程序假死的可能原因 Possible cause of apparent hang

http://stackoverflow.com/a/39229526/404271

It appears that the server you're sending your request to is throttling you - that is, it's sending bytes with less than 1 second between each package (thus not triggering your timeout parameter), but slow enough for it to appear to be stuck.

可能是百度方的限速造成的。