What a miner does?

[blap]

Just to understand the process, what a miner does? Hash the block header (https://en.bitcoin.it/wiki/Block_hashing_algorithm)? Someone has a pseudo-code for that? I have looked inside m0mchil-poclbm and jsMiner.js... It was confusing for me...
 

[Pieter Wuille]

loop:
  var blockheader = DoGetWorkRPCCall()
  var target = ExtractTarget(blockheader)
  for nonce in 0..4294967295:
    var attempt = ModifyNonce(blockheader, nonce)
    var hash = SHA256(SHA256(attempt))
    if (hash < target)
      ReportSolution(attempt)

[compro01]

loop:
  var blockheader = DoGetWorkRPCCall()
  var target = ExtractTarget(blockheader)
  for nonce in 0..4294967295:
    var attempt = ModifyNonce(blockheader, nonce)
    var hash = SHA256(SHA256(attempt))
    if (hash < target)
      ReportSolution(attempt)

i believe should be (hash <= target)

otherwise, looks right to me.

[blap]

What is "ModifyNonce(blockheader, nonce)"?

[compro01]

What is "ModifyNonce(blockheader, nonce)"?

sticks the incremented nonce into the block header, replacing the previously tried one.

[dserrano5]

What is "ModifyNonce(blockheader, nonce)"?

sticks the incremented nonce into the block header, replacing the previously tried one.

I'm a total noob at this but, if I didn't misunderstand this, the current timestamp is also took into account. Else, a given block could be unsolvable if it happens that none of the 2**32 nonces result in a hash less than the target.

[compro01]

What is "ModifyNonce(blockheader, nonce)"?

sticks the incremented nonce into the block header, replacing the previously tried one.

I'm a total noob at this but, if I didn't misunderstand this, the current timestamp is also took into account. Else, a given block could be unsolvable if it happens that none of the 2**32 nonces result in a hash less than the target.

Yes, there would need to be a ModifyTimestamp(blockheaders, timestamp) step, but whenever the nonce overflows, the ExtraNonce part of the generation transaction gets incremented.

[Pieter Wuille]

Miners typically do not modify the timestamp - they just use the timestamp in the block, as received by the getwork call.