Common Backend Impl (CBI)

The common backend implementations are implementations for re-use by other backends. For example, instead of the Linux, FreeBSD, and macOS backends all implement the same POSIX asynchronous I/O interface, then it is instead provided here, and the can all include it in their support for async. interfaces.

Similarly, then xNVMe provide several software-only implementations of the xNVMe API, such as the thrpool which implements the asynchronous parts of the xNVMe API by using a thread-pool.

This composability grants convenience during development and interesting experiments when mixing abstractions and system interfaces. In addition to providin common implementations, interface emulation, then xNVMe also provide simple device emulation via the ramdisk backend implementation.

Instrumentation

• Memory Allocators

  • posix`, Use libc malloc()/free() with sysconf() for alignment, add link to CBI

• Asynchronous Interfaces

  • nil, xNVMe null-IO, does nothing but complete submitted commands, for experimentation only to evaluate xNVMe encapsulation overhead

  • emu, ..

  • thrpool, ..

  • posix, ..

• Synchronous Interfaces

  • psync, Use pread()/write() for synchronous I/O