040000 tree ef6d9d2c244628c85527307e2ab9c2da2773bd60	bidir
040000 tree 57d81d4a3f3636e073b55bafb38655179f86abe3	fifo
040000 tree 1dd891a8101439ac8f145d6e5751d9937c22e1ba	hierarchy
040000 tree 153d1708a9af71dd9ad1307e68c87db0d689de2e	producer_consumer