osfmk/kern/task_policy.c

   1 /*
   2  * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22
  23 #include <mach/mach_types.h>
  24 #include <mach/task_server.h>
  25
  26 #include <kern/sched.h>
  27 #include <kern/task.h>
  28
  29 static void
  30 task_priority(
  31         task_t                  task,
  32         integer_t               priority,
  33         integer_t               max_priority);
  34
  35 kern_return_t
  36 task_policy_set(
  37         task_t                                  task,
  38         task_policy_flavor_t    flavor,
  39         task_policy_t                   policy_info,
  40         mach_msg_type_number_t  count)
  41 {
  42         kern_return_t           result = KERN_SUCCESS;
  43
  44         if (task == TASK_NULL || task == kernel_task)
  45                 return (KERN_INVALID_ARGUMENT);
  46
  47         switch (flavor) {
  48
  49         case TASK_CATEGORY_POLICY:
  50         {
  51                 task_category_policy_t          info = (task_category_policy_t)policy_info;
  52
  53                 if (count < TASK_CATEGORY_POLICY_COUNT)
  54                         return (KERN_INVALID_ARGUMENT);
  55
  56                 task_lock(task);
  57
  58                 if (    info->role == TASK_FOREGROUND_APPLICATION       ||
  59                                 info->role == TASK_BACKGROUND_APPLICATION               ) {
  60                         switch (task->role) {
  61
  62                         case TASK_FOREGROUND_APPLICATION:
  63                         case TASK_BACKGROUND_APPLICATION:
  64                         case TASK_UNSPECIFIED:
  65                                 task_priority(task,
  66                                                                 ((info->role == TASK_FOREGROUND_APPLICATION)?
  67                                                                         BASEPRI_FOREGROUND: BASEPRI_BACKGROUND),
  68                                                           task->max_priority);
  69                                 task->role = info->role;
  70                                 break;
  71
  72                         case TASK_CONTROL_APPLICATION:
  73                         case TASK_RENICED:
  74                                 /* fail silently */
  75                                 break;
  76
  77                         default:
  78                                 result = KERN_INVALID_ARGUMENT;
  79                                 break;
  80                         }
  81                 }
  82                 else
  83                 if (info->role == TASK_CONTROL_APPLICATION) {
  84                         if (    task != current_task()                  ||
  85                                         task->sec_token.val[0] != 0                     )
  86                                 result = KERN_INVALID_ARGUMENT;
  87                         else {
  88                                 task_priority(task, BASEPRI_CONTROL, task->max_priority);
  89                                 task->role = info->role;
  90                         }
  91                 }
  92                 else
  93                 if (info->role == TASK_GRAPHICS_SERVER) {
  94                         if (    task != current_task()                  ||
  95                                         task->sec_token.val[0] != 0                     )
  96                                 result = KERN_INVALID_ARGUMENT;
  97                         else {
  98                                 task_priority(task, MAXPRI_RESERVED - 3, MAXPRI_RESERVED);
  99                                 task->role = info->role;
 100                         }
 101                 }
 102                 else
 103                         result = KERN_INVALID_ARGUMENT;
 104
 105                 task_unlock(task);
 106
 107                 break;
 108         }
 109
 110         default:
 111                 result = KERN_INVALID_ARGUMENT;
 112                 break;
 113         }
 114
 115         return (result);
 116 }
 117
 118 static void
 119 task_priority(
 120         task_t                  task,
 121         integer_t               priority,
 122         integer_t               max_priority)
 123 {
 124         thread_t                thread;
 125
 126         task->max_priority = max_priority;
 127
 128         if (priority > task->max_priority)
 129                 priority = task->max_priority;
 130         else
 131         if (priority < MINPRI)
 132                 priority = MINPRI;
 133
 134         task->priority = priority;
 135
 136         queue_iterate(&task->threads, thread, thread_t, task_threads) {
 137                 thread_mtx_lock(thread);
 138
 139                 if (thread->active)
 140                         thread_task_priority(thread, priority, max_priority);
 141
 142                 thread_mtx_unlock(thread);
 143         }
 144 }
 145
 146 kern_return_t
 147 task_importance(
 148         task_t                          task,
 149         integer_t                       importance)
 150 {
 151         if (task == TASK_NULL || task == kernel_task)
 152                 return (KERN_INVALID_ARGUMENT);
 153
 154         task_lock(task);
 155
 156         if (!task->active) {
 157                 task_unlock(task);
 158
 159                 return (KERN_TERMINATED);
 160         }
 161
 162         if (task->role >= TASK_CONTROL_APPLICATION) {
 163                 task_unlock(task);
 164
 165                 return (KERN_INVALID_ARGUMENT);
 166         }
 167
 168         task_priority(task, importance + BASEPRI_DEFAULT, task->max_priority);
 169         task->role = TASK_RENICED;
 170
 171         task_unlock(task);
 172
 173         return (KERN_SUCCESS);
 174 }
 175
 176 kern_return_t
 177 task_policy_get(
 178         task_t                                  task,
 179         task_policy_flavor_t    flavor,
 180         task_policy_t                   policy_info,
 181         mach_msg_type_number_t  *count,
 182         boolean_t                               *get_default)
 183 {
 184         if (task == TASK_NULL || task == kernel_task)
 185                 return (KERN_INVALID_ARGUMENT);
 186
 187         switch (flavor) {
 188
 189         case TASK_CATEGORY_POLICY:
 190         {
 191                 task_category_policy_t          info = (task_category_policy_t)policy_info;
 192
 193                 if (*count < TASK_CATEGORY_POLICY_COUNT)
 194                         return (KERN_INVALID_ARGUMENT);
 195
 196                 if (*get_default)
 197                         info->role = TASK_UNSPECIFIED;
 198                 else {
 199                         task_lock(task);
 200                         info->role = task->role;
 201                         task_unlock(task);
 202                 }
 203                 break;
 204         }
 205
 206         default:
 207                 return (KERN_INVALID_ARGUMENT);
 208         }
 209
 210         return (KERN_SUCCESS);
 211 }