No empty and initial advance for self-clocked round robin scheduler

A computer system, comprising:

• a processor;
• and
• a storage device storing instructions that when executed by the processor cause the processor to perform the instructions to:
• maintain a queue structure comprising a plurality of sub-queues used for storing packets,
• wherein packets in the sub-queues are to be dequeued and forwarded,
• wherein a respective packet is enqueued into a sub-queue, and
• wherein a virtual time associated with the respective packet is based on a current sub-queue virtual time corresponding to a previously enqueued packet in the sub-queue;
• track a global virtual time based on dequeuing packets from the sub-queues;
• identify one or more non-empty sub-queues;
• insert a packet into a first sub-queue comprising a previously empty sub-queue which was empty immediately prior to inserting of the packet;
• determine whether a virtual time associated with the first sub-queue is earlier than or equal to a current global virtual time of a currently scheduling round prior to scheduling the first sub-queue into the current scheduling round;
• schedule the first sub-queue for forwarding packets before the non-empty sub-queues in response to the virtual time associated with the first sub-queue being earlier than or equal to the current global virtual time;
• and
• in response to the virtual time associated with the first sub-queue being later than the current global virtual time:
• refrain from scheduling the first sub-queue during the current scheduling round;
• and
• schedule the first sub-queue for forwarding packets after the non-empty sub-queues.

A non-transitory computer-readable storage medium storing instructions to:

• maintain a queue structure comprising sub-queues used for storing packets to be forwarded,
• wherein packets in the sub-queues are to be dequeued and forwarded,
• wherein a respective packet is enqueued into a sub-queue, and
• wherein a virtual time associated with the respective packet is based on a current sub-queue virtual time corresponding to a previously enqueued packet in the sub-queue;
• track a global virtual time based on dequeuing packets from the sub-queues;
• identify one or more non-empty sub-queues;
• insert a packet into a first sub-queue which has been previously empty;
• determine whether a virtual time associated with the first sub-queue is earlier than or equal to a current global virtual time of a current scheduling round prior to scheduling the first sub-queue into the current scheduling round;
• schedule the first sub-queue for forwarding packets before the non-empty sub-queues in response to at least one of:
• a virtual time associated with a most recently dequeued packet from the first sub-queue being earlier than or equal to the global virtual time associated with a previous scheduling round;
• a virtual time associated with a packet at a head of the first sub-queue being earlier than or equal to the global virtual time associated with a current scheduling round;
• or
• a finish time associated with a packet at a tail of the first sub-queue being earlier than or equal to the global virtual time associated with a current scheduling round;
• and
• in response to the virtual time associated with the first sub-queue being later than the current global virtual time:
• refrain from scheduling the first sub-queue during the current scheduling round;
• and
• schedule the first sub-queue for forwarding packets after the non-empty sub-queues.