1036 
1037     /**
1038      * The increment of seeder per new instance.
1039      */
1040     private static final long SEEDER_INCREMENT = 0xbb67ae8584caa73bL;
1041 
1042     /**
1043      * The least non-zero value returned by nextDouble(). This value
1044      * is scaled by a random value of 53 bits to produce a result.
1045      */
1046     private static final double DOUBLE_UNIT = 0x1.0p-53;  // 1.0  / (1L << 53)
1047     private static final float  FLOAT_UNIT  = 0x1.0p-24f; // 1.0f / (1 << 24)
1048 
1049     // IllegalArgumentException messages
1050     static final String BAD_BOUND = "bound must be positive";
1051     static final String BAD_RANGE = "bound must be greater than origin";
1052     static final String BAD_SIZE  = "size must be non-negative";
1053 
1054     // Unsafe mechanics
1055     private static final Unsafe U = Unsafe.getUnsafe();
1056     private static final long SEED = U.objectFieldOffset
1057             (Thread.class, "threadLocalRandomSeed");
1058     private static final long PROBE = U.objectFieldOffset
1059             (Thread.class, "threadLocalRandomProbe");
1060     private static final long SECONDARY = U.objectFieldOffset
1061             (Thread.class, "threadLocalRandomSecondarySeed");
1062     private static final long THREADLOCALS = U.objectFieldOffset
1063             (Thread.class, "threadLocals");
1064     private static final long INHERITABLETHREADLOCALS = U.objectFieldOffset
1065             (Thread.class, "inheritableThreadLocals");
1066     private static final long INHERITEDACCESSCONTROLCONTEXT = U.objectFieldOffset
1067             (Thread.class, "inheritedAccessControlContext");
1068 
1069     /** Rarely-used holder for the second of a pair of Gaussians */
1070     private static final ThreadLocal<Double> nextLocalGaussian =
1071         new ThreadLocal<>();
1072 
1073     /** Generates per-thread initialization/probe field */
1074     private static final AtomicInteger probeGenerator = new AtomicInteger();
1075 
1076     /** The common ThreadLocalRandom */
1077     static final ThreadLocalRandom instance = new ThreadLocalRandom();
1078 
1079     /**
1080      * The next seed for default constructors.
1081      */
1082     private static final AtomicLong seeder
1083         = new AtomicLong(mix64(System.currentTimeMillis()) ^
1084                          mix64(System.nanoTime()));
1085 
1086     // at end of <clinit> to survive static initialization circularity
1087     static {

1036 
1037     /**
1038      * The increment of seeder per new instance.
1039      */
1040     private static final long SEEDER_INCREMENT = 0xbb67ae8584caa73bL;
1041 
1042     /**
1043      * The least non-zero value returned by nextDouble(). This value
1044      * is scaled by a random value of 53 bits to produce a result.
1045      */
1046     private static final double DOUBLE_UNIT = 0x1.0p-53;  // 1.0  / (1L << 53)
1047     private static final float  FLOAT_UNIT  = 0x1.0p-24f; // 1.0f / (1 << 24)
1048 
1049     // IllegalArgumentException messages
1050     static final String BAD_BOUND = "bound must be positive";
1051     static final String BAD_RANGE = "bound must be greater than origin";
1052     static final String BAD_SIZE  = "size must be non-negative";
1053 
1054     // Unsafe mechanics
1055     private static final Unsafe U = Unsafe.getUnsafe();
1056     private static final long SEED
1057         = U.objectFieldOffset(Thread.class, "threadLocalRandomSeed");
1058     private static final long PROBE
1059         = U.objectFieldOffset(Thread.class, "threadLocalRandomProbe");
1060     private static final long SECONDARY
1061         = U.objectFieldOffset(Thread.class, "threadLocalRandomSecondarySeed");
1062     private static final long THREADLOCALS
1063         = U.objectFieldOffset(Thread.class, "threadLocals");
1064     private static final long INHERITABLETHREADLOCALS
1065         = U.objectFieldOffset(Thread.class, "inheritableThreadLocals");
1066     private static final long INHERITEDACCESSCONTROLCONTEXT
1067         = U.objectFieldOffset(Thread.class, "inheritedAccessControlContext");
1068 
1069     /** Rarely-used holder for the second of a pair of Gaussians */
1070     private static final ThreadLocal<Double> nextLocalGaussian =
1071         new ThreadLocal<>();
1072 
1073     /** Generates per-thread initialization/probe field */
1074     private static final AtomicInteger probeGenerator = new AtomicInteger();
1075 
1076     /** The common ThreadLocalRandom */
1077     static final ThreadLocalRandom instance = new ThreadLocalRandom();
1078 
1079     /**
1080      * The next seed for default constructors.
1081      */
1082     private static final AtomicLong seeder
1083         = new AtomicLong(mix64(System.currentTimeMillis()) ^
1084                          mix64(System.nanoTime()));
1085 
1086     // at end of <clinit> to survive static initialization circularity
1087     static {