before lock #1 before lock #2 before lock #3 before unlock #1 before unlock #2 before unlock #3 before unlock #4 Mutex not locked by calling thread: mutex 0x........, recursion count 0, owner 1. at 0x........: pthread_mutex_unlock (drd_pthread_intercepts.c:?) by 0x........: nearly_main (tc10_rec_lock.c:42) by 0x........: main (tc10_rec_lock.c:47) mutex 0x........ was first observed at: at 0x........: pthread_mutex_init (drd_pthread_intercepts.c:?) by 0x........: nearly_main (tc10_rec_lock.c:24) by 0x........: main (tc10_rec_lock.c:47) ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)