package org.infinispan.api.mvcc;

import java.util.LinkedList;
import java.util.List;
import java.util.concurrent.CountDownLatch;

import org.infinispan.configuration.cache.ConfigurationBuilder;
import org.infinispan.manager.EmbeddedCacheManager;
import org.infinispan.test.SingleCacheManagerTest;
import org.infinispan.test.TestingUtil;
import org.infinispan.test.fwk.TestCacheManagerFactory;
import org.infinispan.util.concurrent.locks.LockManager;
import org.infinispan.util.concurrent.locks.impl.LockContainer;
import org.testng.annotations.Test;

@Test(groups = "functional", singleThreaded = true, testName = "api.mvcc.LockPerEntryTest")
public class LockPerEntryTest extends SingleCacheManagerTest {

   @Override
   protected EmbeddedCacheManager createCacheManager() throws Exception {
      ConfigurationBuilder cfg = new ConfigurationBuilder();
      cfg.locking().useLockStriping(false);
      return TestCacheManagerFactory.createCacheManager(cfg);
   }

   public void testLocksCleanedUp() {
      cache = cacheManager.getCache();
      cache.put("/a/b/c", "v");
      cache.put("/a/b/d", "v");
      assertNoLocks();
   }

   @Test (groups = "unstable")
   public void testLocksConcurrency() throws Exception {
      cache = cacheManager.getCache();
      final int NUM_THREADS = 10;
      final CountDownLatch l = new CountDownLatch(1);
      final int numLoops = 1000;
      final List<Exception> exceptions = new LinkedList<>();

      Thread[] t = new Thread[NUM_THREADS];
      for (int i = 0; i < NUM_THREADS; i++)
         t[i] = new Thread() {
            @Override
            public void run() {
               try {
                  l.await();
               }
               catch (Exception e) {
                  // ignore
               }
               for (int i = 0; i < numLoops; i++) {
                  try {
                     switch (i % 2) {
                        case 0:
                           cache.put("Key" + i, "v");
                           break;
                        case 1:
                           cache.remove("Key" + i);
                           break;
                     }
                  }
                  catch (Exception e) {
                     exceptions.add(e);
                  }
               }
            }
         };

      for (Thread th : t) th.start();
      l.countDown();
      for (Thread th : t) th.join();

      if (!exceptions.isEmpty()) throw exceptions.get(0);
      assertNoLocks();
   }

   private void assertNoLocks() {
      LockManager lm = TestingUtil.extractLockManager(cache);
      LockAssert.assertNoLocks(lm);

      LockContainer lc = TestingUtil.extractField(lm, "lockContainer");
      assert lc.size() == 0;
   }
}