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| <header/> |
| <div class="refentry" id="eglClientWaitSync"> |
| <div class="titlepage"/> |
| <div class="refnamediv"> |
| <h2>Name</h2> |
| <p>eglClientWaitSync — |
| Wait in the client for a sync object to be signalled |
| </p> |
| </div> |
| <div class="refsynopsisdiv"> |
| <h2>C Specification</h2> |
| <div class="funcsynopsis"> |
| <table style="border: 0; cellspacing: 0; cellpadding: 0;" class="funcprototype-table"> |
| <tr> |
| <td> |
| <code class="funcdef">EGLint <strong class="fsfunc">eglClientWaitSync</strong>(</code> |
| </td> |
| <td>(EGLDisplay <var class="pdparam">display</var>, </td> |
| </tr> |
| <tr> |
| <td> </td> |
| <td>EGLSync <var class="pdparam">sync</var>, </td> |
| </tr> |
| <tr> |
| <td> </td> |
| <td>EGLint <var class="pdparam">flags</var>, </td> |
| </tr> |
| <tr> |
| <td> </td> |
| <td>EGLTime <var class="pdparam">timeout</var><code>)</code>;</td> |
| </tr> |
| </table> |
| <div class="funcprototype-spacer"> </div> |
| </div> |
| </div> |
| <div class="refsect1" id="parameters"> |
| <h2>Parameters</h2> |
| <div class="variablelist"> |
| <dl class="variablelist"> |
| <dt> |
| <span class="term"> |
| <em class="parameter"> |
| <code>display</code> |
| </em> |
| </span> |
| </dt> |
| <dd> |
| <p> |
| Specifies the <abbr class="acronym">EGL</abbr> display connection. |
| </p> |
| </dd> |
| <dt> |
| <span class="term"> |
| <em class="parameter"> |
| <code>sync</code> |
| </em> |
| </span> |
| </dt> |
| <dd> |
| <p> |
| Specifies the sync object to wait on. |
| </p> |
| </dd> |
| <dt> |
| <span class="term"> |
| <em class="parameter"> |
| <code>flags</code> |
| </em> |
| </span> |
| </dt> |
| <dd> |
| <p> |
| Specifies flags controlling wait behavior. |
| </p> |
| </dd> |
| <dt> |
| <span class="term"> |
| <em class="parameter"> |
| <code>timeout</code> |
| </em> |
| </span> |
| </dt> |
| <dd> |
| <p> |
| Specifies wait timeout interval. |
| </p> |
| </dd> |
| </dl> |
| </div> |
| </div> |
| <div class="refsect1" id="description"> |
| <h2>Description</h2> |
| <p> |
| <code class="function">eglClientWaitSync</code> blocks the calling thread |
| until the specified sync object <em class="parameter"><code>sync</code></em> is |
| signaled, or until <em class="parameter"><code>timeout</code></em> nanoseconds |
| have passed. |
| </p> |
| <p> |
| More than one <code class="function">eglClientWaitSync</code> may be |
| outstanding on the same <em class="parameter"><code>sync</code></em> at any given |
| time. When there are multiple threads blocked on the same |
| <em class="parameter"><code>sync</code></em> and the sync object is signaled, all |
| such threads are released, but the order in which they are |
| released is not defined. |
| </p> |
| <p> |
| If the value of <em class="parameter"><code>timeout</code></em> is zero, then |
| <code class="function">eglClientWaitSync</code> simply tests the current |
| status of <em class="parameter"><code>sync</code></em>. If the value of |
| <em class="parameter"><code>timeout</code></em> is the special value |
| <code class="constant">EGL_FOREVER</code>, then |
| <code class="function">eglClientWaitSync</code> does not time out. For |
| all other values, <em class="parameter"><code>timeout</code></em> is adjusted to |
| the closest value allowed by the implementation-dependent |
| timeout accuracy, which may be substantially longer than one |
| nanosecond. |
| </p> |
| <p> |
| <code class="function">eglClientWaitSync</code> returns one of three |
| status values describing the reason for returning. A return |
| value of <code class="constant">EGL_TIMEOUT_EXPIRED</code> indicates that |
| the specified timeout period expired before |
| <em class="parameter"><code>sync</code></em> was signaled, or if |
| <em class="parameter"><code>timeout</code></em> is zero, indicates that |
| <em class="parameter"><code>sync</code></em> is not signaled. A return value of |
| <code class="constant">EGL_CONDITION_SATISFIED</code> indicates that |
| <em class="parameter"><code>sync</code></em> was signaled before the timeout |
