osfmk/kern/task_policy.c

   1 /*
   2  * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_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
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30
  31 #include <mach/mach_types.h>
  32 #include <mach/task_server.h>
  33
  34 #include <kern/sched.h>
  35 #include <kern/task.h>
  36
  37 static void
  38 task_priority(
  39         task_t                  task,
  40         integer_t               priority,
  41         integer_t               max_priority);
  42
  43 kern_return_t
  44 task_policy_set(
  45         task_t                                  task,
  46         task_policy_flavor_t    flavor,
  47         task_policy_t                   policy_info,
  48         mach_msg_type_number_t  count)
  49 {
  50         kern_return_t           result = KERN_SUCCESS;
  51
  52         if (task == TASK_NULL || task == kernel_task)
  53                 return (KERN_INVALID_ARGUMENT);
  54
  55         switch (flavor) {
  56
  57         case TASK_CATEGORY_POLICY:
  58         {
  59                 task_category_policy_t          info = (task_category_policy_t)policy_info;
  60
  61                 if (count < TASK_CATEGORY_POLICY_COUNT)
  62                         return (KERN_INVALID_ARGUMENT);
  63
  64                 task_lock(task);
  65
  66                 if (    info->role == TASK_FOREGROUND_APPLICATION       ||
  67                                 info->role == TASK_BACKGROUND_APPLICATION               ) {
  68                         switch (task->role) {
  69
  70                         case TASK_FOREGROUND_APPLICATION:
  71                         case TASK_BACKGROUND_APPLICATION:
  72                         case TASK_UNSPECIFIED:
  73                                 task_priority(task,
  74                                                                 ((info->role == TASK_FOREGROUND_APPLICATION)?
  75                                                                         BASEPRI_FOREGROUND: BASEPRI_BACKGROUND),
  76                                                           task->max_priority);
  77                                 task->role = info->role;
  78                                 break;
  79
  80                         case TASK_CONTROL_APPLICATION:
  81                         case TASK_RENICED:
  82                                 /* fail silently */
  83                                 break;
  84
  85                         default:
  86                                 result = KERN_INVALID_ARGUMENT;
  87                                 break;
  88                         }
  89                 }
  90                 else
  91                 if (info->role == TASK_CONTROL_APPLICATION) {
  92                         if (    task != current_task()                  ||
  93                                         task->sec_token.val[0] != 0                     )
  94                                 result = KERN_INVALID_ARGUMENT;
  95                         else {
  96                                 task_priority(task, BASEPRI_CONTROL, task->max_priority);
  97                                 task->role = info->role;
  98                         }
  99                 }
 100                 else
 101                 if (info->role == TASK_GRAPHICS_SERVER) {
 102                         if (    task != current_task()                  ||
 103                                         task->sec_token.val[0] != 0                     )
 104                                 result = KERN_INVALID_ARGUMENT;
 105                         else {
 106                                 task_priority(task, MAXPRI_RESERVED - 3, MAXPRI_RESERVED);
 107                                 task->role = info->role;
 108                         }
 109                 }
 110                 else
 111                         result = KERN_INVALID_ARGUMENT;
 112
 113                 task_unlock(task);
 114
 115                 break;
 116         }
 117
 118         default:
 119                 result = KERN_INVALID_ARGUMENT;
 120                 break;
 121         }
 122
 123         return (result);
 124 }
 125
 126 static void
 127 task_priority(
 128         task_t                  task,
 129         integer_t               priority,
 130         integer_t               max_priority)
 131 {
 132         thread_t                thread;
 133
 134         task->max_priority = max_priority;
 135
 136         if (priority > task->max_priority)
 137                 priority = task->max_priority;
 138         else
 139         if (priority < MINPRI)
 140                 priority = MINPRI;
 141
 142         task->priority = priority;
 143
 144         queue_iterate(&task->threads, thread, thread_t, task_threads) {
 145                 thread_mtx_lock(thread);
 146
 147                 if (thread->active)
 148                         thread_task_priority(thread, priority, max_priority);
 149
 150                 thread_mtx_unlock(thread);
 151         }
 152 }
 153
 154 kern_return_t
 155 task_importance(
 156         task_t                          task,
 157         integer_t                       importance)
 158 {
 159         if (task == TASK_NULL || task == kernel_task)
 160                 return (KERN_INVALID_ARGUMENT);
 161
 162         task_lock(task);
 163
 164         if (!task->active) {
 165                 task_unlock(task);
 166
 167                 return (KERN_TERMINATED);
 168         }
 169
 170         if (task->role >= TASK_CONTROL_APPLICATION) {
 171                 task_unlock(task);
 172
 173                 return (KERN_INVALID_ARGUMENT);
 174         }
 175
 176         task_priority(task, importance + BASEPRI_DEFAULT, task->max_priority);
 177         task->role = TASK_RENICED;
 178
 179         task_unlock(task);
 180
 181         return (KERN_SUCCESS);
 182 }
 183
 184 kern_return_t
 185 task_policy_get(
 186         task_t                                  task,
 187         task_policy_flavor_t    flavor,
 188         task_policy_t                   policy_info,
 189         mach_msg_type_number_t  *count,
 190         boolean_t                               *get_default)
 191 {
 192         if (task == TASK_NULL || task == kernel_task)
 193                 return (KERN_INVALID_ARGUMENT);
 194
 195         switch (flavor) {
 196
 197         case TASK_CATEGORY_POLICY:
 198         {
 199                 task_category_policy_t          info = (task_category_policy_t)policy_info;
 200
 201                 if (*count < TASK_CATEGORY_POLICY_COUNT)
 202                         return (KERN_INVALID_ARGUMENT);
 203
 204                 if (*get_default)
 205                         info->role = TASK_UNSPECIFIED;
 206                 else {
 207                         task_lock(task);
 208                         info->role = task->role;
 209                         task_unlock(task);
 210                 }
 211                 break;
 212         }
 213
 214         default:
 215                 return (KERN_INVALID_ARGUMENT);
 216         }
 217
 218         return (KERN_SUCCESS);
 219 }