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25 lines
1.1 KiB
TeX
25 lines
1.1 KiB
TeX
\pagebreak
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\chapter{The \code{omp\_set\_dynamic} and \\
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\code{omp\_set\_num\_threads} Routines}
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\label{chap:set_dynamic_nthrs}
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Some programs rely on a fixed, prespecified number of threads to execute correctly.
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Because the default setting for the dynamic adjustment of the number of threads
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is implementation defined, such programs can choose to turn off the dynamic threads
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capability and set the number of threads explicitly to ensure portability. The
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following example shows how to do this using \code{omp\_set\_dynamic}, and \code{omp\_set\_num\_threads}.
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In this example, the program executes correctly only if it is executed by 16 threads.
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If the implementation is not capable of supporting 16 threads, the behavior of
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this example is implementation defined. Note that the number of threads executing
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a \code{parallel} region remains constant during the region, regardless of the
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dynamic threads setting. The dynamic threads mechanism determines the number of
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threads to use at the start of the \code{parallel} region and keeps it constant
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for the duration of the region.
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\cexample{set_dynamic_nthrs}{1c}
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\fexample{set_dynamic_nthrs}{1f}
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