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Leonid Shalupovandintellij-monorepo-bot
40795fe787
GitOrigin-RevId: 8b2b63fc6db476ca0c2cfe5cadd84db6c4236d0f
52 lines
1.3 KiB
HTML
52 lines
1.3 KiB
HTML
<html>
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<body>
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Reports <code>while</code> loops that spin on the
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value of a non-<code>volatile</code> field, waiting for it to be changed by another thread.
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<p>
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In addition to being potentially extremely CPU intensive when little work is done inside the loop, such
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loops are likely to have different semantics from what was intended.
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The Java Memory Model allows such loops to never complete even if another thread changes the field's value.
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</p>
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<p>
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Additionally, since Java 9 it's recommended to call <code>Thread.onSpinWait()</code> inside a spin loop
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on a <code>volatile</code> field, which may significantly improve performance on some hardware.
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</p>
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<p><b>Example:</b></p>
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<pre><code>
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class SpinsOnField {
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boolean ready = false;
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void run() {
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while (!ready) {
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}
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// do some work
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}
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void markAsReady() {
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ready = true;
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}
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}
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</code></pre>
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<p>After the quick-fix is applied:</p>
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<pre><code>
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class SpinsOnField {
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volatile boolean ready = false;
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void run() {
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while (!ready) {
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Thread.onSpinWait();
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}
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// do some work
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}
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void markAsReady() {
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ready = true;
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}
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}
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</code></pre>
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<!-- tooltip end -->
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<p>
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Use the inspection options to only report empty <code>while</code> loops.
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<p>
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</body>
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</html> |