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= nng_cv_wake1(3supp)
//
// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
// Copyright 2018 Capitar IT Group BV <info@capitar.com>
//
// This document is supplied under the terms of the MIT License, a
// copy of which should be located in the distribution where this
// file was obtained (LICENSE.txt). A copy of the license may also be
// found online at https://opensource.org/licenses/MIT.
//
== NAME
nng_cv_wake1 - wake one waiter
== SYNOPSIS
[source, c]
----
#include <nng/nng.h>
#include <nng/supplemental/util/platform.h>
void nng_cv_wake1(nng_cv *cv);
----
== DESCRIPTION
The `nng_cv_wake1()` wakes at most one thread waiting for the condition
variable _cv_
to be signaled in the xref:nng_cv_wait.3supp.adoc[`nng_cv_wait()`] or
xref:nng_cv_until.3supp.adoc[`nng_cv_until()`] functions.
The caller must have have ownership of the mutex that was used when
_cv_ was allocated.
NOTE: The caller should already have set the condition that the waiters
will check, while holding the mutex.
TIP: While this function avoids the "`thundering herd`" problem, the
caller cannot predict which waiter will be woken, and so the design must
ensure that it is sufficient that _any_ waiter be woken.
When in doubt, it is safer to use xref:nng_cv_wake.3supp.adoc[`nng_cv_wake()`].
== RETURN VALUES
None.
== ERRORS
None.
== SEE ALSO
[.text-left]
xref:nng_cv_alloc.3supp.adoc[nng_cv_alloc(3supp)],
xref:nng_cv_until.3supp.adoc[nng_cv_until(3supp)],
xref:nng_cv_wait.3supp.adoc[nng_cv_wait(3supp)],
xref:nng_cv_wake.3supp.adoc[nng_cv_wake(3supp)],
xref:nng_mtx_alloc.3supp.adoc[nng_mtx_alloc(3supp)],
xref:nng_mtx_lock.3supp.adoc[nng_mtx_lock(3supp)],
xref:nng_mtx_unlock.3supp.adoc[nng_mtx_unlock(3supp)],
xref:nng.7.adoc[nng(7)]
|
