a9d0ebc262 Enable flake8 warnings for all currently non-violated rules (practicalswift)
4cbab15e75 tests: Fix accidental redefinition of previously defined variable via list comprehension (practicalswift)
0b9207efbe Enable flake8 warning for "list comprehension redefines 'foo' from line N" (F812) (practicalswift)
Pull request description:
* Enable `flake8` warnings for all currently non-violated rules
* Fix accidental redefinition via list comprehension
Tree-SHA512: 738b87789e99d02abb2c6b8ff58f65c0cbfeb93e3bf320763e033e510ebd0a4f72861bc8faaf42c14a056a5d4659c33dc70a63730a32cc15159559427bf21193
ada1af6d8f Fix typo in test_runner.py causing error (MeshCollider)
Pull request description:
In the case that a test fails, the typo in run_tests() (introduced in #11858) will cause an error rather than printing out the combined logs, hiding the cause of the failure.
Tree-SHA512: 7d7aa406d92750320ed20610cc5f174cdc94086f630af8c0c4db2003497132e0c56d59b94312fb42ad4507904a2fa858226a4a9337450930bf206183fc35c0a0
faefd29 qa: Prepare functional tests for Windows (MarcoFalke)
Pull request description:
* Pass `sys.executable` when calling a python script via the subprocess
module
* Don't remove the log file while it is still open and written to
* Properly use os.pathsep and os.path.sep when modifying the PATH
environment variable
* util-tests: Use os.path.join for Windows compatibility
Ref: #8227
Tree-SHA512: c507a536af104b3bde4366b6634099db826532bd3e7c35d694b5883c550920643b3eab79c76703ca67e1044ed09979e855088f7324321c8d52112514e334d614
faac7a2db4f9f511c901cb1b4d4e7c599b92884f qa: Avoid checking reject code for now (MarcoFalke)
Pull request description:
The node will often disconnect before sending a reject code. A more
robust solution would be to read from the debug log. See #13006
Tree-SHA512: 1dabf8a43dabbc722f4ffe4fbc1f870090253a66290b2d1a95e7a24e14c6442b493c314480c0314587164eb65e5d468aa9eb5e107ad90bb3ca821a97ea4d373c
cfaac2a60 Add build support for 'gprof' profiling. (murrayn)
Pull request description:
Support for profiling build: `./configure --enable-profiling`
Tree-SHA512: ea983cfce385f1893bb4ab7f94ac141b7d620951dc430da3bbc92ae1357fb05521eac689216e66dc87040171a8a57e76dd7ad98036e12a2896cfe5ab544347f0
937bf4335 Use std:🧵:hardware_concurrency, instead of Boost, to determine available cores (fanquake)
Pull request description:
Following discussion on IRC about replacing Boost usage for detecting available system cores, I've opened this to collect some benchmarks + further discussion.
The current method for detecting available cores was introduced in #6361.
Recap of the IRC chat:
```
21:14:08 fanquake: Since we seem to be giving Boost removal a good shot for 0.15, does anyone have suggestions for replacing GetNumCores?
21:14:26 fanquake: There is std:🧵:hardware_concurrency(), but that seems to count virtual cores, which I don't think we want.
21:14:51 BlueMatt: fanquake: I doubt we'll do boost removal for 0.15
21:14:58 BlueMatt: shit like BOOST_FOREACH, sure
21:15:07 BlueMatt: but all of boost? doubtful, there are still things we need
21:16:36 fanquake: Yea sorry, not the whole lot, but we can remove a decent chunk. Just looking into what else needs to be done to replace some of the less involved Boost usage.
21:16:43 BlueMatt: fair
21:17:14 wumpus: yes, it makes sense to plan ahead a bit, without immediately doing it
21:18:12 wumpus: right, don't count virtual cores, that used to be the case but it makes no sense for our usage
21:19:15 wumpus: it'd create a swarm of threads overwhelming any machine with hyperthreading (+accompanying thread stack overhead), for script validation, and there was no gain at all for that
21:20:03 sipa: BlueMatt: don't worry, there is no hurry
21:59:10 morcos: wumpus: i don't think that is correct
21:59:24 morcos: suppose you have 4 cores (8 virtual cores)
21:59:24 wumpus: fanquake: indeed seems that std has no equivalent to physical_concurrency, on any standard. That's annoying as it is non-trivial to implement
21:59:35 morcos: i think running par=8 (if it let you) would be notably faster
21:59:59 morcos: jeremyrubin and i discussed this at length a while back... i think i commented about it on irc at the time
22:00:21 wumpus: morcos: I think the conclusion at the time was that it made no difference, but sure would make sense to benchmark
22:00:39 morcos: perhaps historical testing on the virtual vs actual cores was polluted by concurrency issues that have now improved
22:00:47 wumpus: I think there are not more ALUs, so there is not really a point in having more threads
22:01:40 wumpus: hyperthreads are basically just a stored register state right?
