ATLAS: Adaptable Thread-Level Address Spaces (DFG: DI 2840/1-1)
Traditionally, an OS process contains a single address space with code and data segments that are shared among all of its threads. The fork() system call creates a new address space (and process) that, even though it starts as an exact clone of its ancestor, provides strong isolation between the respective threads by means of copy-on-write.
The core idea of ATLAS is to provide processes with additional address spaces that are, however, kept in sync with their ancestor: Changes to one of them – we call them address-space views – become immediately visible in the others. Views diverge only in explicitly specified areas. As they still belong to the same process, the threads of this process can be migrated individually between views.
Address-space views provide an efficient mean to implement temporary or permanent thread-level variations in the "view of the world", while threads can still interact with each other regarding the shared parts. In the figure, the code segment diverges and provides a thread-specific variation (e.g., an client-specific optimization or restriction of functionality), while the data segment is shared, so that th1 can still transparently interact with th2 and th3. Such variations can be arbitrary small or complex. They can be prepared in the background in a new view and atomically applied to individual threads by migrating them to the new address space.
Applications
In our OSDI '20 paper, we present a first application of these technique to implement WfPatch, a wait-free dynamic code-patching approch for large multi-threaded server applications.
People
Latest News
- ATLAS: Adaptable Thread-Level Address Spaces (DFG: DI 2840/1-1)
- In the ATLAS project, we investigate dynamic specialization and containment by means of thread-level address-space variations.

Publications
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LCTES
Conference
B
Thread-Level Attack-Surface Reduction -
Proceedings of the 24th ACM SIGPLAN/SIGBED International Conference on Languages, Compilers, and Tools for Embedded SystemsACM Press2023Accepted at LCTES'23, to appear.
[BibTex]
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SIGMOD
Conference
A*
Virtual-Memory Assisted Buffer Management -
Proceedings of the ACM SIGMOD/PODS International Conference on Management of Data (SIGMOD'23)ACM2023Accepted at SIGMOD'23, to appear.
PDF [BibTex]
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LCTES
Conference
B
reUpNix: Reconfigurable and Updateable Embedded Systems -
Proceedings of the 24th ACM SIGPLAN/SIGBED International Conference on Languages, Compilers, and Tools for Embedded SystemsACM Press2023Accepted at LCTES'23, to appear.
[BibTex]
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OSDI
Conference
A*
From Global to Local Quiescence: Wait-Free Code Patching of Multi-Threaded Processes -
14th Symposium on Operating System Design and Implementation (OSDI '20)2020.
PDF Video [BibTex]
Theses
Open Topics
Program Structure for Heterogeneous Instruction Set Architectures
Status: offen
Supervisors: Niklas Gollenstede, Christian Dietrich
Explore new program structures that run on and fully utilize CPUs with heterogeneous ISAs.
Currently Running
Embedded Lua as a Linker-Script Replacement
Status: reserviert
Supervisors: Niklas Gollenstede, Christian Dietrich
Embed Lua into the llvm-lld linker as a Turing-complete alternative to .ld-scripts.