Solution for E1: Blocking Thread Synchronization.

git-svn-id: https://epos.lisha.ufsc.br/svn/branches/ine5424@3102 86035c5f-d46c-4136-a2d5-fe63f1d4a782
Solution for E2: Blocking Thread Joining.

git-svn-id: https://epos.lisha.ufsc.br/svn/branches/ine5424@3104 86035c5f-d46c-4136-a2d5-fe63f1d4a782