<div class="refentry"><a id="glFenceSync"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glFenceSync — create a new sync object and insert it into the GL command stream</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table class="funcprototype-table" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">GLsync <strong class="fsfunc">glFenceSync</strong>(</code></td><td>GLenum <var class="pdparam">condition</var>, </td></tr><tr><td> </td><td>GLbitfield <var class="pdparam">flags</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>condition</code></em></span></dt><dd><p>

Specifies the condition that must be met to set the sync object's state to signaled. <em class="parameter"><code>condition</code></em>

must be <code class="constant">GL_SYNC_GPU_COMMANDS_COMPLETE</code>.

</p></dd><dt><span class="term"><em class="parameter"><code>flags</code></em></span></dt><dd><p>

Specifies a bitwise combination of flags controlling the behavior of the sync object. No flags are presently defined

for this operation and <em class="parameter"><code>flags</code></em> must be zero.<a href="#ftn.idp3515456" class="footnote" id="idp3515456"><sup class="footnote">[1]</sup></a>

</p></dd></dl></div></div><div class="refsect1"><a id="description"></a><h2>Description</h2><p>

<code class="function">glFenceSync</code> creates a new fence sync object, inserts a fence command into the GL command stream and

associates it with that sync object, and returns a non-zero name corresponding to the sync object.

</p><p>

When the specified <em class="parameter"><code>condition</code></em> of the sync object is satisfied by the fence command, the sync object

is signaled by the GL, causing any <a class="citerefentry" href="glWaitSync"><span class="citerefentry"><span class="refentrytitle">glWaitSync</span></span></a>,

<a class="citerefentry" href="glClientWaitSync"><span class="citerefentry"><span class="refentrytitle">glClientWaitSync</span></span></a> commands blocking in <em class="parameter"><code>sync</code></em>

to <span class="emphasis"><em>unblock</em></span>. No other state is affected by <code class="function">glFenceSync</code> or by the execution

of the associated fence command.

</p><p>

<em class="parameter"><code>condition</code></em> must be <code class="constant">GL_SYNC_GPU_COMMANDS_COMPLETE</code>. This condition is satisfied by

completion of the fence command corresponding to the sync object and all preceding commands in the same command stream.

The sync object will not be signaled until all effects from these commands on GL client and server state and the

framebuffer are fully realized. Note that completion of the fence command occurs once the state of the corresponding sync

object has been changed, but commands waiting on that sync object may not be unblocked until after the fence command completes.

</p></div><div class="refsect1"><a id="notes"></a><h2>Notes</h2><code class="function">glFenceSync</code> is only supported if the GL version is 3.2 or greater, or if

the <code class="code">ARB_sync</code> extension is supported.

</div><div class="refsect1"><a id="errors"></a><h2>Errors</h2><p>

<code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>condition</code></em> is not

<code class="constant">GL_SYNC_GPU_COMMANDS_COMPLETE</code>.

</p><p>

<code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>flags</code></em> is not zero.

</p><p>

Additionally, if <code class="function">glFenceSync</code> fails, it will return zero.

</p></div>

{$pipelinestall}{$examples}

<div class="refsect1"><a id="seealso"></a><h2>See Also</h2><p>

<a class="citerefentry" href="glDeleteSync"><span class="citerefentry"><span class="refentrytitle">glDeleteSync</span></span></a>,

<a class="citerefentry" href="glGetSync"><span class="citerefentry"><span class="refentrytitle">glGetSync</span></span></a>,

<a class="citerefentry" href="glWaitSync"><span class="citerefentry"><span class="refentrytitle">glWaitSync</span></span></a>,

<a class="citerefentry" href="glClientWaitSync"><span class="citerefentry"><span class="refentrytitle">glClientWaitSync</span></span></a>

</p></div><div class="refsect1"><div id="Copyright"><h2>Copyright</h2><p>

Copyright © 2010 Khronos Group.

This material may be distributed subject to the terms and conditions set forth in

the Open Publication License, v 1.0, 8 June 1999.

<a class="ulink" href="https://opencontent.org/openpub/" target="_top">https://opencontent.org/openpub/</a>.

</p></div><div class="footnotes"><br /><hr style="width:100; text-align:left;margin-left: 0" /><div id="ftn.idp3515456" class="footnote"><p><a href="#idp3515456" class="para"><sup class="para">[1] </sup></a>

<em class="parameter"><code>flags</code></em> is a placeholder for anticipated future extensions of fence sync object capabilities.

</p></div></div></div></div>