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An infinite loop with an empty body is a suboptimal solution, because it consumes CPU cycles but does nothing. Optimizing compilers and just-in-time systems (JITs) are permitted to (perhaps unexpectedly) remove such a loop, which can lead to unexpected results. Consequently, use of programs must not include infinite loops with empty bodies is forbidden.

Noncompliant Code Example

This noncompliant code example implements an idle task that continuously executes a loop without executing any instructions within the loop. An optimizing compiler or JIT could remove the while loop in the this example.

public int nop() {
  while (true) {}
}

Compliant Solution (Thread.sleep())

This compliant solution avoids use of a meaningless infinite loop by sleeping the current thread invoking Thread.sleep() within the while loop. The loop body contains semantically meaningful operations , and consequently cannot be optimized away.

public final int DURATION=10000; // inIn milliseconds

public void nop() throws InterruptedException {
  while (true) {
    // Useful operations
    Thread.sleep(DURATION);
  }
}

...

This compliant solution invokes Thread.yield(), which causes the thread running this method to consistently defer to other threads.:

public void nop() {
  while (true) {
    Thread.yield();
  }
}

Risk Assessment

Related Guidelines

Bibliography

Automated Detection

Bibliography

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