What causes event system allocations?

Subscribing with closures, boxing event arguments, and allocating new delegate instances per call generate garbage, so a busy event system contributes to GC stutter.

How do I catch this when it only happens for some players?

Capture it automatically from the player's device with the full stack trace, the device and OS, the build, and a breadcrumb trail of what they did. That turns a vague complaint into a specific, reproducible issue you can fix without owning the hardware it happens on.

How to Fix Garbage from a Game's Event System

Quick answer: Avoid closures and per-call delegate allocations in hot events, use struct event args without boxing, and cache delegates so the event system does not allocate each fire.

Event-system garbage is closures and boxing. Avoiding them in hot paths fixes it. Here is how.

How to fix it

1. Avoid closures and per-call delegates

Subscribing with a lambda that captures variables allocates a closure, and creating delegates per call allocates. In hot events, cache the delegate and avoid capturing closures so firing does not allocate.

2. Avoid boxing event args

Passing value-type event arguments as object boxes them onto the heap each fire. Use generic or struct-typed events without boxing so frequent events do not generate garbage.

3. Cache and reuse

Cache delegates and reuse event-argument objects (or pass structs) rather than allocating per invocation. For a frequently-fired event, eliminating its per-fire allocation removes a steady GC source.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.

Ship the fix, watch the signature disappear from the next build. That's how you know it's really gone.