Quality Code: Software Testing Principles, Practices, and Patterns

Example: Injecting Synchronization through Logging

Although I quite melodramatically warned against exploiting logging frameworks for testing, some race conditions require their use. Let’s look at a real-life example I encountered.

Consider the code in Listing 13-11. At first blush, it may appear that this code is thread-safe. Java guarantees that the individual operations of the Vector class are thread-safe. The retrieval of the first element and its removal are in a synchronized block. However, small though it may be, the time between the test for whether logRecords is empty in the while condition and the synchronized block in which that test is acted on represents a classic check-and-modify race condition. When this method in invoked in high ...