New.

Geoffrey Challen
1 parent 1b1ce456
Showing 5 changed files with 37 additions and 23 deletions
certainty.tex
introduction.tex
references.bib
related.tex
usage.tex
@@ -33,9 +33,6 @@ While the \texttt{score} value is used to evaluate the alternative, the
 entire JSON object returned by the \texttt{evaluate} block is delivered to
 the developer for later analysis. This allows \texttt{maybe} statements to be
 connected with end-to-end app performance metrics not visible on the device.
-\texttt{evaluate} blocks may also want to query the user directly, and we are
-exploring ways to make this possible.
-
 We expect that some \texttt{evaluate} blocks may need to know which
 alternative was executed to compute a score---for example, if the two
 alternatives produce different quality output. We are exploring the use of
@@ -98,21 +98,31 @@ them at runtime.}
 \end{figure}
 In this paper, we present a novel a language construct for expressing
-structured uncertainty: the \texttt{maybe} statement. \texttt{maybe} allows
-the programmer to express and structure their uncertainty by providing two or
-more different \textit{alternatives} which together implement multiple
-approaches to runtime adaptation, possibly by making the same
-energy-performance or energy-accuracy tradeoffs described previously.
+structured uncertainty: the \texttt{maybe} statement. Unlike previous
+approaches to adaptation that relied on language support, \texttt{maybe} does
+not attempt to encourage the programmer to provide more information about
+their app to allow the compiler to improve performance or guarantee
+correctness. Rather, \texttt{maybe} allows the programmer to express and
+structure uncertainty by providing two or more different
+\textit{alternatives} implementing multiple approaches to runtime adaptation,
+possibly by making the same energy-performance or energy-accuracy tradeoffs
+described previously. Conceptually, \texttt{maybe} extends the process of
+compilation and optimization to include post-deployment testing while also
+enabling flexible adaptation that may produce per-user, per-device, or
+temporally-varying solutions.
+
 Figure~\ref{fig-example-maybe} shows how our earlier example can be easily
-rewritten to use a \texttt{maybe} statement. However, unlike the previous
-example \texttt{maybe} does not rely on the developer to implement a decision
-process or correctly anticipate the effects of each alternative. Instead, the
+rewritten to use a \texttt{maybe} statement. Unlike the previous example
+\texttt{maybe} does not rely on the developer to implement a decision process
+or correctly anticipate the effects of each alternative. Instead, the
 \texttt{maybe} system makes runtime choices about which alternative to use by
 measuring the tradeoffs produced by each alternative and (in this case)
-activating an energy-saving alternative when appropriate.
+activating an energy-saving alternative when appropriate. All the developer
+has to do is provide alternatives when they are unsure what to do; the
+\texttt{maybe} system does the rest.
-How that choice is made is discussed in the remainder of our paper. We begin
-by providing a more complete description of the \texttt{maybe} statement in
+The rest of our paper is structured as follows. We begin by providing a more
+complete description of the \texttt{maybe} statement in
 Section~\ref{sec-maybe}. Section~\ref{sec-certainty} describes several
 techniques for transforming development-time uncertainty into runtime
 certainty. We continue by describing several example use cases in
@@ -2,6 +2,15 @@
 @string{sosp = "SOSP"}
 @string{osdi = "OSDI"}
+@inproceedings{maui-mobisys10,
+ title={MAUI: making smartphones last longer with code offload},
+ author={Cuervo, Eduardo and Balasubramanian, Aruna and Cho, Dae-ki and Wolman, Alec and Saroiu, Stefan and Chandra, Ranveer and Bahl, Paramvir},
+ booktitle={Proceedings of the 8th international conference on Mobile systems, applications, and services},
+ pages={49--62},
+ year={2010},
+ organization={ACM}
+}
+
 @inproceedings{foraging-mobisys07,
 title={Simplifying cyber foraging for mobile devices},
 author={Balan, Rajesh Krishna and Gergle, Darren and Satyanarayanan, Mahadev and Herbsleb, James},
@@ -33,12 +33,8 @@ powerful by allowing programmers to express uncertainty.
 Recent approaches that allow mobile devices to effectively offload
 computation by automating client-cloud partitioning are also related to the
 \texttt{maybe} statement. Systems such as Tactics~\cite{tactics-mobisys03}
-and MAUI~\cite{FIXME} used a variety of approaches to enabling this form of
-adaptation but are narrowly-focused on harnessing opportunities for remote
-execution. While \texttt{maybe} statements can enable simple decisions about
-whether to offload portions of an app, the \texttt{maybe} approach is not yet
-rich enough to consider how much of the execution should be performed
-remotely or deal with server failures. At present \texttt{maybe} focuses on
-single-device adaptation, but we are interested in exploring the ability to
-use uncertainty to distribute computation between multiple devices as future
-work.
+and MAUI~\cite{maui-mobisys10} used a variety of approaches to enabling this
+form of adaptation but are narrowly-focused on harnessing opportunities for
+remote execution. At present \texttt{maybe} focuses on single-device
+adaptation, but we are interested in exploring the ability to use uncertainty
+to distribute computation between multiple devices as future work.
@@ -33,6 +33,8 @@ may never outperform the app-specific algorithm, in which cases
 \texttt{maybe} allows both alternatives to coexist safely while ensuring that
 each user enjoys whichever approach is most effective for them.
+\newpage
+
 \subsection{\texttt{\large PhoneLab} Conductor}
 \PhoneLab{} is a large scale smartphone platform testbed at the University at