// from gee.cs.oswego.edu/home/jsr166/jsr166
package jsr166tests.loops;
/*
* Written by Doug Lea with assistance from members of JCP JSR-166
* Expert Group and released to the public domain, as explained at
* http://creativecommons.org/licenses/publicdomain
*/
/*
* @test
* @summary basic safety and liveness of ReentrantLocks, and other locks based on them
*/
import java.util.concurrent.*;
import java.util.concurrent.locks.*;
import java.util.*;
public final class UncheckedLockLoops {
static final LoopHelpers.SimpleRandom rng = new LoopHelpers.SimpleRandom();
static boolean print = false;
static boolean doBuiltin = true;
public static void main(String[] args) throws Exception {
int maxThreads = 100;
int iters = 10000000;
if (args.length > 0)
maxThreads = Integer.parseInt(args[0]);
rng.setSeed(3122688L);
print = false;
System.out.println("Warmup...");
oneTest(1, 100000);
Thread.sleep(1000);
oneTest(3, 10000);
Thread.sleep(1000);
oneTest(2, 10000);
Thread.sleep(100);
oneTest(1, 100000);
Thread.sleep(100);
oneTest(1, 100000);
Thread.sleep(1000);
print = true;
System.out.println("Threads:" + 1);
oneTest(1, iters / 1);
Thread.sleep(100);
for (int i = 1; i <= maxThreads; i += (i+1) >>> 1) {
System.out.println("Threads:" + i);
oneTest(i, iters / i);
Thread.sleep(100);
}
}
static void oneTest(int nthreads, int iters) throws Exception {
int fairIters = (nthreads <= 1) ? iters : iters/20;
int v = rng.next();
if (print)
System.out.print("NoLock (1 thread) ");
new NoLockLoop().test(v, 1, iters * nthreads);
Thread.sleep(10);
if (print)
System.out.print("ReentrantLock ");
new ReentrantLockLoop().test(v, nthreads, iters);
Thread.sleep(10);
if (false) {
if (print)
System.out.print("FairReentrantLock ");
new FairReentrantLockLoop().test(v, nthreads, fairIters);
Thread.sleep(10);
}
if (doBuiltin) {
if (print)
System.out.print("builtin lock ");
new BuiltinLockLoop().test(v, nthreads, fairIters);
Thread.sleep(10);
}
if (print)
System.out.print("Mutex ");
new MutexLoop().test(v, nthreads, iters);
Thread.sleep(10);
if (print)
System.out.print("LongMutex ");
new LongMutexLoop().test(v, nthreads, iters);
Thread.sleep(10);
if (print)
System.out.print("Semaphore ");
new SemaphoreLoop().test(v, nthreads, iters);
Thread.sleep(10);
if (print)
System.out.print("FairSemaphore ");
new FairSemaphoreLoop().test(v, nthreads, fairIters);
Thread.sleep(10);
if (print)
System.out.print("ReentrantWriteLock ");
new ReentrantWriteLockLoop().test(v, nthreads, iters);
Thread.sleep(10);
if (print)
System.out.print("FairRWriteLock ");
new FairReentrantWriteLockLoop().test(v, nthreads, fairIters);
Thread.sleep(10);
if (print)
System.out.print("ReentrantReadWriteLock");
new ReentrantReadWriteLockLoop().test(v, nthreads, iters);
Thread.sleep(10);
if (print)
System.out.print("FairRReadWriteLock ");
new FairReentrantReadWriteLockLoop().test(v, nthreads, fairIters);
Thread.sleep(10);
}
static abstract class LockLoop implements Runnable {
int value;
int checkValue;
int iters;
volatile int result;
volatile int failures;
final LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer();
CyclicBarrier barrier;
final int setValue(int v) {
checkValue = v ^ 0x55555555;
value = v;
return v;
}
final int getValue() {
int v = value;
if (checkValue != ~(v ^ 0xAAAAAAAA))
++failures;
return v;
}
final void test(int initialValue, int nthreads, int iters) throws Exception {
setValue(initialValue);
this.iters = iters;
barrier = new CyclicBarrier(nthreads+1, timer);
for (int i = 0; i < nthreads; ++i)
new Thread(this).start();
barrier.await();
barrier.await();
long time = timer.getTime();
if (print) {
long tpi = time / (iters * nthreads);
System.out.print("\t" + LoopHelpers.rightJustify(tpi) + " ns per update");
// double secs = (double) time / 1000000000.0;
// System.out.print("\t " + secs + "s run time");
System.out.println();
}
if (result == 0) // avoid overoptimization
System.out.println("useless result: " + result);
if (failures != 0)
throw new Error("protection failure?");
}
abstract int loop(int n);
public final void run() {
try {
barrier.await();
result += loop(iters);
barrier.await();
}
catch (Exception ie) {
return;
}
}
}
private static class NoLockLoop extends LockLoop {
private volatile int readBarrier;
final int loop(int n) {
int sum = 0;
int x = 0;
while (n-- > 0) {
int r1 = readBarrier;
x = setValue(LoopHelpers.compute1(getValue()));
