libsyscall/wrappers/getiopolicy_np.c

   1 /*
   2  * Copyright (c) 2006 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_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. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 #include <errno.h>
  24 #include <sys/resource.h>
  25 #include <mach/port.h>
  26
  27 extern int __iopolicysys(int, struct _iopol_param_t *);
  28 extern void _pthread_clear_qos_tsd(mach_port_t);
  29
  30 int
  31 getiopolicy_np(int iotype, int scope)
  32 {
  33         int policy, error;
  34         struct _iopol_param_t iop_param;
  35
  36         if ((iotype != IOPOL_TYPE_DISK && iotype != IOPOL_TYPE_VFS_ATIME_UPDATES && iotype != IOPOL_TYPE_VFS_MATERIALIZE_DATALESS_FILES) ||
  37             (scope != IOPOL_SCOPE_PROCESS && scope != IOPOL_SCOPE_THREAD)) {
  38                 errno = EINVAL;
  39                 policy = -1;
  40                 goto exit;
  41         }
  42
  43         iop_param.iop_scope = scope;
  44         iop_param.iop_iotype = iotype;
  45         error = __iopolicysys(IOPOL_CMD_GET, &iop_param);
  46         if (error != 0) {
  47                 errno = error;
  48                 policy = -1;
  49                 goto exit;
  50         }
  51
  52         policy = iop_param.iop_policy;
  53
  54 exit:
  55         return policy;
  56 }
  57
  58 int
  59 setiopolicy_np(int iotype, int scope, int policy)
  60 {
  61         /* kernel validates the indiv values, no need to repeat it */
  62         struct _iopol_param_t iop_param;
  63
  64         iop_param.iop_scope = scope;
  65         iop_param.iop_iotype = iotype;
  66         iop_param.iop_policy = policy;
  67
  68         int rv = __iopolicysys(IOPOL_CMD_SET, &iop_param);
  69         if (rv == -2) {
  70                 /* not an actual error but indication that __iopolicysys removed the thread QoS */
  71                 _pthread_clear_qos_tsd(MACH_PORT_NULL);
  72                 rv = 0;
  73         }
  74
  75         return rv;
  76 }