.\"
.\" Copyright 2014 Samy Al Bahra.
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.Dd April 22, 2014.
.Dt ck_pflock 3
.Sh NAME
.Nm ck_pflock_init ,
.Nm ck_pflock_write_lock ,
.Nm ck_pflock_write_unlock ,
.Nm ck_pflock_read_lock ,
.Nm ck_pflock_read_unlock ,
.Nd centralized phase-fair reader-writer locks
.Sh LIBRARY
Concurrency Kit (libck, \-lck)
.Sh SYNOPSIS
.In ck_pflock.h
.Pp
.Dv ck_pflock_t lock = CK_PFLOCK_INITIALIZER;
.Pp
.Ft void
.Fn ck_pflock_init "ck_pflock_t *lock"
.Ft void
.Fn ck_pflock_write_lock "ck_pflock_t *lock"
.Ft void
.Fn ck_pflock_write_unlock "ck_pflock_t *lock"
.Ft void
.Fn ck_pflock_read_lock "ck_pflock_t *lock"
.Ft void
.Fn ck_pflock_read_unlock "ck_pflock_t *lock"
.Sh DESCRIPTION
This is a centralized phase-fair reader-writer lock. It
requires little space overhead and has a low latency
fast path.
.Sh EXAMPLE
.Bd -literal -offset indent
#include <ck_pflock.h>

static ck_pflock_t lock = CK_TFLOCK_INITIALIZER;

static void
reader(void)
{

	for (;;) {
		ck_pflock_read_lock(&lock);
		/* Read-side critical section. */
		ck_pflock_read_unlock(&lock);
	}

	return;
}

static void
writer(void)
{

	for (;;) {
		ck_pflock_write_lock(&lock);
		/* Write-side critical section. */
		ck_pflock_write_unlock(&lock);
	}

	return;
}
.Ed
.Sh SEE ALSO
.Xr ck_brlock 3 ,
.Xr ck_rwlock 3 ,
.Xr ck_tflock 3 ,
.Xr ck_swlock 3
.Pp
Additional information available at http://concurrencykit.org/