This work is prerequisite to attaching thread names to log lines and deadlock
debug utilities. This code allows setting of an "internal" threadname per
thread on platforms where thread_local is available.
This commit also moves RenameThread() out of a more general module and adds a
numeric suffix to disambiguate between threads with the same name. It
explicitly names a few main threads using the new util::ThreadRename().
c7efb652f3 blockfilter: Update BIP 158 test vectors. (Jim Posen)
19308c9e21 rpc: Add getblockfilter RPC method. (Jim Posen)
ff35105096 init: Add CLI option to enable block filter index. (Jim Posen)
accc8b8b18 index: Access functions for global block filter indexes. (Jim Posen)
2bc90e4e7b test: Unit test for block filter index reorg handling. (Jim Posen)
6bcf0998c0 test: Unit tests for block index filter. (Jim Posen)
b5e8200db7 index: Implement lookup methods on block filter index. (Jim Posen)
75a76e3619 index: Implement block filter index with write operations. (Jim Posen)
2ad2338ef9 serialize: Serialization support for big-endian 32-bit ints. (Jim Posen)
ba6ff9a6f7 blockfilter: Functions to translate filter types to/from names. (Jim Posen)
62b7a4f094 index: Ensure block locator is not stale after chain reorg. (Jim Posen)
4368384f1d index: Allow atomic commits of index state to be extended. (Jim Posen)
Pull request description:
This introduces a new BlockFilterIndex class, which is required for BIP 157 support.
The index is uses the asynchronous BaseIndex infrastructure driven by the ValidationInterface callbacks. Filters are stored sequentially in flat files and the disk location of each filter is indexed in LevelDB along with the filter hash and header. The index is designed to ensure persistence of filters reorganized out of the main chain to simplify the BIP 157 net implementation.
Stats (block height = 565500):
- Syncing the index from scratch takes 45m
- Total index size is 3.8 GiB
ACKs for commit c7efb6:
MarcoFalke:
utACK c7efb652f3
ryanofsky:
Slightly tested ACK c7efb652f3 (I just rebuilt the index with the updated PR and tested the RPC). Changes since last review: rebase, fixed compile errors in internal commits, new comments, updated error messages, tweaked cache size logic, renamed commit method, renamed constants and globals, fixed whitespace, extra BlockFilterIndex::Init error check.
Tree-SHA512: f8ed7a9b6f76df45933aa5eba92b27b3af83f6df2ccb3728a5c89eec80f654344dc14f055f6f63eb9b3a7649dd8af6553fe14969889e7e2fd2f8461574d18f28
4d074e84a2 [build] Move AnalyzePSBT from psbt.cpp to node/psbt.cpp (Russell Yanofsky)
fd509bd1f7 [docs] Document src subdirectories and different libraries (John Newbery)
9eaeb7fb8d [build] Move wallet load functions to wallet/load unit (John Newbery)
91a25d1e71 [build] Add several util units (John Newbery)
99517866b6 [build] Move several units into common libraries (John Newbery)
0509465542 [build] Move rpc rawtransaction util functions to rpc/rawtransaction_util.cpp (John Newbery)
1acc61f874 [build] Move rpc utility methods to rpc/util (John Newbery)
4a75c9d651 [build] Move policy settings to new src/policy/settings unit (John Newbery)
fdf8888b6f [build] Move CheckTransaction from lib_server to lib_consensus (John Newbery)
Pull request description:
This is a move-only commit. No code is changing and the moves can be easily verified with:
```sh
git log -p -n1 --color-moved=dimmed_zebra
```
This commit moves functions and variables that wallet code depends on out of libbitcoin_server.a, so the bitcoin-wallet tool can be built without libbitcoin_server.a in #15639, and attempting to access server state from wallet code will result in link errors instead of silently broken code.
