_cancel_timeout(eloop_timeout_handler handler, |
| 207 | void *eloop_data, void *user_data); |
| 208 | |
| 209 | /** |
Dmitry Shmidt | dc9507e | 2009-04-16 11:38:56 -0700 | [diff] [blame] | 210 | * eloop_is_timeout_registered - Check if a timeout is already registered |
| 211 | * @handler: Matching callback function |
| 212 | * @eloop_data: Matching eloop_data |
| 213 | * @user_data: Matching user_data |
| 214 | * Returns: 1 if the timeout is registered, 0 if the timeout is not registered |
| 215 | * |
| 216 | * Determine if a matching <handler,eloop_data,user_data> timeout is registered |
| 217 | * with eloop_register_timeout(). |
| 218 | */ |
| 219 | int eloop_is_timeout_registered(eloop_timeout_handler handler, |
| 220 | void *eloop_data, void *user_data); |
| 221 | |
| 222 | /** |
The Android Open Source Project | 845e012 | 2009-03-03 19:31:34 -0800 | [diff] [blame] | 223 | * eloop_register_signal - Register handler for signals |
| 224 | * @sig: Signal number (e.g., SIGHUP) |
| 225 | * @handler: Callback function to be called when the signal is received |
| 226 | * @user_data: Callback context data (signal_ctx) |
| 227 | * Returns: 0 on success, -1 on failure |
| 228 | * |
| 229 | * Register a callback function that will be called when a signal is received. |
| 230 | * The callback function is actually called only after the system signal |
| 231 | * handler has returned. This means that the normal limits for sighandlers |
| 232 | * (i.e., only "safe functions" allowed) do not apply for the registered |
| 233 | * callback. |
| 234 | * |
| 235 | * Signals are 'global' events and there is no local eloop_data pointer like |
| 236 | * with other handlers. The global user_data pointer registered with |
| 237 | * eloop_init() will be used as eloop_ctx for signal handlers. |
| 238 | */ |
| 239 | int eloop_register_signal(int sig, eloop_signal_handler handler, |
| 240 | void *user_data); |
| 241 | |
| 242 | /** |
| 243 | * eloop_register_signal_terminate - Register handler for terminate signals |
| 244 | * @handler: Callback function to be called when the signal is received |
| 245 | * @user_data: Callback context data (signal_ctx) |
| 246 | * Returns: 0 on success, -1 on failure |
| 247 | * |
| 248 | * Register a callback function that will be called when a process termination |
| 249 | * signal is received. The callback function is actually called only after the |
| 250 | * system signal handler has returned. This means that the normal limits for |
| 251 | * sighandlers (i.e., only "safe functions" allowed) do not apply for the |
| 252 | * registered callback. |
| 253 | * |
| 254 | * Signals are 'global' events and there is no local eloop_data pointer like |
| 255 | * with other handlers. The global user_data pointer registered with |
| 256 | * eloop_init() will be used as eloop_ctx for signal handlers. |
| 257 | * |
| 258 | * This function is a more portable version of eloop_register_signal() since |
| 259 | * the knowledge of exact details of the signals is hidden in eloop |
| 260 | * implementation. In case of operating systems using signal(), this function |
| 261 | * registers handlers for SIGINT and SIGTERM. |
| 262 | */ |
| 263 | int eloop_register_signal_terminate(eloop_signal_handler handler, |
| 264 | void *user_data); |
| 265 | |
| 266 | /** |
| 267 | * eloop_register_signal_reconfig - Register handler for reconfig signals |
| 268 | * @handler: Callback function to be called when the signal is received |
| 269 | * @user_data: Callback context data (signal_ctx) |
| 270 | * Returns: 0 on success, -1 on failure |
| 271 | * |
| 272 | * Register a callback function that will be called when a reconfiguration / |
| 273 | * hangup signal is received. The callback function is actually called only |
| 274 | * after the system signal handler has returned. This means that the normal |
| 275 | * limits for sighandlers (i.e., only "safe functions" allowed) do not apply |
| 276 | * for the registered callback. |
| 277 | * |
| 278 | * Signals are 'global' events and there is no local eloop_data pointer like |
| 279 | * with other handlers. The global user_data pointer registered with |
| 280 | * eloop_init() will be used as eloop_ctx for signal handlers. |
| 281 | * |
| 282 | * This function is a more portable version of eloop_register_signal() since |
| 283 | * the knowledge of exact details of the signals is hidden in eloop |
| 284 | * implementation. In case of operating systems using signal(), this function |
| 285 | * registers a handler for SIGHUP. |
| 286 | */ |
| 287 | int eloop_register_signal_reconfig(eloop_signal_handler handler, |
| 288 | void *user_data); |
| 289 | |
| 290 | /** |
| 291 | * eloop_run - Start the event loop |
| 292 | * |
| 293 | * Start the event loop and continue running as long as there are any |
| 294 | * registered event handlers. This function is run after event loop has been |
| 295 | * initialized with event_init() and one or more events have been registered. |
| 296 | */ |
| 297 | void eloop_run(void); |
| 298 | |
| 299 | /** |
| 300 | * eloop_terminate - Terminate event loop |
| 301 | * |
| 302 | * Terminate event loop even if there are registered events. This can be used |
| 303 | * to request the program to be terminated cleanly. |
| 304 | */ |
| 305 | void eloop_terminate(void); |
| 306 | |
| 307 | /** |
| 308 | * eloop_destroy - Free any resources allocated for the event loop |
| 309 | * |
| 310 | * After calling eloop_destroy(), other eloop_* functions must not be called |
| 311 | * before re-running eloop_init(). |
| 312 | */ |
| 313 | void eloop_destroy(void); |
| 314 | |
| 315 | /** |
| 316 | * eloop_terminated - Check whether event loop has been terminated |
| 317 | * Returns: 1 = event loop terminate, 0 = event loop still running |
| 318 | * |
| 319 | * This function can be used to check whether eloop_terminate() has been called |
| 320 | * to request termination of the event loop. This is normally used to abort |
| 321 | * operations that may still be queued to be run when eloop_terminate() was |
| 322 | * called. |
| 323 | */ |
| 324 | int eloop_terminated(void); |
| 325 | |
| 326 | /** |
| 327 | * eloop_wait_for_read_sock - Wait for a single reader |
| 328 | * @sock: File descriptor number for the socket |
| 329 | * |
| 330 | * Do a blocking wait for a single read socket. |
| 331 | */ |
| 332 | void eloop_wait_for_read_sock(int sock); |
| 333 | |
| 334 | /** |
| 335 | * eloop_get_user_data - Get global user data |
| 336 | * Returns: user_data pointer that was registered with eloop_init() |
| 337 | */ |
| 338 | void * eloop_get_user_data(void); |
| 339 | |
| 340 | #endif /* ELOOP_H */ |