| expired, which includes the case when |
| <em class="parameter"><code>sync</code></em> was already signaled when |
| <code class="function">eglClientWaitSync</code> was called. If an error |
| occurs then an error is generated and |
| <code class="constant">EGL_FALSE</code> is returned. |
| </p> |
| <p> |
| If the sync object being blocked upon will not be signaled in |
| finite time (for example, by an associated fence command issued |
| previously, but not yet flushed to the graphics pipeline), then |
| <code class="function">eglClientWaitSync</code> may wait forever. To help |
| prevent this behavior, if the |
| <code class="constant">EGL_SYNC_FLUSH_COMMANDS_BIT</code> bit is set in |
| <em class="parameter"><code>flags</code></em>, and <em class="parameter"><code>sync</code></em> is |
| unsignaled when <code class="function">eglClientWaitSync</code> is |
| called, then the equivalent of Flush() will be performed for the |
| current API context (i.e., the context returned by |
| <code class="function">eglGetCurrentContext</code>) before blocking on |
| <em class="parameter"><code>sync</code></em>. If no context is current for the |
| bound API, the <code class="constant">EGL_SYNC_FLUSH_COMMANDS_BIT</code> |
| bit is ignored. |
| </p> |
| <p> |
| Note: the simple Flush behavior defined by |
| <code class="constant">EGL_SYNC_FLUSH_COMMANDS_BIT</code> will not help |
| when waiting for a fence command issued in a different context's |
| command stream. Applications which block on a fence sync object |
| must take additional steps to ensure that the context from which |
| the associated fence command was issued has flushed that command |
| to the graphics pipeline. |
| </p> |
| </div> |
| <div class="refsect1" id="errors"> |
| <h2>Errors</h2> |
| <p> |
| <code class="function">eglClientWaitSync</code> returns |
| <code class="constant">EGL_FALSE</code> on failure. |
| </p> |
| <p> |
| If <em class="parameter"><code>sync</code></em> is not a valid sync object for |
| <em class="parameter"><code>display</code></em>, an |
| <code class="constant">EGL_BAD_PARAMETER</code> error is generated. |
| </p> |
| <p> |
| If <em class="parameter"><code>display</code></em> does not match the |
| <span class="type">EGLDisplay</span> passed to |
| <code class="function">eglCreateSync</code> when |
| <em class="parameter"><code>sync</code></em> was created, the behaviour is |
| undefined. |
| </p> |
| </div> |
| <div class="refsect1" id="notes"> |
| <h2>Notes</h2> |
| <p> |
| <code class="function">eglClientWaitSync</code> is available only if the |
| EGL version is 1.5 or greater. |
| </p> |
| </div> |
| <div class="refsect1" id="seealso"> |
| <h2>See Also</h2> |
| <p> |
| <a class="citerefentry" href="eglCreateSync.xhtml"><span class="citerefentry"><span class="refentrytitle">eglCreateSync</span></span></a>, |
| <a class="citerefentry" href="eglGetCurrentContext.xhtml"><span class="citerefentry"><span class="refentrytitle">eglGetCurrentContext</span></span></a>, |
| <a class="citerefentry" href="eglWaitSync.xhtml"><span class="citerefentry"><span class="refentrytitle">eglWaitSync</span></span></a>, |
| <code class="function">glFinish</code>, |
| <code class="function">vgFinish</code> |
| </p> |
| </div> |
| <p> |
| </p> |
| <div class="refsect3" id="copyright"> |
| <img src="KhronosLogo.jpg"/> |
| <p> |
| Copyright © 2003-2014 The Khronos Group Inc. |
| Permission is hereby granted, free of charge, to any person obtaining a |
| copy of this software and/or associated documentation files (the |
| "Materials"), to deal in the Materials without restriction, including |
| without limitation the rights to use, copy, modify, merge, publish, |
| distribute, sublicense, and/or sell copies of the Materials, and to |
| permit persons to whom the Materials are furnished to do so, subject to |
| the condition that this copyright notice and permission notice shall be included |
| in all copies or substantial portions of the Materials. |
| </p> |
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