[EVM] Ifinite Loop

[hellgate13]

Affected Branch

programmability

Basic Diagnostics

• [X] I've pulled the latest changes on the affected branch and the issue is still present.

• [X] The issue is reproducible in docker

Description

In order to reproduce the issue, follow these steps:

1. Create a smart contract that only issues for testing purposes.
2. Deploy it using hardhat
3. Update Contract Address, Run Web3JS function
   • document : https://web3js.readthedocs.io/en/v3.0.0-rc.5/web3-eth-contract.html#methods-mymethod-call
4. Infinite Loop

For now, based on the logs, it looks like the write locked and not released. do_try_lock_request of type write when m_is_readonly_run = true

The tested logs can be found in the following repositories : https://github.com/Black-NS/opencbdc-erc20-tesing/tree/develop/logs

NOTE : The logs can be updated by testing again.

NOTE : I've seen it behave normally when run via metamask or hardhat because input data into the sendRawTransaction and executing it worked fine. This was the same when I created the Raw Transaction with data.

Thank you.

Code of Conduct

• [X] I agree to follow this project's Code of Conduct

[anders94]

@metalicjames

[AlexRamRam]

Thanks for your report @hellgate13. It's worth pointing out that the server's response to methods.mint.call(...) (which invokes ethereum's eth_call json_rpc) is not well-defined since the mint() call requires an alteration to the contract's state. The system does handle functions that can be run locally (i.e. read-only) without changing state such as: myContract.methods.totalSupply().call().then(console.log).

All of that being said, the system's response is certainly not correct and it should not crash. We will issue a fix in the next few days.

[hellgate13]

Thank you for Response.

However I do have one question.

I think that executing a smart contract by putting ABI code in the input data to sendRawTransxaction also has the commonality of changing the contract state like using eth_call.

{
  ...
  from: '0x01A151CC5ED14d110cc0e6b64360913DE9f453F1',
  to: '0x01A151CC5ED14d110cc0e6b64360913DE9f453F1',
  value: BigNumber { value: "0" },
  data: '0xa0712d6800000000000000000000000000000000000000000000000000000000000003e8', <- this
  ...
}

Arccrding to your answer, System only handles read-only functions, so I think the ABI Byte code in sendRawTransaction shouldn;t have been executed.

I realize i'm asking a dumb question because I don't understand System Architecture, but maybe you can help me out?

[AlexRamRam]

The system, of course, handles transactions that modify state.

The mint() function of your contract - which requires a change to the state of contract - can be invoked with both eth_sendRawTransaction and eth_call. However, as described in the Ethereum JSON-RPC API, eth_call must execute messages "without creating a transaction on the block chain" and hence the system behavior when invoked with a state changing function is not well defined. Note that eth_sendRawTransaction does indeed commit state changes.

Also, note the web3js documentation you linked above on methods.myMethod.call: "Will call a “constant” method and execute its smart contract method in the EVM without sending any transaction. Note calling cannot alter the smart contract state."

I hope I understood your question correctly and you find this helpful.

Again, we will make changes such that the system responds gracefully when eth_call is invoked with a function that requires state changes.

[hellgate13]

thank you for your answering my stupid question.

it made me realize that i need to study much more about blockchain system, Web3JS and OpenCBDC System.

[AlexRamRam]

thank you for your answering my stupid question.

it made me realize that i need to study much more about blockchain system, Web3JS and OpenCBDC System.

Not at all @hellgate13. Your contribution is appreciated and we look forward to hearing more of your work.

[maurermi]

Sounds like this issue has been resolved. Additionally, the referenced commit by @AlexRamRam resolves the infinite loop problem if call() is used in an attempt to change state. @hellgate13 are you comfortable with this issue being closed?

[hellgate13]

thank you for update.

The contract.mint.send(from : address) in web3j library is throwing a signature error, but i'm guessing this is a problem with my setup.

I have checked that when i incorrectly request the mint function with call ( contract.mint.call() ) it returns an empty value.

I agree that this issue is closed.