I am signal two process instance in 2 threads. But got following exceptions, any idea?
### The error may involve org.activiti.persistence.selectExecutionById-Inline
### The error occurred while setting parameters
### Cause: org.h2.jdbc.JdbcSQLException: Timeout trying to lock table "ACT_RU_EXECUTION" [50200-132]
at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:8)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:61)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:53)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectOne(DefaultSqlSession.java:38)
at org.activiti.engine.impl.db.DbSqlSession.selectOne(DbSqlSession.java:175)
at org.activiti.engine.impl.db.DbRuntimeSession.findExecutionById(DbRuntimeSession.java:89)
at org.activiti.engine.impl.cmd.SignalCmd.execute(SignalCmd.java:42)
at org.activiti.engine.impl.interceptor.CommandExecutorImpl.execute(CommandExecutorImpl.java:22)
at org.activiti.engine.impl.interceptor.CommandContextInterceptor.execute(CommandContextInterceptor.java:37)
at org.activiti.spring.SpringTransactionInterceptor$1.doInTransaction(SpringTransactionInterceptor.java:42)
at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:130)
at org.activiti.spring.SpringTransactionInterceptor.execute(SpringTransactionInterceptor.java:40)
at org.activiti.engine.impl.interceptor.LogInterceptor.execute(LogInterceptor.java:33)
at org.activiti.engine.impl.RuntimeServiceImpl.signal(RuntimeServiceImpl.java:131)