Concurrent Programming: c++11 random number repetition problem in multi-threading

Srand (Time (NULL)); we are familiar with C + + random functions, using time to do the seed. However, the random seed is different in the multithreaded environment if you want to randomly make different random numbers in the sub-threads. But time in seconds, slightly insufficient, so refer to this article to solve this problem:

/*Initialize random seed*/voidInitrand () {//if high-performance precision counters are supported, use them to initialize random seeds (microsecond level)Large_integer nfrequency; if(:: QueryPerformanceFrequency (&nfrequency))           {Large_integer nstartcounter; :: QueryPerformanceCounter (&nstartcounter);     :: Srand ((unsigned) nstartcounter.lowpart); }     Else //Otherwise initialize the random seed (millisecond) using the current system time     {         structTimeb STB; :: Ftime (&STB);     :: Srand ((unsigned) stb.millitm); }}

Concurrent Programming: c++11 random number repetition problem in multi-threading