22:02:23 sipa: wumpus: yes but it helps the scheduler
22:02:27 wumpus: in which case the only speedup using "number of cores" threads would give you is, possibly, excluding other software from running on the cores on the same time
22:02:37 morcos: well this is where i get out of my depth
22:02:50 sipa: if one of the threads is waiting on a read from ram, the other can use the arithmetic unit for example
22:02:54 morcos: wumpus: i'm pretty sure though that the speed up is considerably more than what you might expect from that
22:02:59 wumpus: sipa: ok, I back down, I didn't want to argue this at all
22:03:35 morcos: the reason i haven't tested it myself, is the machine i usually use has 16 cores... so not easy due to remaining concurrency issues to get much more speedup
22:03:36 wumpus: I'm fine with restoring it to number of virtual threads if that's faster
22:03:54 morcos: we should have somene with 4 cores (and  actually test it though, i agree
22:03:58 sipa: i would expect (but we should benchmark...) that if 8 scriot validation threads instead of 4 on a quadcore hyperthreading is not faster, it's due to lock contention
22:04:20 morcos: sipa: yeah thats my point, i think lock contention isn't that bad with 8 now
22:04:22 wumpus: on 64-bit systems the additional thread overhead wouldn't be important at least
22:04:23 gmaxwell: I previously benchmarked, a long time ago, it was faster.
22:04:33 gmaxwell: (to use the HT core count)
22:04:44 wumpus: why was this changed at all then?
22:04:47 wumpus: I'm confused
22:05:04 sipa: good question!
22:05:06 gmaxwell: I had no idea we changed it.
22:05:25 wumpus: sigh 
22:05:54 gmaxwell: What PR changed it?
22:06:51 gmaxwell: In any case, on 32-bit it's probably a good tradeoff... the extra ram overhead is worth avoiding.
22:07:22 wumpus: https://github.com/bitcoin/bitcoin/pull/6361
22:07:28 gmaxwell: PR 6461 btw.
22:07:37 gmaxwell: er lol at least you got it right.
22:07:45 wumpus: the complaint was that systems became unsuably slow when using that many thread
22:07:51 wumpus: so at least I got one thing right, woohoo
22:07:55 sipa: seems i even acked it!
22:07:57 BlueMatt: wumpus: there are more alus
22:08:38 BlueMatt: but we need to improve lock contention first
22:08:40 morcos: anywya, i think in the past the lock contention made 8 threads regardless of cores a bit dicey.. now that is much better (although more still to be done)
22:09:01 BlueMatt: or we can just merge #10192, thats fee
22:09:04 gribble: https://github.com/bitcoin/bitcoin/issues/10192 | Cache full script execution results in addition to signatures by TheBlueMatt · Pull Request #10192 · bitcoin/bitcoin · GitHub
22:09:11 BlueMatt: s/fee/free/
22:09:21 morcos: no, we do not need to improve lock contention first. but we should probably do that before we increase the max beyond 16
22:09:26 BlueMatt: then we can toss concurrency issues out the window and get more speedup anyway
22:09:35 gmaxwell: wumpus: yea, well in QT I thought we also diminished the count by 1 or something? but yes, if the motivation was to reduce how heavily the machine was used, thats fair.
22:09:56 sipa: the benefit of using HT cores is certainly not a factor 2
22:09:58 wumpus: gmaxwell: for the default I think this makes a lot of sense, yes
22:10:10 gmaxwell: morcos: right now on my 24/28 physical core hosts going beyond 16 still reduces performance.
