mmisono / bpftrace-tetris

Tetris in bpftrace

bpftrace-tetris

This is the ported version of tetris.spt.

Requirements

• Linux 5.3+
• bcc master branch version
• bpftrace master branch version

How to run

• ./run.sh

In Vagrant

If you do not readily have access to a recent linux kernel and bpftrace, you can try the included Vagrant file which launches ubuntu eoan so you can still play tetris!

Download vagrant from https://www.vagrantup.com/downloads.html, and make sure you have either VMWare or Virtualbox 6.0 installed.

Install both, then run:

vagrant plugin install vagrant-vbguest

You can then run tetris with:

./run-in-vagrant.sh

In Docker

./run-in-docker.sh

Note that this also run with a recent Docker Desktop for Mac.

FAQ

Q. Why is Linux 5.3+ required?

Otherwise the BPF program will be rejected due to the maximum instruction limit (see this commit.)

Q. How do I change the dropping speed?

It can be changed by modifying the interval value of interval:ms:99.

Q. How are blocks represented?

License

GPL v2 or later

bpftrace-tetris's Issues

bounded loop support

Great work developing this!

I see it uses many unroll() loops. Linux 5.3 added bounded loops, which would greatly reduce the instruction count bpftrace generates, plus allow us to implement for and while loops. See bpftrace/bpftrace#872

Once that's done, bpftrace-tetris can either use the new loop syntax (for, while), or at least, the generated instructions from unroll() should be a lot less. Just adding this ticket as a reminder that we do need to do issue 872 on bpftrace.

could use rand

      @t = elapsed % 7; // determin the next block

bpftrace has a rand builtin, which seems like it might be better here.

Syntax error on Fedora 35

Bpftrace-tetris fails on Fedora 35 with the following error:

# bpftrace tetris.bt 
tetris.bt:87:34-36: ERROR: syntax error, unexpected >=, expecting }
       $f += @Z[@h+@B[@t,$i]+$d] >= 0; // destination is free
                                 ~~