链式堆栈的实现以及测试； 实现包括入栈、出栈（后进先出）、2个栈等值判定、栈的拷贝、数据查找。测试包括以上功能的测试和线程安全测试。-Chain, as well as realize stack test realize including入栈, a stack (LIFO), stack 2 equivalents determined that the copy stack, the data search. The tests include the function of tes