This trace follows the actual state transitions behind the companion Heap Allocation and Garbage Collection. It describes a common execution path; implementation details can vary, so keep the contract separate from the mechanism.
Step 1: Allocate and initialize an object
The heap holds objects whose lifetimes are not tied to one simple lexical scope. A runtime allocator reserves space, initializes an object, and returns a reference. Garbage collection reclaims memory that is no longer reachable under the collector’s object graph and root rules.
Step 2: Find roots to live state
A tracing collector starts from roots such as active stacks and global references, follows pointers, and marks reachable objects. A copying collector can move live objects into a new region and update references, while a generational collector uses the observation that many objects die young to focus collection work.
Step 3: Trace reachable references
A tracing collector starts from runtime roots and follows references; an unreachable object can be reclaimed, but a logically obsolete object remains live if a root still references it.
At this point, record the state that changed and check the invariant before advancing. If the operation repeats, make clear which values persist and which are recomputed.
Step 4: Reclaim or move dead/live objects
Garbage collection does not prevent leaks when the program keeps unnecessary references reachable. Collection pauses, write barriers, fragmentation, and allocation rate affect latency. Manual memory management avoids some runtime work but transfers lifetime and aliasing correctness to the programmer.
Step 5: Resume application execution
A cache retains every response forever in a global map. Explain why the collector cannot reclaim those entries and propose a retention policy that bounds memory by behavior rather than hope.
The trace is complete when the result satisfies the stated contract. Compare this model with the concrete runtime or system you are studying before making a performance claim.