In brief: We've open sourced a tool that allows you to provide a callback every time your program performs an allocation. The Java Allocation Instrumenter can be found here. Give it a whirl, if you are interested. One thing that crops up a lot at my employer is the need to take an action on every allocation. This can happen in a lot of different contexts: The programmer has a task, and wants to know how much memory the task allocates, so wants to increment a counter on every allocation. The programmer wants to keep a histogram of most frequently accessed call sites. The programmer wants to prevent a task from allocating too much memory, so it keeps a counter on every allocation and throws an exception when the counter reaches a certain value. Because of the demand for this, a few of us put together a tool that instruments your code and invokes a callback on every allocation. The Allocation Instrumenter is a Java agent written using the java.lang.instrument API and ASM . Each al
Jeremy Manson's blog, which goes into great detail either about concurrency in Java, or anything else that the author happens to feel is interesting or relevant to the target audience.