mpsleep(9r)															       mpsleep(9r)

NAME

       mpsleep - General: Blocks the current kernel thread

SYNOPSIS

       int mpsleep(
	       caddr_t channel,
	       long pri,
	       char *wmesg,
	       long timo,
	       void *lockp,
	       long flags );

ARGUMENTS

       Specifies  an  address associated with the calling kernel thread to be blocked.	Can specify the following values: When set, specifies that
       the sleep request is interruptible.  That is, the kernel thread can take asynchronous signals. Not  setting  the  PCATCH  flag  causes  the
       process to sleep in an uninterruptible state.  When set, specifies that the process can be asynchronously suspended while waiting.

	      On the operating system you cannot use pri to set the scheduling priority of the calling process.  Specifies a mnemonic for the type
	      of wait. The ps command uses this mnemonic in its messages about the process.  Specifies the  maximum  amount  of  time  the  kernel
	      thread  should  block.   The  kernel  thread blocks a maximum of timo divided by hz seconds. If you pass the value 0 (zero), mpsleep
	      assumes there is no timeout.  Specifies a pointer to a lock structure that you want to unlock before the process sleeps. If  you	do
	      not want to release a lock, pass the value 0 (zero).  Specifies the lock type of the lockp argument and how to handle the lock after
	      blocking.

	      You can specify one of the following valid lock types, defined in the <param.h> file: Calls mpsleep with	a  simple  lock  asserted.
	      Calls mpsleep with a read-only lock asserted on entry.  Calls mpsleep with a write lock asserted.

	      In addition, you can specify one of the following ways to handle the lock after blocking: Forces mpsleep to relock the lock on fail-
	      ure.  Forces mpsleep not to relock after blocking.

DESCRIPTION

       The mpsleep routine blocks (puts to sleep) the current kernel thread until a wakeup is issued on the address you  specify  in  the  channel
       argument.  This routine is the symmetric multiprocessor (SMP) sleep call. The kernel thread blocks a maximum of timo divided by hz seconds.
       The value0 (zero) means there is no timeout.

       If you pass the PCATCH flag to the pri argument, the sleep request is interruptible, and the kernel thread can take  asynchronous  signals.
       If you pass the PSUSP flag, the process can be asynchronously suspended while waiting.

       The  mpsleep  routine  allows you to specify a pointer to a simple or complex lock structure that is associated with some resource.  If the
       MS_LOCK_NO_RELOCK flag is set, it does not relock the lock after blocking. If the MS_LOCK_ON_ERROR flag is set (or no flag is set), mpsleep
       relocks the lock on failure.

NOTES

       This routine is not intended for general use.  It is mostly used by sleep and tsleep and by knowledgeable callers.

       The mpsleep routine cannot be called from within an Interrupt Service routine (ISI) because it is illegal to block at interrupt context.

RETURN VALUES

       The  mpsleep  routine returns the following values: Successful completion.  The sleep has been interrupted by a signal.	The sleep has been
       interrupted by a signal on a restartable system call.  The timeout has expired.

SEE ALSO

       Routines: assert_wait_mesg(9r), clear_wait(9r), thread_block(9r), thread_wakeup(9r), thread_wakeup_one(9r)

																       mpsleep(9r)