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> Note that some of these bugs are in an optimizer, something a security-focused package handling money shouldn't even need Contract callers pay gas fees to ex

• kevingadd 9y ago
  You're accepting the assumption/abstraction made by Ethereum here, where "gas" is equivalent to performance, even though gas is an arbitrary measurement. You could easily build your own gas-focused optimizer for a toolchain like llvm or for a compiler like ocaml's. Ethereum could bill contracts based on the actual cycle count they take to execute on the CPU, or some other metric. Then you wouldn't need to use a specialized bytecode designed for the gas system with its own optimizer. Of course, then people would potentially be tuning for the most common CPUs (or ASICs, or whatever) used by miners. But again, it's not necessary to roll your own solution. Consider also whether gas makes any sense in the long run: Compute power continues to increase, and the cost of compute power continues to drop. If smart contracts are really going to be the foundation of a new economy and people are going to build applications on top of them, does gas make that much sense vs billing for actual compute and network resources like AWS or EC2? Is gas even a meaningful abstraction? I'd argue it isn't. If the 'value' of executing contracts in $/gas exceeds the cost of renting AWS/EC2 nodes you're basically created a market for mining arbitrage, and perverse incentives where those miners want to push the prices in one direction. Event-oriented programming is old hat in every modern programming language. C/C++ have plenty of frameworks out there you can use to get at it, so do other languages. In some environments it's the de-facto way to write code. Alternate frontends for the EVM potentially address some issues - which is great - but it doesn't get around the fact that EVM itself is poorly designed, and this is reflected in the system all the way from top to bottom. Some of the errata in the post I linked earlier were ways to exploit design flaws in both the VM and compiler to manipulate contracts, and instead of fixing that in the VM they make you put checking prologues in your functions :/
  • DennisP 9y ago
    > Ethereum could bill contracts based on the actual cycle count they take to execute on the CPU No, you can't, because (1) you need consensus on the results, so you can't just have everybody measure CPU cycles on their own machines, and (2) you also can't trust miners to correctly report cycles on their own machines. > cost of compute power continues to drop Which is fine because gas is an abstraction. The price per unit of gas is market based.
    • kevingadd 9y ago
      You can absolutely use a consensus model with cycle counting. The cycle count for x86 instructions (ignoring unpredictable factors like cache misses) is well-defined on all the modern architectures, you can find tables of the latencies and everything. There's no reason you couldn't do this instead of gas (though I don't know if I would argue that you should)
      • DennisP 9y ago
        If you are ignoring cache misses, and using a particular CPU architecture instead of whatever is actually running, then you're back to using gas. You still have a fixed list of costs for different operations, it's just a different list. But CPU cycles aren't actually a sufficient cost model, since you also have to pay for storage.
        • kevingadd 9y ago
          The original argument (not yours, to be fair) was that EVM/solidity + an optimizer are necessary because contracts are billed for gas. I was attempting to illustrate that you can build a platform around a more representative billing system (you can pick one!) such that existing, world-class languages can be used instead. This pays security dividends and reduces the cost of your system (for everyone, not just you). Whether or not gas is a useful solution as-is isn't a particularly important question to me, and I don't see any reason why you'd want to replace it now. It's just a poor excuse for Solidity/EVM.