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Improve use of specific terms and definitions.

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gmcgarry 2000-07-07 01:26:13 +00:00
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1 changed files with 29 additions and 20 deletions
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49
share/man/man9/lock.9
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@ -1,4 +1,4 @@
.\" $NetBSD: lock.9,v 1.1 2000/06/25 23:45:22 gmcgarry Exp $
.\" $NetBSD: lock.9,v 1.2 2000/07/07 01:26:13 gmcgarry Exp $
.\"
.\" Copyright (c) 2000 The NetBSD Foundation, Inc.
.\" All rights reserved.
@ -80,8 +80,9 @@
.Pp
The
.Nm
functions provide synchronisation capabilities for the kernel. A number
of different locks are available:
functions provide synchronisation capabilities in the kernel by preventing
multiple threads from simultaneously executing critical section of code which
access shared data. A number of different locks are available:
.Pp
.Bl -tag -width compact
.It struct simplelock
@ -94,7 +95,7 @@ gained.
.El
.Pp
If the kernel option LOCKDEBUG is enabled, additional facilities
are provided to record the owner of a lock. These facilities are
are provided to record additional lock information. These facilities are
provided to assist in determining deadlock occurrences.
.Sh FUNCTIONS
The functions which operate on simplelocks are:
@ -103,34 +104,42 @@ The functions which operate on simplelocks are:
.It Fn simple_lock_init "slock"
The simplelock
.Fa slock
is initialised to the unlocked state. A simplelock also may be initialised
statically, for example,
is initialised to the unlocked state. A statically allocated simplelock
also can be initialised with the macro SIMPLELOCK_INITIALIZER. The
effect is the same as the dynamic initialisation by a call to
simple_lock_init. For example,
.Pp
struct simplelock slock = SIMPLELOCK_INITIALIZER;
.It Fn simple_lock "slock"
The simplelock
.Fa slock
is locked. If the simplelock is held then execution will
spin until the simplelock is acquired.
spin until the simplelock is acquired. Care must be taken that the
calling thread does not already hold the simplelock. In this case, the
simplelock can never be acquired. If kernel option LOCKDEBUG is enabled,
a "locking against myself" panic will occur.
.It Fn simple_lock_try "slock"
Try to acquire the simplelock
.Fa slock
without spinnning. If the simplelock is being held by someone else
without spinning. If the simplelock is held by another thread
then the return value is 0. If the simplelock was acquired
successfully then the return value is 1.
.It Fn simple_lock_unlock "slock"
The simplelock
.Fa slock
is unlocked. The simplelock must be unlocked only by its owner.
is unlocked. The simplelock must be locked and the calling thread must
be the one that last acquired the simplelock. If the calling
thread does not hold the simplelock, the simplelock will be released
but the kernel behaviour is undefined.
.It Fn simple_lock_freecheck "start" "end"
Check that all simplelocks in the range
Check that all simplelocks in the address range
.Fa start
to
.Fa end
are not held. If a simplelock with the range is round, the kernel
drops to the debugger. This function is available only with kernel
option LOCKDEBUG. It provides a mechanism for simple simplelock
consistency check.
are not held. If a simplelock within the range is found, the kernel
enters the debugger. This function is available only with kernel
option LOCKDEBUG. It provides a mechanism for basic simplelock
consistency checks.
.It Fn simple_lock_dump "void"
Dump the state of all simplelocks in the kernel. This function is
available only with kernel option LOCKDEBUG.
@ -222,7 +231,7 @@ Simplelock interlock. The simplelock
.Fa slock
is set by the caller. When the lock
.Fa lock
is acquired, the simplelock is relinquished.
is acquired, the simplelock is released.
.El
.It Fn lockstatus "lock"
Determine the status of lock
@ -260,7 +269,7 @@ Simplelock interlock. The simplelock
.Fa slock
is set by the caller. When the lock
.Fa lock
is acquired, the simplelock is relinquished.
is acquired, the simplelock is released.
.El
.El
.Sh RETURN VALUES
@ -271,12 +280,12 @@ unless one of the following is true:
LK_FORCEUPGRADE is requested and some other process has already
requested a lock upgrade (returns EBUSY).
.It
LK_WAIT is set and a sleep would be required (returns EBUSY) .
LK_WAIT is set and a sleep would be required (returns EBUSY).
.It
LK_SLEEPFAIL is set and a sleep was done (returns ENOLCK) .
LK_SLEEPFAIL is set and a sleep was done (returns ENOLCK).
.It
PCATCH is set in lock priority and a signal arrives (returns
either EINTR or ERESTART if system calls is to be restarted) .
either EINTR or ERESTART if system calls is to be restarted).
.It
Non-null lock timeout and timeout expires (returns EWOULDBLOCK).
.It