code.delx.au - pulseaudio/blob - src/pulsecore/rtpoll.h

   1 #ifndef foopulsertpollhfoo
   2 #define foopulsertpollhfoo
   3
   4 /***
   5   This file is part of PulseAudio.
   6
   7   Copyright 2004-2006 Lennart Poettering
   8
   9   PulseAudio is free software; you can redistribute it and/or modify
  10   it under the terms of the GNU Lesser General Public License as
  11   published by the Free Software Foundation; either version 2.1 of the
  12   License, or (at your option) any later version.
  13
  14   PulseAudio is distributed in the hope that it will be useful, but
  15   WITHOUT ANY WARRANTY; without even the implied warranty of
  16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17   Lesser General Public License for more details.
  18
  19   You should have received a copy of the GNU Lesser General Public
  20   License along with PulseAudio; if not, write to the Free Software
  21   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  22   USA.
  23 ***/
  24
  25 #include <sys/types.h>
  26 #include <limits.h>
  27
  28 #include <pulse/sample.h>
  29 #include <pulsecore/asyncmsgq.h>
  30 #include <pulsecore/fdsem.h>
  31 #include <pulsecore/macro.h>
  32
  33 /* An implementation of a "real-time" poll loop. Basically, this is
  34  * yet another wrapper around poll(). However it has certain
  35  * advantages over pa_mainloop and suchlike:
  36  *
  37  * 1) High resolution timers are used
  38  *
  39  * 2) It allows raw access to the pollfd data to users
  40  *
  41  * 3) It allows arbitrary functions to be run before entering the
  42  * actual poll() and after it.
  43  *
  44  * Only a single interval timer is supported..*/
  45
  46 typedef struct pa_rtpoll pa_rtpoll;
  47 typedef struct pa_rtpoll_item pa_rtpoll_item;
  48
  49 typedef enum pa_rtpoll_priority {
  50     PA_RTPOLL_EARLY  = -100,          /* For very important stuff, like handling control messages */
  51     PA_RTPOLL_NORMAL = 0,             /* For normal stuff */
  52     PA_RTPOLL_LATE   = +100,          /* For housekeeping */
  53     PA_RTPOLL_NEVER  = INT_MAX,       /* For stuff that doesn't register any callbacks, but only fds to listen on */
  54 } pa_rtpoll_priority_t;
  55
  56 pa_rtpoll *pa_rtpoll_new(void);
  57 void pa_rtpoll_free(pa_rtpoll *p);
  58
  59 /* Sleep on the rtpoll until the time event, or any of the fd events
  60  * is triggered. If "wait" is 0 we don't sleep but only update the
  61  * struct pollfd. Returns negative on error, positive if the loop
  62  * should continue to run, 0 when the loop should be terminated
  63  * cleanly. */
  64 int pa_rtpoll_run(pa_rtpoll *f, bool wait);
  65
  66 void pa_rtpoll_set_timer_absolute(pa_rtpoll *p, pa_usec_t usec);
  67 void pa_rtpoll_set_timer_relative(pa_rtpoll *p, pa_usec_t usec);
  68 void pa_rtpoll_set_timer_disabled(pa_rtpoll *p);
  69
  70 /* Return true when the elapsed timer was the reason for
  71  * the last pa_rtpoll_run() invocation to finish */
  72 bool pa_rtpoll_timer_elapsed(pa_rtpoll *p);
  73
  74 /* A new fd wakeup item for pa_rtpoll */
  75 pa_rtpoll_item *pa_rtpoll_item_new(pa_rtpoll *p, pa_rtpoll_priority_t prio, unsigned n_fds);
  76 void pa_rtpoll_item_free(pa_rtpoll_item *i);
  77
  78 /* Please note that this pointer might change on every call and when
  79  * pa_rtpoll_run() is called. Hence: call this immediately before
  80  * using the pointer and don't save the result anywhere */
  81 struct pollfd *pa_rtpoll_item_get_pollfd(pa_rtpoll_item *i, unsigned *n_fds);
  82
  83 /* Set the callback that shall be called when there's time to do some work: If the
  84  * callback returns a value > 0, the poll is skipped and the next
  85  * iteration of the loop will start immediately. */
  86 void pa_rtpoll_item_set_work_callback(pa_rtpoll_item *i, int (*work_cb)(pa_rtpoll_item *i));
  87
  88 /* Set the callback that shall be called immediately before entering
  89  * the sleeping poll: If the callback returns a value > 0, the poll is
  90  * skipped and the next iteration of the loop will start immediately. */
  91 void pa_rtpoll_item_set_before_callback(pa_rtpoll_item *i, int (*before_cb)(pa_rtpoll_item *i));
  92
  93 /* Set the callback that shall be called immediately after having
  94  * entered the sleeping poll */
  95 void pa_rtpoll_item_set_after_callback(pa_rtpoll_item *i, void (*after_cb)(pa_rtpoll_item *i));
  96
  97 void pa_rtpoll_item_set_userdata(pa_rtpoll_item *i, void *userdata);
  98 void* pa_rtpoll_item_get_userdata(pa_rtpoll_item *i);
  99
 100 pa_rtpoll_item *pa_rtpoll_item_new_fdsem(pa_rtpoll *p, pa_rtpoll_priority_t prio, pa_fdsem *s);
 101 pa_rtpoll_item *pa_rtpoll_item_new_asyncmsgq_read(pa_rtpoll *p, pa_rtpoll_priority_t prio, pa_asyncmsgq *q);
 102 pa_rtpoll_item *pa_rtpoll_item_new_asyncmsgq_write(pa_rtpoll *p, pa_rtpoll_priority_t prio, pa_asyncmsgq *q);
 103
 104 /* Requests the loop to exit. Will cause the next iteration of
 105  * pa_rtpoll_run() to return 0 */
 106 void pa_rtpoll_quit(pa_rtpoll *p);
 107
 108 #endif