22:10:11 wumpus: gmaxwell: do we also restrict the maximum par using this? that'd make less sense
22:10:51 wumpus: if someone *wants* to use the virtual cores they should be able to by setting -par=
22:10:51 sipa: *flies to US*
22:10:52 BlueMatt: sipa: sure, but the shared cache helps us get more out of it than some others, as morcos points out
22:11:30 BlueMatt: (because it means our thread contention issues are less)
22:12:05 morcos: gmaxwell: yeah i've been bogged down in fee estimation as well (and the rest of life) for a while now.. otherwise i would have put more effort into jeremy's checkqueue
22:12:36 BlueMatt: morcos: heh, well now you can do other stuff while the rest of us get bogged down in understanding fee estimation enough to review it 
22:12:37 wumpus: [to answer my own question: no, the limit for par is MAX_SCRIPTCHECK_THREADS, or 16]
22:12:54 morcos: but to me optimizing for more than 16 cores is pretty valuable as miners could use beefy machines and be less concerned by block validation time
22:14:38 BlueMatt: morcos: i think you may be surprised by the number of mining pools that are on VPSes that do not have 16 cores 
22:15:34 gmaxwell: I assume right now most of the time block validation is bogged in the parts that are not as concurrent. simple because caching makes the concurrent parts so fast. (and soon to hopefully increase with bluematt's patch)
22:17:55 gmaxwell: improving sha2 speed, or transaction malloc overhead are probably bigger wins now for connection at the tip than parallelism beyond 16 (though I'd like that too).
22:18:21 BlueMatt: sha2 speed is big
22:18:27 morcos: yeah lots of things to do actually...
22:18:57 gmaxwell: BlueMatt: might be a tiny bit less big if we didn't hash the block header 8 times for every block. 
22:21:27 BlueMatt: ehh, probably, but I'm less rushed there
22:21:43 BlueMatt: my new cache thing is about to add a bunch of hashing
22:21:50 BlueMatt: 1 sha round per tx
22:22:25 BlueMatt: and sigcache is obviously a ton
```
Tree-SHA512: a594430e2a77d8cc741ea8c664a2867b1e1693e5050a4bbc8511e8d66a2bffe241a9965f6dff1e7fbb99f21dd1fdeb95b826365da8bd8f9fab2d0ffd80d5059c
741f0177c Add DynamicMemoryUsage() to LevelDB (Evan Klitzke)
Pull request description:
This adds a new method `CDBWrapper::DynamicMemoryUsage()` similar to Bitcoin's existing methods of the same name. It's implemented by asking LevelDB for the information, and then parsing the string response. I've also added logging to `CDBWrapper::WriteBatch()` to track this information:
```
$ tail -f ~/.bitcoin/testnet3/debug.log | grep WriteBatch
2018-03-05 19:34:55 WriteBatch memory usage: db=chainstate, before=0.0MiB, after=0.0MiB
2018-03-05 19:35:17 WriteBatch memory usage: db=index, before=0.0MiB, after=0.0MiB
2018-03-05 19:35:17 WriteBatch memory usage: db=chainstate, before=0.0MiB, after=8.0MiB
2018-03-05 19:35:22 WriteBatch memory usage: db=index, before=0.0MiB, after=0.0MiB
2018-03-05 19:35:22 WriteBatch memory usage: db=chainstate, before=8.0MiB, after=17.0MiB
2018-03-05 19:35:26 WriteBatch memory usage: db=index, before=0.0MiB, after=0.0MiB
2018-03-05 19:35:27 WriteBatch memory usage: db=chainstate, before=9.0MiB, after=18.0MiB
2018-03-05 19:35:40 WriteBatch memory usage: db=index, before=0.0MiB, after=0.0MiB
2018-03-05 19:35:41 WriteBatch memory usage: db=chainstate, before=9.0MiB, after=7.0MiB
2018-03-05 19:35:52 WriteBatch memory usage: db=index, before=0.0MiB, after=0.0MiB
2018-03-05 19:35:52 WriteBatch memory usage: db=chainstate, before=7.0MiB, after=9.0MiB
^C
```
As LevelDB doesn't seem to provide a way to get the database name, I've also added a new `m_name` field to the `CDBWrapper`. This is necessary because we have multiple LevelDB databases (two now, and possibly more later, e.g. #11857).
I am using this information in other branches where I'm experimenting with changing LevelDB buffer sizes.
Tree-SHA512: 7ea8ff5484bb07ef806af17d000c74ccca27d2e0f6c3229e12d93818f00874553335d87428482bd8acbcae81ea35aef2a243326f9fccbfac25989323d24391b4
874e81808 Allow dustrelayfee to be set to zero (Luke Dashjr)
Pull request description:
I don't see and can't think of any rationale for forbidding this configuration.
