294 research outputs found
UEFI BIOS Accessibility for the Visually Impaired
People with some kind of disability face a high level of difficulty for
everyday tasks because, in many cases, accessibility was not considered
necessary when the task or process was designed. An example of this scenario is
a computer's BIOS configuration screens, which do not consider the specific
needs, such as screen readers, of visually impaired people. This paper proposes
the idea that it is possible to make the pre-operating system environment
accessible to visually impaired people. We report our work-in-progress in
creating a screen reader prototype, accessing audio cards compatible with the
High Definition Audio specification in systems running UEFI compliant firmware.Comment: 6 page
Transparent Replication Using Metaprogramming in Cyan
Replication can be used to increase the availability of a service by creating
many operational copies of its data called replicas. Active replication is a
form of replication that has strong consistency semantics, easier to reason
about and program. However, creating replicated services using active
replication still demands from the programmer the knowledge of subtleties of
the replication mechanism. In this paper we show how to use the metaprogramming
infrastructure of the Cyan language to shield the application programmer from
these details, allowing easier creation of fault-tolerant replicated
applications through simple annotations.Comment: 8 page
Characterizing Synchronous Writes in Stable Memory Devices
Distributed algorithms that operate in the fail-recovery model rely on the
state stored in stable memory to guarantee the irreversibility of operations
even in the presence of failures. The performance of these algorithms lean
heavily on the performance of stable memory. Current storage technologies have
a defined performance profile: data is accessed in blocks of hundreds or
thousands of bytes, random access to these blocks is expensive and sequential
access is somewhat better. File system implementations hide some of the
performance limitations of the underlying storage devices using buffers and
caches. However, fail-recovery distributed algorithms bypass some of these
techniques and perform synchronous writes to be able to tolerate a failure
during the write itself. Assuming the distributed system designer is able to
buffer the algorithm's writes, we ask how buffer size and latency complement
each other. In this paper we start to answer this question by characterizing
the performance (throughput and latency) of typical stable memory devices using
a representative set of current file systems.Comment: 14 page
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