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.\" Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions are met:
.\"
.\" 1. Redistributions of source code must retain the above copyright notice,
.\" this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\" 3. Neither the name of Hyra nor the names of its
.\" contributors may be used to endorse or promote products derived from
.\" this software without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
.\" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
.\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.Dd Dec 16 2024
.Dt SPINLOCK 9
.Os Hyra
.Sh NAME
.Nm spinlock - generic spinlock for syncronization
.Sh SYNOPSIS
.In sys/spinlock.h
.Ft void
.Fn spinlock_acquire "struct spinlock *lock"
.Ft void
.Fn spinlock_release "struct spinlock *lock"
.Ft int
.Fn spinlock_usleep "struct spinlock *lock" "size_t usec_max"
.Sh DESCRIPTION
The set of functions provide a simple spin-based locking mechanism
to ensure mutual exclusion between threads.
The
.Ft spinlock_acquire
function is used to acquire a spinlock pointed to by
.Fa lock .
If the lock is unavailable (being held by another thread), it
will wait until the lock owner releases it.
The
.Ft spinlock_release
function is used to release a spinlock pointed to by
.Fa lock .
This allows other threads to hold it.
The
.Ft spinlock_usleep
function attempts to acquire a spinlock pointed to by
.Fa lock .
If the lock is unavailable, it waits up to a maximum
duration of
.Fa usec_max
microseconds. If the lock is still being held, it will return
a non-zero value indicating a timeout. If the lock is successfully
acquired, a value of 0 is returned.
.Sh AUTHORS
.An Ian Moffett Aq Mt ian@osmora.org
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