Go - read write lock

• Add number to 10000.
• RWLock (Use Lock/Unlock to read): 19ms, 92202 read count
  
• RWLock (Use RLock/RUnlock to read): 597ms, 4789798 read count
  
• We can say read lock get more chances to read.. overall make write become slower because limited CPU Core Size (8 in my machine)
• Here is code for copy/paste and try
package main


import (
     "fmt"
     "sync"
     "sync/atomic"
     "time"
)


var rc int32
var n int
var m sync.RWMutex
var wg sync.WaitGroup


func main() {
     from := time.Now()
     for i := 0; i < 100; i++ {
         round := 100
         wg.Add(round)
         go func() {
             for {
                 m.RLock()
                 atomic.AddInt32(&rc, 1)
                 fmt.Sprint(n)
                 m.RUnlock()


             }
         }()
         go func() {
             for i := 0; i < round; i++ {
                 m.Lock()
                 n++
                 m.Unlock()
                 wg.Done()
             }
         }()
     }
     wg.Wait()
     duration := time.Now().Sub(from)
     fmt.Println("readCount:", rc, "n:", n, "duration:", duration)


}