040000 tree e17742bebe45fb700ea7a56728f19a0c6f987725	thread.lock.algorithm
040000 tree e1879b48c942455d76727b472f06f7f5b62c8489	thread.lock
040000 tree f6c17820698619a3e7c3a047a5e64c557378c12f	thread.mutex.requirements
040000 tree 8276dbc864812447578c203f3d440b37b73bcf28	thread.once