This page is a snapshot from the LWG issues list, see the Library Active Issues List for more information and the meaning of NAD Editorial status.
Section: 30.4 [thread.mutex] Status: NAD Editorial Submitter: Switzerland Opened: 2010-08-25 Last modified: 2017-02-03
Priority: Not Prioritized
View all other issues in [thread.mutex].
View all issues with NAD Editorial status.
Specifications of unlock member functions and unlock mutex requirements are inconsistent wrt to exceptions and pre- and postconditions.
[ Resolution proposed by ballot comment: ]
unlock should specifiy the precondition that the current thread "owns the lock", this will make calls without holding the locks "undefined behavior". unlock in [mutex.requirements] should either be noexcept(true) or be allowed to throw system_error like unique_lock::unlock, or the latter should be nothrow(true) and have the precondition owns == true. Furthermore unique_lock's postcondition is wrong in the case of a recursive mutex where owns might stay true, when it is not the last unlock needed to be called.