What does immutability really mean?(self.ethereum)submitted by Parity - Gavin WoodSo thinking a little about blockchain immutability - what does it really mean and is it black and white or are there shades of grey in there?I would suggest that EIP-150 was compliant from a "don't mess with the chain" immutability point of view.To start I'd set down these basic rules about what hard-forks should comply to for at least a minimum grade of immutability: hard-forks should not alter the functional state of the system (i.e.all other things being equal, the outcome of a future transaction should stay exactly the same).hard-forks should not result in the removal of data from the pre-existing chain.These two points are designed to address two separate kinds of "messing with the chain": In the first case, the idea of altering pre-existing state information (where it is still meaningful) as happened in the DAO hard-fork.In the second case it's the chain rollback situations where the chain-head is determined to be actually invalid and new blocks are mined in their position (presumably leaving out irksome transactions or under new rules).

EIP-150 was compliant under these rules even though it facilitates the alteration of the state trie in new ways (i.e.pinging an empty account with zero ether in order to "garbage collect" it from the state trie).This is because the state transition system can be demonstrated to imply a strict equivalence between empty and non-existent accounts.There are those who would argue that EIP-150 was not entirely compliant with the notional "immutability maxim" since it still facilitated the alteration of the trie in new ways that can effect pre-existent state.π Rendered by PID 12824 on app-281 at 2017-06-24 10:58:41.021291+00:00 running 3522178 country code: SG.Bitcoin Sign up or log in to customize your list._ Here's how it works: Anybody can ask a question Anybody can answer The best answers are voted up and rise to the top up vote down vote favorite 9 What is the function of Gas Limit parameter in Ethereum?Is it involved in mining or something else?

ethereum mining-theory up vote down vote In Ethereum, gas is a measure of computational effort.To each operation, a fixed amount of gas is assigned (e.g.fastest litecoin mining rigadding two numbers costs 3 gas, calculating a hash costs 30 gas, sending a transaction costs 21000 gas [1]).bitcoin restore from backupSince computation is expensive (mind that it has to be done by every full node in the network), excessive consumption of gas needs to be discouraged.ethereum mining difficultyTherefore, each unit of gas must be paid for (in Ether) by the sender of the transaction that triggered the computation.bitcoin mining i7 cpuUnfortunately, it is often not easy and in general even impossible to know in advance how much gas a transaction will need eventually.bitcoin wallet api java

Therefore, transactions have a gas limit field to specify the maximum amount of gas the sender is willing to buy.If the gas used exceeds this limit during execution, processing is stopped.bitcoin etf yahooThe sender still has to pay for the performed computation, but they are protected from running completely out of funds.bitcoin gambling with faucetThe transaction gas limit also protects full nodes from attackers, who could, without a gas limit, make them execute effective infinity loops.tor bitcoin donationIf such a transaction would take longer than one block to process, it could never be included in a block, and, thus, the attacker wouldn't need to pay for it.bitcoin geld ohne staat

[2] Additionally, blocks, too, have a field called gas limit.It defines the maximum amount of gas all transactions in the whole block combined are allowed to consume.hyip using bitcoinSimilar to the maximum block size in Bitcoin (measured in bytes), its purpose is to keep block propagation and processing time low, thereby allowing for a sufficiently decentralized network.bitcoin hyip reviewIn contrast to Bitcoin, it is however not a constant.bitcoin loan in nigeriaInstead, miners have the option to increase or decrease it every block by a certain factor.bitcoin loan script[3] [1] See the Yellow Paper for a breakdown of operations and the respective gas costs (Appendices G and H) [/ethereum/wiki/wiki/Design-Rationale#gas-and-fees [3] See the Yellow Paper Equations 40 to 42 for the exact rules up vote 3 down vote The current gas limit can be checked on the network stats page.bitcoin news the hindu

It's currently 3,141,592 (pi million).The gas limit per block is not fixed, though.The number of contract calls and standard transactions is limited by the gas limit, which is 1.2x of the exponential moving average.bitcoin black swanSo there's only so much gas that can be expended per block, even though it can grow, of course.bitcoin yearly returnNote that each call to the contract to the caller cost an amount of Ether defined by (gas sent to contract)*(price of gas as defined by caller) so sending 10 thousend transactions per block could end up quite a pricey endeavour.buy litecoin perfectmoneyBrowse other questions tagged ethereum mining-theory or ask your own question.litecoin amd cpuSign In Register Categories Recent Discussions Activity Unanswered Best Of... Categories All Categories Mining Pool Discussion General Project Discussion (non-technical) Education Protocol and Client discussion web3-js Whisper Swarm 2 RLP IoT & Hardware Smart Contracts and Dapps Serpent Solidity Projects Reference clients code and builds Eth & AlethZero- Cpp Implementation Geth - Go Implementation Mist Node.js Implementation Python Implementation Mix Other Implementations Meetups Other Events Jobs & Skills Press and Articles Audio/Video Ether Sale Other Languages Chinese German Italian French 2 Hebrew 6 Japanese Portugese Romanian Russian Spanish Turkish Watercooler Error with Pyethereum abi_contract() importing Serpent: "Not a function or opcode: def" godelzilla 3 September 2015 in Python Implementation I'm trying to run some very basic code with pyethereum (see below).top 5 litecoin pool

However, I keep getting this error when trying to import the serpent code with abi_contract: "Exception: Error (file "main", line 2, char 14): Not a function or opcode: def".bitcoin aktie chartI'm trying to define a function with "def" so I don't understand this error.beast options bitcoinI get the same error whether I save the code inline or in a file.Any help would be greatly appreciated!bitcoin lottery by hacking# Import tester and utils.litecoin price december 2013Initiate block.import serpentimport ethereum.tester as timport ethereum.utils as us = t.state()# Setup test keys and addresses.key1 = u.sha3("this is an insecure passphrase")addr1 = u.privtoaddr(key1)# Write contract and commit to blockchain.serpent_code='''def multiply(a): return(a*2)'''#serpent_code = open('multiply.se').read()c = s.abi_contract(serpent_code, sender=key1)o = c.multiply(5)print(str(o)) 0 Comments BlackShift 2 December 2015 0 astronaut 2 January 2016 0 Sign In or Register to comment.litecoin history data