Tree-SHA512: df09441f4aec63e79bea94838b7f8e336cebaeb0a22b5e58d27937bbeb1377f229921aeae43674e0b63fc40a39ae51a264d48aa1cdb4cbd0e3339d32856698bf
9c5a4a6ed Stop special-casing phashBlock handling in validation for TBV (Matt Corallo)
Pull request description:
There is no reason to do this, really, we already have "ignore PoW" flags. Motivated by https://github.com/bitcoin/bitcoin/pull/11739#discussion_r155841721
Tree-SHA512: 37cb1ae5b11c9e8ed7a679bb07ad3b119a2a014744b26d197d67ba21beb19fe6815271df935e40f7c7bd5f2e4d7ae4dad7bd4d00fa230a8d789f37e9de31a769
7eb665fc8 [Trivial] link mentioned scripted-diff-commit (Felix Wolfsteller)
Pull request description:
Make it easier for people who do not operate on a cloned repository to access the example mentioned.
Tree-SHA512: 1c06e551c68cad03e6bd541bf0e0076cdf0b48ef9b8b4e4a61435367c3435e2e4ccb934112e8dc29d3d70217d8834924704aaf839e25d1133312df86848ca1a1
fa9461473 [doc] dev-notes: Members should be initialized (MarcoFalke)
Pull request description:
Also, remove mention of threads that were removed long ago.
Motivation:
Make it easier to spot bugs such as #11654 and #12426
Tree-SHA512: 8ca1cb54e830e9368803bd98a8b08c39bf2d46f079094ed7e070b32ae15a6e611ce98d7a614f897803309f4728575e6bc9357fab1157c53d2536417eb8271653
e7d9fc5 [qt] navigate to transaction history page after send (Sjors Provoost)
Pull request description:
Before this change QT just remained on the Send tab, which I found confusing. Now it switches to the Transactions tab. This makes it more clear to the user that the send actually succeeded, and here they can monitor progress.
Ideally I would like to highlight the transaction, e.g. by refactoring `TransactionView::focusTransaction(const QModelIndex &idx)` to accept a transaction hash, but I'm not sure how to do that.
Tree-SHA512: 8aa93e03874de8434e18951f8aec47377814c0bcaf7eda4766fc41d5a4e32806346e12e4139e4d45468dfdf0b786f5a7faa393a31b8cd6c65ccac21fb3782c33
d6f3a73 Remove redundant locks (practicalswift)
Pull request description:
Remove redundant locks:
* ~~`FindNode(...)` is locking `cs_vNodes` internally~~
* `SetAddressBook(...)` is locking `cs_wallet` internally
* `DelAddressBook(...)` is locking `cs_wallet` internally
**Note to reviewers:** From what I can tell these locks are redundantly held from a data integrity perspective (guarding specific variables), and they do not appear to be needed from a data consistency perspective (ensuring a consistent state at the right points). Review thoroughly and please let me know if I'm mistaken :-)
Tree-SHA512: 7e3ca2d52fecb16385dc65051b5b20d81b502c0025d70b0c489eb3881866bdd57947a9c96931f7b213f5a8a76b6d2c7b084dff0ef2028a1e9ca9ccfd83e5b91e
a25cb0f Use ptrdiff_t type to more precisely indicate usage and avoid compiler warnings. (murrayn)
Pull request description:
ptrdiff_t is a more strictly correct type, and gets rid of compiler warnings.
Tree-SHA512: 39718a5cdc10e698f14185f4622a9b439728bce619bd8b3a86f2b99ed5b056cf5a8545a3e5c4bc8a6a01b845fb73510036cee5e6d2629c58df26be692a957fba
4ae7d15 init: Fix help message for checkblockindex (MarcoFalke)
Pull request description:
Minor fixup for my commit fa6ab96799.
Tree-SHA512: 18f9255bf1342007be2bdc26d6f688bcd27ba8eebfc709bd9ee31dfd2e4d955d2b699686492ccf59e94eb4b1cc7bf3332376aa151a68cb0b21695b3f67d4a940
57dae3fc4a Replace boost::call_once with std::call_once (donaloconnor)
Pull request description:
This replaces boost::call_once with the C++11 std::call_once. The aim is to remove unnecessary boost code.
