lib/kernel/time/timer.cc

   1 // lib/kernel/time/timer.cc -- Generic timer multiplexing
   2 //
   3 // This software is copyright (c) 2006 Scott Wood <scott@buserror.net>.
   4 //
   5 // This software is provided 'as-is', without any express or implied warranty.
   6 // In no event will the authors or contributors be held liable for any damages
   7 // arising from the use of this software.
   8 //
   9 // Permission is hereby granted to everyone, free of charge, to use, copy,
  10 // modify, prepare derivative works of, publish, distribute, perform,
  11 // sublicense, and/or sell copies of the Software, provided that the above
  12 // copyright notice and disclaimer of warranty be included in all copies or
  13 // substantial portions of this software.
  14
  15 #include <kernel/time.h>
  16 #include <lowlevel/clock.h>
  17
  18 namespace Time {
  19         void TimerMux::arm(TimerEntry *entry, Time expiry)
  20         {
  21                 AutoSpinLockRecIRQ autolock(lock);
  22
  23                 bool was_empty = heap.empty();
  24                 Time oldexpiry;
  25
  26                 if (!was_empty) {
  27                         oldexpiry = heap.get_top()->expiry;
  28                 } else {
  29                         // Shut up the compiler
  30                         oldexpiry.seconds = 0;
  31                         oldexpiry.nanos = 0;
  32                 }
  33
  34                 entry->expiry = expiry;
  35
  36                 if (entry->is_armed())
  37                         heap.requeue(entry);
  38                 else
  39                         heap.add(entry);
  40
  41                 Time newexpiry = heap.get_top()->expiry;
  42                 if (was_empty || oldexpiry != newexpiry)
  43                         parent.arm(newexpiry);
  44         }
  45
  46         void TimerMux::disarm(TimerEntry *entry)
  47         {
  48                 AutoSpinLockRecIRQ autolock(lock);
  49
  50                 if (entry->is_armed()) {
  51                         bool was_top = entry == heap.get_top();
  52
  53                         heap.del(entry);
  54
  55                         if (was_top)
  56                                 parent.arm(heap.get_top()->expiry);
  57                 }
  58         }
  59
  60         void TimerMux::run()
  61         {
  62                 DroppableAutoSpinLockRecIRQ autolock(lock);
  63
  64                 while (true) {
  65                         TimerEntry *top = heap.get_top();
  66                         Time now;
  67                         clock.get_time(&now);
  68
  69                         if (now < top->expiry)
  70                                 break;
  71
  72                         heap.del(top);
  73
  74                         autolock.unlock();
  75                         top->action();
  76                         autolock.lock();
  77                 }
  78
  79                 if (!heap.empty())
  80                         parent.arm(heap.get_top()->expiry);
  81         }
  82
  83         void TimerEntry::set_action(System::Events::Event *event)
  84         {
  85                 // FIXME
  86         }
  87
  88         void TimerEntry::action()
  89         {
  90                 // FIXME
  91         }
  92 }
  93
  94 #include _KERNEL_SERVER(time/timer/footer.cc)