Changeset 79949 in vbox for trunk/src/VBox/Runtime/include

Timestamp:

Jul 24, 2019 11:05:45 AM (5 years ago)

Author:

vboxsync

Message:

Runtime: bugref:8231 Starting on defining and implementing a new RTIoQueue API to replace RTFileAio mid term.

The RTIoQueue API is meant to be more efficient as it doesn't require allocation
of request structures and is only meant as a thin layer around host dependent APIs.
It will support mutiple providers for different handle types and the best suited provider
supported on a particular host can be selected. This allows multiple implementations
to coexist for the same host in an easy manner.
The providers currently being implemented are (in various stages of the implementation):

• ioqueue-stdfile-provider.cpp:

A fallback provider if nothing else is available using the synchronous RTFile* APIs
emulating asynchronous behavior by using a dedicated worker thread.

• ioqueue-aiofile-provider.cpp:

Uses the current RTFileAio* API, will get replaced by dedicated provider implementations for
each host later on.

• ioqueue-iouringfile-provider.cpp:

Uses the recently added io_uring interface for Linux kernels 5.1 and newer. The new interface
is a great improvement over the old aio interface which is cumbersome to use and has various
restrictions. If not available on a host the code can fall back to one of the other providers.

The I/O queue interface is also meant to be suitable for sockets which can be implemented later.

File:

• trunk/src/VBox/Runtime/include/internal/ioqueue.h (added)