HIPPODROME

This is an automatic program repair tool for Java programs. It statically detects and fixes data race conditions for small to large scale Java programs. The bug detection part is enabled by a modified version of Infer, while the patch algorithm is detailed in this technical report.

Fixes come in the form of introducing synchronized blocks or adding the volatile annotation.

Setup and Build

Dependencies:

• Make sure you have JDK version 1.7 or higher installed on your machine
• maven
• infer (RacerD) - the extended version which tackles a more fine grained tracking of the locks when analysing for data races:
• antlr for java

For each of the above just follow the given instructions.

Install HIPPODROME:

1. install antlr to your local maven repository:

mvn install:install-file -Dfile="<path-to-your-antlr-for-java-jar>" -DgroupId=org.racerdfix.antlr -DartifactId=antlr -Dversion=1.0 -Dpackaging=jar

2. set the path to local infer (the version recommended earlier) and the options expected to run with in src/main/resources/APP_CONFIG.json:

{
  "infer": "<path-to-infer>/infer/infer/bin/infer",
  "infer_options": ["--racerdfix-only", "--starvation", "--no-deduplicate", <list-of-strings-representing-additional-infer-options>],
  "json_path": "./infer-out/",
}

where

• infer sets the path to the running infer
• options sets the options passed to the infer process
• json_path indicates the path to the directory where infer writes its reports

3. install HIPPODROME: mvn install (from the project's main directory); use mvn install -Dmaven.test.skip=true to skip the testing phase

Run

HIPPODROME requires a configuration file to indicate which files to analyse. The config file is in json format, as follows:

{
 "infer": "<path-to-infer>/infer/infer/bin/infer",
 "infer_options": ["--racerdfix-only", "--starvation", "--no-deduplicate", <list-of-strings-representing-additional-infer-options>],
 "json_path": "./infer-out/",
 "target_options": ["--", "javac", "<java-files-to-be-analysed>"],
 "prio_file": [],
 "iterations": 10,
 "hippodrome_options": ["--atomicity=true"]
}

where

• [optional] infer sets the path to the running infer (overwrites the corresponding confing set in APP_CONFIG.json)
• [optional] options sets the options passed to the infer process (overwrites the corresponding confing set in APP_CONFIG.json)
• [optional] json_path indicates the path to the directory where infer writes its reports (overwrites the corresponding confing set in APP_CONFIG.json)
• target_options sets the compiler used by infer and the target files
• prio_files selects only these files to be fixed. If left empty, HIPPODROME will attempt to fix all the files
• [optional] iterations sets the max number of iterations to re-analyse and re-patch the target files before stopping the patching process.
• [optional] hippodrome_options enables other options specific to hippodrome.

See the CONFIG.json file in the project's root directory for a config file example.

Assuming that the name of the resulted jar is hippodrome.jar you could test it as follows:

java -jar hippodrome.jar --config_file="CONFIG.json"

Example

Say we have a directory /tmp/ with the following content:

.
├── CONFIG.json
├── RacerDFix-1.0.jar
└── java
    └── RacyFalseNeg.java

and the following content for CONFIG.json:

{"infer":"infer",
 "options":["--racerdfix-only", "--starvation"],
 "json_path": "./infer-out/",
 "target_options": ["--", "javac", "java/RacyFalseNeg.java"],
 "prio_files": [],
 "iterations": 3
}

Running HIPPPODROME in this setting leads to the following structure:

.
├── CONFIG.json
├── RacerDFix-1.0.jar
├── infer-out
...
└── java
    ├── RacyFalseNeg.java
    └── RacyFalseNeg.java.orig

• The infer-out directory has beed created by infer to store the results of the analysis in json format.
• The java directory now contains the fixed java file RacyFalseNeg.java and its original counterpart RacyFalseNeg.java.orig

ADD RACE EXAMPLE, PATCH AND FIX EXAMPLE

Common execution issues

• If you get bounced back due to options which are not recognized by infer, it could be the case that HIPPODROME makes calls to a version of infer which is different that the recommended one:

/usr/local/bin/infer: unknown option '--racerdfix-olny'.

Solution: makes sure you have installed the infer version we recommended and that you have correctly set the path to this version in your APP_CONFIG.json file, or in CONFIG.json.

• If a race is not detected:

  • make sure that threads are spawned from non-anonymous classes, since the summaries collected by Infer have to be ascribed to methods of named classes.

  • In the absence of any evidence of concurrency, e.g usage of the sychronized methods or blocks, locks, annotations, etc, you can help the analyzer by annotating with @ThreadSafe those classes which contain code intended to be executed in a concurrent context.