All you need to know about memory
The story
“Today I was asked about what happens when new() an object during the interview.” my friend said.
“Ok looks like a basic question, how did you answer,” I said.
“Yes, basic but not easy to answer”. he said.
“I talked about heap, object lifecycle, GC, reference counting,” he said.
“Well that should be good enough for a junior position. You do not have to mention virtual memory, swap, pages all those”.
“Yes but then that’s what my interviewer asked. ‘Do you know what exactly happens on the heap? And what will happen when there is not enough RAM on the heap?’ and I was stuck there”.
“Maybe he wants to touch the limit, should not affect your interview result,” I said.
Let’s discuss it today.
Memory structure
Before we talk about new() let’s look at memory structure when a process starts.
As we can see. after the code has been compiled or interpreted. It will be loaded into RAM. the RAM is located in the user space. 4 parts.
Code. binary code after compilation or interpretation.
