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2024-03-31treewide: future-proof frozen_string_literal changes
Once again Ruby seems ready to introduce more incompatibilities and force busywork upon maintainers[1]. In order to avoid incompatibilities in the future, I used a Perl script[2] to prepend `frozen_string_literal: false' to every Ruby file. Somebody interested will have to go through every Ruby source file and enable frozen_string_literal once they've thoroughly verified it's safe to do so. [1] https://bugs.ruby-lang.org/issues/20205 [2] https://yhbt.net/add-fsl.git/74d7689/s/?b=add-fsl.perl
2024-01-15kill off remaining kgio uses
kgio is an extra download and shared object which costs users bandwidth, disk space, startup time and memory. Ruby 2.3+ provides `Socket#accept_nonblock(exception: false)' support in addition to `exception: false' support in IO#*_nonblock methods from Ruby 2.1. We no longer distinguish between TCPServer and UNIXServer as separate classes internally; instead favoring the `Socket' class of Ruby for both. This allows us to use `Socket#accept_nonblock' and get a populated `Addrinfo' object off accept4(2)/accept(2) without resorting to a getpeername(2) syscall (kgio avoided getpeername(2) in the same way). The downside is there's more Ruby-level argument passing and stack usage on our end with HttpRequest#read_headers (formerly HttpRequest#read). I chose this tradeoff since advancements in Ruby itself can theoretically mitigate the cost of argument passing, while syscalls are a high fixed cost given modern CPU vulnerability mitigations. Note: no benchmarks have been run since I don't have a suitable system.
2023-06-05chunk unterminated HTTP/1.1 responses
Rack::Chunked will be gone in Rack 3.1, so provide a non-middleware fallback which takes advantage of IO#write supporting multiple arguments in Ruby 2.5+. We still need to support Ruby 2.4, at least, since Rack 3.0 does. So a new (GC-unfriendly) Unicorn::WriteSplat module now exists for Ruby <= 2.4 users.
2018-08-20socket_helper: add hint for FreeBSD users for accf_http(9)
Because I forget to load accf_http on new FreeBSD installs, too :x
2018-05-01quiet some mismatched indentation warnings
Ruby trunk started warning about more mismatched indentations starting around r62836.
2017-04-08reduce method calls with String#start_with?
These three cold call sites instruction sequence size by a few hundred bytes combined since we no longer support Ruby 1.8.6. The "?/" shorthand is esoteric and no longer avoids allocation in Ruby 1.9+ (not that this is hot code).
2017-03-15Merge remote-tracking branch 'origin/ccc-tcp-v3'
* origin/ccc-tcp-v3: http_request: reduce insn size for check_client_connection support "struct tcp_info" on non-Linux and Ruby 2.2+ revert signature change to HttpServer#process_client new test for check_client_connection check_client_connection: use tcp state on linux
2017-03-14freebsd: avoid EINVAL when setting accept filter
Accept filters can only be set on listen sockets, and it also fails with EINVAL if it's already set. Untested, but I suppose changing the accept filter on a listening socket is not supported, either; since that could affect in-flight sockets.
2017-03-08revert signature change to HttpServer#process_client
We can force kgio_tryaccept to return an internal class for TCP objects by subclassing Kgio::TCPServer. This avoids breakage in any unfortunate projects which depend on our undocumented internal APIs, such as gctools <https://github.com/tmm1/gctools>
2015-07-15doc: remove references to old servers
They'll continue to be maintained, but we're no longer advertising them. Also, favor lowercase "unicorn" while we're at it since that matches the executable and gem name to avoid unnecessary escaping for RDoc.
2015-04-07favor more string literals for cold call sites
Literal regexps cost over 450 bytes of memory per-site and unnecessary use of them costs memory in places where raw execution speed does not matter. Nowadays, we can rely on String#end_with? (introduced in 1.8.7) for improved readability, too.
2015-03-02socket_helper: update comments
We had HTTPS support but dropped it(*) and some wacky servers out there do work better with TCP_DEFER_ACCEPT disabled. (*) No, we will not support HTTP/2, that is for nginx
2015-02-05remove 1.8, <= 1.9.1 fallback for missing IO#autoclose=
We're requiring Ruby 1.9.3+, so we can safely depend on IO#autoclose= being available in 1.9+ and shave off some bloat.
