Credit mechanisms for packet policing

An integrated circuit, comprising:

• a memory configured to store a policing context;
• a counter;
• and
• a pipeline;
• wherein the integrated circuit is configured to, upon receiving packet information describing a packet:
• determine, using the pipeline, a drop status for the packet, wherein determining the drop status includes:
• determining, from the policing context, a previous number of credits available;
• determining, using the counter and a rate value provided by the policing context, a number of new credits available;
• determining, using the previous number of credits available and the number of new credits available, a current number of credits available;
• determining, using the policing context and the packet information, a number of credits needed to transmit the packet;
• and
• determining the drop status for the packet, wherein determining the drop status includes comparing the number of credits needed to transmit the packet against the current number of credits available;
• update information stored for the policing context in the memory based on the drop status and the number of credits needed to transmit the packet;
• and
• upon determining that the policing context has not been accessed for a pre-determined period of time, update, using the pipeline, the information stored for the policing context in the memory, wherein updating the policing context includes:
• determining, from the policing context, a second previous number of credits available;
• determining, using the counter and the rate value provided by the policing context, a second number of new credits available;
• determining, using the second previous number of credits available and the second number of new credits available, a second current number of credits available;
• and
• updating the information stored for policing context in the memory by assigning the second current number of credits available to a value in the memory that stores the previous number of credits available for the policing context.

A method, comprising:

• upon receiving, at an integrated circuit, packet information describing a packet, determining a drop status for the packet, wherein determining the drop status includes:
• determining, using a policing context, a previous number of credits available;
• determining, using a counter of the integrated circuit and a rate value provided by the policing context, a current number of credits available;
• determining, using the packet information, a number of credits needed to transmit the packet;
• and
• determining the drop status for the packet, wherein determining the drop status includes comparing the number of credits needed to transmit the packet against the current number of credits available;
• updating the policing context based on the drop status and the number of credits needed to transmit the packet;
• upon determining that the policing context has not been accessed for a pre-determined period of time, updating information stored for the policing context, wherein updating the policing context includes:
• determining, from the policing context, a second previous number of credits available;
• determining, using the counter and a second rate value provided by the policing context, a second number of new credits available;
• determining, using the second previous number of credits available and the second number of new credits available, a second current number of credits available;
• and
• updating the policing context by assigning the second current number of credits available to a value in the policing context for the previous number of credits available for the policing context.