Update a java thread's stack size at runtime

Question

Does anyone know if there is a way to dynamically (runtime) increase the stack size of the main Thread? Also, and I believe it is the same question, is it possible to increa

Answer 1

The stack size dynamcally updates itself as it is used so you never need to so this.

What you can set is the maximum size it can be with -Xss This is the virtual memory size used and you can make it as large as you like on 64-bit JVMs. The actual memory used is based on the amount of memory you use. ;)

EDIT: The important distinction is that the maximum size is reserved as virtual memory (so is the heap btw). i.e. the address space is reserved, which is also why it cannot be extended. In 32-bit systems you have limited address space and this can still be a problem. But in 64-bit systems, you usually have up to 256 TB of virtual memory (a processor limitation) so virtual memory is cheap. The actual memory is allocated in pages (typically 4 KB) and they are only allocated when used. This is why the memory of a Java application appears to grow over time even though the maximum heap size is allocated on startup. The same thing happens with thread stacks. Only the pages actually touched are allocated.