By checking the shutdown flag every loop we can use the entire 32 bit nonce space instead of breaking every 16 bits to check the flag.
This is possible now because the shutdown flag is an atomic where before it was controlled by a condition variable and lock.
ACK 8f0291f
Thank you. :)
122@@ -124,14 +123,17 @@ static UniValue generateBlocks(const CScript& coinbase_script, int nGenerate, ui
123 LOCK(cs_main);
124 IncrementExtraNonce(pblock, ::ChainActive().Tip(), nExtraNonce);
125 }
126- while (nMaxTries > 0 && pblock->nNonce < nInnerLoopCount && !CheckProofOfWork(pblock->GetHash(), pblock->nBits, Params().GetConsensus())) {
127+ while (nMaxTries > 0 && pblock->nNonce < std::numeric_limits<uint32_t>::max() && !CheckProofOfWork(pblock->GetHash(), pblock->nBits, Params().GetConsensus()) && !ShutdownRequested()) {
128 ++pblock->nNonce;
129 --nMaxTries;
130 }
131+ if(ShutdownRequested()) {
if
128 ++pblock->nNonce;
129 --nMaxTries;
130 }
131+ if (ShutdownRequested()) {
132+ break;
133+ }
No biggie but you could just do
0if (nMaxTries == 0 || ShutdownRequested()) {
1 break;
2}
i.e. merge the above and below blocks into one.
The replacement of 0x10000 (65536) with std::numeric_limits<uint32_t>::max() (4294967295) looks incorrect.
0x10000 is std::numeric_limits<uint16_t>::max() + 1, right? :-)
0$ cling
1****************** CLING ******************
2* Type C++ code and press enter to run it *
3* Type .q to exit *
4*******************************************
5[cling]$ #include <cstdint>
6[cling]$ #include <limits>
7[cling]$ 0x10000 == std::numeric_limits<uint16_t>::max() + 1
8(bool) true
Edit: OP has now been updated. This comment is no longer relevant.
@practicalswift That’s the point. Previous code only uses up to 16 bits of the 32 bit nonce, because it wanted to regularly check ShutdownRequested() state. We can use all 32 bits by just checking every iteration.
Edit: I realize OP did not actually mention this detail.
By checking the shutdown flag every loop we can use the entire nonce space
instead of breaking every 16 bits to check the shutdown flag.
This has been possible since the shutdown flag was switched to an atomic,
before that change it was controlled by a condition variable and lock.
&& !ShutdownRequested() could be removed from:
https://github.com/bitcoin/bitcoin/blob/e115a21f79c4121a78e7c889c17c3b5d3680d15b/src/rpc/mining.cpp#L117