b37b7e655b
The algorithm here is important and took some time to get right. Instead of comparing whether the current number of connected nodes minus the number of unevictable nodes is greater than the number of max connections, check that: * there are any evictable nodes (connected nodes minus unevictable nodes) * there are more nodes connected than requested (connected nodes minus max connections) While we could wait for nodes to disconnect organically, it's more important to run the eviction logic frequently enough that we can tell when it will have an effect. Whitelisted connections and protected inbound connections are unevictable, and max connections should account for inbound connections. Because the evictor will never evict protected inbound connections, the maximum connection count should always be at least as large as the protected connection count. Note that the tests for this use a delay and test that the delay has not expired. This helps improve determinism in the testing. Otherwise, a strict test for a fixed number of disconnections is susceptible to things like CPU jitter, especially when running through CI. Patrick ran this test for 1000 runs on busy CPUs and saw no failures.
Regression tests
test_framework/authproxy.py
Taken from the python-bitcoinrpc repository.
test_framework/test_framework.py
Base class for new regression tests.
test_framework/util.py
Generally useful functions.
test_framework/mininode.py
Basic code to support p2p connectivity to a bitcoind.
test_framework/comptool.py
Framework for comparison-tool style, p2p tests.
test_framework/script.py
Utilities for manipulating transaction scripts (originally from python-bitcoinlib)
test_framework/blockstore.py
Implements disk-backed block and tx storage.
test_framework/key.py
Wrapper around OpenSSL EC_Key (originally from python-bitcoinlib)
test_framework/bignum.py
Helpers for script.py
test_framework/blocktools.py
Helper functions for creating blocks and transactions.
P2P test design notes
Mininode
-
mininode.pycontains all the definitions for objects that pass over the network (CBlock,CTransaction, etc, along with the network-level wrappers for them,msg_block,msg_tx, etc). -
P2P tests have two threads. One thread handles all network communication with the bitcoind(s) being tested (using python's asyncore package); the other implements the test logic.
-
NodeConnis the class used to connect to a bitcoind. If you implement a callback class that derives fromNodeConnCBand pass that to theNodeConnobject, your code will receive the appropriate callbacks when events of interest arrive. -
You can pass the same handler to multiple
NodeConn's if you like, or pass different ones to each -- whatever makes the most sense for your test. -
Call
NetworkThread.start()after allNodeConnobjects are created to start the networking thread. (Continue with the test logic in your existing thread.) -
RPC calls are available in p2p tests.
-
Can be used to write free-form tests, where specific p2p-protocol behavior is tested. Examples:
p2p-accept-block.py,maxblocksinflight.py.
Comptool
-
Testing framework for writing tests that compare the block/tx acceptance behavior of a bitcoind against 1 or more other bitcoind instances, or against known outcomes, or both.
-
Set the
num_nodesvariable (defined inComparisonTestFramework) to start up 1 or more nodes. If using 1 node, then--testbinarycan be used as a command line option to change the bitcoind binary used by the test. If using 2 or more nodes, then--refbinarycan be optionally used to change the bitcoind that will be used on nodes 2 and up. -
Implement a (generator) function called
get_tests()which yieldsTestInstances. EachTestInstanceconsists of:- a list of
[object, outcome, hash]entriesobjectis aCBlock,CTransaction, orCBlockHeader.CBlock's andCTransaction's are tested for acceptance.CBlockHeaders can be used so that the test runner can deliver complete headers-chains when requested from the bitcoind, to allow writing tests where blocks can be delivered out of order but still processed by headers-first bitcoind's.outcomeisTrue,False, orNone. IfTrueorFalse, the tip is compared with the expected tip -- either the block passed in, or the hash specified as the optional 3rd entry. IfNoneis specified, then the test will compare all the bitcoind's being tested to see if they all agree on what the best tip is.hashis the block hash of the tip to compare against. Optional to specify; if left out then the hash of the block passed in will be used as the expected tip. This allows for specifying an expected tip while testing the handling of either invalid blocks or blocks delivered out of order, which complete a longer chain.
sync_every_block:True/False. IfFalse, then all blocks are inv'ed together, and the test runner waits until the node receives the last one, and tests only the last block for tip acceptance using the outcome and specified tip. IfTrue, then each block is tested in sequence and synced (this is slower when processing many blocks).sync_every_transaction:True/False. Analogous tosync_every_block, except if the outcome on the last tx is "None", then the contents of the entire mempool are compared across all bitcoind connections. IfTrueorFalse, then only the last tx's acceptance is tested against the given outcome.
- a list of
-
For examples of tests written in this framework, see
invalidblockrequest.pyandp2p-fullblocktest.py.