[Boost-users] [threads] calling unlock twice

Hello *, I wrote a code which used a RAII idiom to lock multiple mutex instances in ctor and unlock them in dtor. This resulted in the class similar to: struct lock_many { lock_many(mutex& m1, mutex& m2, ...) : m1_(m1), ... { boost::lock(*m1_, *m2_, ...); } ~lock_many() { //some asserts here, which ensure that either all mutex pointers are NULL or unequl to each other if(m1_==NULL && m2_==NULL && ...) return; // all are NULL no unlock needed } private: mutex* m1_; mutex* m2_; };