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Improved POW test

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This commit is contained in:
Christian Basler 2015-10-28 16:56:09 +01:00
parent b496f81b20
commit 9c2d8589bf
3 changed files with 20 additions and 16 deletions
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5
domain/src/main/java/ch/dissem/bitmessage/ports/MultiThreadedPOWEngine.java
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@ -36,8 +36,9 @@ public class MultiThreadedPOWEngine implements ProofOfWorkEngine {
private static final Semaphore semaphore = new Semaphore(1, true);
/**
* Although it has a callback, this method will block until all pending nonce calculations are done. (It gets very
* inefficient if multiple nonce are calculated at the same time.
* This method will block until all pending nonce calculations are done, but not wait for its own calculation
* to finish.
* (This implementation becomes very inefficient if multiple nonce are calculated at the same time.)
*
* @param initialHash the SHA-512 hash of the object to send, sans nonce
* @param target the target, representing an unsigned long

11
domain/src/main/java/ch/dissem/bitmessage/utils/CallbackWaiter.java
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@ -20,13 +20,16 @@ package ch.dissem.bitmessage.utils;
* Waits for a value within a callback method to be set.
*/
public class CallbackWaiter<T> {
private final long startTime = System.currentTimeMillis();
private volatile boolean isSet;
private volatile T value;
private T value;
private long time;
public void setValue(T value) {
synchronized (this) {
this.isSet = true;
this.time = System.currentTimeMillis() - startTime;
this.value = value;
this.isSet = true;
}
}
@ -38,4 +41,8 @@ public class CallbackWaiter<T> {
return value;
}
}
public long getTime() {
return time;
}
}

20
domain/src/test/java/ch/dissem/bitmessage/ports/ProofOfWorkEngineTest.java
View File

@ -36,27 +36,24 @@ public class ProofOfWorkEngineTest extends TestBase {
}
private void testPOW(ProofOfWorkEngine engine) throws InterruptedException {
long time = System.currentTimeMillis();
byte[] initialHash = security().sha512(new byte[]{1, 3, 6, 4});
byte[] target = {0, 0, -1, -1, -1, -1, -1, -1};
byte[] target = {0, 0, 0, -1, -1, -1, -1, -1};
final CallbackWaiter<byte[]> waiter = new CallbackWaiter<>();
final CallbackWaiter<byte[]> waiter1 = new CallbackWaiter<>();
engine.calculateNonce(initialHash, target,
new ProofOfWorkEngine.Callback() {
@Override
public void onNonceCalculated(byte[] nonce) {
waiter.setValue(nonce);
waiter1.setValue(nonce);
}
});
byte[] nonce = waiter.waitForValue();
time = System.currentTimeMillis() - time;
System.out.println("Calculating nonce took " + time + "ms");
byte[] nonce = waiter1.waitForValue();
System.out.println("Calculating nonce took " + waiter1.getTime() + "ms");
assertTrue(Bytes.lt(security().doubleSha512(nonce, initialHash), target, 8));
// Let's add a second (shorter) run to find possible multi threading issues
long time2 = System.currentTimeMillis();
byte[] initialHash2 = security().sha512(new byte[]{1, 3, 6, 5});
byte[] target2 = {0, -1, -1, -1, -1, -1, -1, -1};
byte[] target2 = {0, 0, -1, -1, -1, -1, -1, -1};
final CallbackWaiter<byte[]> waiter2 = new CallbackWaiter<>();
engine.calculateNonce(initialHash2, target2,
@ -67,10 +64,9 @@ public class ProofOfWorkEngineTest extends TestBase {
}
});
byte[] nonce2 = waiter2.waitForValue();
time2 = System.currentTimeMillis() - time2;
System.out.println("Calculating nonce took " + time2 + "ms");
System.out.println("Calculating nonce took " + waiter2.getTime() + "ms");
assertTrue(Bytes.lt(security().doubleSha512(nonce2, initialHash2), target2, 8));
assertTrue("Second nonce must be quicker to find", time > time2);
assertTrue("Second nonce must be quicker to find", waiter1.getTime() > waiter2.getTime());
}
}