Tested on Windows/MSVC
Tree-SHA512: 5e98ea6e5052fffeaf29f845f4ecf1078b38cbb27671c5b7b6167e7f074a391e10020445107979d9e220d029bc9464fb8b2ccb0bea664eeb7af59a789c988b10
8b2ef27 tests: Test connecting with non-existing RPC cookie file (practicalswift)
a2b2476 tests: Test connecting to a non-existing server (practicalswift)
de04fde bitcoin-cli: Provide a better error message when bitcoind is not running (practicalswift)
Pull request description:
Provide a better `bitcoin-cli` error message when `bitcoind` is not running.
Before this patch:
```
$ killall -9 bitcoind
$ bitcoin-cli -testnet echo 'hello world'
error: Could not locate RPC credentials. No authentication cookie could be found, and RPC password is not set. See -rpcpassword and -stdinrpcpass. Configuration file: (/root/.bitcoin/bitcoin.conf)
```
After this patch:
```
$ killall -9 bitcoind
$ bitcoin-cli -testnet echo 'hello world'
error: Could not connect to the server 127.0.0.1:18332
Make sure the bitcoind server is running and that you are connecting to the correct RPC port.
```
Tree-SHA512: bb16e1a9a1ac110ee202c3cb99b5d7c5c1e5487a17e6cd101e12dc69e9525c14dc71f37b128c26ad615369a57547f15d0f1e29b207c1b2f2ee4b4ba7105f3433
Signed-off-by: Pasta <pasta@dashboost.org>
d843db7 Qt: remove "new" button during receive-mode in addressbook (Jonas Schnelli)
Pull request description:
There are currently two ways how to generate new receiving addresses in the GUI (which leads to code duplication or required refactoring, see #12520).
Since the address-book is probably something that should be removed in the long run, suppressing the new-button in receive-mode could be a first step in deprecating the address book.
With this PR, users can still edit existing receiving address book entries and they can still create new sending address book entries.
Tree-SHA512: abe8d1b44bc3e1b53826ccf9d2b3f764264337758d95ca1fe1ef1bac72d47608cf454055fce3720e06634f0a5841a752ce643b4505b47d6e322b6fc71296e961
bb079a0e2c Remove unused variable in SortForBlock (Drew Rasmussen)
Pull request description:
Although txiter is passed to BlockAssembler::SortForBlock, it is never used. Other than BlockAssembler::addPackageTxs, no other method ever makes a call to SortForBlock, thus making this change harmless.
Tree-SHA512: c7df948c5f75f7371844200e0227a26476437f300148d29020e01041b382f5bda31d9c520c9c5425aee88ce8f4a52cd0e594985d69ed8a081b878cda2e4de8c5
f98b54352 Only call NotifyBlockTip when the active chain changes (James O'Beirne)
152b7fb25 [tests] Add a (failing) test for waitforblockheight (James O'Beirne)
Pull request description:
This is a subset of the more controversial https://github.com/bitcoin/bitcoin/pull/12407, but this also adds a test demonstrating the bug.
In InvalidateBlock, we're calling NotifyBlockTip with the now-invalid block's prev regardless of what chain the ancestor block is on. This could create numerous issues, but it at least screws up `waitforblockheight` (or anything else relying on `rpc/blockchain.cpp:latestblock`) when InvalidateBlock is called on a block not in chainActive, which can happen via RPC.
Only call NotifyBlockTip when the block being marked invalid is on the active chain.
Tree-SHA512: 9a54fe5e8c7eb489daf5df4483c0986129e871e2ca931a456ba869ecb5d5a8d4f7bd27ccc9e711e9292c9ed79ddef896c85d0e81fc76883503e327995b0e914f
8172d3a configure: UniValue 1.0.4 is required for pushKV(, bool) (Luke Dashjr)
Pull request description:
The breaking changes (#12193) are already merged, so this blocks 0.17.0.
It depends on jgarzik/univalue#42 or jgarzik/univalue#50 being merged and released in UniValue 1.0.4.
Tree-SHA512: 3a21bbc72d6632bd07ee60ad7780b9ee95908357bcf59b4795b693d8a5d8c88943d6451482f11916ff5417e3bdbb9916062f87d0d73e79f50eb95ddabe21f943
fac70134a rpc: Update createrawtransaction examples (MarcoFalke)
fa06dfce0 [rpc] createrawtransaction: Accept sorted outputs (MarcoFalke)
8acd25d85 rpc: Allow typeAny in RPCTypeCheck (MarcoFalke)
Pull request description:
The second parameter of the `createrawtransaction` is a dictionary of the outputs. This comes with at least two drawbacks:
* In case of duplicate keys, either of them might silently disappear, with no user feedback at all. A user needs to make other mistakes, but this could eventually lead to abnormal tx fees.