List of moves:
- `CheckTransaction` moves from `consensus/tx_verify.cpp` to `consensus/tx_check.cpp`
- `urlDecode` moves from `httpserver.cpp` to `util/url.cpp`
- `TransactionErrorString` moves from `node/transaction.cpp` to `util/error.cpp`
- `StringForFeeReason` and `FeeModeFromString` move from `policy/fees.cpp` to `util/fees.cpp`
- `incrementalRelayFee` `dustRelayFee` and `nBytesPerSigOp` move from `policy/policy.cpp` to `policy/settings.cpp`
- `SignalsOptInRBF` moves from `policy/rbf.cpp` to `util/rbf.cpp`
- `fIsBareMultisigStd` moves from `validation.cpp` to `policy/settings.cpp`
- `ConstructTransaction` `TxInErrorToJSON` and `SignTransaction` move from `rpc/rawtransaction.cpp` to `rpc/rawtransaction_util.cpp`
- `RPCTypeCheck` `RPCTypeCheckArgument` `RPCTypeCheckObj` `AmountFromValue` `ParseHashV``ParseHashO` `ParseHexV` `ParseHexO` `HelpExampleCli` and `HelpExampleRpc` move from `rpc/server.cpp` to `rpc/util.cpp`
- `AmountHighWarn` and `AmountErrMsg` move from `ui_interface.cpp` to `util/error.cpp`
- `FormatStateMessage` and `strMessageMagic` move from `validation.cpp` to `util/validation.cpp`
- `VerifyWallets` `LoadWallets` `StartWallets` `FlushWallets` `StopWallets` and `UnloadWallets` move from `wallet/init.cpp` to `wallet/node.cpp`
ACKs for commit 4d074e:
jnewbery:
utACK 4d074e84a2 (checked by doing the rebase myself and verifying no difference between my branch and 4d074e84a2)
Tree-SHA512: 5e1604a9fb06475f2b96da0de0baa8330f4dda834dc20a0183ef11e1e4c27631d1d1bbb9abf0054efc03d56945fdf9920f63366b6a4f200f665b742a479ff75c
fae38c3dc6 doc: Fix all typos reported by codespell (MarcoFalke)
fa9058f0ed doc: Add release notes for 15629 (MarcoFalke)
fa4a922d78 qa: Add test for missing testnet section in conf file (MarcoFalke)
dddd6f0f58 init: Throw error when network specific config is ignored (MarcoFalke)
Pull request description:
This should have no effect on mainnet users, but simplifies testing, where config settings are currently ignored with only a warning. Fix this by making it an error.
Issues:
* bitcoin client 0.17.0 ignores wallet's name (file) #14523
* Can't set custom rpcport on testnet #13777
* ...
ACKs for commit fae38c:
Tree-SHA512: 2e209526898eea6e444c803ec2666989cee4ca137492d32984998733c50a70056cb54657df8dc3027a6a0612738a8afce0bc35824b868c5f22281e00e0188530
Adds the following util units and adds them to libbitcoin_util:
- `util/url.cpp` takes `urlDecode` from `httpserver.cpp`
- `util/error.cpp` takes `TransactionErrorString` from
`node/transaction.cpp` and `AmountHighWarn` and `AmountErrMsg` from
`ui_interface.cpp`
- `util/fees.cpp` takes `StringForFeeReason` and `FeeModeFromString` from `policy/fees.cpp`
- `util/rbf.cpp` takes `SignalsOptInRBF` from `policy/rbf.cpp`
- 'util/validation.cpp` takes `FormatStateMessage` and `strMessageMagic` from 'validation.cpp`
This moves the following policy settings functions and globals to a new
src/policy/settings unit in lib_server:
- `incrementalRelayFee`
- `dustRelayFee`
- `nBytesPerSigOp`
- `fIsBareMultisigStd`
These settings are only required by the node and should not be accessed
by other libraries.
