Bad file descriptor when opening file after USR2

[geoffgarside]

I'm experiencing an odd issue after issuing a USR2 signal to my process. I've got an OnSIGHUP handler which opens some files and reloads data from them. On the first HUP after USR2 I get

read file.txt: bad file descriptor

if I HUP the process again it all works fine. I've been able to hack around this by setting a global variable after USR2 and if its the first HUP after a USR2 and doing

f, err := os.Open(os.DevNull)
if err == nil {
    defer f.Close()
}

and then running the code to reload the data from the files. Is this anything you've seen before, is there likely to be anything common I've not done correctly.

My use of goagain effectively matches the examples/simple/main.go example with the addition of the OnSIGHUP handler.

I'll try to replicate the issue with the simple example.

[mtharp]

Figured it out. Whenever the garbage collector runs it was closing the inherited FD a second time, either doing nothing or killing whatever file happened to be opened next after the restart. See pull request #28.