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Due to these reasons, checking the condition after wait is called is indispensable.

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Noncompliant Code Example

This non-compliant noncompliant example invokes the wait method inside a traditional if block and fails to check the post condition after the (accidental or malicious) notification is received. This means that the thread can waken when it is not supposed to.

synchronized(object) {
  if(<condition does not hold>)
    object.wait();
  //proceed when condition holds
}

Compliant Solution

The compliant solution encloses the wait method in a while loop and thus as a result checks the condition during both pre and post wait invocation times.

//condition predicate is guarded by a lock on the shared object/variable
synchronized (object) {
  while (<condition does not hold>) {
    object.wait(); 
  }

  //proceed when condition holds
}

Risk Assessment

TODO

Automated Detection

TODO

Related Vulnerabilities

Search for vulnerabilities resulting from the violation of this rule on the CERT website.

References

EJPLG Item 50, Never invoke wait outside a loop
Doug Lea 3.2.2 Monitor Mechanics, 1.3.2 Liveness
Concurrency 14.2. Using Condition Queues
Java Documentation, Object http://java.sun.com/j2se/1.4.2/docs/api/java/lang/Object.html