1/* 2 * sched_get_priority_max.c 3 * 4 * Description: 5 * POSIX thread functions that deal with thread scheduling. 6 * 7 * -------------------------------------------------------------------------- 8 * 9 * Pthreads-win32 - POSIX Threads Library for Win32 10 * Copyright(C) 1998 John E. Bossom 11 * Copyright(C) 1999,2005 Pthreads-win32 contributors 12 * 13 * Contact Email: rpj@callisto.canberra.edu.au 14 * 15 * The current list of contributors is contained 16 * in the file CONTRIBUTORS included with the source 17 * code distribution. The list can also be seen at the 18 * following World Wide Web location: 19 * http://sources.redhat.com/pthreads-win32/contributors.html 20 * 21 * This library is free software; you can redistribute it and/or 22 * modify it under the terms of the GNU Lesser General Public 23 * License as published by the Free Software Foundation; either 24 * version 2 of the License, or (at your option) any later version. 25 * 26 * This library is distributed in the hope that it will be useful, 27 * but WITHOUT ANY WARRANTY; without even the implied warranty of 28 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 29 * Lesser General Public License for more details. 30 * 31 * You should have received a copy of the GNU Lesser General Public 32 * License along with this library in the file COPYING.LIB; 33 * if not, write to the Free Software Foundation, Inc., 34 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA 35 */ 36 37#include "pthread.h" 38#include "implement.h" 39#include "sched.h" 40 41/* 42 * On Windows98, THREAD_PRIORITY_LOWEST is (-2) and 43 * THREAD_PRIORITY_HIGHEST is 2, and everything works just fine. 44 * 45 * On WinCE 3.0, it so happen that THREAD_PRIORITY_LOWEST is 5 46 * and THREAD_PRIORITY_HIGHEST is 1 (yes, I know, it is funny: 47 * highest priority use smaller numbers) and the following happens: 48 * 49 * sched_get_priority_min() returns 5 50 * sched_get_priority_max() returns 1 51 * 52 * The following table shows the base priority levels for combinations 53 * of priority class and priority value in Win32. 54 * 55 * Process Priority Class Thread Priority Level 56 * ----------------------------------------------------------------- 57 * 1 IDLE_PRIORITY_CLASS THREAD_PRIORITY_IDLE 58 * 1 BELOW_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_IDLE 59 * 1 NORMAL_PRIORITY_CLASS THREAD_PRIORITY_IDLE 60 * 1 ABOVE_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_IDLE 61 * 1 HIGH_PRIORITY_CLASS THREAD_PRIORITY_IDLE 62 * 2 IDLE_PRIORITY_CLASS THREAD_PRIORITY_LOWEST 63 * 3 IDLE_PRIORITY_CLASS THREAD_PRIORITY_BELOW_NORMAL 64 * 4 IDLE_PRIORITY_CLASS THREAD_PRIORITY_NORMAL 65 * 4 BELOW_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_LOWEST 66 * 5 IDLE_PRIORITY_CLASS THREAD_PRIORITY_ABOVE_NORMAL 67 * 5 BELOW_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_BELOW_NORMAL 68 * 5 Background NORMAL_PRIORITY_CLASS THREAD_PRIORITY_LOWEST 69 * 6 IDLE_PRIORITY_CLASS THREAD_PRIORITY_HIGHEST 70 * 6 BELOW_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_NORMAL 