An invalid open_timeout raised before the waiter was assigned, so the cleanup closed fd 0 left by memset and took the process's stdin with it.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
ADDRESS_FAMILIES[:family_name] used the Symbol :family_name as the key
instead of the local variable family_name, so the address family was
always nil. This is a follow-up to b896f80598 [Bug #21512].
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
hostname is added as a suffix to getaddrinfo error messages. for
example, a "name or service not known" error message becomes "name or
service not known for `invalidthost.com`.
Linux 2.6.18 was the kernel of RHEL 5, whose Extended Life-cycle Support ended in 2020. Every supported kernel honors O_CLOEXEC and F_DUPFD_CLOEXEC, so there is no need to detect at runtime whether they work.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
EAI_ADDRFAMILY left the IPv6 result looking successful, so a later IPv4 resolution error was not recorded and TCPSocket.new raised Socket::ResolutionError with error_code 0. When the IPv6 notification failed, EAI_ADDRFAMILY was recorded instead and hid the IPv4 error.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
When a socket has buffered output (`sync == false`) and `#close_write` is
called, the write side was shut down via `shutdown(SHUT_WR)` without first
flushing the buffer. This had two bad consequences:
- the buffered bytes were silently dropped (never delivered to the peer);
- a subsequent `#close` tried to flush the still-populated write buffer
into the now `shutdown(SHUT_WR)` socket and raised `Errno::EPIPE`.
Flush the buffer before shutting down the write side, matching the
write-only branch (which flushes via `rb_io_close`) and the non-socket
`IO#close_write` path. `IO#close_write` for a plain `IO` wrapping a socket
fd is fixed in the same way.
Assisted-By: devx/2c064143-8655-4631-a7cd-6395bb241bdc
server_thread.value waited for an accept that never returned once TCPSocket.new had raised, hiding the failure behind a hang. Use stop_accept_thread as the newer tests do.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Only test_mode_settings itself was checked to be a Hash, and its delay and error values were passed to rb_hash_aref as they were.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Winsock reports a failed non-blocking connect(2) only through the
exceptfds of select(2), which IO#wait_writable never asks for. So
Addrinfo#connect_internal kept waiting on a socket whose connection had
already been refused, and burned the whole connect_timeout before
raising Errno::ETIMEDOUT instead of the real error.
Ask for the priority event on Windows alone. The M:N thread scheduler
refuses any wait carrying another event, so requesting it where it
cannot fire would take the wait off that scheduler for nothing.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Winsock leaves a WSA error code in SO_ERROR, while the socket library
reads it as an errno everywhere. wait_connectable() compares it with
ECONNREFUSED and friends, and Socket.tcp hands it to SystemCallError, so
a connection refused on Windows surfaced as a bare SystemCallError
rather than Errno::ECONNREFUSED.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
The signal handling bug behind these was fixed in FreeBSD 13.3, and 13 is
now EOL. Each of them ran 30 times, and the affected files together 20
times, on the rubyci FreeBSD 14.5 amd64 and 15.1 arm64 machines with no
failure.
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=277429
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Darwin 27 answers the retry connect(2) on a refused nonblocking socket
with EISCONN, so the retry idiom in Addrinfo#connect_internal returned
an unconnected socket. SO_ERROR still holds the real error, so consult
it after wait_writable, as wait_connectable() in init.c already does.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Some fast_fallback tests inject an artificial delay to test timing-sensitive behavior. Under CI's parallel test execution, threadscheduling jitter can make the delay longer than expected, and in that case these tests may fail to connect to the server process they are actually supposed to connect to.
For example:
1. The IPv6 name resolution is artificially delayed by 25ms, so the IPv4 name resolution succeeds first.
2. If the IPv6 name resolution succeeds within 25ms, the client starts connecting to the `::1` server process and the test passes. However, if the IPv6 name resolution is delayed by more than 50ms for some reason, fast_fallback starts connecting to `127.0.0.1` instead, by design.
3. If another test happens to have a server listening on `127.0.0.1` with the same port number, the connection accidentally succeeds.
4. The `::1` server process is left waiting, and the thread cleanup hangs.
To address this, the listening server process now receives the result of `accept` through a local variable instead of `Thread#value`. On success, it joins the thread with a short timeout; otherwise, it terminates the thread with `Thread#kill.join`.
This change is expected to prevent hangs even when such a wrong connection occurs.
- Avoid unnecessarily binding sender sockets, as ephemeral ports can
very occasionally conflict on Linux. This investigation is assisted
by Claude Code.
- Compare timestamps using a range instead of relying on `inspect`.
- Use the `timestamp_retry_rw` helper in `test_bintime` as well.
- Use `String#unpack1` with offset to extract the timestamp data.
Co-authored-by: Koichi Sasada <ko1@atdot.net>
The 1-second Timeout.timeout for IO.select waiting on a localhost
empty UDP packet is too tight for loaded CI runners, causing spurious
Timeout::Error failures. Increase to 30 seconds, which is only a
safety net against indefinite hangs.
https://github.com/ruby/ruby/actions/runs/23585200531/job/68676546959
The server thread's msg_src.reply can raise Errno::ENOBUFS
("No buffer space available") transiently on macOS CI. This
exception was not caught, propagating through th.join in the
ensure block and failing the test.
Rescue it in the server thread so the client side times out on
IO.select, raises RuntimeError, and hits the existing omit path.
