Programs are not cleaned up under some circumstances

[raxod502]

Suppose I write this program in C++:

#include <iostream>

int main() {
  while (1) {
    std::cout << "yes" << std::endl;
  }
}

Then if I run it, say, four times using the Run button, I'll end up with this output from within the container (via docker exec):

root@cpp:~/src# pstree -a
my_init -u /usr/local/sbin/my_init --quiet --skip-runit -- bash -c...
  └─bash -c...
      ├─bash -c...
      │   └─bash -c...
      │       └─runuser -u riju -- bash -c exec /var/cache/riju/share/riju-pty "$@" -- bash -c...
      │           └─riju-pty bash -c set -euo pipefail; stty cols 80 rows 24; ( clang++ -std=c++17 -pedantic -Wall -Wextra main.cpp -o main ) && ( ./main )
      │               ├─bash -c set -euo pipefail; stty cols 80 rows 24; ( clang++ -std=c++17 -pedantic -Wall -Wextra main.cpp -o main ) && ( ./main )
      │               │   └─main
      │               └─(riju-pty)
      ├─bash -c...
      │   └─bash -c...
      │       └─runuser -u riju -- bash -c exec /var/cache/riju/share/riju-pty "$@" -- bash -c...
      │           └─riju-pty bash -c set -euo pipefail; stty cols 80 rows 24; ( clang++ -std=c++17 -pedantic -Wall -Wextra main.cpp -o main ) && ( ./main )
      │               ├─bash -c set -euo pipefail; stty cols 80 rows 24; ( clang++ -std=c++17 -pedantic -Wall -Wextra main.cpp -o main ) && ( ./main )
      │               │   └─main
      │               └─(riju-pty)
      ├─bash -c...
      │   └─bash -c...
      │       └─runuser -u riju -- bash -c exec /var/cache/riju/share/riju-pty "$@" -- bash -c...
      │           └─riju-pty bash -c set -euo pipefail; stty cols 80 rows 24; ( clang++ -std=c++17 -pedantic -Wall -Wextra main.cpp -o main ) && ( ./main )
      │               ├─bash -c set -euo pipefail; stty cols 80 rows 24; ( clang++ -std=c++17 -pedantic -Wall -Wextra main.cpp -o main ) && ( ./main )
      │               │   └─main
      │               └─(riju-pty)
      ├─bash -c...
      │   └─bash -c...
      │       └─runuser -u riju -- bash -c exec /var/cache/riju/share/riju-pty "$@" -- bash -c...
      │           └─riju-pty bash -c set -euo pipefail; stty cols 80 rows 24; ( clang++ -std=c++17 -pedantic -Wall -Wextra main.cpp -o main ) && ( ./main )
      │               ├─bash -c set -euo pipefail; stty cols 80 rows 24; ( clang++ -std=c++17 -pedantic -Wall -Wextra main.cpp -o main ) && ( ./main )
      │               │   └─main
      │               └─riju-pty bash -c set -euo pipefail; stty cols 80 rows 24; ( clang++ -std=c++17 -pedantic -Wall -Wextra main.cpp -o main ) && ( ./main )
      │                   └─riju-pty bash -c set -euo pipefail; stty cols 80 rows 24; ( clang++ -std=c++17 -pedantic -Wall -Wextra main.cpp -o main ) && ( ./main )
      └─bash -c...
          └─sleep 1
r

And this:

root@cpp:~/src# ps aux
USER         PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root           1  0.0  0.0  15204 11020 ?        Ss   03:46   0:00 /usr/bin/python3 -u /usr/local/sbin/my_init --quiet --skip-runit -- bash -c #!/usr/bin/env bash  set -euo pipefail  umask 0
root           7  0.3  0.0   6532  4016 ?        S    03:46   0:00 bash -c #!/usr/bin/env bash  set -euo pipefail  umask 077  while read -t2 -r cmdline; do     cmd=(${cmdline})     for (( i=
root         210  0.0  0.0   6016   952 ?        S    03:46   0:00 bash -c #!/usr/bin/env bash  set -euo pipefail  umask 077  while read -t2 -r cmdline; do     cmd=(${cmdline})     for (( i=
root         212  0.0  0.0   6016  2116 ?        S    03:46   0:00 bash -c #!/usr/bin/env bash  set -euo pipefail  umask 077  while read -t2 -r cmdline; do     cmd=(${cmdline})     for (( i=
root         214  0.0  0.0   8232  4016 ?        S    03:46   0:00 runuser -u riju -- bash -c exec /var/cache/riju/share/riju-pty "$@" -- bash -c set -euo pipefail; stty cols 80 rows 24; ( c
riju         215  0.0  0.0   2376   768 ?        S    03:46   0:00 /var/cache/riju/share/riju-pty bash -c set -euo pipefail; stty cols 80 rows 24; ( clang++ -std=c++17 -pedantic -Wall -Wextr
riju         216  0.0  0.0   6148  3648 pts/0    Ss+  03:46   0:00 bash -c set -euo pipefail; stty cols 80 rows 24; ( clang++ -std=c++17 -pedantic -Wall -Wextra main.cpp -o main ) && ( ./mai
riju         218  0.5  0.0      0     0 ?        Z    03:46   0:00 [riju-pty] <defunct>
riju         231  0.7  0.0   6108  1648 pts/0    S+   03:46   0:00 ./main
root         338  0.0  0.0   6016   956 ?        S    03:46   0:00 bash -c #!/usr/bin/env bash  set -euo pipefail  umask 077  while read -t2 -r cmdline; do     cmd=(${cmdline})     for (( i=
root         340  0.0  0.0   6016  2116 ?        S    03:46   0:00 bash -c #!/usr/bin/env bash  set -euo pipefail  umask 077  while read -t2 -r cmdline; do     cmd=(${cmdline})     for (( i=
root         341  0.0  0.0   8232  3912 ?        S    03:46   0:00 runuser -u riju -- bash -c exec /var/cache/riju/share/riju-pty "$@" -- bash -c set -euo pipefail; stty cols 80 rows 24; ( c
riju         343  0.0  0.0   2376   692 ?        S    03:46   0:00 /var/cache/riju/share/riju-pty bash -c set -euo pipefail; stty cols 80 rows 24; ( clang++ -std=c++17 -pedantic -Wall -Wextr
riju         344  0.0  0.0   6148  3632 pts/1    Ss+  03:46   0:00 bash -c set -euo pipefail; stty cols 80 rows 24; ( clang++ -std=c++17 -pedantic -Wall -Wextra main.cpp -o main ) && ( ./mai
riju         345  0.1  0.0      0     0 ?        Z    03:46   0:00 [riju-pty] <defunct>
riju         359  0.1  0.0   6108  1720 pts/1    S+   03:46   0:00 ./main
root         448  0.0  0.0   6016   956 ?        S    03:46   0:00 bash -c #!/usr/bin/env bash  set -euo pipefail  umask 077  while read -t2 -r cmdline; do     cmd=(${cmdline})     for (( i=
root         450  0.0  0.0   6016  2116 ?        S    03:46   0:00 bash -c #!/usr/bin/env bash  set -euo pipefail  umask 077  while read -t2 -r cmdline; do     cmd=(${cmdline})     for (( i=
root         454  0.0  0.0   8232  3672 ?        S    03:46   0:00 runuser -u riju -- bash -c exec /var/cache/riju/share/riju-pty "$@" -- bash -c set -euo pipefail; stty cols 80 rows 24; ( c
riju         459  0.0  0.0   2376   696 ?        S    03:46   0:00 /var/cache/riju/share/riju-pty bash -c set -euo pipefail; stty cols 80 rows 24; ( clang++ -std=c++17 -pedantic -Wall -Wextr
riju         462  0.0  0.0   6148  3728 pts/2    Ss+  03:46   0:00 bash -c set -euo pipefail; stty cols 80 rows 24; ( clang++ -std=c++17 -pedantic -Wall -Wextra main.cpp -o main ) && ( ./mai
riju         463  0.1  0.0      0     0 ?        Z    03:46   0:00 [riju-pty] <defunct>
riju         477  0.2  0.0   6108  1708 pts/2    S+   03:46   0:00 ./main
root         567  0.0  0.0   6016   956 ?        S    03:46   0:00 bash -c #!/usr/bin/env bash  set -euo pipefail  umask 077  while read -t2 -r cmdline; do     cmd=(${cmdline})     for (( i=
root         568  0.0  0.0   6016  2244 ?        S    03:46   0:00 bash -c #!/usr/bin/env bash  set -euo pipefail  umask 077  while read -t2 -r cmdline; do     cmd=(${cmdline})     for (( i=
root         569  0.0  0.0   6016  2116 ?        S    03:46   0:00 bash -c #!/usr/bin/env bash  set -euo pipefail  umask 077  while read -t2 -r cmdline; do     cmd=(${cmdline})     for (( i=
root         572  0.0  0.0   8232  3968 ?        S    03:46   0:00 runuser -u riju -- bash -c exec /var/cache/riju/share/riju-pty "$@" -- bash -c set -euo pipefail; stty cols 80 rows 24; ( c
riju         580  0.0  0.0   2376   756 ?        S    03:46   0:00 /var/cache/riju/share/riju-pty bash -c set -euo pipefail; stty cols 80 rows 24; ( clang++ -std=c++17 -pedantic -Wall -Wextr
riju         581  0.0  0.0   6148  3668 pts/3    Ss+  03:46   0:00 bash -c set -euo pipefail; stty cols 80 rows 24; ( clang++ -std=c++17 -pedantic -Wall -Wextra main.cpp -o main ) && ( ./mai
riju         582 23.7  0.0   2376    84 ?        R    03:46   0:16 /var/cache/riju/share/riju-pty bash -c set -euo pipefail; stty cols 80 rows 24; ( clang++ -std=c++17 -pedantic -Wall -Wextr
riju         583  0.0  0.0   2376    84 ?        S    03:46   0:00 /var/cache/riju/share/riju-pty bash -c set -euo pipefail; stty cols 80 rows 24; ( clang++ -std=c++17 -pedantic -Wall -Wextr
riju         588 33.8  0.0   6108  1772 pts/3    R+   03:47   0:22 ./main
root         652  0.1  0.0   6364  4160 pts/4    Ss   03:47   0:00 bash
root        1205  0.0  0.0   4428   768 ?        S    03:48   0:00 sleep 1
root        1214  0.0  0.0   8732  3384 pts/4    R+   03:48   0:00 ps aux

So the user code is not being terminated! That's very bad since it causes CPU to be eaten up forever, until the container is shut down entirely. I found this out after getting paged for sustained CPU usage on Riju.