kern/kern_policy.c

   1 /*
   2  * Copyright (c) 2013 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 #include "kern_internal.h"
  30 #include <kern/debug.h>
  31 #include <kern/assert.h>
  32
  33 pthread_priority_t
  34 thread_qos_get_pthread_priority(int qos)
  35 {
  36         /* Map the buckets we have in pthread_priority_t into a QoS tier. */
  37         switch (qos) {
  38                 case THREAD_QOS_USER_INTERACTIVE: return _pthread_priority_make_newest(QOS_CLASS_USER_INTERACTIVE, 0, 0);
  39                 case THREAD_QOS_USER_INITIATED: return _pthread_priority_make_newest(QOS_CLASS_USER_INITIATED, 0, 0);
  40                 case THREAD_QOS_LEGACY: return _pthread_priority_make_newest(QOS_CLASS_DEFAULT, 0, 0);
  41                 case THREAD_QOS_UTILITY: return _pthread_priority_make_newest(QOS_CLASS_UTILITY, 0, 0);
  42                 case THREAD_QOS_BACKGROUND: return _pthread_priority_make_newest(QOS_CLASS_BACKGROUND, 0, 0);
  43                 case THREAD_QOS_MAINTENANCE: return _pthread_priority_make_newest(QOS_CLASS_MAINTENANCE, 0, 0);
  44                 default: return _pthread_priority_make_newest(QOS_CLASS_UNSPECIFIED, 0, 0);
  45         }
  46 }
  47
  48 int
  49 thread_qos_get_class_index(int qos)
  50 {
  51     switch (qos) {
  52                 case THREAD_QOS_USER_INTERACTIVE: return 0;
  53                 case THREAD_QOS_USER_INITIATED: return 1;
  54                 case THREAD_QOS_LEGACY: return 2;
  55                 case THREAD_QOS_UTILITY: return 3;
  56                 case THREAD_QOS_BACKGROUND: return 4;
  57                 case THREAD_QOS_MAINTENANCE: return 5;
  58                 default: return 2;
  59     }
  60 }
  61
  62 int
  63 pthread_priority_get_thread_qos(pthread_priority_t priority)
  64 {
  65         /* Map the buckets we have in pthread_priority_t into a QoS tier. */
  66         switch (_pthread_priority_get_qos_newest(priority)) {
  67                 case QOS_CLASS_USER_INTERACTIVE: return THREAD_QOS_USER_INTERACTIVE;
  68                 case QOS_CLASS_USER_INITIATED: return THREAD_QOS_USER_INITIATED;
  69                 case QOS_CLASS_DEFAULT: return THREAD_QOS_LEGACY;
  70                 case QOS_CLASS_UTILITY: return THREAD_QOS_UTILITY;
  71                 case QOS_CLASS_BACKGROUND: return THREAD_QOS_BACKGROUND;
  72                 case QOS_CLASS_MAINTENANCE: return THREAD_QOS_MAINTENANCE;
  73                 default: return THREAD_QOS_UNSPECIFIED;
  74         }
  75 }
  76
  77 int
  78 pthread_priority_get_class_index(pthread_priority_t priority)
  79 {
  80         return qos_class_get_class_index(_pthread_priority_get_qos_newest(priority));
  81 }
  82
  83 pthread_priority_t
  84 class_index_get_pthread_priority(int index)
  85 {
  86         qos_class_t qos;
  87         switch (index) {
  88                 case 0: qos = QOS_CLASS_USER_INTERACTIVE; break;
  89                 case 1: qos = QOS_CLASS_USER_INITIATED; break;
  90                 case 2: qos = QOS_CLASS_DEFAULT; break;
  91                 case 3: qos = QOS_CLASS_UTILITY; break;
  92                 case 4: qos = QOS_CLASS_BACKGROUND; break;
  93                 case 5: qos = QOS_CLASS_MAINTENANCE; break;
  94                 case 6: assert(index != 6); // EVENT_MANAGER should be handled specially
  95                 default:
  96                         /* Return the utility band if we don't understand the input. */
