HRTIME
Section: High-resolution timing (2)
Updated: Release 0.5
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NAME
get_hrtime_self, get_hrvtime_self, get_hrutime_self, get_hrstime_self,
- self timing functions
SYNOPSIS
#include <hrtime.h>
void get_hrtime_self(hrtime_t *dest);
void get_hrvtime_self(hrtime_t *dest);
void get_hrutime_self(hrtime_t *dest);
void get_hrstime_self(hrtime_t *dest);
ARGUMENTS
- dest
-
Specifies the location to which the desired timing value should be
written. Again, it is the responsibility of the caller to insure that
dest is non-null.
DESCRIPTION
- get_hrtime_self
-
writes the wall time of the current process, in timestamp counter
ticks, to the location specified by dest. hrtime_init
must be called prior to calling this function.
- get_hrvtime_self
-
writes the total virtual time of the current process, in timestamp
counter ticks, to the location specified by dest.
hrtime_init must be called prior to calling this function.
- get_hrutime_self
-
writes the virtualized user time of the current process, in timestamp
counter ticks, to the location specified by dest. This function
returns an undefined value if the kernel was not configured with
CONFIG_HRUSTIME, the option enabling additional instrumentation
on the system call path. You can check for this at runtime by mapping
a struct hrtime and looking at hr->has_ustime.
hrtime_init must be called prior to calling this function.
- get_hrstime_self
-
writes the virtualized system time of the current process, in
timestamp counter ticks, to the location specified by dest.
This function returns an undefined value if the kernel was not
configured with CONFIG_HRUSTIME, the option enabling additional
instrumentation on the system call path. You can check for this at
runtime by mapping a struct hrtime and looking at
hr->has_ustime. hrtime_init must be called prior to
calling this function.
BUGS
The current implementation is based on the flawed assumption that the
timestamp counter is incremented once per clock cycle (this is true on
all current implementations of Intel processors, but not guaranteed in
the specification).
AUTHOR
Nick Rasmussen <nick@jive.org>
SEE ALSO
get_hrtime(2), get_hrvtime(2), get_hrutime(2),
get_hrstime(2), get_hrtime_struct(2), free_hrtime_struct(2),
hrtime_init(2), times(2), gettimeofday(2)
Index
- NAME
-
- SYNOPSIS
-
- ARGUMENTS
-
- DESCRIPTION
-
- BUGS
-
- AUTHOR
-
- SEE ALSO
-
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Time: 16:52:45 GMT, May 04, 2000