src/main/select.h

   1 #ifndef EL__MAIN_SELECT_H
   2 #define EL__MAIN_SELECT_H
   3
   4 typedef void (*select_handler_T)(void *);
   5
   6 /* Start the select loop after calling the passed @init() function. */
   7 void select_loop(void (*init)(void));
   8
   9 /* Get information about the number of descriptors being checked by the select
  10  * loop. */
  11 int get_file_handles_count(void);
  12
  13 /* Schedule work to be done when appropriate in the future. */
  14 int register_bottom_half_do(select_handler_T work_handler, void *data);
  15
  16 /* Wrapper to remove a lot of casts from users of bottom halves. */
  17 #define register_bottom_half(fn, data) \
  18         register_bottom_half_do((select_handler_T) (fn), (void *) (data))
  19
  20 /* Check and run scheduled work. */
  21 void check_bottom_halves(void);
  22
  23 enum select_handler_type {
  24         SELECT_HANDLER_READ,
  25         SELECT_HANDLER_WRITE,
  26         SELECT_HANDLER_ERROR,
  27         SELECT_HANDLER_DATA,
  28 };
  29
  30 /* Get a registered select handler. */
  31 select_handler_T get_handler(int fd, enum select_handler_type type);
  32
  33 /* Set handlers and callback @data for the @fd descriptor. */
  34 void set_handlers(int fd,
  35                   select_handler_T read_handler,
  36                   select_handler_T write_handler,
  37                   select_handler_T error_handler,
  38                   void *data);
  39
  40 /* Clear handlers associated with @fd. */
  41 #define clear_handlers(fd) \
  42         set_handlers(fd, NULL, NULL, NULL, NULL)
  43
  44 /* Checks which can be used for querying the read/write state of the @fd
  45  * descriptor without blocking. The interlink code are the only users. */
  46 int can_read(int fd);
  47 int can_write(int fd);
  48
  49 #endif