diff --git a/src/com/yahoo/ycsb/BasicDB.java b/src/com/yahoo/ycsb/BasicDB.java
index 3b4adf63c4712c5704226990563676428d514490..9490451eff7e3be3d22ad30cbb1392d0712d8d6d 100644
--- a/src/com/yahoo/ycsb/BasicDB.java
+++ b/src/com/yahoo/ycsb/BasicDB.java
@@ -21,7 +21,6 @@ import java.util.HashMap;
import java.util.Properties;
import java.util.Set;
import java.util.Enumeration;
-import java.util.Random;
import java.util.Vector;
@@ -37,13 +36,11 @@ public class BasicDB extends DB
public static final String SIMULATE_DELAY_DEFAULT="0";
- Random random;
boolean verbose;
int todelay;
public BasicDB()
{
- random=new Random();
todelay=0;
}
@@ -54,7 +51,7 @@ public class BasicDB extends DB
{
try
{
- Thread.sleep((long)random.nextInt(todelay));
+ Thread.sleep((long)Utils.random().nextInt(todelay));
}
catch (InterruptedException e)
{
diff --git a/src/com/yahoo/ycsb/Client.java b/src/com/yahoo/ycsb/Client.java
index 9da86041a6c2c601737b9681fb5e53bca2ed0894..64585f81a02276d04f0ba9142a9d7bf7375889f3 100644
--- a/src/com/yahoo/ycsb/Client.java
+++ b/src/com/yahoo/ycsb/Client.java
@@ -137,8 +137,6 @@ class StatusThread extends Thread
*/
class ClientThread extends Thread
{
- static Random random=new Random();
-
DB _db;
boolean _dotransactions;
Workload _workload;
@@ -215,7 +213,7 @@ class ClientThread extends Thread
//and the sleep() doesn't make sense for granularities < 1 ms anyway
if ( (_target>0) && (_target<=1.0) )
{
- sleep(random.nextInt((int)(1.0/_target)));
+ sleep(Utils.random().nextInt((int)(1.0/_target)));
}
}
catch (InterruptedException e)
diff --git a/src/com/yahoo/ycsb/RandomByteIterator.java b/src/com/yahoo/ycsb/RandomByteIterator.java
index 3e6cba18f95a336ea37364d5ff0f6820d040a7a2..99239f859fb8011e663af50acaa985b09a6d0586 100644
--- a/src/com/yahoo/ycsb/RandomByteIterator.java
+++ b/src/com/yahoo/ycsb/RandomByteIterator.java
@@ -16,10 +16,7 @@
*/
package com.yahoo.ycsb;
-import java.util.Random;
-
public class RandomByteIterator extends ByteIterator {
- static Random random=new Random();
long len;
long off;
int buf_off;
@@ -31,7 +28,7 @@ public class RandomByteIterator extends ByteIterator {
}
private void fillBytesImpl(byte[] buf, int base) {
- int bytes = random.nextInt();
+ int bytes = Utils.random().nextInt();
try {
buf[base+0] = (byte)(((bytes ) & 31) + ' ');
buf[base+1] = (byte)(((bytes >> 5 ) & 31) + ' ');
diff --git a/src/com/yahoo/ycsb/Utils.java b/src/com/yahoo/ycsb/Utils.java
index 57dd141a066bd0145d1f2f617d4c9045e71ec36a..f49bc0f5c03cd1b3cd7993d9d97ba619cc5cde37 100644
--- a/src/com/yahoo/ycsb/Utils.java
+++ b/src/com/yahoo/ycsb/Utils.java
@@ -24,8 +24,17 @@ import java.util.Random;
*/
public class Utils
{
- static Random random=new Random();
-
+ private static final Random rand = new Random();
+ private static final ThreadLocal<Random> rng = new ThreadLocal<Random>();
+
+ public static Random random() {
+ Random ret = rng.get();
+ if(ret == null) {
+ ret = new Random(rand.nextLong());
+ rng.set(ret);
+ }
+ return ret;
+ }
/**
* Generate a random ASCII string of a given length.
