use inotify in a for loop

inotifywait.md

Initially, I tried to run inotifywait in monitor mode, like this:

for i in $(seq 1 3)
do
    echo "stage $i"
    train_model &
    pid=$!
    inotifywait -mq -e close_write --format '%f' $MODEL_SAVE_PATH | while read FILE
    do
        echo "[`date "+%F %T"`] new model: $FILE"
        if ps -p $pid > /dev/null  # train_model is finished
        then
            kill -2 -$$
        done
    done
done

Sadly, the kill -2 -$$ command will kill the whole script, which means it won't run the remaining loops.

I also tried to run the inotifywait part in a subshell, still got no luck.

So, I need to use a for loop to control how many times inotifywait should be executed in each stage, which is ugly, like this:

for i in $(seq 1 3)
do
    echo "stage $i"
    train_model &
    for _ in $(seq 100)
    do
        inotifywait -q -e close_write --format '%f' $MODEL_SAVE_PATH | while read FILE
        do
            echo "[`date "+%F %T"`] new model: $FILE"
        done
    done
done

In the first solution, ideally, inotifywait will exit when train_model is finished, this is exactly what I want. In the second solution, I need to rely on an extra variable, which feels redundant. However, before I find a more elegant way to achieve this, I'm afraid I'll be stuck with solution 2 for some time :(