71 * 6 Background NORMAL_PRIORITY_CLASS THREAD_PRIORITY_BELOW_NORMAL 72 * 7 BELOW_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_ABOVE_NORMAL 73 * 7 Background NORMAL_PRIORITY_CLASS THREAD_PRIORITY_NORMAL 74 * 7 Foreground NORMAL_PRIORITY_CLASS THREAD_PRIORITY_LOWEST 75 * 8 BELOW_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_HIGHEST 76 * 8 NORMAL_PRIORITY_CLASS THREAD_PRIORITY_ABOVE_NORMAL 77 * 8 Foreground NORMAL_PRIORITY_CLASS THREAD_PRIORITY_BELOW_NORMAL 78 * 8 ABOVE_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_LOWEST 79 * 9 NORMAL_PRIORITY_CLASS THREAD_PRIORITY_HIGHEST 80 * 9 Foreground NORMAL_PRIORITY_CLASS THREAD_PRIORITY_NORMAL 81 * 9 ABOVE_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_BELOW_NORMAL 82 * 10 Foreground NORMAL_PRIORITY_CLASS THREAD_PRIORITY_ABOVE_NORMAL 83 * 10 ABOVE_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_NORMAL 84 * 11 Foreground NORMAL_PRIORITY_CLASS THREAD_PRIORITY_HIGHEST 85 * 11 ABOVE_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_ABOVE_NORMAL 86 * 11 HIGH_PRIORITY_CLASS THREAD_PRIORITY_LOWEST 87 * 12 ABOVE_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_HIGHEST 88 * 12 HIGH_PRIORITY_CLASS THREAD_PRIORITY_BELOW_NORMAL 89 * 13 HIGH_PRIORITY_CLASS THREAD_PRIORITY_NORMAL 90 * 14 HIGH_PRIORITY_CLASS THREAD_PRIORITY_ABOVE_NORMAL 91 * 15 HIGH_PRIORITY_CLASS THREAD_PRIORITY_HIGHEST 92 * 15 HIGH_PRIORITY_CLASS THREAD_PRIORITY_TIME_CRITICAL 93 * 15 IDLE_PRIORITY_CLASS THREAD_PRIORITY_TIME_CRITICAL 94 * 15 BELOW_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_TIME_CRITICAL 95 * 15 NORMAL_PRIORITY_CLASS THREAD_PRIORITY_TIME_CRITICAL 96 * 15 ABOVE_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_TIME_CRITICAL 97 * 16 REALTIME_PRIORITY_CLASS THREAD_PRIORITY_IDLE 98 * 17 REALTIME_PRIORITY_CLASS -7 99 * 18 REALTIME_PRIORITY_CLASS -6 100 * 19 REALTIME_PRIORITY_CLASS -5 101 * 20 REALTIME_PRIORITY_CLASS -4 102 * 21 REALTIME_PRIORITY_CLASS -3 103 * 22 REALTIME_PRIORITY_CLASS THREAD_PRIORITY_LOWEST 104 * 23 REALTIME_PRIORITY_CLASS THREAD_PRIORITY_BELOW_NORMAL 105 * 24 REALTIME_PRIORITY_CLASS THREAD_PRIORITY_NORMAL 106 * 25 REALTIME_PRIORITY_CLASS THREAD_PRIORITY_ABOVE_NORMAL 107 * 26 REALTIME_PRIORITY_CLASS THREAD_PRIORITY_HIGHEST 108 * 27 REALTIME_PRIORITY_CLASS 3 109 * 28 REALTIME_PRIORITY_CLASS 4 110 * 29 REALTIME_PRIORITY_CLASS 5 111 * 30 REALTIME_PRIORITY_CLASS 6 112 * 31 REALTIME_PRIORITY_CLASS THREAD_PRIORITY_TIME_CRITICAL 113 * 114 * Windows NT: Values -7, -6, -5, -4, -3, 3, 4, 5, and 6 are not supported. 115 */ 116 117 118int 119sched_get_priority_max (int policy) 120{ 121 if (policy < SCHED_MIN || policy > SCHED_MAX) 122 { 123 errno = EINVAL; 124 return -1; 125 } 126 127#if (THREAD_PRIORITY_LOWEST > THREAD_PRIORITY_NORMAL) 128 /* WinCE? */ 129 return PTW32_MAX (THREAD_PRIORITY_IDLE, THREAD_PRIORITY_TIME_CRITICAL); 130#else 131 /* This is independent of scheduling policy in Win32. */ 132 return PTW32_MAX (THREAD_PRIORITY_IDLE, THREAD_PRIORITY_TIME_CRITICAL); 133#endif 134} 135