Semaphore soft and hard hybrid architecture

A packet processing device, comprising:

• a plurality of processing stages arranged as a packet processing pipeline;
• the processing stages each having processor cores and buffers;
• the processor cores and buffers of the processing stages defining a plurality of paths, for simultaneous packet processing, through the packet processing pipeline;
• an ingress front end configured to direct each packet of an incoming stream of packets into one of the plurality of paths;
• the plurality of paths including a hard path and a soft path, the hard path being configured to process received ones of the incoming stream of packets with fixed latency, the soft path being configured to process received ones of the incoming stream of packets with variable latency;
• and
• the processing stages each further including a respective resource manager configured to request allocation of a remote resource, for a given packet of the incoming stream of packets in the soft path, in response to an instruction from one of the processor cores, whereby the remote resource is allocated for processing of only the given packet.

A packet processing method, for a processing stage of a pipeline packet processing device, comprising:

• receiving, at a processor of a first processing stage, a first packet and a request for allocation of a remote resource;
• responding, by the processor, to the allocation request, by setting a semaphore corresponding to the remote resource to indicate a locked status;
• implementing a first packet processing operation, in association with the allocated remote resource, and in association with the first packet, to obtain a processed first packet;
• and
• outputting the processed first packet to a next processing stage of the pipeline packet processing device.

A packet processing device comprising:

• a plurality of processing stages, arranged as a packet processing pipeline, configured to process packets in a first direction along the packet processing pipeline;
• a lock release message path connecting the plurality of processing stages, configured to communicate along a second direction opposite to said first direction;
• each of the plurality of processing stages including:
• a respective local resource lock, and
• a respective processor core;
• and
• the respective processor core being configured to send, along the lock release message path, a resource lock release request message identifying one of the plurality of processing stages and identifying a resource to be released.