519b0bc5dc Make last disconnected block BLOCK_FAILED_VALID, even when aborted (Pieter Wuille)
8d220417cd Optimization: don't add txn back to mempool after 10 invalidates (Pieter Wuille)
9ce9c37004 Prevent callback overruns in InvalidateBlock and RewindBlockIndex (Pieter Wuille)
9bb32eb571 Release cs_main during InvalidateBlock iterations (Pieter Wuille)
9b1ff5c742 Call InvalidateBlock without cs_main held (Pieter Wuille)
241b2c74ac Make RewindBlockIndex interruptible (Pieter Wuille)
880ce7d46b Call RewindBlockIndex without cs_main held (Pieter Wuille)
436f7d735f Release cs_main during RewindBlockIndex operation (Pieter Wuille)
1d342875c2 Merge the disconnection and erasing loops in RewindBlockIndex (Pieter Wuille)
32b2696ab4 Move erasure of non-active blocks to a separate loop in RewindBlockIndex (Pieter Wuille)
9d6dcc52c6 Abstract EraseBlockData out of RewindBlockIndex (Pieter Wuille)
Pull request description:
This PR makes a number of improvements to the InvalidateBlock (`invalidateblock` RPC) and RewindBlockIndex functions, primarily around breaking up their long-term cs_main holding. In addition:
* They're made safely interruptible (`bitcoind` can be shutdown, and no progress in either will be lost, though if incomplete, `invalidateblock` won't continue after restart and will need to be called again)
* The validation queue is prevented from overflowing (meaning `invalidateblock` on a very old block will not drive bitcoind OOM) (see #14289).
* `invalidateblock` won't bother to move transactions back into the mempool after 10 blocks (optimization).
This is not an optimal solution, as we're relying on the scheduler call sites to make sure the scheduler doesn't overflow. Ideally, the scheduler would guarantee this directly, but that needs a few further changes (moving the signal emissions out of cs_main) to prevent deadlocks.
I have manually tested the `invalidateblock` changes (including interrupting, and running with -checkblockindex and -checkmempool), but haven't tried the rewinding (which is probably becoming increasingly unnecessary, as very few pre-0.13.1 nodes remain that would care to upgrade).
Tree-SHA512: 692e42758bd3d3efc2eb701984a8cb5db25fbeee32e7575df0183a00d0c2c30fdf72ce64c7625c32ad8c8bdc56313da72a7471658faeb0d39eefe39c4b8b8474
04cca33094 Style cleanup. (Jim Posen)
4c01e4e159 flatfile: Unit tests for FlatFileSeq methods. (Jim Posen)
65a489e93d scripted-diff: Rename CBlockDiskPos to FlatFilePos. (Jim Posen)
d6d8a78f26 Move CDiskBlockPos from chain to flatfile. (Jim Posen)
e0380933e3 validation: Refactor file flush logic into FlatFileSeq. (Jim Posen)
992404b31e validation: Refactor block file pre-allocation into FlatFileSeq. (Jim Posen)
e2d2abb99f validation: Refactor OpenDiskFile into method on FlatFileSeq. (Jim Posen)
9183d6ef65 validation: Extract basic block file logic into FlatFileSeq class. (Jim Posen)
62e7addb63 util: Move CheckDiskSpace to util. (Jim Posen)
Pull request description:
This cleans up and refactors block file helpers so that they may be used by the block filter indexer. Per [design discussion](https://github.com/bitcoin/bitcoin/pull/14121#issuecomment-451252591) about storing BIP 157 block filters, it has been suggested that they are stored in the same way as block and undo data. This refactor is sufficient to simplify file operations for this use case, though in the future perhaps more pruning-related logic ought to be moved into the new classes.
The basic abstraction is a `FlatFileSeq` which manages access to a sequence of numbered files into which raw data is written.
Tree-SHA512: b2108756777f2dad8964a1a2ef2764486e708a4a4a8cfac47b5de8bcb0625388964438eb096b10cfd9ea39212c299b5cb32fa943e768db2333cf49ea7def157e
1a7ba84e11 Fix lack of warning of unrecognized section names (Akio Nakamura)
Pull request description:
In #14708, It was introduced that to warn when unrecognized section names are exist in the config file.