* A dictionary does not guarantee that keys are sorted. Again, a user needs to keep this in mind, as it could eventually lead to excessive tx fees.
Even though my scenario of loss-of-funds is unlikely to happen, I see it as a inconvenience that should be fixed.
Tree-SHA512: cd562f34f7f9f79c7d3433805971325c388c2035611be283980f4049066a622df4f0afdc11d7ac96662260ec0115147cb65e1ab5268f5a1b063242f3fe425f77
b4db76c55 net: Correct addrman logging (Wladimir J. van der Laan)
Pull request description:
These were introduced in #9037.
Found by @theuni (https://github.com/bitcoin/bitcoin/pull/9037#pullrequestreview-101704656).
Tree-SHA512: 9b5153da8a8e5d4ddf9513a5c453f9609cffd4df2924fd48c7b36c1b1055748c7077d4fc0e70be62ca36af87df7f621a744bb374a234baba271ce4982a240825
1dfb4e7d7 [Tests] Check output of parent/child tx list from getrawmempool, getmempooldescendants, getmempoolancestors, and REST interface (Conor Scott)
fc44cb108 [RPC] Add list of child transactions to verbose output of getrawmempool (Conor Scott)
Pull request description:
`bitcoin-cli getrawmempool true` only lists a transaction's parents in the `depends` field. This change adds a `spentby` field to the json response, which lists the transaction's children in the mempool.
Currently the only way to find child transactions is to use `getrawmempool` or make another call to `getmempooldescendants` and search the response for transactions that list the parent_txid in the `depends` list, which is inefficient.
This change allows direct lookup of children.
Example Output
```
"9a9b5733c0d89f207908cfa3fe17809bee71f629aa095c9f8754524e29e98ba4": {
...other geterawmempool data...
"wtxid": "9a9b5733c0d89f207908cfa3fe17809bee71f629aa095c9f8754524e29e98ba4",
"depends": [
"bdd92851d5766a42aeb62af667bb422a116cab4e032bba5e3dd6efe5b4b40aa0"
],
"spentby": [
"dc5d3ec388a9121421208738a041ac30a22163bc2e17758f2275b6c51a15ba7b"
]
},
```
Tree-SHA512: 83da7d421c9799a40ef65af3b7fdb586d6d87385f3f2ede3afd2c311725444b858f9d91cc110422a0fa31905779934fee07211ca6fe6b746792b83692c94b3ce
22b4aae02 [arith_uint256] Avoid unnecessary this-copy using prefix operator (Karl-Johan Alm)
Pull request description:
I noticed while profiling a related project that `operator-()` actually calls the `base_uint` constructor, which is because the postfix operator version of `operator++` (used in `operator-()`) creates a copy of `this` and returns it.
Tree-SHA512: d9a2665caa3d93f064cdeaf1c6fada101b9943bb53d93ccac6d9a0edac20279d2e921349e30239039c71e0a9629e45c29ec9f10d8d7499e936cdba6cb7c3c3eb
e68172ed9 Add test-before-evict discipline to addrman (Ethan Heilman)
Pull request description:
This change implement countermeasures 3 (test-before-evict) suggested in our paper: ["Eclipse Attacks on Bitcoin’s Peer-to-Peer Network"](http://cs-people.bu.edu/heilman/eclipse/).
# Design:
A collision occurs when an address, addr1, is being moved to the tried table from the new table, but maps to a position in the tried table which already contains an address (addr2). The current behavior is that addr1 would evict addr2 from the tried table.
This change ensures that during a collision, addr1 is not inserted into tried but instead inserted into a buffer (setTriedCollisions). The to-be-evicted address, addr2, is then tested by [a feeler connection](https://github.com/bitcoin/bitcoin/pull/8282). If addr2 is found to be online, we remove addr1 from the buffer and addr2 is not evicted, on the other hand if addr2 is found be offline it is replaced by addr1.
An additional small advantage of this change is that, as no more than ten addresses can be in the test buffer at once, and addresses are only cleared one at a time from the test buffer (at 2 minute intervals), thus an attacker is forced to wait at least two minutes to insert a new address into tried after filling up the test buffer. This rate limits an attacker attempting to launch an eclipse attack.
