{"id":1839,"date":"2015-11-16T07:47:59","date_gmt":"2015-11-16T07:47:59","guid":{"rendered":"http:\/\/mevss.jku.at\/?page_id=1839"},"modified":"2017-08-30T08:18:25","modified_gmt":"2017-08-30T08:18:25","slug":"lock-contention-tracing","status":"publish","type":"page","link":"http:\/\/mevss.jku.at\/?page_id=1839","title":{"rendered":"Lock Contention Tracing"},"content":{"rendered":"

Efficient Tracing and Versatile Analysis of Lock Contention in Java Applications on the Virtual Machine Level<\/h3>\n
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Overview<\/h2>\n
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Multi-core processors have become the norm from server-class machines to phones, and software developers must write concurrent code to benefit from their increasing processing power. However, implementing correct and scalable locking for accessing shared resources remains a challenge. Examining lock contention in an application at run time is vital to determine where more sophisticated but error-prone locking pays off.<\/p>\n

In our paper Efficient Tracing and Versatile Analysis of Lock Contention in Java Applications on the Virtual Machine Level,<\/i> we describe a novel approach for analyzing lock contention in Java applications by tracing locking events in the Java Virtual Machine. Unlike common methods, our approach observes not only when a thread is blocked on a lock, but also which other thread blocked it by holding that lock, and records both their stack traces. This reveals the causes of lock contention instead of showing only its symptoms. We further devised a versatile tool for the analysis of the traces which enables users to identify locking bottlenecks and their characteristics in an effective way. We implemented our approach in the widely used HotSpot Virtual Machine, and with a mean run-time overhead of 7.8% for real-world multi-threaded benchmarks, we consider it efficient enough to monitor production systems.<\/p>\n

On this website, we provide downloads for our prototype Java Development Kit (JDK) and for our trace analysis tool, as well as their source code.<\/b><\/p>\n

Our research is supported by Dynatrace Austria and by the Christian Doppler Forschungsgesellschaft.<\/p>\n

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The trace events which we record indicate which threads, methods and call chains are responsible for lock contention<\/figcaption><\/figure>\n
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Our analysis tool breaks down the recorded contention by different aspects<\/figcaption><\/figure>\n

Team<\/h4>\n