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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 .sp 69 .LP 70 The \fBpthread_getschedparam()\fR and \fBpthread_setschedparam()\fR functions 71 allow the scheduling policy and scheduling parameters of individual threads 72 within a multithreaded process to be retrieved and set. Supported policies are 73 : 74 .sp 75 .ne 2 76 .na 77 \fB\fBSCHED_OTHER\fR\fR 78 .ad 79 .RS 15n 80 traditional time-sharing scheduling class 81 .RE 82 83 .sp 84 .ne 2 85 .na 86 \fB\fBSCHED_FIFO\fR\fR 87 .ad 88 .RS 15n 89 real-time class: run to completion 90 .RE 91 92 .sp 93 .ne 2 94 .na 95 \fB\fBSCHED_RR\fR\fR 96 .ad 97 .RS 15n 98 real-time class: round-robin 99 .RE 100 101 .sp 102 .ne 2 103 .na 104 \fB\fBSCHED_IA\fR\fR 105 .ad 106 .RS 15n 107 interactive time-sharing class 108 .RE 109 110 .sp 111 .ne 2 112 .na 113 \fB\fBSCHED_FSS\fR\fR 114 .ad 115 .RS 15n 116 fair-share scheduling class 117 .RE 118 119 .sp 120 .ne 2 121 .na 122 \fB\fBSCHED_FX\fR\fR 123 .ad 124 .RS 15n 125 fixed priority scheduling class 126 .RE 127 128 .sp 129 .LP 130 See \fBpthreads\fR(5). The affected scheduling parameter is the 131 \fIsched_priority\fR member of the \fBsched_param\fR structure. 132 .sp 133 .LP 134 The \fBpthread_getschedparam()\fR function retrieves the scheduling policy and 135 scheduling parameters for the thread whose thread \fBID\fR is given by 136 \fIthread\fR and stores those values in \fIpolicy\fR and \fIparam\fR, 137 respectively. The priority value returned from \fBpthread_getschedparam()\fR is 138 the value specified by the most recent \fBpthread_setschedparam()\fR or 139 \fBpthread_create()\fR call affecting the target thread, and does not reflect 140 any temporary adjustments to its priority as a result of any priority 141 inheritance or ceiling functions. The \fBpthread_setschedparam()\fR function 142 sets the scheduling policy and associated scheduling parameters for the thread 143 whose thread \fBID\fR is given by \fIthread\fR to the policy and associated 144 parameters provided in \fIpolicy\fR and \fIparam\fR, respectively. 145 .sp 146 .LP 147 If the \fBpthread_setschedparam()\fR function fails, no scheduling parameters 148 will be changed for the target thread. 149 .SH RETURN VALUES 150 .sp 151 .LP 152 If successful, the \fBpthread_getschedparam()\fR and 153 \fBpthread_setschedparam()\fR functions return \fB0\fR. Otherwise, an error 154 number is returned to indicate the error. 155 .SH ERRORS 156 .sp 157 .LP 158 The \fBpthread_getschedparam()\fR and \fBpthread_gsetschedparam()\fR functions 159 will fail if: 160 .sp 161 .ne 2 162 .na 163 \fB\fBESRCH\fR\fR 164 .ad 165 .RS 9n 166 The value specified by \fIthread\fR does not refer to an existing thread. 167 .RE 168 169 .sp 170 .LP 171 The \fBpthread_setschedparam()\fR function will fail if: 172 .sp 173 .ne 2 174 .na 175 \fB\fBEINVAL\fR\fR 176 .ad 177 .RS 10n 178 The value specified by \fIpolicy\fR or one of the scheduling parameters 179 associated with the scheduling policy \fIpolicy\fR is invalid. 180 .RE 181 182 .sp 183 .ne 2 184 .na 185 \fB\fBEPERM\fR\fR 186 .ad 187 .RS 10n 188 The caller does not have the appropriate permission to set either the 189 scheduling parameters or the scheduling policy of the specified thread. 190 .RE 191 192 .SH ATTRIBUTES 193 .sp 194 .LP 195 See \fBattributes\fR(5) for descriptions of the following attributes: 196 .sp 197 198 .sp 199 .TS 200 box; 201 c | c 202 l | l . 203 ATTRIBUTE TYPE ATTRIBUTE VALUE 204 _ 205 Interface Stability Committed 206 _ 207 MT-Level MT-Safe 208 _ 209 Standard See \fBstandards\fR(5). 210 .TE 211 212 .SH SEE ALSO 213 .sp 214 .LP 215 \fBpthread_attr_init\fR(3C), \fBsched_getparam\fR(3C), 216 \fBsched_get_priority_max\fR(3C), \fBsched_get_priority_max\fR(3C), 217 \fBsched_get_priority_min\fR(3C), \fBsched_setparam\fR(3C), 218 \fBsched_getscheduler\fR(3C), \fBsched_setscheduler\fR(3C), 219 \fBattributes\fR(5), \fBpthreads\fR(5), \fBstandards\fR(5)