1 .\" Hey Emacs! This file is -*- nroff -*- source.
3 .\" Copyright (c) 2003 Nick Clifford (zaf@nrc.co.nz), Jan 25, 2003
4 .\" Copyright (c) 2003 Andries Brouwer (aeb@cwi.nl), Aug 24, 2003
6 .\" Permission is granted to make and distribute verbatim copies of this
7 .\" manual provided the copyright notice and this permission notice are
8 .\" preserved on all copies.
10 .\" Permission is granted to copy and distribute modified versions of this
11 .\" manual under the conditions for verbatim copying, provided that the
12 .\" entire resulting derived work is distributed under the terms of a
13 .\" permission notice identical to this one.
15 .\" Since the Linux kernel and libraries are constantly changing, this
16 .\" manual page may be incorrect or out-of-date. The author(s) assume no
17 .\" responsibility for errors or omissions, or for damages resulting from
18 .\" the use of the information contained herein. The author(s) may not
19 .\" have taken the same level of care in the production of this manual,
20 .\" which is licensed free of charge, as they might when working
23 .\" Formatted or processed versions of this manual, if unaccompanied by
24 .\" the source, must acknowledge the copyright and authors of this work.
26 .\" 2003-08-23 Martin Schulze <joey@infodrom.org> improvements
27 .\" 2003-08-24 aeb, large parts rewritten
28 .\" 2004-08-06 Christoph Lameter <clameter@sgi.com>, SMP note
30 .\" FIXME: Linux 2.6.39 adds CLOCK_BOOTTIME
32 .\" Japanese Version Copyright (c) 2004-2005 Yuichi SATO
33 .\" all rights reserved.
34 .\" Translated 2004-07-19, Yuichi SATO <ysato444@yahoo.co.jp>
35 .\" Updated & Modified 2005-01-10, Yuichi SATO
36 .\" Updated 2010-04-11, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>
38 .TH CLOCK_GETRES 2 2010-02-03 "" "Linux Programmer's Manual"
40 clock_getres, clock_gettime, clock_settime \- ¥¯¥í¥Ã¥¯¤È»þ´Ö¤Î´Ø¿ô
44 .BI "int clock_getres(clockid_t " clk_id ", struct timespec *" res );
46 .BI "int clock_gettime(clockid_t " clk_id ", struct timespec *" tp );
48 .BI "int clock_settime(clockid_t " clk_id ", const struct timespec *" tp );
50 \fI\-lrt\fP ¤È¥ê¥ó¥¯¤¹¤ë¡£
53 glibc ¸þ¤±¤Îµ¡Ç½¸¡ºº¥Þ¥¯¥í¤ÎÍ×·ï
54 .RB ( feature_test_macros (7)
63 _POSIX_C_SOURCE\ >=\ 199309L
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74 ¤¬ NULL ¤Ç¤Ê¤¤¾ì¹ç¡¢¤½¤Îʬ²òǽ¤ò
76 ¤Ç»Ø¤µ¤ì¤ë \fIstruct timespec\fP ¤Ë³ÊǼ¤¹¤ë¡£
77 ¥¯¥í¥Ã¥¯¤Îʬ²òǽ¤Ï¼ÂÁõ¤Ë°Í¸¤·¡¢
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103 ¤Ç°Ê²¼¤Î¤è¤¦¤Ëµ¬Äꤵ¤ì¤Æ¤¤¤ë:
108 time_t tv_sec; /* seconds */
109 long tv_nsec; /* nanoseconds */
115 °ú¤¿ô¤ÏÆÃÄê¤Î¥¯¥í¥Ã¥¯¤Î¼±Ê̻ҤǤ¢¤ê¡¢¤½¤Î¥¯¥í¥Ã¥¯¤ÇÆ°ºî¤¹¤ë¡£
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131 glibc ¤È Linux ¥«¡¼¥Í¥ë¤ÎºÇ¿·¤Î¥Ð¡¼¥¸¥ç¥ó¤Ç¤Ï¡¢
