Re: [BUG?] Very strange behavior, execution of a function is interrupted

[Sebastian Gniazdowski <sgniazdowski@gmail.com>]

I've found the cause. `compinit' does `read -q' when occurring
insecure directories. If this happens from `sched' with possibly Zle
being active, then following call inside bin_read() uses Zle's
raw_getbyte() to read a character:

zleentry(ZLE_CMD_GET_KEY, izle_timeout, NULL, &val);

This means that `read' can make all the rich side-effects of the regular
command-line to activate. I think this has significant importance, is
severe. I wouldn't expect the `read' builtin to bring up whole `zle -F'
handling, waiting for inputs, invoking callbacks.

Below test code confirms the above thesis. Its execution is recorded
here: https://asciinema.org/a/199265 Basically, my problem is that
Zplugin's scheduler gets invoked in nested manner because of
compinit's `read -q' (I was doing stress tests with compaudit
activating) and data structures go to improper state.


FD=1337; setup() {
    exec {FD}< <( sleep 1; echo run )
    zle -F $FD -my-scheduler
    echo "Sched call reporting being called"
    read -q "?[y/n]?"
    echo "Sched call reporting exiting"
}
-my-scheduler() {
    local THEFD="$1"; zle -F "$THEFD"; exec {THEFD}<&- # remove zle -F handler
    echo "Zle -F handler reporting being called"
}
sched +1 setup


On Sat, 1 Sep 2018 at 00:01, Sebastian Gniazdowski
<sgniazdowski@gmail.com> wrote:
>
> Hello,
> it's quite a lost game to explain this, but I'll try:
>
> - there is a scheduler called from sched +1 and once from zle -F
> - it detects timed-out tasks, moves them to ZPLG_RUN, then executes
> them reading them from this array
>
> Problem: sometimes execution never reaches this line and beyond:
> https://github.com/zdharma/zplugin/blob/7a24478e5862a1359b6cfb2887a792213be07e3a/zplugin.zsh#L1485
>
> Some cycles of the preceding loop are then also skipped.
>
> I feel very helpless in explaining this, maybe there's standard
> questions sheet for situation where bug in exec.c is suspected?
>
> I know `break 2' inside a function will break out of loop that
> contains the function call. But I don't know what could exit a
> function. I have debug prints and observe this clearly. At the
> mentioned line, no execution occurs, ZPLG_RUN isn't cleared, I get to
> run some tasks twice.
>
> Twice when I checked, it was happening when zle -F was called so near
> next second, that timeout'd tasks detection included two time slots:
> "0" (0 seconds after first precmd, handled by zle -F) and "1" (1
> second after first precmd, handled by sched +1).
> --
> Sebastian Gniazdowski
> News: https://twitter.com/ZdharmaI
> IRC: https://kiwiirc.com/client/chat.freenode.net:+6697/#zplugin
> Blog: http://zdharma.org



--
Sebastian Gniazdowski
News: https://twitter.com/ZdharmaI
IRC: https://kiwiirc.com/client/chat.freenode.net:+6697/#zplugin
Blog: http://zdharma.org