How does the garbage collection mechanism in the system recognize objects that should be removed?

The garbage collection (GC) mechanism in a system, such as Flutter (Dart VM), determines objects for removal based on object reachability.

The main principle is "reachability-based garbage collection":

• The garbage collector starts with root objects, such as global variables, call stacks, and registers.
• It marks all objects reachable through references from the roots.
• All objects that are not reachable from the roots are considered garbage and are eligible for removal.

Thus, if an object is not used by the program and has no references to it, the garbage collector will delete it.

In Dart VM, a mark-and-sweep algorithm is typically used, sometimes with optimizations to reduce pauses.

This allows automatic memory management without explicit object deallocation by the programmer.