Solutions for ReuseTTL Context Cancellation Issue

[derlaft]

If ReuseTTL is used, then, after TTL amount of time a background refresh expected to happen if there are any calls to the same key.

However, this interacts/conflicts with providing contexts into the cached function. It might be called with an already aborted context which results in a failure.

Example: https://go.dev/play/p/p3hdad2N7af

[ahuigo]

@derlaft
Maybe there is only two option:

• Use independent context with context.WithoutCancel(ctx)
• Do not use ReuseTTL if you has a cancelable context

Do you have any ideas?

Problem Summary

When using ReuseTTL, background refresh goroutines may receive already-canceled contexts from the original function calls, leading to panics when the cached function checks ctx.Err().

Solution Options

Option 1: Create a new context without cancel

This is not a general solution.

Note: this method is only suitable for cancel that do not close necessary object.

ctx, cancel := context.WithCancel(context.Background())
defer cancel()

// delete:  cachedFn(ctx, "test")
cachedFn(context.WithoutCancel(ctx),"test")

Option2: Do not use ReuseTTL when we need to cancel a context

No ReuseTTL and no background goroutine.