*/
@@ -34,7 +43,7 @@ public class Utils
int interval='~'-' '+1;
byte []buf = new byte[length];
- random.nextBytes(buf);
+ random().nextBytes(buf);
for (int i = 0; i < length; i++) {
if (buf[i] < 0) {
buf[i] = (byte)((-buf[i] % interval) + ' ');
diff --git a/src/com/yahoo/ycsb/generator/CounterGenerator.java b/src/com/yahoo/ycsb/generator/CounterGenerator.java
index 11db1cf1307404ee87f9caf1e03e6d56af41aa37..df37b2398c5f0f46e886d7df7367398f68d86b90 100644
--- a/src/com/yahoo/ycsb/generator/CounterGenerator.java
+++ b/src/com/yahoo/ycsb/generator/CounterGenerator.java
@@ -17,34 +17,39 @@
package com.yahoo.ycsb.generator;
+import java.util.concurrent.atomic.AtomicInteger;
+
/**
* Generates a sequence of integers 0, 1, ...
*/
public class CounterGenerator extends IntegerGenerator
{
- int counter;
+ final AtomicInteger counter;
/**
* Create a counter that starts at countstart
*/
public CounterGenerator(int countstart)
{
- counter=countstart;
- setLastInt(countstart-1);
+ counter=new AtomicInteger(countstart);
+ setLastInt(counter.get()-1);
}
/**
* If the generator returns numeric (integer) values, return the next value as an int. Default is to return -1, which
* is appropriate for generators that do not return numeric values.
*/
- public synchronized int nextInt()
+ public int nextInt()
{
- int lastint=counter;
- counter++;
- setLastInt(lastint);
- return lastint;
+ int ret = counter.getAndIncrement();
+ setLastInt(ret);
+ return ret;
+ }
+ @Override
+ public int lastInt()
+ {
+ return counter.get() - 1;
}
-
@Override
public double mean() {
throw new UnsupportedOperationException("Can't compute mean of non-stationary distribution!");
diff --git a/src/com/yahoo/ycsb/generator/DiscreteGenerator.java b/src/com/yahoo/ycsb/generator/DiscreteGenerator.java
index 087312c03519bbc50ef69f04f63288125c3c0b97..c28f3ae771e1bbe667902e925bf0a16f0bdf8fe3 100644
--- a/src/com/yahoo/ycsb/generator/DiscreteGenerator.java
+++ b/src/com/yahoo/ycsb/generator/DiscreteGenerator.java
@@ -20,6 +20,7 @@ package com.yahoo.ycsb.generator;
import java.util.Vector;
import java.util.Random;
+import com.yahoo.ycsb.Utils;
import com.yahoo.ycsb.WorkloadException;
/**
@@ -40,13 +41,11 @@ public class DiscreteGenerator extends Generator
}
Vector<Pair> _values;
- Random _random;
String _lastvalue;
public DiscreteGenerator()
{
_values=new Vector<Pair>();
- _random=new Random();
_lastvalue=null;
}
@@ -62,7 +61,7 @@ public class DiscreteGenerator extends Generator
sum+=p._weight;
}
- double val=_random.nextDouble();
+ double val=Utils.random().nextDouble();
for (Pair p : _values)
{
diff --git a/src/com/yahoo/ycsb/generator/ExponentialGenerator.java b/src/com/yahoo/ycsb/generator/ExponentialGenerator.java
index 7a9187e1083783236b3c83c475873c8e046a4699..de1a2760c4b02b308666dbc7ceaefb9cc8805cfd 100644
--- a/src/com/yahoo/ycsb/generator/ExponentialGenerator.java
+++ b/src/com/yahoo/ycsb/generator/ExponentialGenerator.java
@@ -19,6 +19,8 @@ package com.yahoo.ycsb.generator;
import java.util.Random;
+import com.yahoo.ycsb.Utils;
+
/**
* A generator of an exponential distribution. It produces a sequence
* of time intervals (integers) according to an exponential
@@ -43,8 +45,6 @@ public class ExponentialGenerator extends IntegerGenerator
*/
double _gamma;
- Random _random;
-
/******************************* Constructors **************************************/
/**
@@ -54,12 +54,10 @@ public class ExponentialGenerator extends IntegerGenerator
public ExponentialGenerator(double mean)
{
_gamma = 1.0/mean;
- _random = new Random();
}
public ExponentialGenerator(double percentile, double range)
{
