rspec/rules/S2273/java/rule.adoc

== Why is this an issue?

By contract, the method ``++Object.wait(...)++``, ``++Object.notify()++`` and ``++Object.notifyAll()++`` should be called by a thread that is the owner of the object's monitor. If this is not the case an ``++IllegalMonitorStateException++`` exception is thrown. This rule reinforces this constraint by making it mandatory to call one of these methods only inside a ``++synchronized++`` method or statement. 


=== Noncompliant code example

[source,java]
----
private void removeElement() {
  while (!suitableCondition()){
    obj.wait();
  }
  ... // Perform removal
}
----

or


[source,java]
----
private void removeElement() {
  while (!suitableCondition()){
    wait();
  }
  ... // Perform removal
}
----


=== Compliant solution

[source,java]
----
private void removeElement() {
  synchronized(obj) {
    while (!suitableCondition()){
      obj.wait();
    }
    ... // Perform removal
  }
}
----

or


[source,java]
----
private synchronized void removeElement() {
  while (!suitableCondition()){
    wait();
  }
  ... // Perform removal
}
----

ifdef::env-github,rspecator-view[]

'''
== Implementation Specification
(visible only on this page)

=== Message

Make this call to "[wait(...)|notify()|notifyAll()]" only inside a synchronized block to be sure to hold the monitor on "[this|xxx]" object.


endif::env-github,rspecator-view[]