SLEEP_LOCK_SIG(D3) SLEEP_LOCK_SIG(D3)
NAME
SLEEP_LOCK_SIG - acquire a sleep lock
SYNOPSIS
#include <sys/types.h>
#include <sys/ksynch.h>
#include <sys/ddi.h>
bool_t SLEEP_LOCK_SIG(sleep_t *lockp, int priority);
Arguments
lockp Pointer to the sleep lock to be acquired.
priority A hint to the scheduling policy as to the relative
priority the caller wishes to be assigned while
running in the kernel after waking up.
DESCRIPTION
SLEEP_LOCK_SIG acquires the sleep lock specified by lockp. If
the lock is not immediately available, the caller is put to
sleep (the caller's execution is suspended and other processes
may be scheduled) until the lock becomes available to the
caller, at which point the caller wakes up and returns with
the lock held.
SLEEP_LOCK_SIG may be interrupted by a signal, in which case
it may return early without acquiring the lock.
If the function is interrupted by a job control stop signal
(e.g. SIGSTOP, SIGTSTP, SIGTTIN, SIGTTOU) which results in the
caller entering a stopped state, the SLEEP_LOCK_SIG function
will transparently retry the lock operation upon continuing
(the call will not return without the lock).
If the function is interrupted by a signal other than a job
control stop signal, or by a job control stop signal that does
not result in the caller stopping (because the signal has a
non-default disposition), the SLEEP_LOCK_SIG call will return
early without acquiring the lock.
Return Values
SLEEP_LOCK_SIG returns TRUE (a non-zero value) if the lock is
successfully acquired or FALSE (zero) if the function returned
early because of a signal.
Copyright 1994 Novell, Inc. Page 1
SLEEP_LOCK_SIG(D3) SLEEP_LOCK_SIG(D3)
USAGE
priority Argument
Valid values for priority are:
pridisk Priority appropriate for disk driver.
prinet Priority appropriate for network driver.
pritty Priority appropriate for terminal driver.
pritape Priority appropriate for tape driver.
prihi High priority.
primed Medium priority.
prilo Low priority.
Drivers may use these values to request a priority appropriate
to a given type of device or to request a priority that is
high, medium or low relative to other activities within the
kernel.
It is also permissible to specify positive or negative offsets
from the values defined above. Positive offsets result in
more favorable priority. The maximum allowable offset in all
cases is 3 (that is, pridisk+3 and pridisk-3 are valid values
but pridisk+4 and pridisk-4 are not valid). Offsets can be
useful in defining the relative importance of different locks
or resources that may be held by a given driver. In general,
a higher relative priority should be used when the caller is
attempting to acquire a highly contended lock or resource, or
when the caller is already holding one or more locks or kernel
resources upon entry to SLEEP_LOCK_SIG.
The exact semantic of the priority argument is specific to the
scheduling class of the caller, and some scheduling classes
may choose to ignore the argument for the purposes of assign-
ing a scheduling priority.
Level
Base only.
Synchronization Constraints
Can sleep.
Copyright 1994 Novell, Inc. Page 2
SLEEP_LOCK_SIG(D3) SLEEP_LOCK_SIG(D3)
Driver-defined basic locks and read/write locks may not be
held across calls to this function.
Driver-defined sleep locks may be held across calls to this
function subject to the recursion restrictions described
below.
Warnings
Sleep locks are not recursive. A call to SLEEP_LOCK_SIG
attempting to acquire a lock that is currently held by the
calling context will result in deadlock.
REFERENCES
SLEEP_ALLOC(D3), SLEEP_DEALLOC(D3), SLEEP_LOCK(D3),
SLEEP_LOCKAVAIL(D3), SLEEP_LOCKOWNED(D3), SLEEP_TRYLOCK(D3),
SLEEP_UNLOCK(D3), signals(D5)
NOTICES
Portability
All processors
Applicability
ddi: 5, 5mp, 6, 6mp, 7, 7mp
Copyright 1994 Novell, Inc. Page 3