The blockchain that provides the digital content namespace for the LBRY protocol

bitcoin blockchain c-plus-plus cryptocurrency decentralized lbry

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Wladimir J. van der Laan a88bd3186d Merge #14670 : http: Fix HTTP server shutdown `28479f926f` qa: Test bitcond shutdown (João Barbosa) `8d3f46ec39` http: Remove timeout to exit event loop (João Barbosa) `e98a9eede2` http: Remove unnecessary event_base_loopexit call (João Barbosa) `6b13580f4e` http: Unlisten sockets after all workers quit (João Barbosa) `18e9685816` http: Send "Connection: close" header if shutdown is requested (João Barbosa) `02e1e4eff6` rpc: Add wait argument to stop (João Barbosa) Pull request description: Fixes #11777. Reverts #11006. Replaces #13501. With this change the HTTP server will exit gracefully, meaning that all requests will finish processing and sending the response, even if this means to wait more than 2 seconds (current time allowed to exit the event loop). Another small change is that connections are accepted even when the server is stopping, but HTTP requests are rejected. This can be improved later, especially if chunked replies are implemented. Briefly, before this PR, this is the order or events when a request arrives (RPC `stop`): 1. `bufferevent_disable(..., EV_READ)` 2. `StartShutdown()` 3. `evhttp_del_accept_socket(...)` 4. `ThreadHTTP` terminates (event loop exits) because there are no active or pending events thanks to 1. and 3. 5. client doesn't get the response thanks to 4. This can be verified by applying ```diff // Event loop will exit after current HTTP requests have been handled, so // this reply will get back to the client. StartShutdown(); + MilliSleep(2000); return "Bitcoin server stopping"; } ``` and checking the log output: ``` Received a POST request for / from 127.0.0.1:62443 ThreadRPCServer method=stop user=__cookie__ Interrupting HTTP server ** Exited http event loop Interrupting HTTP RPC server Interrupting RPC tor: Thread interrupt Shutdown: In progress... torcontrol thread exit Stopping HTTP RPC server addcon thread exit opencon thread exit Unregistering HTTP handler for / (exactmatch 1) Unregistering HTTP handler for /wallet/ (exactmatch 0) Stopping RPC RPC stopped. Stopping HTTP server Waiting for HTTP worker threads to exit msghand thread exit net thread exit ... sleep 2 seconds ... Waiting for HTTP event thread to exit Stopped HTTP server ``` For this reason point 3. is moved right after all HTTP workers quit. In that moment HTTP replies are queued in the event loop which keeps spinning util all connections are closed. In order to trigger the server side close with keep alive connections (implicit in HTTP/1.1) the header `Connection: close` is sent if shutdown was requested. This can be tested by ``` bitcoind -regtest nc localhost 18443 POST / HTTP/1.1 Authorization: Basic ... Content-Type: application/json Content-Length: 44 {"jsonrpc": "2.0","method":"stop","id":123} ``` Summing up, this PR: - removes explicit event loop exit — event loop exits once there are no active or pending events - changes the moment the listening sockets are removed — explained above - sends header `Connection: close` on active requests when shutdown was requested which is relevant when it's a persistent connection (default in HTTP 1.1) — libevent is aware of this header and closes the connection gracefully - removes event loop explicit break after 2 seconds timeout Tree-SHA512: 4dac1e86abe388697c1e2dedbf31fb36a394cfafe5e64eadbf6ed01d829542785a8c3b91d1ab680d3f03f912d14fc87176428041141441d25dcb6c98a1e069d8		2018-12-06 17:43:07 +01:00
.github	doc: Add GitHub pr template	2018-09-23 08:31:11 -04:00
.travis	Add ASan Travis build	2018-11-26 22:20:46 +01:00
.tx	tx: Update transifex slug 016x→017x	2018-08-02 13:42:15 +02:00
build-aux/m4	Bump the minimum Qt version to 5.2	2018-11-14 01:32:51 +02:00
build_msvc	Add skeleton chain and client classes	2018-11-06 11:44:40 -04:00
contrib	Merge #14869 : scripts: Add trusted key for Samuel Dobson	2018-12-06 15:56:52 +01:00
depends	build: Remove illegal spacing in darwin.mk	2018-11-03 05:03:50 -05:00
doc	Merge #14882 : [doc] developer-notes.md: point out that UniValue deviates from upstream	2018-12-06 11:33:39 -05:00
share	rpcauth: Improve by using argparse and getpass modules	2018-11-21 22:30:07 +00:00
src	Merge #14670 : http: Fix HTTP server shutdown	2018-12-06 17:43:07 +01:00
test	Merge #14670 : http: Fix HTTP server shutdown	2018-12-06 17:43:07 +01:00
.appveyor.yml	appveyor: Script improvement part II	2018-11-06 10:58:10 +08:00
.gitattributes	Separate protocol versioning from clientversion	2014-10-29 00:24:40 -04:00
.gitignore	gitignore contents of db4 folder	2018-10-19 12:15:47 +08:00
.travis.yml	Merge #14231 : travis: Save cache even when build or test fail	2018-12-03 11:07:19 -05:00
autogen.sh	Add "export LC_ALL=C" to all shell scripts	2018-06-14 15:27:52 +02:00
configure.ac	build: include rc number in version number	2018-10-30 15:02:26 -04:00
CONTRIBUTING.md	added details about commit messages	2018-10-30 07:59:10 +01:00
COPYING	[Trivial] Update license year range to 2018	2018-01-01 04:33:09 +09:00
INSTALL.md	Update INSTALL landing redirection notice for build instructions.	2016-10-06 12:27:23 +13:00
libbitcoinconsensus.pc.in	Unify package name to as few places as possible without major changes	2015-12-14 02:11:10 +00:00
Makefile.am	build: Add bitcoin-tx.exe into Windows installer	2018-11-09 21:57:13 +08:00
README.md	[doc] conf: Remove deprecated options from docs, Other cleanup	2018-11-07 13:30:03 -05:00

README.md

Bitcoin Core integration/staging tree

https://bitcoincore.org

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, as well as an immediately useable, binary version of the Bitcoin Core software, see https://bitcoincore.org/en/download/, or read the original 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 and tested, but is not guaranteed to be completely stable. Tags are created regularly to indicate new official, stable release versions of Bitcoin Core.

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, that are run automatically on the build server. These tests can be run (if the test dependencies are installed) with: test/functional/test_runner.py

The Travis CI system makes 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.

Translators should also subscribe to the mailing list.