But ```m_config_sections.clear()``` in ```ArgsManager::ReadConfigStream()``` is called every time when reading each configuration file, so it can warn about only last reading file if ```includeconf``` exists.
This PR fix lack of warning by collecting all section names by moving ```m_config_sections.clear()``` to ```ArgsManager::ReadConfigFiles()``` .
Also add a test code to confirm this situation.
Tree-SHA512: 26aa0cbe3e4ae2e58cbe73d4492ee5cf465fd4c3e5df2c8ca7e282b627df9e637267af1e3816386b1dc6db2398b31936925ce0e432219fec3a9b3398f01e3e65
3f5ad622e5 Enable PID file creation on Windows - Add available WIN PID function - Consider WIN32 in each relevant case - Add new preprocessor definitions to suppress warning - Update error message for generic OS (riordant)
Pull request description:
# Introduction
As discussed with @laanwj on IRC:
- PID file creation was never enabled for Windows, as the `pid_t` filetype is not available for it. However, the WIN32 API contains the header [`Processthreadsapi.h`](https://github.com/CodeShark/x86_64-w64-mingw32/blob/master/include/processthreadsapi.h) which in turn contains the function [`GetCurrentProcessId()`](https://docs.microsoft.com/en-gb/windows/desktop/api/processthreadsapi/nf-processthreadsapi-getcurrentprocessid). ~~This function is called at a higher level by [`_getpid()`](https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/getpid?view=vs-2017)~~ EDIT: `_getpid()` is not available to the MSVC compiler used in the AppVeyor build. As a result, I have changed the function call to`GetCurrentProcessId()`, which performs the same function and is available to both MinGW & MSVC.
This allows one to capture the PID in Windows, without any additional includes - the above function is already available.
- Within this PR, I have added a separate line that calls `GetCurrentProcessId()` in the case of a WIN compilation, and the usual `getpid()` otherwise. All code blocks processing PID file logic that avoid WIN32 have been changed to consider it. I have also updated the preprocessor definitions in `libbitcoin_server.vcxproj.in` to suppress a warning related to `std::strerror` for the MSVC build, that was causing the AppVeyor build to fail (see @fanquake comment below).
# Rationale
- Consistency between OS's running Bitcoin
- Applications which build off of `bitcoind`, such as novel front-end clients, often need access to the PID in order to control the daemon. Instead of designing some alternate way of doing this for one system, it should be consistent between all of them.
In collaboration with @joernroeder
Tree-SHA512: 22fcbf866e99115d12ed29716e68d200d4c118ae2f7b188b7705dc0cf5f0cd0ce5fb18f772744c6238eecd9e6d0922c615e2f0e12a7fe7c810062a79d97aa6a2
- Add available WIN PID function
- Consider WIN32 in each relevant case
- Add new preprocessor definitions to suppress warning
- Update error message for generic OS
Co-authored-by: Jörn Röder <kontakt@joernroeder.de>
7cb1a1401d Explain that unused mempool memory is added to -dbcache (Sjors Provoost)
Pull request description:
Since `-maxmempool` is 450 MB by default it's quite possible for a user to accidentally OOM a low
memory device if they increase `-dbcache` beyond the default.
<img width="563" alt="schermafbeelding 2018-09-06 om 17 02 40" src="https://user-images.githubusercontent.com/10217/45166219-c9c4f700-b1f6-11e8-9ee5-14b8b3a9830b.png">
Tree-SHA512: 44c7419d0b06c14aee5d2c02a41e5da488bcb40a5f65ba24554a45707b222f1e4b03d42486dfef9336d917ac2990eef2b1aec287a75b3ef1ccca0e88ac86a0c0
3782075a5f Move all PID file stuff to init.cpp (Hennadii Stepanov)
561e375c73 Make PID file creating errors fatal (Hennadii Stepanov)
745a2ace18 Improve PID file removing errors logging (Hennadii Stepanov)
Pull request description:
Digging into #15240 the lack of the proper logging has been discovered.
Fixed by this PR.
