diff options
Diffstat (limited to 'man2/timerfd_create.2')
| -rw-r--r-- | man2/timerfd_create.2 | 50 |
1 files changed, 27 insertions, 23 deletions
diff --git a/man2/timerfd_create.2 b/man2/timerfd_create.2 index 6ceea56..1d6a0d2 100644 --- a/man2/timerfd_create.2 +++ b/man2/timerfd_create.2 @@ -2,7 +2,7 @@ .\" .\" SPDX-License-Identifier: GPL-2.0-or-later .\" -.TH timerfd_create 2 2023-05-03 "Linux man-pages 6.05.01" +.TH timerfd_create 2 2023-10-31 "Linux man-pages 6.7" .SH NAME timerfd_create, timerfd_settime, timerfd_gettime \- timers that notify via file descriptors @@ -12,9 +12,9 @@ Standard C library .SH SYNOPSIS .nf .B #include <sys/timerfd.h> -.PP +.P .BI "int timerfd_create(int " clockid ", int " flags ); -.PP +.P .BI "int timerfd_settime(int " fd ", int " flags , .BI " const struct itimerspec *" new_value , .BI " struct itimerspec *_Nullable " old_value ); @@ -32,7 +32,7 @@ with the advantage that the file descriptor may be monitored by .BR poll (2), and .BR epoll (7). -.PP +.P The use of these three system calls is analogous to the use of .BR timer_create (2), .BR timer_settime (2), @@ -93,14 +93,14 @@ but will wake the system if it is suspended. The caller must have the .B CAP_WAKE_ALARM capability in order to set a timer against this clock. -.PP +.P See .BR clock_getres (2) for some further details on the above clocks. -.PP +.P The current value of each of these clocks can be retrieved using .BR clock_gettime (2). -.PP +.P Starting with Linux 2.6.27, the following values may be bitwise ORed in .I flags to change the behavior of @@ -125,7 +125,7 @@ See the description of the flag in .BR open (2) for reasons why this may be useful. -.PP +.P In Linux versions up to and including 2.6.26, .I flags must be specified as zero. @@ -134,7 +134,7 @@ must be specified as zero. arms (starts) or disarms (stops) the timer referred to by the file descriptor .IR fd . -.PP +.P The .I new_value argument specifies the initial expiration and interval for the timer. @@ -142,7 +142,7 @@ The .I itimerspec structure used for this argument is described in .BR itimerspec (3type). -.PP +.P .I new_value.it_value specifies the initial expiration of the timer, in seconds and nanoseconds. @@ -152,7 +152,7 @@ to a nonzero value arms the timer. Setting both fields of .I new_value.it_value to zero disarms the timer. -.PP +.P Setting one or both fields of .I new_value.it_interval to nonzero values specifies the period, in seconds and nanoseconds, @@ -161,7 +161,7 @@ If both fields of .I new_value.it_interval are zero, the timer expires just once, at the time specified by .IR new_value.it_value . -.PP +.P By default, the initial expiration time specified in .I new_value @@ -173,7 +173,7 @@ specifies a time relative to the current value of the clock specified by An absolute timeout can be selected via the .I flags argument. -.PP +.P The .I flags argument is a bit mask that can include the following values: @@ -202,7 +202,7 @@ When such changes occur, a current or future .BR read (2) from the file descriptor will fail with the error .BR ECANCELED . -.PP +.P If the .I old_value argument is not NULL, then the @@ -222,7 +222,7 @@ an structure that contains the current setting of the timer referred to by the file descriptor .IR fd . -.PP +.P The .I it_value field returns the amount of time @@ -232,7 +232,7 @@ then the timer is currently disarmed. This field always contains a relative value, regardless of whether the .B TFD_TIMER_ABSTIME flag was specified when setting the timer. -.PP +.P The .I it_interval field returns the interval of the timer. @@ -317,7 +317,11 @@ but before the .BR read (2) on the file descriptor. .TP -.BR poll "(2), " select "(2) (and similar)" +.BR poll (2) +.TQ +.BR select (2) +.TQ +(and similar) The file descriptor is readable (the .BR select (2) @@ -384,7 +388,7 @@ returns a new file descriptor. On error, \-1 is returned and .I errno is set to indicate the error. -.PP +.P .BR timerfd_settime () and .BR timerfd_gettime () @@ -430,7 +434,7 @@ or but the caller did not have the .B CAP_WAKE_ALARM capability. -.PP +.P .BR timerfd_settime () and .BR timerfd_gettime () @@ -450,7 +454,7 @@ is not a valid pointer. .B EINVAL .I fd is not a valid timerfd file descriptor. -.PP +.P .BR timerfd_settime () can also fail with the following errors: .TP @@ -500,7 +504,7 @@ the caller once more calls to rearm the timer (without first doing a .BR read (2) on the file descriptor). -.PP +.P In this case the following occurs: .IP \[bu] 3 The @@ -534,9 +538,9 @@ The second argument specifies the interval for the timer, in seconds. The third argument specifies the number of times the program should allow the timer to expire before terminating. The second and third command-line arguments are optional. -.PP +.P The following shell session demonstrates the use of the program: -.PP +.P .in +4n .EX .RB "$" " a.out 3 1 100" |