_gamma = -Math.log(1.0-percentile/100.0) / range; //1.0/mean;
- _random = new Random();
}
/****************************************************************************************/
@@ -84,7 +82,7 @@ public class ExponentialGenerator extends IntegerGenerator
*/
public long nextLong()
{
- return (long) (-Math.log(_random.nextDouble()) / _gamma);
+ return (long) (-Math.log(Utils.random().nextDouble()) / _gamma);
}
@Override
diff --git a/src/com/yahoo/ycsb/generator/HistogramGenerator.java b/src/com/yahoo/ycsb/generator/HistogramGenerator.java
index baaf358851d14caf7d1d6f3e5f20fe3c1ea84496..aba42c47b0c060a92b667c7d6808f3b608c37dac 100644
--- a/src/com/yahoo/ycsb/generator/HistogramGenerator.java
+++ b/src/com/yahoo/ycsb/generator/HistogramGenerator.java
@@ -20,6 +20,8 @@ import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Random;
+
+import com.yahoo.ycsb.Utils;
import com.yahoo.ycsb.generator.IntegerGenerator;
/**
@@ -41,7 +43,6 @@ public class HistogramGenerator extends IntegerGenerator {
long block_size;
long[] buckets;
long area;
- Random rand = new Random();
long weighted_area = 0;
double mean_size = 0;
@@ -93,7 +94,7 @@ public class HistogramGenerator extends IntegerGenerator {
@Override
public int nextInt() {
- int number = rand.nextInt((int)area);
+ int number = Utils.random().nextInt((int)area);
int i;
for(i = 0; i < (buckets.length - 1); i++){
diff --git a/src/com/yahoo/ycsb/generator/HotspotIntegerGenerator.java b/src/com/yahoo/ycsb/generator/HotspotIntegerGenerator.java
index 2ede01b9ebad58a560074942a30c10b18b4562cf..969ae7706d781b48e50f2289db602eb666a761d9 100644
--- a/src/com/yahoo/ycsb/generator/HotspotIntegerGenerator.java
+++ b/src/com/yahoo/ycsb/generator/HotspotIntegerGenerator.java
@@ -18,6 +18,8 @@ package com.yahoo.ycsb.generator;
import java.util.Random;
+import com.yahoo.ycsb.Utils;
+
/**
* Generate integers resembling a hotspot distribution where x% of operations
* access y% of data items. The parameters specify the bounds for the numbers,
@@ -37,7 +39,6 @@ public class HotspotIntegerGenerator extends IntegerGenerator {
private final int coldInterval;
private final double hotsetFraction;
private final double hotOpnFraction;
- private final Random random;
/**
* Create a generator for Hotspot distributions.
@@ -71,12 +72,12 @@ public class HotspotIntegerGenerator extends IntegerGenerator {
this.hotInterval = (int)(interval * hotsetFraction);
this.coldInterval = interval - hotInterval;
this.hotOpnFraction = hotOpnFraction;
- random = new Random();
}
@Override
public int nextInt() {
int value = 0;
+ Random random = Utils.random();
if (random.nextDouble() < hotOpnFraction) {
// Choose a value from the hot set.
value = lowerBound + random.nextInt(hotInterval);
diff --git a/src/com/yahoo/ycsb/generator/IntegerGenerator.java b/src/com/yahoo/ycsb/generator/IntegerGenerator.java
index a49d9b4765729aa83200a55420d205d7383845bb..13d36cd1f1f423e7cd97b36789e2e02152d1ef09 100644
--- a/src/com/yahoo/ycsb/generator/IntegerGenerator.java
+++ b/src/com/yahoo/ycsb/generator/IntegerGenerator.java
@@ -31,7 +31,7 @@ public abstract class IntegerGenerator extends Generator
* Set the last value generated. IntegerGenerator subclasses must use this call
* to properly set the last string value, or the lastString() and lastInt() calls won't work.
*/
- public void setLastInt(int last)
+ protected void setLastInt(int last)
{
lastint=last;
}
@@ -54,9 +54,10 @@ public abstract class IntegerGenerator extends Generator
* Calling lastString() should not advance the distribution or have any side effects. If nextString() has not yet
* been called, lastString() should return something reasonable.
