bug: full crash when evaluating some invalid contracts

[balthazar]

Happens when the contract in question is invalid.

For example F2V2zXs1ylUO4hskxfNOvPlceLlk1hp_q-xEMQCPbBQ which is missing an await and thus make the main process crash.

Some others:

• aWZe5ZZIBOKZYEQuZRZRw1ElwRnZUsk3Y_4LMoN7UC4
• 0CFuevmMBfylDZkAFV_HETPZZDh2VFRbHZnq2QGUTjw
• hfb7rGeMsc58G3fjnVBJaP9ogXumUE6Oc_st-QJQkLE

[ppedziwiatr]

This happens for contracts that

1. have missing await
2. have a bug in code that is causing the contract code to throw an exception

In case of F2V2zXs1ylUO4hskxfNOvPlceLlk1hp_q-xEMQCPbBQ

• missing await while calling createTemplate function in switch
• error while calling Object.values, because options.options is undefined

[ppedziwiatr]

Hey @balthazar .
I'm currently working on replacing VM2 with https://github.com/laverdet/isolated-vm#isolated-vm----access-to-multiple-isolates-in-nodejs
It will probably take a while (as the documentation is not that great and it's a bit tricky to add support from external async calls (like reading other contract state) in the isolate) - in the meantime - can you please simply add

process
  .on('unhandledRejection', (reason, p) => {
    console.error(reason, 'Unhandled Rejection at Promise', p);
  })
  .on('uncaughtException', err => {
    console.error(err, 'Uncaught Exception thrown');
  });

in your host code?

This should allow to parent process to work properly, eg:
https://github.com/warp-contracts/warp/blob/ppe/isolate-vm/tools/async-test.js

• with the unhandledRejection handler added, the After timeout log shows properly (it does not however without this handler)

[balthazar]

Yeah was hoping there would be a better solution than this, as it would mean some unhandled errors of the main code will get swallowed when the process should actually crash in order to be fixed.

[ppedziwiatr]

probably the other option for now would be to run the contract evaluation in a separate worker thread.

The isolated vm fixes this issue (ie. only the isolate crashes, not the host process), but as I've mentioned - I need a few days to implement it fully (for example - I need to manually map each of the function from the Arweave library...)

[balthazar]

Yeah will probably be the only way while waiting for the new integration, thanks

[ppedziwiatr]

Hey @balthazar , the isolated-vm version has been deployed in 1.1.5-beta.0.
In order to use the isolated-vm, set the useIVM in the evaluation options - like here: https://github.com/warp-contracts/warp/pull/168/files#diff-cf0d865821a10d5af3908fb2ac0246a7a7671e9460d97d7ce89946e913e88cf2R100

Can you please test it on your side and share your feedback?

The useIVM should now properly handle the exception and move on..

for a comparison - the non-useIVM is causing the process to exit

[balthazar]

Works perfectly, thanks 😃

[ppedziwiatr]

Issue with isolated-vm - requires at least 2GB of ram to be installed via npm (i.e. the c++ compilation requires at least this amount of memory).
This is an issue for "minimal" instances (like t3.micro on AWS or basic droplets on DigitalOcean).

Re. VM2 - turns out that adding a global handler for dealing with async errors is a solution suggested be the readme - https://github.com/patriksimek/vm2#error-handling

I've created an issue whether this can be fixed/enhanced - patriksimek/vm2#441

[balthazar]

A global error handler isn't an ideal "solution" as it simply catches any unhandled error of the process, not just vm-related errors which might result in some important errors being caught by it and overlooked.

Wouldn't there be a way to copy built binaries and headers over if the memory requirement is just at build time?

[ppedziwiatr]

yeah yeah, I'm fully aware of the issues with global handler (this probably could be minimized by analyzing the stack trace (i.e. Error.stack), but still..)

Copying is one solution, dockerization - another..

The biggest issue is that in general - isolated-vm can introduce some issues for the warp library users (probably those on Windows - but - for example - I also wasn't able to install it out of the box (after adding g++ etc.) on my prev. development machine - with Fedora 34)...

[ppedziwiatr]

quickjs-emscripten - justjake/quickjs-emscripten#70 (comment) - no luck so far.