Duplicate uniqid in PHP in high concurrency

The uniqid in PHP is duplicate in high concurrency. recently, the token verification has been generated in the project. First, use the uniqid () function in php to generate random strings. However, this function is based on microsecond time. In the case of high concurrency, the same value may be generated.

Solution 1: uniqid (rand (). The first parameter of this function can be used as the prefix of the number of generations, which greatly reduces the repetition rate of the number of generators. But the possibility of repetition still exists.

Solution 2: md5 (uniqid (). use the md5 () function to generate an absolutely unique value.