| Methods Summary |
|---|
| static void | cleanGC()
System.gc();
System.runFinalization();
System.gc();
|
| static void | doTest(java.util.Map m)
targetMap = m;
Thread[] t = new Thread[nThreads];
Runnable r = new HashTest();
for (int i = 0; i < nThreads; i++)
t[i] = new Thread(r);
for (int i = 0; i < nThreads; i++)
t[i].start();
for (int i = 0; i < nThreads; i++)
try { t[i].join(); } catch (Exception e) {}
|
| public static void | main(java.lang.String[] args)
nLoops = 1000000;
nThreads = 1;
doTest(new Hashtable());
doTest(new HashMap());
doTest(new ConcurrentHashMap());
nLoops = Integer.parseInt(args[0]);
System.out.println("Starting standard hashmap test");
cleanGC();
Timestamp hashTS = new Timestamp();
doTest(new HashMap());
hashTS.stop();
System.out.println("Standard hashmap (1 thread) took " + hashTS);
System.out.println("Starting standard hashtable test");
cleanGC();
Timestamp hashtableTS = new Timestamp();
doTest(new Hashtable());
hashtableTS.stop();
System.out.println("Standard hashtable (1 thread) took " + hashtableTS);
System.out.println("Starting concurrent hashmap test");
cleanGC();
Timestamp concTS = new Timestamp();
doTest(new ConcurrentHashMap());
concTS.stop();
System.out.println("Concurrent hashmap (1 thread) took " + concTS);
nThreads = Integer.parseInt(args[1]);
System.out.println("Starting standard hashtable test");
cleanGC();
Timestamp hashNTS = new Timestamp();
doTest(new Hashtable());
hashNTS.stop();
System.out.println("Standard hashtable (" + nThreads + " threads) took " + hashNTS);
System.out.println("Starting concurrent hashmap test");
cleanGC();
Timestamp concNTS = new Timestamp();
doTest(new ConcurrentHashMap());
concNTS.stop();
System.out.println("Concurrent hashmap (" + nThreads + " threads) took " + concNTS);
double d = ((double) (hashtableTS.elapsedTime() - hashTS.elapsedTime())) /
nLoops;
System.out.println("Hashmap saves " + d + " " + hashTS.units() + " per call vs. hashtable");
d = ((double) (hashTS.elapsedTime() - concTS.elapsedTime())) /
nLoops;
System.out.println("Unsynchronized operation (1 thread) saves " + d + " " + concTS.units() + " per call");
d = ((double) (hashNTS.elapsedTime() - concNTS.elapsedTime())) /
(nLoops * nThreads);
System.out.println("Unsynchronized operation (" + nThreads + " threads) saves " + d + " " + concNTS.units() + " per call");
|
| public void | run()
for (int i = 0; i < nLoops; i++) {
Integer I = new Integer(i);
targetMap.put(I, I);
targetMap.get(I);
}
|