# Risk mitigation:
- To prevent this functionality from being used as a DoS vector, we limit the number of addresses which are to be tested to ten. If we have more than ten addresses to test, we drop new addresses being added to tried if they would evict an address. Since the feeler thread only creates one new connection every 2 minutes the additional network overhead is limited.
- An address in tried gains immunity from tests for 4 hours after it has been tested or successfully connected to.
# Tests:
This change includes additional addrman unittests which test this behavior.
I ran an instance of this change with a much smaller tried table (2 buckets of 64 addresses) so that collisions were much more likely and observed evictions.
```
2016-10-27 07:20:26 Swapping 208.12.64.252:8333 for 68.62.95.247:8333 in tried table
2016-10-27 07:20:26 Moving 208.12.64.252:8333 to tried
```
I documented tests we ran against similar earlier versions of this change in #6355.
# Security Benefit
This is was originally posted in PR #8282 see [this comment for full details](https://github.com/bitcoin/bitcoin/pull/8282#issuecomment-237255215).
To determine the security benefit of these larger numbers of IPs in the tried table I modeled the attack presented in [Eclipse Attacks on Bitcoin’s Peer-to-Peer Network](https://eprint.iacr.org/2015/263).
**Default node:** 595 attacker IPs for ~50% attack success.
**Default node + test-before-evict:** 620 attacker IPs for ~50% attack success.
**Feeler node:** 5540 attacker IPs for ~50% attack success.
**Feeler node + test-before-evict:** 8600 attacker IPs for ~50% attack success.
The node running feeler connections has 10 times as many online IP addresses in its tried table making an attack 10 times harder (i.e. requiring the an attacker require 10 times as many IP addresses in different /16s). Adding test-before-evict increases resistance of the node by an additional 3000 attacker IP addresses.
Below I graph the attack over even greater attacker resources (i.e. more attacker controled IP addresses). Note that test-before-evict maintains some security far longer even against an attacker with 50,000 IPs. If this node had a larger tried table test-before-evict could greatly boost a nodes resistance to eclipse attacks.
Tree-SHA512: fdad4d26aadeaad9bcdc71929b3eb4e1f855b3ee3541fbfbe25dca8d7d0a1667815402db0cb4319db6bd3fcd32d67b5bbc0e12045c4252d62d6239b7d77c4395
bls dependency defines a macro BASIC as 1 in relic_conf.h.
This caused blockfilter.h to not compile after macro expansion when it says BASIC = 0.
Maybe there is a fancy C++ way to solve this, but renaming it seemed good to me :)
Signed-off-by: Pasta <pasta@dashboost.org>
254c85b68794ada713dbdae415db72adf5fcbaf3 bench: Benchmark GCS filter creation and matching. (Jim Posen)
f33b717a85363e067316c133a542559d2f4aaeca blockfilter: Optimization on compilers with int128 support. (Jim Posen)
97b64d67daf0336dfb64b132f3e4d6a4c1967da4 blockfilter: Unit test against BIP 158 test vectors. (Jim Posen)
a4afb9cadbaecb0676e6475ab8d32a52faecb47a blockfilter: Additional helper methods to compute hash and header. (Jim Posen)
cd09c7925b5af4104834971cfe072251e3ac2bda blockfilter: Serialization methods on BlockFilter. (Jim Posen)
c1855f6052aca806fdb51be01b30dfeee8b55f40 blockfilter: Construction of basic block filters. (Jim Posen)
53e7874e079f9ddfe8b176f11d46e6b59c7283d5 blockfilter: Simple test for GCSFilter construction and Match. (Jim Posen)
558c536e35a25594881693e6ff01d275c88d7af1 blockfilter: Implement GCSFilter Match methods. (Jim Posen)
cf70b550054eed36f194eaa13f4a9cb31e32df38 blockfilter: Implement GCSFilter constructors. (Jim Posen)
c454f0ac63c6028f54c7eb51683b3ccdb475b19b blockfilter: Declare GCSFilter class for BIP 158 impl. (Jim Posen)
9b622dc72279b027c59d6541cddff53800fc689b streams: Unit tests for BitStreamReader and BitStreamWriter. (Jim Posen)
fe943f99bf0a2bbb12e30bc4803c0337e3c95b93 streams: Implement BitStreamReader/Writer classes. (Jim Posen)
87f2d9ee43a9220076b1959d1ca65245d9591be9 streams: Unit test for VectorReader class. (Jim Posen)
947133dec92cd25ec2b3358c09b8614ba6fb40d4 streams: Create VectorReader stream interface for vectors. (Jim Posen)
Pull request description:
This implements the compact block filter construction in [BIP 158](https://github.com/bitcoin/bips/blob/master/bip-0158.mediawiki). The code is not used anywhere in the Bitcoin Core code base yet. The next step towards [BIP 157](https://github.com/bitcoin/bips/blob/master/bip-0157.mediawiki) support would be to create an indexing module similar to `TxIndex` that constructs the basic and extended filters for each validated block.