2015-02-05socket_helper: reduce constant lookups and caching
In Ruby 1.9.2+, socket options may be specified using symbols instead of constants to avoid the need to import Socket::Constants into the namespace. This also has a nice side-effect of reducing the size of the bytecode by trading 3 instructions (getinlinecache, getconstant, setinlinecache) for one "putobject" instruction. Nowadays, we may also avoid defining OS-specific constants ourselves since 1.9+ versions of Ruby already provide them to further reduce bytecode size. getsockopt also returns Socket::Option objects in 1.9.2+, allowing us to avoid the larger "unpack('i')" method dispatch for an operand-free "int" method call. Finally, favor Object#nil? calls rather than "== nil" comparisons to reduce bytecode size even more. Since this code is only called at startup time, it does not benefit from inline caching of constant lookups in current mainline Ruby. Combined, these changes reduce YARV bytecode size by around 2K on a 64-bit system.
2013-10-25avoid IO_PURGATORY on Ruby 1.9+
Ruby 1.9 and later includes IO#autoclose=, so we can use it and prevent some dead IO objects from hanging around.
2013-10-25support SO_REUSEPORT on new listeners (:reuseport)
This allows users to start an independent instance of unicorn on a the same port as a running unicorn (as long as both instances use :reuseport). ref: https://lwn.net/Articles/542629/
2012-08-06do not touch TCP_NOPUSH/TCP_CORK at all by default
On a certain FreeBSD 8.1 installation, explicitly setting TCP_NOPUSH to zero (off) can cause EADDRNOTAVAIL errors and also resets the listen backlog to 5. Enabling TCP_NOPUSH explicitly did not exhibit this issue for the user who (privately) reported this issue. To be on the safe side, we won't set/unset TCP_NOPUSH/TCP_CORK at all, which will leave it off on all current systems.
2011-12-05socket_helper: fix grammerr fail
Oops :x
2011-12-05socket_helper: set SO_KEEPALIVE on TCP sockets
Even LANs can break or be unreliable sometimes and socket disconnect messages get lost, which means we fall back to the global (kill -9) timeout in Unicorn. While the default global timeout is much shorter (60s) than typical TCP timeouts, some HTTP application dispatches take much I/O or computational time (streaming many gigabytes), so the global timeout becomes ineffective. Under Linux, sysadmins are encouraged to lower the default net.ipv4.tcp_keepalive_* knobs in sysctl. There should be similar knobs in other operating systems (the default keepalive intervals are usually ridiculously high, too high for anything). When the listen socket has SO_KEEPALIVE set, the flag should be inherited by accept()-ed sockets.
2011-12-05socket_helper: remove out-of-date comment for TCP_NODELAY
We favor low latency and consistency with the Unix socket behavior even with TCP.
2011-07-01socket_helper: fix undefined variable for logging
I corrupted a Ruby build and SOL_TCP didn't get defined :x
2011-06-17error logging is more consistent
Backtraces are now formatted properly (with timestamps) and exceptions will be logged more consistently and similar to Logger defaults: "#{exc.message} (#{e.class})" backtrace.each { |line| ... } This may break some existing monitoring scripts, but errors will be more standardized and easier to check moving forward.
2011-06-13change TCP defaults to favor low latency
These TCP settings are a closer match to the behavior of Unix domain sockets and what users expect for fast streaming responses even if nginx can't provide them just now...
2011-06-07configurator: add :ipv6only directive
Enabling this flag for an IPv6 TCP listener allows users to specify IPv6-only listeners regardless of the OS default. This should be interest to Rainbows! users.
2011-04-18documentation cleanup/reduction
Don't clutter up our RDoc/website with things that users of Unicorn don't need to see. This should make user-relevant documentation easier to find, especially since Unicorn is NOT intended to be an API.
2011-02-02socket_helper: cleanup leftover debugging statement
Oops! Ugh, not my day...
2011-02-02socket_helper: export tcp_name as a module_function
Oops!
2011-02-02allow binding on IPv6 sockets with listen "[#{addr}]:#{port}"
This is much like how nginx does it, except we always require a port when explicitly binding to IPv6 using the "listen" directive. This also adds support to listen with an address-only, which can be useful to Rainbows! users.
2011-01-31force socket options to defaults if unspecified
This reduces surprise when people (correctly) believe removing an option from the config file will return things back to our internal defaults.
2011-01-31enable TCP_NOPUSH/TCP_CORK by default
It's actually harmless since Unicorn only supports "fast" applications that do not trickle, and we don't do keepalive so we'll always flush-on-close. This should reduce wakeups on the nginx proxy server if nginx is over TCP. Mongrel 1.x had TCP_CORK enabled by default, too.
