Spring事务处理Transactional,锁同步和并发线程

package org.springframework.transaction.annotation;
import org.springframework.transaction.TransactionDefinition;
 

public enum Propagation {
 
    
    REQUIRED(TransactionDefinition.PROPAGATION_REQUIRED),
 
    
    SUPPORTS(TransactionDefinition.PROPAGATION_SUPPORTS),
 
    
    MANDATORY(TransactionDefinition.PROPAGATION_MANDATORY),
 
    
    REQUIRES_NEW(TransactionDefinition.PROPAGATION_REQUIRES_NEW),
 
    
    NOT_SUPPORTED(TransactionDefinition.PROPAGATION_NOT_SUPPORTED),
 
    
    NEVER(TransactionDefinition.PROPAGATION_NEVER),
 
    
    NESTED(TransactionDefinition.PROPAGATION_NESTED);
 
 
    private final int value;
 
 
    Propagation(int value) { this.value = value; }
 
    public int value() { return this.value; }
 
}

 
package org.springframework.transaction;
 
import java.sql.Connection;
 

public interface TransactionDefinition {
 
    
    int PROPAGATION_REQUIRED = 0;
 
    
    int PROPAGATION_SUPPORTS = 1;
 
    
    int PROPAGATION_MANDATORY = 2;
 
    
    int PROPAGATION_REQUIRES_NEW = 3;
 
    
    int PROPAGATION_NOT_SUPPORTED = 4;
 
    
    int PROPAGATION_NEVER = 5;
 
    
    int PROPAGATION_NESTED = 6;
 
 
    
    int ISOLATION_DEFAULT = -1;
 
    
    int ISOLATION_READ_UNCOMMITTED = Connection.TRANSACTION_READ_UNCOMMITTED;
 
    
    int ISOLATION_READ_COMMITTED = Connection.TRANSACTION_READ_COMMITTED;
 
    
    int ISOLATION_REPEATABLE_READ = Connection.TRANSACTION_REPEATABLE_READ;
 
    
    int ISOLATION_SERIALIZABLE = Connection.TRANSACTION_SERIALIZABLE;
 
 
    
    int TIMEOUT_DEFAULT = -1;
 
 
    
    int getPropagationBehavior();
 
    
    int getIsolationLevel();
 
    
    int getTimeout();
 
    
    boolean isReadOnly();
 
    
    String getName();
 
}

@Transactional(propagation=Propagation.NESTED)
@Transactional(propagation=Propagation.PROPAGATION_REQUIRES_NEW)
 
 
ServiceA{
  @Autowired
  ServiceB serviceB;
  @Transactional(propagation=Propagation.NESTED)
  public void method1(){
    serviceB.method2();
    int i = 1/0;
  }
}
 
ServiceB{
  @Transactional(propagation=Propagation.NESTED)
  public void method2(){
   xxxxxx
  }
}

ServiceB{
@Transactional(propagation=Propagation.PROPAGATION_REQUIRES_NEW)
  public void method2(){
   xxxxxx
  }
}