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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