int r2 = readBarrier;
if (r1 == r2 && (x & 255) == 0)
++readBarrier;
sum += LoopHelpers.compute2(x);
}
return sum;
}
}
private static class BuiltinLockLoop extends LockLoop {
final int loop(int n) {
int sum = 0;
int x = 0;
while (n-- > 0) {
synchronized(this) {
x = setValue(LoopHelpers.compute1(getValue()));
}
sum += LoopHelpers.compute2(x);
}
return sum;
}
}
private static class ReentrantLockLoop extends LockLoop {
final private ReentrantLock lock = new ReentrantLock();
final int loop(int n) {
final ReentrantLock lock = this.lock;
int sum = 0;
int x = 0;
while (n-- > 0) {
lock.lock();
try {
x = setValue(LoopHelpers.compute1(getValue()));
}
finally {
lock.unlock();
}
sum += LoopHelpers.compute2(x);
}
return sum;
}
}
private static class MutexLoop extends LockLoop {
final private Mutex lock = new Mutex();
final int loop(int n) {
final Mutex lock = this.lock;
int sum = 0;
int x = 0;
while (n-- > 0) {
lock.lock();
try {
x = setValue(LoopHelpers.compute1(getValue()));
}
finally {
lock.unlock();
}
sum += LoopHelpers.compute2(x);
}
return sum;
}
}
private static class LongMutexLoop extends LockLoop {
final private LongMutex lock = new LongMutex();
final int loop(int n) {
final LongMutex lock = this.lock;
int sum = 0;
int x = 0;
while (n-- > 0) {
lock.lock();
try {
x = setValue(LoopHelpers.compute1(getValue()));
}
finally {
lock.unlock();
}
sum += LoopHelpers.compute2(x);
}
return sum;
}
}
private static class FairReentrantLockLoop extends LockLoop {
final private ReentrantLock lock = new ReentrantLock(true);
final int loop(int n) {
final ReentrantLock lock = this.lock;
int sum = 0;
int x = 0;
while (n-- > 0) {
lock.lock();
try {
x = setValue(LoopHelpers.compute1(getValue()));
}
finally {
lock.unlock();
}
sum += LoopHelpers.compute2(x);
}
return sum;
}
}
private static class ReentrantWriteLockLoop extends LockLoop {
final private Lock lock = new ReentrantReadWriteLock().writeLock();
final int loop(int n) {
final Lock lock = this.lock;
int sum = 0;
int x = 0;
while (n-- > 0) {
lock.lock();
try {
x = setValue(LoopHelpers.compute1(getValue()));
}
finally {
lock.unlock();
}
sum += LoopHelpers.compute2(x);
}
return sum;
}
}
private static class FairReentrantWriteLockLoop extends LockLoop {
final Lock lock = new ReentrantReadWriteLock(true).writeLock();
final int loop(int n) {
final Lock lock = this.lock;
int sum = 0;
int x = 0;
while (n-- > 0) {
lock.lock();
try {
x = setValue(LoopHelpers.compute1(getValue()));
}
finally {
lock.unlock();
}
sum += LoopHelpers.compute2(x);
}
return sum;
}
}
private static class SemaphoreLoop extends LockLoop {
final private Semaphore sem = new Semaphore(1, false);
final int loop(int n) {
final Semaphore sem = this.sem;
int sum = 0;
int x = 0;
while (n-- > 0) {
sem.acquireUninterruptibly();
try {
x = setValue(LoopHelpers.compute1(getValue()));
}
finally {
sem.release();
}
sum += LoopHelpers.compute2(x);
}
return sum;
}
}
private static class FairSemaphoreLoop extends LockLoop {
final private Semaphore sem = new Semaphore(1, true);
final int loop(int n) {
final Semaphore sem = this.sem;
int sum = 0;
int x = 0;
while (n-- > 0) {
sem.acquireUninterruptibly();
try {
x = setValue(LoopHelpers.compute1(getValue()));
}
finally {
sem.release();
}
sum += LoopHelpers.compute2(x);
}
return sum;
}
}
private static class ReentrantReadWriteLockLoop extends LockLoop {
final private ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
final int loop(int n) {
final Lock rlock = lock.readLock();
final Lock wlock = lock.writeLock();
int sum = 0;
int x = 0;
while (n-- > 0) {
if ((n & 16) != 0) {
rlock.lock();
try {
x = LoopHelpers.compute1(getValue());
x = LoopHelpers.compute2(x);
}
finally {
rlock.unlock();
}
}
else {
wlock.lock();
try {
setValue(x);
}
finally {
wlock.unlock();
}
sum += LoopHelpers.compute2(x);
}
}
return sum;
}
}
private static class FairReentrantReadWriteLockLoop extends LockLoop {
final private ReentrantReadWriteLock lock = new ReentrantReadWriteLock(true);
final int loop(int n) {
final Lock rlock = lock.readLock();
final Lock wlock = lock.writeLock();
int sum = 0;
int x = 0;
while (n-- > 0) {
if ((n & 16) != 0) {
rlock.lock();
try {
x = LoopHelpers.compute1(getValue());
x = LoopHelpers.compute2(x);
}
finally {
rlock.unlock();
}
}
else {
wlock.lock();
try {
setValue(x);
}
finally {
wlock.unlock();
}
sum += LoopHelpers.compute2(x);
}
}
return sum;
}
}
}