List management system, a list management method, a recording medium wherein a computer program for realizing the list management system is recorded and a packet exchange wherein the list management system is applied

A list management system comprising:

• a trigger generating means for generating a trigger signal every time when a time interval is passed;
• counters each corresponding to each of a plurality of processes;
• a list of elements each corresponding to each of the processes and connected with each other by way of pointer data;
• and
• a CPU (Central Processing Unit) provided for referring to the processes, the CPU further incrementing a count value of one of the counters every time when the CPU refers to one of the processes corresponding to said one of the counters, and rearranging order of the elements according to count values of the counters, when the trigger signal is generated.

A list management system comprising:

• counters each corresponding to each of a plurality of processes;
• a list of elements each corresponding to each of the processes and connected with each other by way of pointer data;
• a CPU provided for referring to the processes, the CPU further incrementing a count value of each of the counters every time when the CPU refers to one of the processes corresponding to said each of the counters, and rearranging order of the elements according to count values of the counters, when a trigger signal is generated;
• and
• an operation monitor for generating the trigger signal when an operational load of the CPU is discriminated to be light.

A method of managing a list of elements each corresponding to each of a plurality of processes and connected with each other by way of pointer data;

• said method comprising:
• a step of generating a trigger signal every time when a time interval is passed;
• a step of counting a reference frequency of each of the processes, the step of counting being performed during the time interval;
• and
• a step of rearranging order of the elements according to the reference frequency counted for each of the processes, the step of rearranging being performed when the trigger signal is generated.

A method of managing a list of elements each corresponding to each of a plurality of processes and connected with each other by way of pointer data;

• said method comprising:
• a step of counting a reference frequency of each of the processes;
• a step of monitoring length of a period wherein any of the processes is not referred to;
• and
• a step of rearranging order of the elements according to the reference frequency counted for each of the processes, the step of rearranging being performed when the length of the period longer than a fixed time is monitored.

A recording medium wherein is recorded a program to be implemented by a computer for managing a list of elements each corresponding to each of a plurality of processes and connected with each other by way of pointer data;

• the program comprising:
• a step of generating a trigger signal every time when a time interval is passed;
• a step of counting a reference frequency of each of the processes, the step of counting being performed during the time interval;
• and
• a step of rearranging order of the elements according to the reference frequency counted for each of the processes, the step of rearranging being performed when the trigger signal is generated.

A recording medium wherein is recorded a program to be implemented by a computer for managing a list of elements each corresponding to each of a plurality of processes and connected with each other by way of pointer data;

• the program comprising:
• a step of counting a reference frequency of each of the processes;
• a step of monitoring length of a period wherein any of the processes is not referred to;
• and
• a step of rearranging order of the elements according to the reference frequency counted for each of the processes, the step of rearranging being performed when the length of the period longer than a fixed time is monitored.

A packet exchange composing a node of a packet transmission network for forwarding each of received packets to a next destination determined according to a final destination described in said each of the received packets;

• the packet exchange comprising:
• a trigger generating means for generating a trigger signal;
• a first memory for storing a plurality of first data sets each including information of a next destination corresponding to each of final destinations which are possible to be described in the received packets;
• a second memory for storing each of second data sets in each of addresses of the second memory, the second data sets being a part of the first data sets and the second memory being accessed with higher speed than the first memory;
• counters each corresponding to each of the addresses of the second memory;
• a first retrieving means for retrieving data of a next destination corresponding to a final destination described in a received packet from the second data sets stored in the second memory;
• a memory management means for incrementing a count value of one of the counters when the first retrieving means successes to retrieve the data of the next destination from an address of the second memory corresponding to said one of the counters;
• a second retrieving means for retrieving data of the next destination corresponding to the final destination described in the received packet from the first data sets stored in the first memory when the first retrieving means can not retrieve the data of the next destination from any address of the second memory;
• and
• a memory maintenance means for revising a necessary number of the second data sets stored in the second memory into data sets each including each of next destinations retrieved by the second retrieving means from the first memory, the necessary number of the second data sets being selected according to count values of the counters at a timing when the trigger signal is generated.