src/system/libroot/os/scheduler.c

   1 /*
   2  * Copyright 2004-2010, Haiku. All rights reserved.
   3  * Distributed under the terms of the MIT License.
   4  *
   5  * Authors:
   6  *      Jérôme Duval, korli@users.sourceforge.net.
   7  *      Michael Pfeiffer, laplace@users.sourceforge.net
   8  */
   9
  10
  11 #include <scheduler.h>
  12
  13 #include <syscalls.h>
  14
  15
  16 static struct {
  17         uint32 what;
  18         int32 priority;
  19 } sWhatPriorityArray[] = {
  20         // highest priority first
  21         {B_MIDI_PROCESSING, 0x78},
  22         {B_AUDIO_RECORDING | B_AUDIO_PLAYBACK, 0x73},
  23         {B_LIVE_AUDIO_MANIPULATION, 0x6e},
  24         {B_VIDEO_RECORDING, 0x19},
  25         {B_VIDEO_PLAYBACK, 0x14},
  26         {B_USER_INPUT_HANDLING, 0x0f},
  27         {B_LIVE_VIDEO_MANIPULATION, 0x0e},
  28         {B_LIVE_3D_RENDERING, 0x0c},
  29         {B_STATUS_RENDERING, 0xa},
  30         {B_OFFLINE_PROCESSING, 0x06},
  31         {B_NUMBER_CRUNCHING, 0x05},
  32         {(uint32)-1, -1}
  33 };
  34
  35 status_t __set_scheduler_mode(int32 mode);
  36 int32 __get_scheduler_mode(void);
  37
  38
  39 int32
  40 suggest_thread_priority(uint32 what, int32 period, bigtime_t jitter,
  41         bigtime_t length)
  42 {
  43         int i;
  44         int32 priority = what == B_DEFAULT_MEDIA_PRIORITY ? 0x0a : 0;
  45                 // default priority
  46
  47         // TODO: this needs kernel support, and is a pretty simplistic solution
  48
  49         for (i = 0; sWhatPriorityArray[i].what != (uint32)-1; i ++) {
  50                 if ((what & sWhatPriorityArray[i].what) != 0) {
  51                         priority = sWhatPriorityArray[i].priority;
  52                         break;
  53                 }
  54         }
  55
  56         return priority;
  57 }
  58
  59
  60 bigtime_t
  61 estimate_max_scheduling_latency(thread_id thread)
  62 {
  63         return _kern_estimate_max_scheduling_latency(thread);
  64 }
  65
  66
  67 status_t
  68 __set_scheduler_mode(int32 mode)
  69 {
  70         return _kern_set_scheduler_mode(mode);
  71 }
  72
  73
  74 int32
  75 __get_scheduler_mode(void)
  76 {
  77         return _kern_get_scheduler_mode();
  78 }
  79
  80
  81 B_DEFINE_WEAK_ALIAS(__set_scheduler_mode, set_scheduler_mode);
  82 B_DEFINE_WEAK_ALIAS(__get_scheduler_mode, get_scheduler_mode);
  83