NANOSLEEP(2) | System Calls Manual | NANOSLEEP(2) |
nanosleep
, clock_nanosleep
—
#include <time.h>
int
clock_nanosleep
(clockid_t
clock_id, int
flags, const struct
timespec *rqtp, struct
timespec *rmtp);
int
nanosleep
(const
struct timespec *rqtp,
struct timespec
*rmtp);
TIMER_ABSTIME
flag is not set in the
flags argument, then
clock_nanosleep
() suspends execution of the calling
thread until either the number of seconds and nanoseconds specified in the
rqtp argument have elapsed using the clock in the
clock_id argument, or a signal is delivered to the
calling process and its action is to invoke a signal catching function or to
terminate the process.
If the TIMER_ABSTIME
flag is set in the
flags argument, then
clock_nanosleep
() suspends execution of the calling
thread until either the value of the clock specified in the
clock_id argument reaches the value of the
rqtp argument in seconds and nanoseconds, or a signal
is delivered to the calling process and its action is to invoke a signal
catching function or to terminate the process.
The suspension time may be longer than requested due to the scheduling of other activity by the system.
The nanosleep
() function behaves like
clock_nanosleep
() with the
clock_id argument equal to
CLOCK_MONOTONIC
and the flags
argument having TIMER_ABSTIME
not set.
The struct timespec is described in timespec(3). The clock_id specified is the time source, which is described in clock_gettime(2).
clock_nanosleep
() or the
nanosleep
() functions return because the requested
time has elapsed, the value returned will be zero.
If the clock_nanosleep
() or the
nanosleep
() functions return due to the delivery of
a signal, then clock_nanosleep
() will return
directly the error number, and nanosleep
() will
return -1, and the global variable errno will be set
to indicate the interruption. If rmtp is
non-NULL
, the timespec structure it references is
updated to contain the unslept amount (the request time minus the time
actually slept), unless it is called from
clock_nanosleep
() with a flags
argument of TIMER_ABSTIME
. In that case, the
rmtp argument is left unmodified.
nanosleep
() function shall return -1 and set
errno to the corresponding value, and the
clock_nanosleep
() function shall return the error
number directly.
EFAULT
]EINTR
]nanosleep
was interrupted by the delivery of a
signal.EINVAL
]ENOSYS
]nanosleep
is not supported by this
implementation.ENOTSUP
]clock_nanosleep
(), the clock specified in the
clock_id argument is not supported.nanosleep
() function conforms to
IEEE Std 1003.1b-1993 (“POSIX.1b”). The
clock_nanosleep
() function conforms to
IEEE Std 1003.1-2008 (“POSIX.1”).
HZ
which is
by default 100
in most architectures. This means that
a request to sleep for less than 10ms
(1 /
HZ
seconds), is rounded up to that.
November 11, 2016 | NetBSD 9.0 |