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All Rights Reserved. 45 .\" Copyright (c) 2008, Sun Microsystems, Inc. All Rights Reserved. 46 .\" 47 .TH PTHREAD_GETSCHEDPARAM 3C "Apr 1, 2008" 48 .SH NAME 49 pthread_getschedparam, pthread_setschedparam \- access dynamic thread 50 scheduling parameters 51 .SH SYNOPSIS 52 .LP 53 .nf 54 cc -mt [ \fIflag\fR... ] \fIfile\fR... -lpthread [ \fIlibrary\fR... ] 55 #include <pthread.h> 56 57 \fBint\fR \fBpthread_getschedparam\fR(\fBpthread_t\fR \fIthread\fR, \fBint *restrict\fR \fIpolicy\fR, 58 \fBstruct sched_param *restrict\fR \fIparam\fR); 59 .fi 60 61 .LP 62 .nf 63 \fBint\fR \fBpthread_setschedparam\fR(\fBpthread_t\fR \fIthread\fR, \fBint\fR \fIpolicy\fR, 64 \fBconst struct sched_param *\fR\fIparam\fR); 65 .fi 66 67 .SH DESCRIPTION 68 .LP 69 The \fBpthread_getschedparam()\fR and \fBpthread_setschedparam()\fR functions 70 allow the scheduling policy and scheduling parameters of individual threads 71 within a multithreaded process to be retrieved and set. Supported policies are 72 : 73 .sp 74 .ne 2 75 .na 76 \fB\fBSCHED_OTHER\fR\fR 77 .ad 78 .RS 15n 79 traditional time-sharing scheduling class 80 .RE 81 82 .sp 83 .ne 2 84 .na 85 \fB\fBSCHED_FIFO\fR\fR 86 .ad 87 .RS 15n 88 real-time class: run to completion 89 .RE 90 91 .sp 92 .ne 2 93 .na 94 \fB\fBSCHED_RR\fR\fR 95 .ad 96 .RS 15n 97 real-time class: round-robin 98 .RE 99 100 .sp 101 .ne 2 102 .na 103 \fB\fBSCHED_IA\fR\fR 104 .ad 105 .RS 15n 106 interactive time-sharing class 107 .RE 108 109 .sp 110 .ne 2 111 .na 112 \fB\fBSCHED_FSS\fR\fR 113 .ad 114 .RS 15n 115 fair-share scheduling class 116 .RE 117 118 .sp 119 .ne 2 120 .na 121 \fB\fBSCHED_FX\fR\fR 122 .ad 123 .RS 15n 124 fixed priority scheduling class 125 .RE 126 127 .sp 128 .LP 129 See \fBpthreads\fR(5). The affected scheduling parameter is the 130 \fIsched_priority\fR member of the \fBsched_param\fR structure. 131 .sp 132 .LP 133 The \fBpthread_getschedparam()\fR function retrieves the scheduling policy and 134 scheduling parameters for the thread whose thread \fBID\fR is given by 135 \fIthread\fR and stores those values in \fIpolicy\fR and \fIparam\fR, 136 respectively. The priority value returned from \fBpthread_getschedparam()\fR is 137 the value specified by the most recent \fBpthread_setschedparam()\fR or 138 \fBpthread_create()\fR call affecting the target thread, and does not reflect 139 any temporary adjustments to its priority as a result of any priority 140 inheritance or ceiling functions. The \fBpthread_setschedparam()\fR function 141 sets the scheduling policy and associated scheduling parameters for the thread 142 whose thread \fBID\fR is given by \fIthread\fR to the policy and associated 143 parameters provided in \fIpolicy\fR and \fIparam\fR, respectively. 144 .sp 145 .LP 146 If the \fBpthread_setschedparam()\fR function fails, no scheduling parameters 147 will be changed for the target thread. 148 .SH RETURN VALUES 149 .LP 150 If successful, the \fBpthread_getschedparam()\fR and 151 \fBpthread_setschedparam()\fR functions return \fB0\fR. Otherwise, an error 152 number is returned to indicate the error. 153 .SH ERRORS 154 .LP 155 The \fBpthread_getschedparam()\fR and \fBpthread_setschedparam()\fR functions 156 will fail if: 157 .sp 158 .ne 2 159 .na 160 \fB\fBESRCH\fR\fR 161 .ad 162 .RS 9n 163 The value specified by \fIthread\fR does not refer to an existing thread. 164 .RE 165 166 .sp 167 .LP 168 The \fBpthread_setschedparam()\fR function will fail if: 169 .sp 170 .ne 2 171 .na 172 \fB\fBEINVAL\fR\fR 173 .ad 174 .RS 10n 175 The value specified by \fIpolicy\fR or one of the scheduling parameters 176 associated with the scheduling policy \fIpolicy\fR is invalid. 177 .RE 178 179 .sp 180 .ne 2 181 .na 182 \fB\fBEPERM\fR\fR 183 .ad 184 .RS 10n 185 The caller does not have the appropriate permission to set either the 186 scheduling parameters or the scheduling policy of the specified thread. 187 .RE 188 189 .SH ATTRIBUTES 190 .LP 191 See \fBattributes\fR(5) for descriptions of the following attributes: 192 .sp 193 194 .sp 195 .TS 196 box; 197 c | c 198 l | l . 199 ATTRIBUTE TYPE ATTRIBUTE VALUE 200 _ 201 Interface Stability Committed 202 _ 203 MT-Level MT-Safe 204 _ 205 Standard See \fBstandards\fR(5). 206 .TE 207 208 .SH SEE ALSO 209 .LP 210 \fBpthread_attr_init\fR(3C), \fBsched_getparam\fR(3C), 211 \fBsched_get_priority_max\fR(3C), \fBsched_get_priority_max\fR(3C), 212 \fBsched_get_priority_min\fR(3C), \fBsched_setparam\fR(3C), 213 \fBsched_getscheduler\fR(3C), \fBsched_setscheduler\fR(3C), 214 \fBattributes\fR(5), \fBpthreads\fR(5), \fBstandards\fR(5)