ECOOP 2018
Sun 15 - Sat 21 July 2018 Amsterdam, Netherlands
co-located with ECOOP and ISSTA
Fri 20 Jul 2018 14:15 - 14:40 at Zurich II - Runtime Systems Chair(s): Christian Hammer

Checkpoint/rollback (CR) mechanisms create snapshots of the state of a running application, allowing it to later be restored to that checkpointed snapshot. Support for checkpoint/rollback enables many program analyses and software engineering techniques, including test generation, fault tolerance, and speculative execution. Fully automatic CR support is built-in to some modern operating systems. However, such systems perform checkpoints at the coarse granularity of whole pages of virtual memory, which imposes relatively high overhead to incrementally capture the changing state of a process, and make it difficult for applications to checkpoint only some logical portions of their state. CR systems implemented at the application level and with a finer granularity typically require complex developer support to identify: (1) where checkpoints can take place, and (2) which program state needs to be copied. A popular compromise is to implement CR support in managed runtime environments, eg the Java Virtual Machine (JVM), but this typically requires specialized, non-standard runtime environments, limiting portability and adoption of this approach.

In this paper, we present a novel approach for Checkpoint ROllbaCk via lightweight HEap Traversal (CROCHET), which enables fully automatic fine-grained lightweight checkpoints within unmodified commodity JVMs (specifically Oracle’s HotSpot and OpenJDK). Leveraging key insights about the internal design common to modern state-of-the-art JVMs, CROCHET works entirely through bytecode rewriting and standard debug APIs, utilizing special proxy objects to perform a lazy heap traversal that starts at the root references and traverses the heap as objects are accessed, copying or restoring state as needed and removing each proxy immediately after it is used. We evaluated CROCHET on the DaCapo benchmark suite, finding it to have very low runtime overhead in steady state (ranging from no overhead to 1.13x slowdown), and that it often outperforms a state-of-the-art system-level checkpoint tool when creating checkpoints.

Fri 20 Jul

13:50 - 15:30: ECOOP Research Papers - Runtime Systems at Zurich II
Chair(s): Christian HammerUniversity of Potsdam
ecoop-2018-papers13:50 - 14:15
Research paper
Mohaned QunaibitUniversity of California, Irvine, Stefan BrunthalerBundeswehr University Munich, Yeoul Na, Stijn VolckaertUniversity of California, Irvine, Michael FranzUniversity of California, Irvine
ecoop-2018-papers14:15 - 14:40
Research paper
Jonathan BellGeorge Mason University, Luís PinaGeorge Mason University
DOI Pre-print Media Attached
ecoop-2018-papers14:40 - 15:05
Research paper
Julien Gascon-Samson, Kumseok JungUniversity of British Columbia, Shivanshu GoyalUniversity of British Columbia, Armin Rezaiean-AselUniversity of British Columbia, Karthik PattabiramanUniversity of British Columbia
ecoop-2018-papers15:05 - 15:30
Research paper
Tianxiao Gu, Xiaoxing MaNanjing University, Chang XuNanjing University, Yanyan JiangNanjing University, Chun CaoNanjing University, Jian LuNanjing University