UPDATE (inspired by @laanwj's [comment](https://github.com/bitcoin/bitcoin/pull/15278#discussion_r252641810)):
Not being able to create the PID file is fatal now.
Output of `bitcoind`:
```
$ src/bitcoind -pid=/run/bitcoind/bitcoind.pid
2019-02-01T23:20:10Z Bitcoin Core version v0.17.99.0-561e375c7 (release build)
2019-02-01T23:20:10Z Assuming ancestors of block 0000000000000037a8cd3e06cd5edbfe9dd1dbcc5dacab279376ef7cfc2b4c75 have valid signatures.
2019-02-01T23:20:10Z Setting nMinimumChainWork=00000000000000000000000000000000000000000000007dbe94253893cbd463
2019-02-01T23:20:10Z Using the 'sse4(1way),sse41(4way),avx2(8way)' SHA256 implementation
2019-02-01T23:20:10Z Using RdRand as an additional entropy source
2019-02-01T23:20:11Z Error: Unable to create the PID file '/run/bitcoind/bitcoind.pid': No such file or directory
Error: Unable to create the PID file '/run/bitcoind/bitcoind.pid': No such file or directory
2019-02-01T23:20:11Z Shutdown: In progress...
2019-02-01T23:20:11Z Shutdown: Unable to remove PID file: File does not exist
2019-02-01T23:20:11Z Shutdown: done
```
Output of `bitcoin-qt`:
![screenshot from 2019-02-02 01-19-05](https://user-images.githubusercontent.com/32963518/52154886-9349b600-2688-11e9-8128-470f16790305.png)
**Notes for reviewers**
1. `CreatePidFile()` has been moved from `util/system.cpp` to `init.cpp` for the following reasons:
- to get the ability to use `InitError()`
- now `init.cpp` contains code of both creating PID file and removing it
2. Regarding 0.18 release process: this PR modifies 1 string and introduces 2 new ones.
Tree-SHA512: ac07d0f800e61ec759e427d0afc0ca43d67f232e977662253963afdd0a220d34b871050f58149fc9fabd427bfc8e0d3f6a6032f2a38f30ad366fc0d074b0f2b3
1. Fix lack of warning by collecting all section names by moving
m_config_sections.clear() to ArgsManager::ReadConfigFiles().
2. Add info(file name, line number) to warning message.
3. Add a test code to confirm this situation.
3. Do clear() in ReadConfigString().
a99999cc04 util: Add SetupHelpOptions() (MarcoFalke)
Pull request description:
Every binary we have sets up the help option in their own way and wording.
Solve that by having one function take care of it for all of them.
Tree-SHA512: 6e947fa8bc2a46fa6ca9f45777020aa269a5df0dd916ebc863224f9a1e0f79e8e7754a1478567307edd9461e8babd77d26bc2710bbd56e8f8da9020aa85a8c9c
0164b0f5cf build: Remove WINVER pre define in Makefile.leveldb.inlcude (Chun Kuan Lee)
d0522ec94e Drop defunct Windows compat fixes (Ben Woosley)
d8a2992067 windows: Call SetProcessDEPPolicy directly (Chun Kuan Lee)
1bd9ffdd44 windows: Set _WIN32_WINNT to 0x0601 (Windows 7) (Chun Kuan Lee)
Pull request description:
The current minimum support Windows version is Vista. So set it to 0x0600
5a88def8ad/mingw-w64-headers/include/sdkddkver.h (L19)
Tree-SHA512: 38e2afc79426ae547131c8ad3db2e0a7f54a95512f341cfa0c06e4b2fe79521ae67d2795ef96b0192e683e4f1ba6183c010d7b4b8d6b3e68b9bf48c374c59e7d
77777c5624 log: Construct global logger on first use (MarcoFalke)
Pull request description:
The (de)initialization order is not well defined in C++, so generally it is not safe to use globals as the (de/con)structor of one global could use the (de/con)structor of another global before/after it has been (con/de)structed.
