update

language_learning/2020.06.01_parallel_calculations_with_python/application_of_parallel_calculations_with_python.py

@@ -10,17 +10,21 @@ def main(parameter_array, task_index):
     for parameter in parameter_array:
         result = parameter*2
         result_array.append(result)
+    time.sleep(np.random.uniform(1,10))
     guan.write_one_dimensional_data(parameter_array, result_array, filename='task_index='+str(task_index))
 
 if __name__ == '__main__':
     cpus = 4
     parameter_array_all = np.arange(0, 17, 1) 
     start_time = time.perf_counter()
+    process_array = []
     for task_index in range(cpus):
         parameter_array = guan.preprocess_for_parallel_calculations(parameter_array_all, cpus, task_index)
-        p = Process(target=main, args=(parameter_array, task_index))
-        p.start()
-    p.join()
+        process_array.append(Process(target=main, args=(parameter_array, task_index)))
+    for process in process_array: # 运行子进程
+        process.start()
+    for process in process_array: # 等待子进程完成
+        process.join() 
     end_time = time.perf_counter()
     print('运行时间=', (end_time-start_time), '\n')
     f = open('result.txt', 'w')

language_learning/2020.06.01_parallel_calculations_with_python/parallel_calculations_with_python.py

@@ -26,14 +26,17 @@ if __name__ == '__main__':
     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
+    p1 = Process(target=run_proc, args=('job1',))
+    p2 = Process(target=run_proc, args=('job2',))
+    p3 = Process(target=run_proc, args=('job3',))
+    p4 = Process(target=run_proc, args=('job4',))
+    p1.start()
+    p2.start()
+    p3.start()
+    p4.start()
+    p1.join()   # join()方法可以等待子进程结束后再继续往下运行
+    p2.join()   # join()方法可以等待子进程结束后再继续往下运行
+    p3.join()   # join()方法可以等待子进程结束后再继续往下运行
+    p4.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('运行时间(s)=', (end_time-start_time))

language_learning/2020.06.01_parallel_calculations_with_python/parallel_calculations_with_python_using_Value.py

@@ -0,0 +1,16 @@
+from multiprocessing import Process, Value
+
+def run_proc(name, a, num): # 要执行的代码
+    num.value = a
+
+if __name__ == '__main__':
+    num1 = Value('d', 0.0)  # 共享内存
+    num2 = Value('d', 0.0)  # 共享内存
+    p1 = Process(target=run_proc, args=('job1', 100, num1))
+    p2 = Process(target=run_proc, args=('job2', 200, num2))
+    p1.start()
+    p2.start()
+    p1.join()
+    p2.join() 
+    print(num1.value)
+    print(num2.value)