111 lines
5.0 KiB
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111 lines
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HTML
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<title>GNU libgomp: GOMP_SPINCOUNT</title>
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<a name="GOMP_005fSPINCOUNT"></a>
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<p>
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Next: <a href="GOMP_005fRTEMS_005fTHREAD_005fPOOLS.html#GOMP_005fRTEMS_005fTHREAD_005fPOOLS" accesskey="n" rel="next">GOMP_RTEMS_THREAD_POOLS</a>, Previous: <a href="GOMP_005fSTACKSIZE.html#GOMP_005fSTACKSIZE" accesskey="p" rel="prev">GOMP_STACKSIZE</a>, Up: <a href="Environment-Variables.html#Environment-Variables" accesskey="u" rel="up">Environment Variables</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Library-Index.html#Library-Index" title="Index" rel="index">Index</a>]</p>
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<hr>
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<a name="GOMP_005fSPINCOUNT-_002d_002d-Set-the-busy_002dwait-spin-count"></a>
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<h3 class="section">3.18 <code>GOMP_SPINCOUNT</code> – Set the busy-wait spin count</h3>
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<a name="index-Environment-Variable-17"></a>
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<a name="index-Implementation-specific-setting-4"></a>
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<dl compact="compact">
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<dt><em>Description</em>:</dt>
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<dd><p>Determines how long a threads waits actively with consuming CPU power
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before waiting passively without consuming CPU power. The value may be
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either <code>INFINITE</code>, <code>INFINITY</code> to always wait actively or an
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integer which gives the number of spins of the busy-wait loop. The
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integer may optionally be followed by the following suffixes acting
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as multiplication factors: <code>k</code> (kilo, thousand), <code>M</code> (mega,
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million), <code>G</code> (giga, billion), or <code>T</code> (tera, trillion).
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If undefined, 0 is used when <code>OMP_WAIT_POLICY</code> is <code>PASSIVE</code>,
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300,000 is used when <code>OMP_WAIT_POLICY</code> is undefined and
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30 billion is used when <code>OMP_WAIT_POLICY</code> is <code>ACTIVE</code>.
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If there are more OpenMP threads than available CPUs, 1000 and 100
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spins are used for <code>OMP_WAIT_POLICY</code> being <code>ACTIVE</code> or
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undefined, respectively; unless the <code>GOMP_SPINCOUNT</code> is lower
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or <code>OMP_WAIT_POLICY</code> is <code>PASSIVE</code>.
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</p>
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</dd>
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<dt><em>See also</em>:</dt>
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<dd><p><a href="OMP_005fWAIT_005fPOLICY.html#OMP_005fWAIT_005fPOLICY">OMP_WAIT_POLICY</a>
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</p></dd>
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</dl>
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