SVR5
drv_usectohz(D3)
drv_usectohz --
convert microseconds to clock ticks
Synopsis
#include <sys/types.h>
#include <sys/ddi.h>
clock_t drv_usectohz(clock_t microsecs);
Description
drv_usectohz converts the length of time expressed by
microsecs, which is in units of microseconds,
into units of clock ticks.
Arguments
microsecs-
The number of microseconds to convert to equivalent clock ticks.
Return values
The value returned is the smallest number of clock ticks that represent
a time interval equal to or greater than the microsecs argument.
No error value is returned.
If the number of ticks equivalent
to the microsecs argument is too large to be represented as a
clock_t,
then the maximum clock_t value will be returned.
Usage
Several functions either take time values expressed in clock ticks as
arguments
[timeout(D3),
timeout(D3),
delay(D3)]
or return time values expressed in clock ticks
[drv_getparm(D3)].
The length of a clock tick can vary across different implementations,
and therefore drivers should not include any hard-coded assumptions
about the length of a tick.
drv_usectohz and the complementary function
drv_hztousec(D3)
can be used, as necessary, to convert between
microseconds and clock ticks.
Context and synchronization
All
contexts.
Hardware applicability
All
Version applicability
ddi:
1, 2, 3, 4, 5, 5mp, 6, 6mp, 7, 7mp, 7.1, 7.1mp, 8, 8mp
References
delay(D3),
drv_getparm(D3),
drv_hztousec(D3),
itimeout(D3)
timeout(D3)
``Delays and busy-waits'' in HDK Technical Reference
19 June 2005
© 2005 The SCO Group, Inc. All rights reserved.
OpenServer 6 and UnixWare (SVR5) HDK - June 2005