The Alchemy Project
Jay Lepreau
Matthew Flatt
Eric Eide Alastair Reid John Regehr
University of Utah
Contract F33615-00-C-1696
October 26, 2001
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Problem Description
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Embedded RT software development
too difficult, prone to error, expensive
System-level programming using
components is especially hard
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Embedded sys, VM, middleware, OS
Non-local constraints
 Need build-time assurance
 Existing code
 Performance
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Project Objectives & Technical Approach
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Robust, flexible component composition
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… provides:
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A mostly static architecture
Design rules checked at system build time
Aspects implemented using components
“Weaving” by composition
“Product line” flexibility, increased reuse
AOP
Architectural clarity
Other:
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Explore new compile-time metaprogramming
system as aspect language for Java
Cross-layer RT QoS provision
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Artist’s Conception
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Knit: Components for C
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External component definition and
linking language
Discussed at previous PI meetings
Released Feb’01, open source
Gaining experience and refining it
Version 2 in progress
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Jiazzi: Components for Java
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Support for component programming
on a large scale
Jiazzi components…
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are not stored in hierarchical namespace.
import and export signatures.
are parameterized by imports.
are defined and composed using an external
language.
Flexible class extensions (mixins)
Groups of related mixin functionality
(aspects)
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Maya: Compile-time
Metaprogramming for Java
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“Macros on crack”
Semantic actions in the parser are
generic functions
Maya “macros” are methods on the
generic functions
New syntax returned to parser
Is hygienic and referentially transparent
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Maya and AspectJ
AspectJ:
language support
for cross-cutting
concerns
Maya:
compile-time
metaprogramming
JSE
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“Task Isolation” in Java
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For real-time in particular
For QoS in general
For robustness
JSR-121… more later
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Contribution to PCES Goals
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Unified model for components and aspects
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Increased predictability, cross-layer
Promote technology adoption
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Functional and non-functional aspects
 Design rule checking (constraints)
Support product families & evolution in Java & C
Java: aspects via components and language
Component mining
Minimal changes to existing code
Usable today: Knit, Jiazzi, Maya: open source
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Contributions to Military Apps
Family of JVMs:
the OVM product line
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Composable RT
schedulers
Task isolation
Resource controls
VM services, footprint
Object representation
Design / configure
time assurances
Component reuse
Principled use of
COTS software
}
}
}
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Predictable, resilient
run-time behavior
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Fit constrained
execution envs.
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Cheaper, faster,
better development
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Military Apps (cont’d)
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Kernel CPU reservations for UAV OEP
Benefits:
Increased predictability
 Isolation of timing faults
 for C++ soon, Java later
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Challenges:
Param calibration for multithreaded apps
 Adjustable safety margin
 Make reservations controllable from
remote nodes
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Military Apps (cont’d)
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Jiazzi’ed event service in Boeing
OEP Java-based ORB (w/ Wash U)
Aspect weaving in UAV Java code
At compile time using Maya
 At runtime using Handi-Wrap
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Metrics
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Systems metrics:
UAV & Linux/RK CPU resv: quantified
improvement in predictability
 OVM product family: footprint
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SW Engineering metrics
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Reduced module “coupling” in Jiazzi’ed
systems
Constraints: fewer incorrect systems
composed by students, in a controlled study
Mining: quicker to componentize, in a
controlled study
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Project Tasks/Schedule
OVM mobile processes
as Alchemy components
Resource management in OVM
w/Alchemy checking
Alchemy-configured memory
management in OVM
Jiazzi + weaver release
CPU resv in UAV
Maya release
Alchemy-configured
data layout in OVM
Alchemy-configured
feature selection in OVM
Jiazzi release
2001
Jiazzi + constraint checker
Initial OVM as Alchemy components
Knit release
Blue: tools
Black: tool use
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Technical Progress &
Accomplishments
1.
Jiazzi: components for Java
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New release (Aug’01)
On-site meeting with OVM team (Sep’01)
Applied Jiazzi to OVM “Repository”
subsystem
OOPSLA paper (Oct’01)
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Accomplishments (cont’d)
2.
Knit: components for C
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“Shearing” -- extracting code that
implements a component
 Required in order to import and
export types
Applied to RTLinux apps, the
MzScheme VM, and the OSKit
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Accomplishments (cont’d)
3.
Component mining tools and
methodology
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Tools to extract components from
existing code
Human-guided heuristic process
(“lather, rinse, repeat”)
Knit/C tools applied to
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Moab active network OS
MzScheme virtual machine
OSKit OS components
… by 3 different people. Tools
improved markedly.
Jiazzi/Java next
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Accomplishments (cont’d)
4.
Maya: Metaprogramming for Java
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Thesis signed (Aug’01)
Implemented Handi-Wrap tool for runtime metaprogramming (Sep’01)
Initial release (Oct ’01)
AOSD paper under review (Oct ’01)
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Next Milestones
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Jiazzi
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CPU reservations in UAV OEP (1Q02)
Java “Task” isolation
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First non-beta release (4Q01)
Construct OVM from Jiazzi components (1Q02)
RT-Java components (4Q02)
G.Back PhD thesis signed (any day!)
JSR-121 release (1Q02)
Maya
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PLDI submission (Nov ’01)
Integrate with Jiazzi?
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Collaborations
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OVM team (Purdue, UMD, SUNY)
BBN:
CPU reservations across UAV/OS
 Alchemy-configured feature selection in
OVM
 Deliver RT-JVM components (w/ Purdue)
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Wash Univ: Jiazzi’ed event service in
Boeing OEP’s Java-based ORB
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Technology Transition/Transfer
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Software releases & users described
earlier: OVM, BBN OEP, Boeing OEP?
Sun JSR-121: “pseudo-task” isolation
Highly relevant to real-time & robustness
 Potential alternate base for RT-Java
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A natural resource boundary
OS abstractions, GC mechanisms
Long line of OS/lang. research at Utah
 Utah has leading role in Expert Group
 Will be in JDK 1.5 (3Q02)
 Just first stage: control;
next: sharing, resource management
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Program Issues
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none
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Utah Alchemy Project
DARPA PCES Program
www.cs.utah.edu/flux/alchemy
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