nachos下线程与同步的实验

				#include "synch-sleep.h"
				
				class Table 
				{
				      public:
				             Table(int size); // create a table to hold at most 'size' entries.
				             ~Table();  //析构函数 
				             
				             // allocate a table slot for 'object'.
				             // return the table index for the slot or -1 on error.
				             int Alloc(void *object);
				             
				             // return the object from table index 'index' or NULL on error.
				             // (assert index is in range).  Leave the table entry allocated
				             // and the pointer in place.
				             void *Get(int index);
				             
				             // free a table slot
				             void Release(int index);
				             
				      private:
				              Lock *lock; 
				              int* L;  //
				              int* value;  //value[0..S-1]:each value in the table
				              int S;  //the size of table
				};