https://github.com/dmoj/java-sandbox-agent

Java class sandbox with instrumentation support for online judges.
https://github.com/dmoj/java-sandbox-agent

instrumentation java online-judge policy sandbox

Last synced: 2 months ago
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Java class sandbox with instrumentation support for online judges.

• Host: GitHub
• URL: https://github.com/dmoj/java-sandbox-agent
• Owner: DMOJ
• License: agpl-3.0
• Created: 2017-11-26T00:44:02.000Z (about 7 years ago)
• Default Branch: master
• Last Pushed: 2023-12-22T16:56:19.000Z (about 1 year ago)
• Last Synced: 2024-04-16T06:54:07.318Z (10 months ago)
• Topics: instrumentation, java, online-judge, policy, sandbox
• Language: Java
• Homepage: https://dmoj.ca
• Size: 46.9 KB
• Stars: 3
• Watchers: 5
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# java-sandbox-agent [![Build Status](https://github.com/DMOJ/java-sandbox-agent/workflows/build/badge.svg)](https://github.com/DMOJ/java-sandbox-agent/actions/)

Java class sandbox with instrumentation support for online judges. 

It implements:

* a much faster, [unsynchronized ASCII-only `System.out` stream](https://github.com/DMOJ/java-sandbox-agent/blob/master/src/main/java/ca/dmoj/java/UnsafePrintStream.java) that's suitable for single-threaded online-judging scenarios

* support for **disallowing particular classes from being loaded**, to force certain solutions trivialized by the standard library

* optional **unbuffering of standard output**, for interactive problems without requiring users to flush manually

* logging of exceptional exits to a state file

## Usage

To run a class `Submission` with agent the following suffices:

```

$ java -client -javaagent:/code/java-sandbox-agent.jar=[option, ...] Submission

```

Supported fields for the `option` list are:

* `nobigmath` — disables `BigInteger` and `BigDecimal`, raising [appropriate exceptions](https://github.com/DMOJ/java-sandbox-agent/blob/master/src/main/java/ca/dmoj/java/BigIntegerDisallowedException.java) if they are used

* `unicode` — encodes `System.out` as UTF-8 instead of ASCII, sacrificing performance for Unicode support

* `nobuf` — sets `System.out` as being line-buffered, for interactive problems

* `unsafe` — enables `sun.misc.Unsafe`, which is disabled by default