  97                         qos = QOS_CLASS_UTILITY;
  98         }
  99
 100         pthread_priority_t priority;
 101         priority = _pthread_priority_make_newest(qos, 0, 0);
 102
 103         return priority;
 104 }
 105
 106 int
 107 class_index_get_thread_qos(int class)
 108 {
 109         int thread_qos;
 110         switch (class) {
 111                 case 0: thread_qos = THREAD_QOS_USER_INTERACTIVE; break;
 112                 case 1: thread_qos = THREAD_QOS_USER_INITIATED; break;
 113                 case 2: thread_qos = THREAD_QOS_LEGACY; break;
 114                 case 3: thread_qos = THREAD_QOS_UTILITY; break;
 115                 case 4: thread_qos = THREAD_QOS_BACKGROUND; break;
 116                 case 5: thread_qos = THREAD_QOS_MAINTENANCE; break;
 117                 case 6: thread_qos = THREAD_QOS_LAST; break;
 118                 default:
 119                         thread_qos = THREAD_QOS_LAST;
 120         }
 121         return thread_qos;
 122 }
 123
 124 int
 125 qos_class_get_class_index(int qos)
 126 {
 127         switch (qos){
 128                 case QOS_CLASS_USER_INTERACTIVE: return 0;
 129                 case QOS_CLASS_USER_INITIATED: return 1;
 130                 case QOS_CLASS_DEFAULT: return 2;
 131                 case QOS_CLASS_UTILITY: return 3;
 132                 case QOS_CLASS_BACKGROUND: return 4;
 133                 case QOS_CLASS_MAINTENANCE: return 5;
 134                 default:
 135                         /* Return the default band if we don't understand the input. */
 136                         return 2;
 137         }
 138 }
 139
 140 /**
 141  * Shims to help the kernel understand pthread_priority_t
 142  */
 143
 144 integer_t
 145 _thread_qos_from_pthread_priority(unsigned long priority, unsigned long *flags)
 146 {
 147     if (flags != NULL){
 148         *flags = (int)_pthread_priority_get_flags(priority);
 149     }
 150     int thread_qos = pthread_priority_get_thread_qos(priority);
 151     if (thread_qos == THREAD_QOS_UNSPECIFIED && flags != NULL){
 152         *flags |= _PTHREAD_PRIORITY_EVENT_MANAGER_FLAG;
 153     }
 154     return thread_qos;
 155 }
 156
 157 pthread_priority_t
 158 _pthread_priority_canonicalize(pthread_priority_t priority, boolean_t for_propagation)
 159 {
 160         qos_class_t qos_class;
 161         int relpri;
 162         unsigned long flags = _pthread_priority_get_flags(priority);
 163         _pthread_priority_split_newest(priority, qos_class, relpri);
 164
 165         if (for_propagation) {
 166                 flags = 0;
 167                 if (relpri > 0 || relpri < -15) relpri = 0;
 168         } else {
 169                 if (qos_class == QOS_CLASS_UNSPECIFIED) {
 170                         flags = _PTHREAD_PRIORITY_EVENT_MANAGER_FLAG;
 171                 } else if (flags & (_PTHREAD_PRIORITY_EVENT_MANAGER_FLAG|_PTHREAD_PRIORITY_SCHED_PRI_FLAG)){
 172                         flags = _PTHREAD_PRIORITY_EVENT_MANAGER_FLAG;
 173                         qos_class = QOS_CLASS_UNSPECIFIED;
 174                 } else {
 175                         flags &= _PTHREAD_PRIORITY_OVERCOMMIT_FLAG|_PTHREAD_PRIORITY_EVENT_MANAGER_FLAG;
 176                 }
 177
 178                 relpri = 0;
 179         }
 180
 181         return _pthread_priority_make_newest(qos_class, relpri, flags);
 182 }