Update execute.py

execute.py

@@ -77,9 +77,9 @@ def unsafe_execute(check_program, output, result, timeout):
         # Run program.
         try:
             with time_limit(timeout):
-                with open("main.py", "w") as f:
+                with open("main_{}.py".format(threading.get_ident()), "w") as f:
                     f.write(check_program)
-                p = subprocess.Popen(["python", "./main.py"], stdout=subprocess.PIPE, stderr=subprocess.PIPE, encoding='utf-8')
+                p = subprocess.Popen(["python", "./main_{}.py".format(threading.get_ident())], stdout=subprocess.PIPE, stderr=subprocess.PIPE, encoding='utf-8')
                 (stdoutdata, stderrdata) = p.communicate()
                 exit_code = p.returncode
                 if stderrdata != '':