This program is not getting compiled:

class SynchSpeed2 {
  public static void main(String[] args) {
    SynchSpeed2 obj = new SynchSpeed2();
    for (int i = 0; i < 10000000; i++) {
      synchronized(obj){};
      synchronized(obj){};
    }
  }
}

while this program is compiled:

class SynchSpeed1 {
  public static void main(String[] args) {
    SynchSpeed1 obj = new SynchSpeed1();
    for (int i = 0; i < 10000000; i++) {
      synchronized(obj){};
    }
  }
}