playing around

gistfile1.txt

BenchmarkSetGetMutex	 2000000	       668 ns/op

lotsofroutines.go

func BenchmarkSetGetMutex(b *testing.B) {                                                                                               
    w := &WithMutex{value: 0, m: &sync.Mutex{}}                                                                                         
                                                                                                                                        
    for i := 0; i < b.N; i++ {                                                                                                          
        go func() {                                                                                                                     
            w.Set(i)                                                                                                                    
            n := w.Get()                                                                                                                
            if n != i {                                                                                                                 
                panic("wrong number")                                                                                                   
            }                                                                                                                           
        }()                                                                                                                             
    }                                                                                                                                   
}