Is this a correct porting of java.util.Random in objectiveC
- by dipu
I have ported the code inside java.util.Random class in objectivec. I want to have an identical random number generator so that it synchs with the server app running on java. Now is this a safe porting and if not is there a way to mimic AtomicLong as it is found in java? Please see my code below.
static long long multiplier = 0x5DEECE66DL;
static long addend = 0xBL;
static long long mask = (0x1000000000000001L << 48) - 1;
-(void) initWithSeed:(long long) seed1 {
[self setRandomSeed: 0L];// = new AtomicLong(0L);
[self setSeed: seed1];
}
-(int) next:(int)bits {
long long oldseed, nextseed;
long long seed1 = [self.randomSeed longLongValue]; //AtomicLong
//do {
oldseed = seed1;
nextseed = (oldseed * multiplier + addend) & mask;
//} while (!seed.compareAndSet(oldseed, nextseed));
[self setRandomSeed: [NSNumber numberWithLongLong:nextseed]];
///int ret = (int)(nextseed >>> (48 - bits));
int ret = (unsigned int)(nextseed >> (48 - bits));
return ret;
}
-(void) setSeed:(long long) seed1 {
seed1 = (seed1 ^ multiplier) & mask;
[self setRandomSeed: [NSNumber numberWithLongLong:seed1]];
}
