Os Memory Management Questions
The mark and sweep garbage collection algorithm is a memory management technique used in operating systems to reclaim memory occupied by objects that are no longer in use. It involves two main steps: marking and sweeping.
During the marking phase, the algorithm traverses the entire memory space, starting from a set of root objects (e.g., global variables, stack frames), and marks all objects that are reachable or in use. This is typically done by setting a flag or a bit in the object's header.
Once the marking phase is complete, the sweeping phase begins. In this phase, the algorithm scans the entire memory space again, but this time it looks for unmarked objects. These unmarked objects are considered garbage or no longer in use, and their memory can be reclaimed. The algorithm then updates the memory management data structures to reflect the freed memory.
The mark and sweep algorithm is known for its simplicity and effectiveness in reclaiming memory. However, it has some drawbacks, such as the need for a stop-the-world pause during garbage collection, as well as potential fragmentation issues if memory is not compacted after collection.