devices/console: Fix a bug which would cause libkrun to hang on exit #261
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Make PortInputEmpty and PortInputSigInt `wait_until_readable` implementations poll the stopfd EventFd to ensure the thread eventually exits. (The thread is joined in Port::shutdown method causing the hang). To replicate the hang, the stdin must not be a terminal. For example you can use a pipe - `echo hello | ./chroot_vm rootfs_fedora /bin/cat` would hang without this fix. This seems to be a regresion introduced by the commit: 4076b7: devices/console: implement reset method Signed-off-by: Matej Hrica <[email protected]>
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This fixes a hang observed when the VM is about to exit. The problem was the console device was joining a thread on vm shutdown (or device reset) which would never exit.
To replicate the hang, the stdin must not be a terminal (for example you can use a pipe).
Before this fix, this would hang:
echo hello | ./chroot_vm rootfs_fedora /bin/cat(Btw libkrun used 100% (1 core) of CPU when it was stuck in this state - I don't know why exactly.)
This seems to be a regression introduced by the commit:
4076b7: devices/console: implement reset method