972c5166ee
There are some mutable, global state variables that are currently reset by UnloadBlockIndex such as pindexBestHeader which should be cleaned up whenever the ChainstateManager is unloaded/reset/destructed/etc. Not cleaning them up leads to bugs like a use-after-free that happens like so: 1. At the end of a test, ChainstateManager is destructed, which also destructs BlockManager, which calls BlockManager::Unload to free all CBlockIndexes in its BlockMap 2. Since pindexBestHeader is not cleaned up, it now points to an invalid location 3. Another test starts to init, and calls LoadGenesisBlock, which calls AddToBlockIndex, which compares the genesis block with an invalid location 4. Cute puppies perish by the hundreds Previously, for normal codepaths (e.g. bitcoind), we relied on the fact that our program will be unloaded by the operating system which effectively resets these variables. The one exception is in QT tests, where these variables had to be manually reset. Since now ChainstateManager is no longer a global, we can just put this logic in its destructor to make sure that callers are always correct. Over time, we should probably move these mutable global state variables into ChainstateManager or CChainState so it's easier to reason about their lifecycles.
Bitcoin Core integration/staging tree
For an immediately usable, binary version of the Bitcoin Core software, see https://bitcoincore.org/en/download/.
Further information about Bitcoin Core is available in the doc folder.
What is Bitcoin?
Bitcoin is an experimental digital currency that enables instant payments to anyone, anywhere in the world. Bitcoin uses peer-to-peer technology to operate with no central authority: managing transactions and issuing money are carried out collectively by the network. Bitcoin Core is the name of open source software which enables the use of this currency.
For more information read the original Bitcoin whitepaper.
License
Bitcoin Core 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 (see doc/build-*.md for instructions) and tested, but it is not guaranteed to be
completely stable. Tags are created
regularly from release branches to indicate new official, stable release versions of Bitcoin Core.
The https://github.com/bitcoin-core/gui repository is used exclusively for the development of the GUI. Its master branch is identical in all monotree repositories. Release branches and tags do not exist, so please do not fork that repository unless it is for development reasons.
The contribution workflow is described in CONTRIBUTING.md and useful hints for developers can be found in doc/developer-notes.md.
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. Further details on running
and extending unit tests can be found in /src/test/README.md.
There are also regression and integration tests, written
in Python.
These tests can be run (if the test dependencies are installed) with: test/functional/test_runner.py
The CI (Continuous Integration) systems make sure that every pull request is built for Windows, Linux, and macOS, 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.
Translations
Changes to translations as well as new translations can be submitted to Bitcoin Core's Transifex page.
Translations are periodically pulled from Transifex and merged into the git repository. See the translation process for details on how this works.
Important: We do not accept translation changes as GitHub pull requests because the next pull from Transifex would automatically overwrite them again.