16f6c0aecf
Inline adoc files when they are included exactly once. Also fix language tags because this inlining gives us better information on what language the code is written in.
68 lines
1.6 KiB
Plaintext
68 lines
1.6 KiB
Plaintext
== Why is this an issue?
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According to the documentation of the Java ``++Condition++`` interface:
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____
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When waiting upon a ``++Condition++``, a "spurious wakeup" is permitted to occur, in general, as a concession to the underlying platform semantics. This has little practical impact on most application programs as a Condition should always be waited upon in a loop, testing the state predicate that is being waited for. An implementation is free to remove the possibility of spurious wakeups but it is recommended that applications programmers always assume that they can occur and so always wait in a loop.
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____
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The same advice is also found for the ``++Object.wait(...)++`` method:
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____
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waits should always occur in loops, like this one:
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----
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synchronized (obj) {
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while (<condition does not hold>){
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obj.wait(timeout);
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}
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... // Perform action appropriate to condition
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}
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----
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____
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=== Noncompliant code example
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[source,java]
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----
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synchronized (obj) {
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if (!suitableCondition()){
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obj.wait(timeout); //the thread can wake up even if the condition is still false
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}
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... // Perform action appropriate to condition
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}
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----
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=== Compliant solution
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[source,java]
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----
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synchronized (obj) {
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while (!suitableCondition()){
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obj.wait(timeout);
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}
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... // Perform action appropriate to condition
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}
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----
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== Resources
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* https://wiki.sei.cmu.edu/confluence/x/EzdGBQ[CERT THI03-J.] - Always invoke wait() and await() methods inside a loop
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ifdef::env-github,rspecator-view[]
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'''
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== Implementation Specification
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(visible only on this page)
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=== Message
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Remove this call to "xxx" or move it into a "while" loop.
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endif::env-github,rspecator-view[]
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