2011-01-05socket_helper: expose more defaults in DEFAULTS hash
This will allow Rainbows! to set :tcp_nodelay=>true and possibly other things in the future.
2010-10-05start using kgio, the kinder, gentler I/O library
This should hopefully make the non-blocking accept() situation more tolerable under Ruby 1.9.2.
2010-10-04avoid unlinking actively listening sockets
While we've always unlinked dead sockets from nuked/leftover processes, blindly unlinking them can cause unnecessary failures when an active process is already listening on them. We now make a simple connect(2) check to ensure the socket is not in use before unlinking it. Thanks to Jordan Ritter for the detailed bug report leading to this fix. ref: http://mid.gmane.org/8D95A44B-A098-43BE-B532-7D74BD957F31@darkridge.com
2010-07-06socket_helper: disable documentation for internals
2010-07-06socket_helper: cleanup FreeBSD accf_* detection
Instead of detecting at startup if filters may be used, just try anyways and log the error. It is better to ask for forgiveness than permission :)
2010-07-06socket_helper: no reason to check for logger method
We only use this module in HttpServer and our unit test mocks it properly.
2010-07-06socket_helper: move defaults to the DEFAULTS constant
This is to allow Rainbows! to override the defaults.
2010-07-03socket_helper: tunables for tcp_defer_accept/accept_filter
Under Linux, this allows users to tune the time (in seconds) to defer connections before allowing them to be accepted. The behavior of TCP_DEFER_ACCEPT changed with Linux 2.6.32 and idle connections may still be accept()-ed after the specified value in seconds. A small value of '1' remains the default for Unicorn as Unicorn does not worry about slow clients. Higher values provide better DoS protection for Rainbows! but also increases kernel memory usage. Allowing "dataready" for FreeBSD accept filters will allow SSL sockets to be used in the future for HTTPS, too.
2010-04-30add global Unicorn.listener_names method
This is useful as a :listeners argument when setting up Raindrops::Middleware (http://raindrops.bogomips.org/), as it can be done automatically.
2009-11-15socket_helper: RDoc for constants
2009-11-15socket_helper: do not hide errors when setting socket options
Since they're all optional, make them non-fatal, but make sure we log them so we can diagnose what (if anything) is going wrong.
2009-11-14configurator: listen :umask parameter for UNIX sockets
Typically UNIX domain sockets are created with more liberal file permissions than the rest of the application. By default, we create UNIX domain sockets to be readable and writable by all local users to give them the same accessibility as locally-bound TCP listeners. This only has an effect on UNIX domain sockets. This was inspired by Suraj Kurapati in cfbcd2f00911121536rd0582b8u961f7f2a8c6e546a@mail.gmail.com
2009-09-30cleanup: use question mark op for 1-byte comparisons
It's compatible with both Ruby 1.8 and 1.9 without needing a Range object.
2009-09-16socket_helper: (FreeBSD) don't freeze the accept filter constant
We may add support for the Gopher protocol in the future...
2009-09-08"encoding: binary" comments for all sources (1.9)
This ensures any string literals that pop up in *our* code will just be a bag of bytes. This shouldn't affect/fix/break existing apps in most cases, but most constants will always have the "correct" encoding (none!) to be consistent with HTTP/socket expectations. Since this comment affects things only on a per-source basis, it won't affect existing apps with the exception of strings we pass to the Rack application. This will eventually allow us to get rid of that Unicorn::Z constant, too.
2009-07-01Re-add support for non-portable socket options
Now that we support tunnelling arbitrary protocols over HTTP as well as "100 Continue" responses, TCP_NODELAY actually becomes useful to us. TCP_NODELAY is actually reasonably portable nowadays; even. While we're adding non-portable options, TCP_CORK/TCP_NOPUSH can be enabled, too. Unlike some other servers, these can't be disabled explicitly/intelligently to force a flush, however. However, these may still improve performance with "normal" HTTP applications (Mongrel has always had TCP_CORK enabled in Linux). While we're adding OS-specific features, we might as well support TCP_DEFER_ACCEPT in Linux and FreeBSD the "httpready" accept filter to prevent abuse. These options can all be enabled on a per-listener basis.
2009-04-21rename socket.rb => socket_helper.rb
We no longer have anything outside of SocketHelper module in that file, so just give it a more obvious name.