*/
+ @Override
public String lastString()
{
- return ""+lastint;
+ return ""+lastInt();
}
/**
diff --git a/src/com/yahoo/ycsb/generator/SkewedLatestGenerator.java b/src/com/yahoo/ycsb/generator/SkewedLatestGenerator.java
index 6d07c5fc9e129ef204ec757fdbc211718382612b..376eb7775c6b7cf6c44549728d4a03a4d47916b6 100644
--- a/src/com/yahoo/ycsb/generator/SkewedLatestGenerator.java
+++ b/src/com/yahoo/ycsb/generator/SkewedLatestGenerator.java
@@ -28,7 +28,7 @@ public class SkewedLatestGenerator extends IntegerGenerator
public SkewedLatestGenerator(CounterGenerator basis)
{
_basis=basis;
- _zipfian=new ZipfianGenerator(Integer.parseInt(_basis.lastString()));
+ _zipfian=new ZipfianGenerator(_basis.lastInt());
nextInt();
}
@@ -37,7 +37,7 @@ public class SkewedLatestGenerator extends IntegerGenerator
*/
public int nextInt()
{
- int max=Integer.parseInt(_basis.lastString());
+ int max=_basis.lastInt();
int nextint=max-_zipfian.nextInt(max);
setLastInt(nextint);
return nextint;
diff --git a/src/com/yahoo/ycsb/generator/UniformIntegerGenerator.java b/src/com/yahoo/ycsb/generator/UniformIntegerGenerator.java
index a6ae08a6de87b49c43566c941e30e96a367d9eff..fa6af1316ca3d156653d9b362f1f59debd451a97 100644
--- a/src/com/yahoo/ycsb/generator/UniformIntegerGenerator.java
+++ b/src/com/yahoo/ycsb/generator/UniformIntegerGenerator.java
@@ -19,12 +19,13 @@ package com.yahoo.ycsb.generator;
import java.util.Random;
+import com.yahoo.ycsb.Utils;
+
/**
* Generates integers randomly uniform from an interval.
*/
public class UniformIntegerGenerator extends IntegerGenerator
{
- Random _random;
int _lb,_ub,_interval;
/**
@@ -35,7 +36,6 @@ public class UniformIntegerGenerator extends IntegerGenerator
*/
public UniformIntegerGenerator(int lb, int ub)
{
- _random=new Random();
_lb=lb;
_ub=ub;
_interval=_ub-_lb+1;
@@ -44,7 +44,7 @@ public class UniformIntegerGenerator extends IntegerGenerator
@Override
public int nextInt()
{
- int ret=_random.nextInt(_interval)+_lb;
+ int ret=Utils.random().nextInt(_interval)+_lb;
setLastInt(ret);
return ret;
diff --git a/src/com/yahoo/ycsb/generator/ZipfianGenerator.java b/src/com/yahoo/ycsb/generator/ZipfianGenerator.java
index 5a4c0198dedd75cbce17620051990fb19d8d5051..8a70f0869a16c7d2776072c1b6c4ed2e94e38e27 100644
--- a/src/com/yahoo/ycsb/generator/ZipfianGenerator.java
+++ b/src/com/yahoo/ycsb/generator/ZipfianGenerator.java
@@ -19,6 +19,8 @@ package com.yahoo.ycsb.generator;
import java.util.Random;
+import com.yahoo.ycsb.Utils;
+
/**
* A generator of a zipfian distribution. It produces a sequence of items, such that some items are more popular than others, according
* to a zipfian distribution. When you construct an instance of this class, you specify the number of items in the set to draw from, either
@@ -61,8 +63,6 @@ public class ZipfianGenerator extends IntegerGenerator
*/
double alpha,zetan,eta,theta,zeta2theta;
- Random random;
-
/**
* The number of items used to compute zetan the last time.
*/
@@ -136,8 +136,6 @@ public class ZipfianGenerator extends IntegerGenerator
base=min;
zipfianconstant=_zipfianconstant;
- random=new Random();
-
theta=zipfianconstant;
zeta2theta=zeta(2,theta);
@@ -273,7 +271,7 @@ public class ZipfianGenerator extends IntegerGenerator
}
}
- double u=random.nextDouble();
+ double u=Utils.random().nextDouble();
double uz=u*zetan;
if (uz<1.0)