protected void treeReadLock()

in hbase-oss/src/main/java/org/apache/hadoop/hbase/oss/sync/TreeLockManager.java [315:345]

• 28 lines of code
• 7 McCabe index (conditional complexity)

  protected void treeReadLock(Path path) throws IOException {
    int outerRetries = 0;
    long outerInitAttempt = System.currentTimeMillis();
    do {
      int innerRetries = 0;
      long innerInitAttempt = System.currentTimeMillis();
      do {
        // If there's a write lock above us, wait
        if (writeLockAbove(path)) {
          if (warnIfAboveThreshold(innerInitAttempt,
            "Blocked waiting for some parent write lock, waiting: {}", path.toString())){
            innerInitAttempt = System.currentTimeMillis();
          }
          continue;
        }
        break;
      } while (retryBackoff(innerRetries++));
      // Try obtain the read-lock just for our node
      readLock(path);
      // If there's a write lock above us, release the lock and try again
      if (writeLockAbove(path)) {
        if (warnIfAboveThreshold(outerInitAttempt,
          "Blocked waiting for some parent write lock, retrying: {}", path.toString())){
          outerInitAttempt = System.currentTimeMillis();
        }
        readUnlock(path);
        continue;
      }
      break;
    } while (retryBackoff(outerRetries++));
  }