Specifically this fixes:
* `g_logger` might not be initialized on the first use, so do that. (Fixes#15111)
Tree-SHA512: eb9c22f4baf31ebc5b0b9ee6a51d1354bae1f0df186cc0ce818b4483c7b5a7f90268d2b549ee96b4c57f8ef36ab239dc6497f74f3e2ef166038f7437c368297d
6f6514a080 Correct units for "-dbcache" and "-prune" (Hennadii Stepanov)
Pull request description:
Actually, all `dbcache`-related values in the code are measured in MiB (not in megabytes, MB) or in bytes (e.g., `nTotalCache`).
See: https://github.com/bitcoin/bitcoin/blob/master/src/txdb.hba8c8b2227/src/init.cpp (L1405-L1424)
Also, "-prune" is fixed:
1. The GUI values in GB are translated to the node values in MiB correctly.
2. The maximum of the "prune" `QSpinBox` is not limited by default value of 99 (GB).
Fix: #15106
Tree-SHA512: 151ec43b31b1074db8b345fedb1dcc10bde225899a5296bfc183f57e1553d13ac27db8db100226646769ad03c9fcab29d88763065a471757c6c41ac51108459d
All dbcache-related values in the code are measured in MiB (not in
megabytes, MB) or in bytes.
The GUI "-prune" values in GB are translated to the node values in MiB
correctly. The maximum of the "-prune" QSpinBox is not limited by the
default value of 99 (GB).
Also, this improves log readability.
e4a0c3547e Improve blocksdir functional test. (Hennadii Stepanov)
c3f1821ac7 Make blockdir always net specific (Hennadii Stepanov)
Pull request description:
The blocks directory is net specific by definition.
Also this prevents the side effect of calling `GetBlocksDir(false)` in the non-mainnet environment.
Currently a new node creates an unused `blocks\` directory in the root of the data directory when `-testnet` or `-regtest` is specified.
Refs:
- #12653
- https://github.com/bitcoin/bitcoin/pull/12653#discussion_r174784834 by @laanwj
- https://github.com/bitcoin/bitcoin/issues/14595#issuecomment-436011186
Tree-SHA512: c9957a68a4a200ebd2010823a56db7e61563afedcb7c9828e86b13f3af2990e07854b622c1f3374756f94574acb3ea32de7d2a399eef6c0623f0e11265155627
645e905c32 doc: Add release notes for unloadwallet change to synchronous call (João Barbosa)
c37851de57 rpc: Make unloadwallet wait for complete wallet unload (João Barbosa)
Pull request description:
Currently the `unloadwallet` RPC is asynchronous, it only signals the intent to unload the wallet and then returns the response to the client. The actual unload can happen later and the client has no way to be notified of that.
This PR makes the `unloadwallet` RPC synchronous, meaning that it blocks until the wallet is fully unloaded.
Replaces #14919, fixes#14917.
Tree-SHA512: ad88b980e2f3652809a58f904afbfe020299f3aa6a517f495ba943b8d54d4520f6e70074d6749be8f5967065c0f476e0faedcde64c8b4899e5f99c70f0fd6534
4927bf2f25 Increase maxconnections limit when using poll. (Patrick Strateman)
11cc491a28 Implement poll() on systems which support it properly. (Patrick Strateman)
28211a4bc9 Move SocketEvents logic to private method. (Patrick Strateman)
7e403c0ae7 Move GenerateSelectSet logic to private method. (Patrick Strateman)
1e6afd0dbc Introduce and use constant SELECT_TIMEOUT_MILLISECONDS. (Patrick Strateman)
Pull request description:
Implement poll() on systems which support it properly.
This eliminates the restriction on maximum socket descriptor number.
Tree-SHA512: b945cd9294afdafcce96d547f67679d5cdd684cf257904a239cd1248de3b5e093b8d6d28d8d1b7cc923dc0b2b5723faef9bc9bf118a9ce1bdcf357c2323f5573
cb53b825c2 scripted-diff: Replace boost::bind with std::bind (Chun Kuan Lee)
2196c51821 refactor: Use boost::scoped_connection in signal/slot, also prefer range-based loop instead of std::transform (Chun Kuan Lee)
Pull request description:
Replace boost::bind with std::bind
- In `src/rpc/server.cpp`, replace `std::transform` with simple loop.
