Suppose that we have a transaction that calls a contract method with an i.e. 200,000 gas limit. While the transaction is mining, the called contract finds out that it will run out of gas before completion (We cannot estimate required gas beforehand for some reasons). We have enough eth available in the contract and also in the tx.origin account. Is there any way to use either contract's or EOA balance to re-balance the limit and complete the execution?
Solidity Gas Limit – Can Gas Limit Get Increased While Transaction Is Executing?
gasgas-limitout-of-gassolidity
Related Solutions
The gas limit should be as high as your transaction will consume, and no higher. The amount of gas a transaction consumes depends on what it does. (Bear in mind that if your transaction results in gas refunds, for example because it deletes storage data, you still need to account for it in the gas you supply.)
Most miners will fill blocks up to the limit, and it's OK to set a limit that takes close to or all the gas available in a block, but since miners take transactions with higher fees first, this will increase the gas level you will need to set to outbid other transactions that could fit in the block. So you will need to compensate for the higher gas limit by setting a higher gas price. See https://ethgasstation.info/ for specific data on how high a gas price you are likely to need for any given gas limit.
If you're just doing a simple send, just use 21,000.
Someone correct me if I'm wrong, but 21000 is not the gas limit. Remember that the gas limit is what the sender is willing to pay at most for the execution of the transaction. On the other hand, each opcode carries a gas price as you can see in the picture. Then the cost of performing a simple transaction is 21000, but if more opcodes are executed, the gas price of the transaction will increase (the prices of each opcode vary over time).
Best Answer
The executed contract method can't make changes to gas limit, the tx originator must replace that tx with another one in order to change it.
Change to a tx must be done by sending another tx with the same nonce but using higher gas price. If you managed to send it before the previous one gets mined, most likely (but not guaranteed) that a miner will mine it first, causing the older tx with same nocne to be removed from the mempool.