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.

delay(9f)

delay(9F)                      Kernel Functions                      delay(9F)



NAME
       delay - delay execution for a specified number of clock ticks

SYNOPSIS
       #include <sys/ddi.h>

       void delay(clock_t ticks);

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

PARAMETERS
       ticks    The number of clock cycles to delay.


DESCRIPTION
       delay()  provides a mechanism for a driver to delay its execution for a
       given period of time. Since the speed of the clock  varies  among  sys‐
       tems,  drivers  should  base  their time values on microseconds and use
       drv_usectohz(9F) to convert microseconds into clock ticks.


       delay() uses timeout(9F) to schedule an internal function to be  called
       after  the  specified  amount  of  time has elapsed. delay() then waits
       until the function is called. Because timeout() is subject to  priority
       inversion,  drivers  waiting on behalf of processes with real-time con‐
       straints should use cv_timedwait(9F) rather than delay().


       delay()  does  not  busy-wait.  If  busy-waiting   is   required,   use
       drv_usecwait(9F).

CONTEXT
       delay() can be called from user and kernel contexts.

EXAMPLES
       Example 1 delay() Example



       Before  a driver I/O routine allocates buffers and stores any user data
       in them, it checks the status of the device (line 12).  If  the  device
       needs manual intervention (such as, needing to be refilled with paper),
       a message is displayed on the system  console  (line  14).  The  driver
       waits an allotted time (line 17) before repeating the procedure.


          1  struct  device  {    /* layout of physical device registers */
          2          int      control; /* physical device control word */
          3          int      status;  /* physical device status word */
          4          short    xmit_char;    /* transmit character to device */
          5  };
          6
          7
                . . .
          9   /* get device registers  */
         10      register struct device *rp = ...
         11
         12      while (rp->status & NOPAPER) {  /* while printer is out of paper */
         13       /* display message and ring bell */
                  /* on system console */
         14          cmn_err(CE_WARN, "^\007",
         15                            (getminor(dev) & 0xf));
         16          /* wait one minute and try again */
         17          delay(60 * drv_usectohz(1000000));
         18      }


SEE ALSO
       drv_usecwait(9F),     biodone(9F),    biowait(9F),    cv_timedwait(9F),
       ddi_in_panic(9F),  drv_hztousec(9F),   drv_usectohz(9F),   timeout(9F),
       untimeout(9F)


       Writing Device Drivers in Oracle Solaris 11.4



Oracle Solaris 11.4               15 Oct 2001                        delay(9F)