Golang and python thread details and simple examples, golangpython thread

Golang and python thread details and simple examples, golangpython thread

Golang and python thread details and simple examples

In GO, 15 threads are enabled, and each thread increases global variable traversal by 100000 times. Therefore, the prediction result is 15*100000 = 1500000.

var sum intvar cccc intvar m *sync.Mutexfunc Count1(i int, ch chan int) {  for j := 0; j < 100000; j++ {   cccc = cccc + 1  }  ch <- cccc}func main() {  m = new(sync.Mutex)  ch := make(chan int, 15)  for i := 0; i < 15; i++ {   go Count1(i, ch)  }  for i := 0; i < 15; i++ {   select {   case msg := <-ch:     fmt.Println(msg)   }  }}

But the final result is 406527.

The lock is required.

func Count1(i int, ch chan int) {  m.Lock()  for j := 0; j < 100000; j++ {   cccc = cccc + 1  }  ch <- cccc  m.Unlock()}

Final output: 1500000

In python: implementation in the same way does not work.

count = 0def sumCount(temp):  global count  for i in range(temp):    count = count + 1li = []for i in range(15):  th = threading.Thread(target=sumCount, args=(1000000,))  th.start()  li.append(th)for i in li:  i.join()print(count)

Output result: 3004737

It also requires locking:

mutex = threading.Lock()count = 0def sumCount(temp):  global count  mutex.acquire()  for i in range(temp):    count = count + 1  mutex.release()li = []for i in range(15):  th = threading.Thread(target=sumCount, args=(1000000,))  th.start()  li.append(th)for i in li:  i.join()print(count)

1500000 output

OK, the lock column.

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