Mechanism for a Lockless Ring Buffer in Overwrite Mode

A system, comprising:

• a storage device to store a ring buffer with memory addresses for each page of the ring buffer aligned to form maskable bits to be used as a state flag for the page represented by the address;
• one or more device drivers to control the storage device;
• and
• a kernel to communicably coupled to the one or more device drivers and the storage device, the kernel including a tracing utility to:
• utilize at least a two least significant bits of each address for each page of the ring buffer to represent the state flag associated with the page represented by the address, wherein the state flag indicates one of three states including a header state, an update state, and a normal state;
• combine a movement of a head page pointer to a head page of the ring buffer with a swap of the head page and a reader page associated with the ring buffer, the combining comprising updating the state flag of the head page pointer to the normal state and updating the state flag of a pointer to the page after the head page to the header state;
• and
• move the head page and a tail page of the ring buffer, the moving comprising updating the state flags of one or more pointers in the ring buffer;
• wherein the reader page is used solely by a reader of the ring buffer and is not part of the ring buffer.

An article of manufacture comprising a machine-readable storage medium including data that, when accessed by a machine, cause the machine to perform operations comprising:

• aligning memory addresses for each page of a ring buffer to form maskable bits in the address to be used as a state flag for the page;
• utilizing at least a two least significant bits of each of the addresses to represent the state flag associated with the page represented by the address, wherein the state flag indicates one of three states including a header state, an update state, and a normal state;
• combining a movement of a head page pointer to a head page of the ring buffer with a swapping of the head page and a reader page, the combining comprising updating the state flag of the head page pointer to the normal state and updating the state flag of a pointer to the page after the head page to the header state;
• and
• moving the head page and a tail page of the ring buffer, the moving comprising updating the state flags of one or more pointers in the ring buffer associated with the head page and the tail page;
• wherein the reader page is used solely by a reader of the ring buffer and is not part of the ring buffer.