개요

• 솔라나라에 설명된 어플리케이션에 대해 맨 페이지를 찾아 출력한다.
• MAN 페이지에 대한 설명은 윈디하나의 솔라나라: MAN 페이지을 참고하자.
• svcadm(8)을 검색하려면 섹션에서 8 을 선택하고, 맨 페이지 이름에 svcadm을 입력하고 검색을 누른다.

drv_usecwait(9f)

drv_usecwait(9F)               Kernel Functions               drv_usecwait(9F)



NAME
       drv_usecwait - busy-wait for specified interval

SYNOPSIS
       #include <sys/types.h>
       #include <sys/ddi.h>

       void drv_usecwait(clock_t microsecs);

INTERFACE LEVEL
       Architecture independent level 1 (DDI/DKI).

PARAMETERS
       microsecs    The number of microseconds to busy-wait.


DESCRIPTION
       The drv_usecwait() function gives drivers a means of busy-waiting for a
       specified microsecond count. The amount of time spent busy-waiting  may
       be  greater than the microsecond count but will minimally be the number
       of microseconds specified.


       delay(9F) can be used by a driver to delay for a  specified  number  of
       system ticks, but it has two limitations. First, the granularity of the
       wait time is limited to one clock tick, which may be more time than  is
       needed  for  the  delay.  Second, delay(9F) can be invoked from user or
       kernel context and hence cannot be used at  interrupt  time  or  system
       initialization.


       Often, drivers need to delay for only a few microseconds, waiting for a
       write to a device register to be picked up by the device. In this case,
       even in user context, delay(9F) produces too long a wait period.

CONTEXT
       The drv_usecwait() function can be called from user, interrupt, or ker‐
       nel context.

SEE ALSO
       delay(9F), timeout(9F), untimeout(9F)


       Writing Device Drivers in Oracle Solaris 11.4

NOTES
       The  driver  wastes  processor  time  by   making   this   call   since
       drv_usecwait()  does not block but simply busy-waits. The driver should
       only make calls to drv_usecwait() as needed, and only for as much  time
       as needed. The drv_usecwait() function does not mask out interrupts.



Oracle Solaris 11.4               16 Jan 2006                 drv_usecwait(9F)