- In `src/validation.cpp`, store the `boost::signals2::connection` object and use it to disconnect.
- In `src/validationinterface.cpp`, use 2 map to store the `boost::signals2::scoped_connection` object.
Tree-SHA512: 6653cbe00036fecfc495340618efcba6d7be0227c752b37b81a27184433330f817e8de9257774e9b35828026cb55f11ee7f17d6c388aebe22c4a3df13b5092f0
dcb70b1522 Indicate -rpcauth option password hashing alg (Carl Dong)
Pull request description:
By indicating the password hashing algorithm, users of bitcoin distributions without the script in `share/rpcauth` and users who don't want to rely on said script can use alternative means to generate the password hash.
Question for reviewers: perhaps we should also indicate that it is specifically a HMAC-SHA-256 of the _**UTF-8**_ encoding of their password?
Tree-SHA512: 86b546c2e78699fa253da0c1e76b21ef60e9b6a5778826ac5136e764d70e3213044cc05cdb4786ba27968781647c46e358a823bbc2db7d45d041d291ee03b83c
48b37db50 make peertimeout a debug argument, remove error message translation (Zain Iqbal Allarakhia)
8042bbfbf p2p: allow p2ptimeout to be configurable, speed up slow test (Zain Iqbal Allarakhia)
Pull request description:
**Summary:**
1. _Primary_: Adds a `debug_only=true` flag for peertimeout, defaults to 60 sec., the current hard-coded setting.
2. _Secondary_: Drastically speeds up `p2p_timeout.py` test.
3. _Secondary_: Tests that the correct code path is being tested by adding log assertions to the test.
**Rationale:**
- P2P timeout was hard-coded: make it explicitly specified and configurable, instead of a magic number.
- Addresses #13518; `p2p_timeout.py` takes 4 sec. to run instead of 61 sec.
- Makes `p2p_timeout.py` more explicit. Previously, we relied on a comment to inform us of the timeout amount being tested. Now it is specified directly in the test via passing in the new arg; `-peertimeout=3`.
- Opens us up to testing more P2P scenarios; oftentimes slow tests are the reason we don't test.
**Locally verified changes:**
_With Proposed Change (4.7 sec.):_
```
$ time ./test/functional/p2p_timeouts.py
2018-11-19T00:04:19.077000Z TestFramework (INFO): Initializing test directory /tmp/testhja7g2n7
2018-11-19T00:04:23.479000Z TestFramework (INFO): Stopping nodes
2018-11-19T00:04:23.683000Z TestFramework (INFO): Cleaning up /tmp/testhja7g2n7 on exit
2018-11-19T00:04:23.683000Z TestFramework (INFO): Tests successful
real 0m4.743s
```
_Currently on master (62.8 sec.):_
```
$ time ./test/functional/p2p_timeouts.py
2018-11-19T00:06:10.948000Z TestFramework (INFO): Initializing test directory /tmp/test6mo6k21h
2018-11-19T00:07:13.376000Z TestFramework (INFO): Stopping nodes
2018-11-19T00:07:13.631000Z TestFramework (INFO): Cleaning up /tmp/test6mo6k21h on exit
2018-11-19T00:07:13.631000Z TestFramework (INFO): Tests successful
real 1m2.836s
```
_Error message demonstrated for new argument `-peertimeout`:_
```
$ ./bitcoind -peertimeout=-5
...
Error: peertimeout cannot be configured with a negative value.
```
Tree-SHA512: ff7a244ebea54c4059407bf4fb86465714e6a79cef5d2bcaa22cfe831a81761aaf597ba4d5172fc2ec12266f54712216fc41b5d24849e5d9dab39ba6f09e3a2a