### Filter Sizes
[Here](https://gateway.ipfs.io/ipfs/QmRqaAAQZ5ZX5eqxP7J2R1MzFrc2WDdKSWJEKtQzyawqog) is a CSV of filter sizes for blocks in the main chain.
As you can see below, the ratio of filter size to block size drops after the first ~150,000 blocks:
The reason for the relatively large filter sizes is that Golomb-coded sets only achieve good compression with a sufficient number of elements. Empirically, the average element size with 100 elements is 14% larger than with 10,000 elements.
The ratio of filter size to block size is computed without witness data for basic filters. Here is a summary table of filter size ratios *for blocks after height 150,000*:
| Stat | Filter Type |
|-------|--------------|
| Weighted Size Ratio Mean | 0.0198 |
| Size Ratio Mean | 0.0224 |
| Size Ratio Std Deviation | 0.0202 |
| Mean Element Size (bits) | 21.145 |
| Approx Theoretical Min Element Size (bits) | 21.025 |
Tree-SHA512: 2d045fbfc3fc45490ecb9b08d2f7e4dbbe7cd8c1c939f06bbdb8e8aacfe4c495cdb67c820e52520baebbf8a8305a0efd8e59d3fa8e367574a4b830509a39223f
* Merge #12381: Remove more boost threads
004f999 boost: drop boost threads for [alert|block|wallet]notify (Cory Fields)
0827267 boost: drop boost threads from torcontrol (Cory Fields)
ba91724 boost: remove useless threadGroup parameter from Discover (Cory Fields)
f26866b boost: drop boost threads for upnp (Cory Fields)
Pull request description:
This doesn't completely get rid of boost::thread, but this batch should be easy to review, and leaves us with only threadGroup (scheduler + scriptcheck) remaining.
Note to reviewers: The upnp diff changes a bunch of whitespace, it's much more clear with 'git diff -w'
Tree-SHA512: 5a356798d0785f93ed143d1f0afafe890bc82f0d470bc969473da2d2aa78bcb9b096f7ba11b92564d546fb447d4bd0d347e7842994ea0170aafd53fda7e0a66e
* fix using std::thread
Signed-off-by: pasta <pasta@dashboost.org>
* Switch to std::thread in NotifyTransactionLock
* Move StopTorControl call from Shutdown to PrepareShutdown
Co-authored-by: Wladimir J. van der Laan <laanwj@gmail.com>
Co-authored-by: UdjinM6 <UdjinM6@users.noreply.github.com>
* enable privatesend by default in litemode
Signed-off-by: Pasta <pasta@dashboost.org>
* remove useless litemode check in CPrivateSendServer::ProcessMessage, must be MN, so must have litemode off already
Signed-off-by: Pasta <pasta@dashboost.org>
* change litemode to mean, doesn't validate governance, but has all other dash features
Signed-off-by: Pasta <pasta@dashboost.org>
* litemode must be off for MNs cont
Signed-off-by: Pasta <pasta@dashboost.org>
* change litemode help text
Signed-off-by: Pasta <pasta@dashboost.org>
* don't skip MN sync in litemode
Signed-off-by: Pasta <pasta@dashboost.org>
* drop fLiteMode in bitcoingui.cpp
Signed-off-by: Pasta <pasta@dashboost.org>
* skip governance sync in litemode
Signed-off-by: pasta <pasta@dashboost.org>
* remove fLiteMode in walletview.cpp
Signed-off-by: pasta <pasta@dashboost.org>
* add back
Signed-off-by: pasta <pasta@dashboost.org>
* fix comments
* fix cache loading
* fix scheduled tasks
* Fix help text for some rpcs (revert what's left of 3478)
Co-authored-by: UdjinM6 <UdjinM6@users.noreply.github.com>
