This is a monitoring tool for go's finalizer go routine.
The routine is spawned by the function runfinq under the runtime package in go's source code (mfinal.go).
The Go runtime uses a single goroutine for all finalizer execution. A slow-running finalizer can cause a significant delay in the execution of subsequent finalizers. Furthermore, a blocking finalizer halts the finalizer goroutine, preventing the cleanup of resources for other objects awaiting finalization, which results in a memory leak.
go finq.Monitor(ctx, &MonitorOpts{
StallingInterval: time.Minute,
OnStalling: func(d time.Duration) {
log.Println("waiting for finalizer to execute for:", d)
// you can use this functionality to retrieve the stacktrace of the blocking routine
trace := finq.GetFinalizerStackTrace()
if trace != "" {
log.Println("blocking routine trace:", trace)
}
},
OnComplete: func(d time.Duration) {
log.Println("finalizer executed after:", d)
},
ImmediatelyTriggerGC: false,
})Blogpost: Leak and Seek: A Go Runtime Mystery
Discussion: golang-nuts
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