update

language_learning/2020.06.01_parallel_calculations_with_python/parallel_calculations_with_python.py

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+from multiprocessing import Process
+import os
+import time
+
+def run_proc(name): # 要执行的代码
+    start_time = time.perf_counter()
+    for i in range(300000000):
+        x = 100000^1000000000000
+    end_time = time.perf_counter()
+    print ('Process id running on %s = %s' % (name, os.getpid()), '; running time = %s' % (end_time-start_time))
+
+
+if __name__ == '__main__':
+
+    # 串行
+    print('串行程序')
+    print('Process id = %s.' % os.getpid())
+    start_time = time.perf_counter()
+    run_proc('job1')
+    run_proc('job2')
+    run_proc('job3')
+    run_proc('job4')
+    end_time = time.perf_counter()
+    print('CPU执行时间(s)=', (end_time-start_time), '\n')
+
+    # 并行
+    print('并行程序')
+    print('Process id = %s.' % os.getpid())
+    start_time = time.perf_counter()
+    p = Process(target=run_proc, args=('job1',))
+    p.start()
+    p = Process(target=run_proc, args=('job2',))
+    p.start()
+    p = Process(target=run_proc, args=('job3',))
+    p.start()
+    p = Process(target=run_proc, args=('job4',))
+    p.start()
+    p.join()   # join()方法可以等待子进程结束后再继续往下运行
+    end_time = time.perf_counter()
+    print('CPU执行时间(s)=', (end_time-start_time))
+