5eaaa83ac1
There are only a few uses of `insecure_random` outside the tests. This PR replaces uses of insecure_random (and its accompanying global state) in the core code with an FastRandomContext that is automatically seeded on creation. This is meant to be used for inner loops. The FastRandomContext can be in the outer scope, or the class itself, then rand32() is used inside the loop. Useful e.g. for pushing addresses in CNode or the fee rounding, or randomization for coin selection. As a context is created per purpose, thus it gets rid of cross-thread unprotected shared usage of a single set of globals, this should also get rid of the potential race conditions. - I'd say TxMempool::check is not called enough to warrant using a special fast random context, this is switched to GetRand() (open for discussion...) - The use of `insecure_rand` in ConnectThroughProxy has been replaced by an atomic integer counter. The only goal here is to have a different credentials pair for each connection to go on a different Tor circuit, it does not need to be random nor unpredictable. - To avoid having a FastRandomContext on every CNode, the context is passed into PushAddress as appropriate. There remains an insecure_random for test usage in `test_random.h`.
Notes
The sources in this directory are unit test cases. Boost includes a unit testing framework, and since bitcoin already uses boost, it makes sense to simply use this framework rather than require developers to configure some other framework (we want as few impediments to creating unit tests as possible).
The build system is setup to compile an executable called test_bitcoin
that runs all of the unit tests. The main source file is called
test_bitcoin.cpp. To add a new unit test file to our test suite you need
to add the file to src/Makefile.test.include. The pattern is to create
one test file for each class or source file for which you want to create
unit tests. The file naming convention is <source_filename>_tests.cpp
and such files should wrap their tests in a test suite
called <source_filename>_tests. For an example of this pattern,
examine uint256_tests.cpp.
For further reading, I found the following website to be helpful in explaining how the boost unit test framework works: http://www.alittlemadness.com/2009/03/31/c-unit-testing-with-boosttest/.
test_bitcoin has some built-in command-line arguments; for example, to run just the getarg_tests verbosely:
test_bitcoin --log_level=all --run_test=getarg_tests
... or to run just the doubledash test:
test_bitcoin --run_test=getarg_tests/doubledash
Run test_bitcoin --help for the full list.
bitcoin-util-test.py
The test directory also contains the bitcoin-util-test.py tool, which tests bitcoin utils (currently just bitcoin-tx). This test gets run automatically during the make check build process. It is also possible to run the test manually from the src directory:
test/bitcoin-util-test.py --srcdir=[current directory]