Example usage for org.apache.commons.pool VisitTracker getValidateCount

Introduction

In this page you can find the example usage for org.apache.commons.pool VisitTracker getValidateCount.

Prototype

public int getValidateCount() 

Source Link

Usage

From source file:edu.illinois.enforcemop.examples.apache.pool.TestGenericObjectPool.java

private void checkEvictorVisiting(boolean lifo) throws Exception {
    VisitTrackerFactory factory = new VisitTrackerFactory();
    GenericObjectPool pool = new GenericObjectPool(factory);
    pool.setNumTestsPerEvictionRun(2);/*from  w  w  w  .ja va 2  s  .co  m*/
    pool.setMinEvictableIdleTimeMillis(-1);
    pool.setTestWhileIdle(true);
    pool.setLifo(lifo);
    pool.setTestOnReturn(false);
    pool.setTestOnBorrow(false);
    for (int i = 0; i < 8; i++) {
        pool.addObject();
    }
    pool.evict(); // Visit oldest 2 - 0 and 1
    Object obj = pool.borrowObject();
    pool.returnObject(obj);
    obj = pool.borrowObject();
    pool.returnObject(obj);
    // borrow, return, borrow, return
    // FIFO will move 0 and 1 to end
    // LIFO, 7 out, then in, then out, then in
    pool.evict(); // Should visit 2 and 3 in either case
    for (int i = 0; i < 8; i++) {
        VisitTracker tracker = (VisitTracker) pool.borrowObject();
        if (tracker.getId() >= 4) {
            assertEquals("Unexpected instance visited " + tracker.getId(), 0, tracker.getValidateCount());
        } else {
            assertEquals("Instance " + tracker.getId() + " visited wrong number of times.", 1,
                    tracker.getValidateCount());
        }
    }

    factory = new VisitTrackerFactory();
    pool = new GenericObjectPool(factory);
    pool.setNumTestsPerEvictionRun(3);
    pool.setMinEvictableIdleTimeMillis(-1);
    pool.setTestWhileIdle(true);
    pool.setLifo(lifo);
    pool.setTestOnReturn(false);
    pool.setTestOnBorrow(false);
    for (int i = 0; i < 8; i++) {
        pool.addObject();
    }
    pool.evict(); // 0, 1, 2
    pool.evict(); // 3, 4, 5
    obj = pool.borrowObject();
    pool.returnObject(obj);
    obj = pool.borrowObject();
    pool.returnObject(obj);
    obj = pool.borrowObject();
    pool.returnObject(obj);
    // borrow, return, borrow, return
    // FIFO 3,4,5,6,7,0,1,2
    // LIFO 7,6,5,4,3,2,1,0
    // In either case, pointer should be at 6
    pool.evict();
    // Should hit 6,7,0 - 0 for second time
    for (int i = 0; i < 8; i++) {
        VisitTracker tracker = (VisitTracker) pool.borrowObject();
        if (tracker.getId() != 0) {
            assertEquals("Instance " + tracker.getId() + " visited wrong number of times.", 1,
                    tracker.getValidateCount());
        } else {
            assertEquals("Instance " + tracker.getId() + " visited wrong number of times.", 2,
                    tracker.getValidateCount());
        }
    }
    // Randomly generate a pools with random numTests
    // and make sure evictor cycles through elements appropriately
    int[] smallPrimes = { 2, 3, 5, 7 };
    Random random = new Random();
    random.setSeed(System.currentTimeMillis());
    for (int i = 0; i < 4; i++) {
        pool.setNumTestsPerEvictionRun(smallPrimes[i]);
        for (int j = 0; j < 5; j++) {
            pool = new GenericObjectPool(factory);
            pool.setNumTestsPerEvictionRun(3);
            pool.setMinEvictableIdleTimeMillis(-1);
            pool.setTestWhileIdle(true);
            pool.setLifo(lifo);
            pool.setTestOnReturn(false);
            pool.setTestOnBorrow(false);
            pool.setMaxIdle(-1);
            int instanceCount = 10 + random.nextInt(20);
            pool.setMaxActive(instanceCount);
            for (int k = 0; k < instanceCount; k++) {
                pool.addObject();
            }

            // Execute a random number of evictor runs
            int runs = 10 + random.nextInt(50);
            for (int k = 0; k < runs; k++) {
                pool.evict();
            }

            // Number of times evictor should have cycled through the pool
            int cycleCount = (runs * pool.getNumTestsPerEvictionRun()) / instanceCount;

            // Look at elements and make sure they are visited cycleCount
            // or cycleCount + 1 times
            VisitTracker tracker = null;
            int visitCount = 0;
            for (int k = 0; k < instanceCount; k++) {
                tracker = (VisitTracker) pool.borrowObject();
                assertTrue(pool.getNumActive() <= pool.getMaxActive());
                visitCount = tracker.getValidateCount();
                assertTrue(visitCount >= cycleCount && visitCount <= cycleCount + 1);
            }
        }
    }
}

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