9e09ec5d6b
Previously the benchmark code used an integer division (%) with a non-constant in the inner-loop. This is quite slow on many processors, especially ones like ARM that lack a hardware divide. Even on fairly recent x86_64 like haswell an integer division can take something like 100 cycles-- making it comparable to the runtime of siphash. This change avoids the division by using bitmasking instead. This was especially easy since the count was only increased by doubling. This change also restarts the timing when the execution time was very low this avoids mintimes of zero in cases where one execution ends up below the timer resolution. It also reduces the impact of the overhead on the final result. The formatting of the prints is changed to not use scientific notation make it more machine readable (in particular, gnuplot croaks on the non-fixedpoint, and it doesn't sort correctly). This also hoists out all the floating point divisions out of the semi-hot path because it was easy to do so. It might be prudent to break out the critical test into a macro just to guarantee that it gets inlined. It might also make sense to just save out the intermediate counts and times and get the floating point completely out of the timing loop (because e.g. on hardware without a fast hardware FPU like some ARM it will still be slow enough to distort the results). I haven't done either of these in this commit.
Blackcoin More
What is Blackcoin?
Blackcoin is a decentralised digital currency with near-instant transaction speeds and negligible transaction fees built upon Proof of Stake 3.0 as introduced by the Blackcoin development team.
Blackcoin More is the name of open source software which enables the use of this currency. It takes Blackcoin to the next level by building upon Bitcoin Core 0.12.2 with some patches from newer Bitcoin Core versions to offer performance enhancements, wider compatibility with third party services and a more advanced base.
For more information, as well as an immediately useable, binary version of the Blackcoin More software, see https://blackcoin.org.
License
Blackcoin More is released under the terms of the MIT license. See COPYING for more information or see https://opensource.org/licenses/MIT.
Development Process
The master branch is regularly built and tested, but is not guaranteed to be
completely stable. Tags are created
regularly to indicate new official, stable release versions of Blackcoin More.
Change log can be found in CHANGELOG.md.
The contribution workflow is described in CONTRIBUTING.md.
The best place to get started is to join the Development channel on Gitter: https://gitter.im/Blackcoin_Hub/Development
Testing
Testing and code review is the bottleneck for development; we get more pull requests than we can review and test on short notice. Please be patient and help out by testing other people's pull requests, and remember this is a security-critical project where any mistake might cost people lots of money.
Automated Testing
Developers are strongly encouraged to write unit tests for new code, and to
submit new unit tests for old code. Unit tests can be compiled and run
(assuming they weren't disabled in configure) with: make check
There are also regression and integration tests of the RPC interface, written
in Python, that are run automatically on the build server.
These tests can be run (if the test dependencies are installed) with: qa/pull-tester/rpc-tests.py
The Travis CI system makes sure that every pull request is built for Windows, Linux, and OS X, and that unit/sanity tests are run automatically.
Manual Quality Assurance (QA) Testing
Changes should be tested by somebody other than the developer who wrote the code. This is especially important for large or high-risk changes. It is useful to add a test plan to the pull request description if testing the changes is not straightforward.