Dogcows Code - chaz/openbox/blob - otk_c/timerqueue.c

   1 // -*- mode: C; indent-tabs-mode: nil; c-basic-offset: 2; -*-
   2
   3 #include "../config.h"
   4 #include "timerqueue.h"
   5 #include "display.h"
   6
   7 #include <X11/Xlib.h>
   8 #include <Python.h>
   9
  10 static PyObject *list = NULL; // PyListObject
  11
  12 void OtkTimerQueue_Initialize()
  13 {
  14   list = PyList_New(0);
  15 }
  16
  17 void OtkTimerQueue_Add(OtkTimer* timer)
  18 {
  19   PyList_Append(list, (PyObject*)timer);
  20   PyList_Sort(list);
  21 }
  22
  23 void OtkTimerQueue_Remove(OtkTimer* timer)
  24 {
  25   int index;
  26
  27   index = PySequence_Index(list, (PyObject*)timer);
  28   if (index >= 0)
  29     PySequence_DelItem(list, index);
  30 }
  31
  32 static Bool shouldFire(OtkTimer *timer, const struct timeval *now)
  33 {
  34   return ! ((now->tv_sec < timer->end.tv_sec) ||
  35             (now->tv_sec == timer->end.tv_sec &&
  36              now->tv_usec < timer->end.tv_usec));
  37 }
  38
  39 static void normalizeTimeval(struct timeval *time)
  40 {
  41   while (time->tv_usec < 0) {
  42     if (time->tv_sec > 0) {
  43       --time->tv_sec;
  44       time->tv_usec += 1000000;
  45     } else {
  46       time->tv_usec = 0;
  47     }
  48   }
  49
  50   if (time->tv_usec >= 1000000) {
  51     time->tv_sec += time->tv_usec / 1000000;
  52     time->tv_usec %= 1000000;
  53   }
  54
  55   if (time->tv_sec < 0) time->tv_sec = 0;
  56 }
  57
  58 void OtkTimerQueue_Fire()
  59 {
  60   fd_set rfds;
  61   struct timeval now, tm, *timeout = NULL;
  62
  63   const int xfd = ConnectionNumber(OBDisplay->display);
  64
  65   FD_ZERO(&rfds);
  66   FD_SET(xfd, &rfds); // break on any x events
  67
  68   // check for timer timeout
  69   gettimeofday(&now, 0);
  70
  71   // there is a small chance for deadlock here:
  72   // *IF* the timer list keeps getting refreshed *AND* the time between
  73   // timer->start() and timer->shouldFire() is within the timer's period
  74   // then the timer will keep firing.  This should be VERY near impossible.
  75   while (PyList_Size(list)) {
  76     OtkTimer *timer = (OtkTimer*)PyList_GetItem(list, 0);
  77
  78     if (! shouldFire(timer, &now)) {
  79       tm.tv_sec = timer->end.tv_sec - now.tv_sec;
  80       tm.tv_usec = timer->end.tv_usec - now.tv_usec;
  81       normalizeTimeval(&tm);
  82       timeout = &tm; // set the timeout for the select
  83       break; // go on and wait
  84     }
  85
  86     // stop and remove the timer from the queue
  87     PySequence_DelItem(list, 0);
  88     timer->timing = False;
  89
  90     if (timer->handler)
  91       timer->handler(timer->data);
  92
  93     if (timer->recur)
  94       OtkTimer_Start(timer);
  95   }
  96
  97   select(xfd + 1, &rfds, 0, 0, timeout);
  98 }