Posix AIO Integration

[janjurca]

No description provided.

[Copilot]

Pull Request Overview

Adds a new POSIX AIO I/O engine to support asynchronous file operations with configurable depth.

• Introduces POSIXAIOEngine with read, write, and complete methods managing aiocb structures.
• Registers a CLI parameter --iodepth to control concurrent I/O depth.
• Implements polling-based completion via wait_for_some_completions.

Comments suppressed due to low confidence (1)

source/ioengines/engines/posixaio.cpp:31

• [nitpick] Consider renaming 'submitted_cbs' to 'submitted_cbs_' to match the member naming convention using a trailing underscore.

unsigned submitted_cbs = 0;

[Copilot]

The loop in complete() busy-waits without blocking when no operations complete, which can cause high CPU usage. Consider using aio_suspend or adding a short sleep/delay to avoid spinning.

Suggested change

	while (submitted_cbs > 0) {
	while (submitted_cbs > 0) {
	if (!io_requests_.empty()) {
	const struct aiocb* const requests[io_requests_.size()];
	std::copy(io_requests_.begin(), io_requests_.end(), const_cast<struct aiocb**>(requests));
	int ret = aio_suspend(requests, io_requests_.size(), nullptr);
	if (ret < 0) {
	throw std::runtime_error(std::string("aio_suspend failed: ") + std::strerror(errno));
	}
	}