Re: [go-nuts] interpreting runtime.Stack()

[Andrew Athan]

Alex: I’ll see how/if this can happen. Among other strangeness in this stack is that Err() doesn’t take a param but I guess it may be displaying the implicit “this”? btw this is not from a panic, but from a call to runtime.Stack(). The program experiences unbounded growth in cpu  utilization as it runs so either these stacks are a recursion bc there is a context “pointing” to itself as parent or a very deep reference stack. I’m going to guess there is a captured continuation variable somewhere that is incorrectly updated to a new value ctx with each new connection made or inside some loop instead of using the oroginal basr ctx. I looked for that originally but didn’t find it, but I’ll look again. I’m concerned that net.Conn’s or tls.Conn’s setRead/WriteDeadline() calls are at fault somehow. A. On May 12, 2023, at 12:38 AM, Axel Wagner <axel.wagner...@googlemail.com> wrote:  Ouh, I bet I know what's happening: You are using a concrete Context implementation that defines its methods on a value receiver, but pass it in as a nil-pointer: https://go.dev/play/p/JH9MxwvmTw7 That way, the panic happens in autogenerated code (the implicit promoted method from the value-type to the pointer-type) which then panics due to a nil-pointer dereference. The panic message should then actually tell you exactly that, though. On Fri, May 12, 2023 at 9:32 AM Axel Wagner <axel.wagner...@googlemail.com> wrote: What does the panic say? If it says "stack overflow", then yes, that's likely an infinite recursion. If not, then, no. My guess is, that it says "nil-pointer dereference". The `<autogenerated>` part probably means this is due to embedding. That is, the `Err` method on `valueCtx` is promoted from an embedded Context: https://cs.opensource.google/go/go/+/refs/tags/go1.20.4:src/context/context.go;l=599 If that context was `nil` or otherwise invalid, that would explain why the panic happens. Though I'm not sure how that would happen, unless you use `unsafe` somewhere. On Fri, May 12, 2023 at 5:03 AM Andrew Athan <andrew...@gmail.com> wrote: goroutine 1299607 [runnable]: context.(*valueCtx).Err(0xc00a52c3c0?) <autogenerated>:1 +0x3e context.(*valueCtx).Err(0x48860a?) <autogenerated>:1 +0x2a ... repeats many many many times ... ...additional frames elided... created by ....one_of_my_functions() somefile.go:2092 +0x4a5 What is going on here? is this likely to be an infinite recursion or similar within the context implementation or is this a normal thing to see? -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/095c81e9-15c2-4c27-b913-f85a16ee4968n%40googlegroups.com. -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/BBBF1FFC-FFCF-4FA7-B636-BC8B5B4911C1%40gmail.com.