132 °Ê²¼¤Î¤è¤¦¤Ê½½Ê¬¤Ê¥¯¥í¥Ã¥¯¤¬¥µ¥Ý¡¼¥È¤µ¤ì¤Æ¤¤¤ë¡£
135 ¥·¥¹¥Æ¥àÁ´ÂΤΥꥢ¥ë¥¿¥¤¥à¥¯¥í¥Ã¥¯¡£
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140 ¥¯¥í¥Ã¥¯¤¬¥â¥Î¥È¥Ë¥Ã¥¯¥¿¥¤¥à¤òÀßÄꤷ¤¿¤êɽ¸½¤·¤¿¤ê¤Ç¤¤Ê¤¤¡£
142 .BR CLOCK_MONOTONIC_RAW " (Linux 2.6.28 °Ê¹ß; Linux ÆÃÍ)"
143 .\" Added in commit 2d42244ae71d6c7b0884b5664cf2eda30fb2ae68, John Stultz
145 ¤ÈƱÍͤÀ¤¬¡¢NTP ¤Ë¤è¤ëÄ´À°¤Î±Æ¶Á¤ò¼õ¤±¤Ê¤¤¡¢¥Ï¡¼¥É¥¦¥§¥¢¤Ë¤è¤ë
146 À¸¤Î»þ¹ï¤Ø¤Î¥¢¥¯¥»¥¹¤¬¤Ç¤¤ë¡£
148 .B CLOCK_PROCESS_CPUTIME_ID
149 CPU ¤Ë¤è¤ë¹âʬ²òǽ¤Î¥×¥í¥»¥¹Ëè¤Î¥¿¥¤¥Þ¡£
151 .B CLOCK_THREAD_CPUTIME_ID
152 ¥¹¥ì¥Ã¥É¸ÇͤΠCPU ¥¿¥¤¥à¥¯¥í¥Ã¥¯¡£
154 .BR clock_gettime (),
155 .BR clock_settime (),
157 ¤ÏÀ®¸ù¤·¤¿¾ì¹ç¤Ë 0 ¤òÊÖ¤·¡¢¼ºÇÔ¤·¤¿¾ì¹ç¤Ë \-1 ¤òÊÖ¤¹
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165 ¤¬¥¢¥¯¥»¥¹²Äǽ¤Ê¥¢¥É¥ì¥¹¶õ´Ö¤Î³°¤ò»Ø¤·¤¿¡£
168 .\" Linux also gives this error on attempts to set CLOCK_PROCESS_CPUTIME_ID
169 .\" and CLOCK_THREAD_CPUTIME_ID, when probably the proper error should be
173 ¤¬¤³¤Î¥·¥¹¥Æ¥à¤Ç¥µ¥Ý¡¼¥È¤µ¤ì¤Æ¤¤¤Ê¤¤¡£
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182 ¤³¤ì¤é¤Î´Ø¿ô¤¬ÍøÍѲÄǽ¤Ê POSIX ¥·¥¹¥Æ¥à¤Ç¤Ï¡¢\fI<unistd.h>\fP ¤Ë¤ª¤¤¤Æ¥·¥ó¥Ü¥ë
184 ¤¬ 0 ¤è¤êÂ礤¤ÃͤËÄêµÁ¤µ¤ì¤Æ¤¤¤ë¡£
186 .BR _POSIX_MONOTONIC_CLOCK ,
188 .B _POSIX_THREAD_CPUTIME
190 .BR CLOCK_MONOTONIC ,
191 .BR CLOCK_PROCESS_CPUTIME_ID ,
192 .B CLOCK_THREAD_CPUTIME_ID
193 ¤¬ÍøÍѲÄǽ¤Ê¤³¤È¤ò¼¨¤¹¡£
197 .SS "SMP ¥·¥¹¥Æ¥à¤Ë¤Ä¤¤¤Æ¤ÎÃí°Õ"
198 .B CLOCK_PROCESS_CPUTIME_ID
200 .B CLOCK_THREAD_CPUTIME_ID
201 ¥¯¥í¥Ã¥¯¤Ï¡¢CPU ¤«¤é¤Î¥¿¥¤¥Þ
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204 ¥×¥í¥»¥¹¤¬Â¾¤Î CPU ¤Ë°ÜÆ°¤µ¤»¤é¤ì¤¿¾ì¹ç¡¢
205 ·ë²Ì¤È¤·¤Æ¤³¤ì¤é¤Î¥¯¥í¥Ã¥¯¤¬\fBµ¶¤Î·ë²Ì\fR
206 (bogus results) ¤òÊÖ¤¹¤«¤â¤·¤ì¤Ê¤¤¡£
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209 ¥¿¥¤¥Þ¥ì¥¸¥¹¥¿´Ö¤ÎÁê¸ß´Ø·¸¤ò´ÉÍý¤¹¤ëÊýË¡¤Ï¤Ê¤¤¡£
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212 .I clock_getcpuclockid(0)
215 ¤òÊÖ¤·¤Æ¡¢¤½¤Î¾õ¶·¤òɽ¤¹¡£
216 2 ¤Ä¤Î¥¯¥í¥Ã¥¯¤Ï¡¢¥×¥í¥»¥¹¤¬ÆÃÄê¤Î CPU ¾å¤Ëα¤Þ¤Ã¤Æ¤¤¤ë¤³¤È¤¬
217 ÊݾڤǤ¤ë¾ì¹ç¤Ë¤Î¤ß͸ú¤Ç¤¢¤ë¡£
219 SMP ¥·¥¹¥Æ¥à¤Î³Æ¥×¥í¥»¥Ã¥µ¤ÏÁ´¤¯Æ±¤¸»þ¹ï¤Ëµ¯Æ°¤¹¤ëÌõ¤Ç¤Ï¤Ê¤¤¤Î¤Ç¡¢
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223 glibc ¤Ï (Linux ¥«¡¼¥Í¥ë¤È¤Ï°Û¤Ê¤ê) ¥ª¥Õ¥»¥Ã¥È¤ò°·¤¦¤¿¤á¤Î¥³¡¼¥É¤òÄ󶡤·¤Ê¤¤¡£
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227 ¡ÖŬÀÚ¤ÊÆø¢ (appropriate privileges)¡×¤ò»ý¤Ã¤¿¥×¥í¥»¥¹¤Ï¡¢
230 .B CLOCK_PROCESS_CPUTIME_ID
232 .B CLOCK_THREAD_CPUTIME_ID
233 ¤òÀßÄꤹ¤ë¤³¤È¤¬¤Ç¤¤ë¤È¤µ¤ì¤Æ¤¤¤ë¡£
234 Linux ¤Ç¤Ï¡¢¤³¤ì¤é¤Î¥¯¥í¥Ã¥¯¤ÏÀßÄê²Äǽ¤Ç¤Ï¤Ê¤¤
235 (¤¹¤Ê¤ï¤Á¡¢¤É¤Î¥×¥í¥»¥¹¤â¡ÖŬÀÚ¤ÊÆø¢¡×¤ò»ý¤¿¤Ê¤¤)¡£
236 .\" See http://bugzilla.kernel.org/show_bug.cgi?id=11972
240 .BR gettimeofday (2),
241 .BR settimeofday (2),
243 .BR clock_getcpuclockid (3),
246 .BR pthread_getcpuclockid (3),