Ut test opinion

1) memory check: whether memory leaks, empty pointers, wild pointers, and variables are initialized.

2) input check: whether all input conditions can be properly handled, including exceptions, such as null pointers and abnormal integers.

3) character type check: whether Unicode, multi-byte, and single-byte conversion are properly processed.

4) language check: tests are performed in various language Environments. text input parameters can also be set to text in different languages.

5) signal check: Check whether the signal will affect the program, especially the blocked system functions in the program.

6) multi-threaded check: if the program is running in a multi-threaded environment, check whether a system function that cannot be reloaded is used and whether the global variables are locked.