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sleep(9r)
NAME
  sleep - General: Puts a calling process to sleep

SYNOPSIS
  void sleep(
	  caddr_t *channel,
	  long pri );

ARGUMENTS
  channel
      Specifies a unique address associated with the calling kernel thread to
      be put to sleep.

  pri Specifies whether the sleep request is interruptible. Setting this
      argument to the PCATCH flag causes the process to sleep in an
      interruptible state (that is, the kernel thread can take asynchronous
      signals). Not setting the PCATCH flag causes the process to sleep in an
      uninterruptible state (that is, the kernel thread cannot take
      asynchronous signals).

DESCRIPTION
  The sleep routine puts a calling process to sleep on the address specified
  by the channel argument. Some common addresses are the lbolt argument, a
  buf structure, and a proc structure.	This address should be unique to
  prevent unexpected wake/sleep cycles, which can occur if different
  processes are sleeping on the same address accidentally.  If you set the
  PCATCH flag in the pri argument, the sleep routine puts signals on the
  queue and does not wake up the sleeping process.

  The sleep and wakeup routines block and then wake up a process. Generally,
  device drivers call these routines to wait for the transfer to complete an
  interrupt from the device. That is, the write routine of the device driver
  sleeps on the address of a known location, and the device's Interrupt
  Service Interface (ISI) wakes the process when the device interrupts. It is
  the responsibility of the wakened process to check if the condition for
  which it was sleeping has been removed.

NOTES
  The operating system provides two ways to put a process to sleep:
  interruptible and uninterruptible. The sleep routine performs an
  uninterruptible sleep operation if you do not set the PCATCH flag and an
  interruptible sleep operation if you set the PCATCH flag.  This means that
  device drivers cannot call sleep at interrupt context because at interrupt
  context there is no calling process to be put to sleep. Thus, a device
  driver's Interrupt Service Interface (ISI) and those routines called from
  within the ISI must not call the sleep routine.

  On this operating system, you cannot use pri to set the scheduling priority
  of the calling process.

RETURN VALUES
  None

FILES
  <param.h>

SEE ALSO
  Routines: wakeup(9r)

Index for Section 9r

Alphabetical listing for S

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