This change fixes a bug in which specifying 0 for timeout-related options (such as the `timeout` option of `Addrinfo.getaddrinfo`) incorrectly results in an infinite wait.
(This change overwrites https://github.com/ruby/ruby/pull/15626 .)
* `Socket.tcp` and `TCPSocket.new` raises `IO::TiemoutError` with user specified timeout
In https://github.com/ruby/ruby/pull/11880, `rsock_connect()` was changed to raise `IO::TimeoutError` when a user-specified timeout occurs.
However, when `TCPSocket.new` attempts to connect to multiple destinations, it does not use `rsock_connect()`, and instead raises `Errno::ETIMEDOUT` on timeout.
As a result, the exception class raised on timeout could differ depending on whether there were multiple destinations or not.
To align this behavior with the implementation of `rsock_connect()`, this change makes `TCPSocket.new` raise `IO::TimeoutError` when a user-specified timeout occurs.
Similarly, `Socket.tcp` is updated to raise `IO::TimeoutError` when a timeout occurs within the method.
(Note that the existing behavior of `Addrinfo#connect_internal`, which Socket.tcp depends on internally and which raises `Errno::ETIMEDOUT` on timeout, is not changed.)
* [ruby/net-http] Raise `Net::OpenTimeout` when `TCPSocket.open` raises `IO::TimeoutError`.
With the changes in https://github.com/ruby/ruby/pull/15602, `TCPSocket.open` now raises `IO::TimeoutError` when a user-specified timeout occurs.
This change updates #connect to handle this case accordingly.
https://github.com/ruby/net-http/commit/f64109e1cf
* [Feature #21347] Add `open_timeout` as an overall timeout option for `TCPSocket.new`
With this change, `TCPSocket.new` now accepts the `open_timeout` option.
This option raises an exception if the specified number of seconds has elapsed since the start of the method call,
even if the operation is still in the middle of name resolution or connection attempts.
The addition of this option follows the same intent as the previously merged change to `Socket.tcp`.
[Feature #21347](https://bugs.ruby-lang.org/issues/21347)
https://github.com/ruby/ruby/pull/13368
* Tidy up: Extract rsock_raise_user_specified_timeout()
* Added a note to the documentation of `Socket.tcp`
* Fix `rsock_init_inetsock` for `FAST_FALLBACK_INIT_INETSOCK_IMPL`
* Add `open_timeout` as an overall timeout option for `Socket.tcp`
[Background]
Currently, `TCPSocket.new` and `Socket.tcp` accept two kind of timeout options:
- `resolv_timeout`, which controls the timeout for DNS resolution
- `connect_timeout`, which controls the timeout for the connection attempt
With the introduction of Happy Eyeballs Version 2 (as per [RFC 8305](https://datatracker.ietf.org/doc/html/rfc8305)) in[ Feature #20108](https://bugs.ruby-lang.org/issues/20108) and [Feature #20782](https://bugs.ruby-lang.org/issues/20782), both address resolution and connection attempts are now parallelized.
As a result, the sum of `resolv_timeout` and `connect_timeout` no longer represents the total timeout duration. This is because, in HEv2, name resolution and connection attempts are performed concurrently, causing the two timeouts to overlap.
Example:
When `resolv_timeout: 200ms` and `connect_timeout: 100ms` are set:
1. An IPv6 address is resolved after the method starts immediately (IPv4 is still being resolved).
2. A connection attempt is initiated to the IPv6 address
3. After 100ms, `connect_timeout` is exceeded. However, since `resolv_timeout` still has 100ms left, the IPv4 resolution continues.
4. After 200ms from the start, the method raises a `resolv_timeout` error.
In this case, the total elapsed time before a timeout is 200ms, not the expected 300ms (100ms + 200ms).
Furthermore, in HEv2, connection attempts are also parallelized.
It starts a new connection attempts every 250ms for resolved addresses. This makes the definition of `connect_timeout` even more ambiguous—specifically, it becomes unclear from which point the timeout is counted.
Additionally, these methods initiate new connection attempts every 250ms (Connection Attempt Delay) for each candidate address, thereby parallelizing connection attempts. However, this behavior makes it unclear from which point in time the connect_timeout is actually measured.
Currently, a `connect_timeout` is raised only after the last connection attempt exceeds the timeout.
Example:
When `connect_timeout: 100ms` is set and 3 address candidates:
1. Start a connection attempt to the address `a`
2. 250ms after step 1, start a new connection attempt to the address `b`
3. 500ms after step 1, start a new connection attempt to the address `c`
4. 1000ms after step 3 (1000ms after starting the connection to `c`, 1250ms after starting the connection to `b,` and 1500ms after starting the connection to `a`) `connect_timeout` is raised
This behavior aims to favor successful connections by allowing more time for each attempt, but it results in a timeout model that is difficult to reason about.
These methods have supported `resolv_timeout` and `connect_timeout` options even before the introduction of HEv2. However, in many use cases, it would be more convenient if a timeout occurred after a specified duration from the start of the method. Similar functions in other languages (such as PHP, Python, and Go) typically allow specifying only an overall timeout.
[Proposal]
I propose adding an `open_timeout` option to `Socket.tcp` in this PR, which triggers a timeout after a specified duration has elapsed from the start of the method.
The name `open_timeout` aligns with the existing accessor used in `Net::HTTP`.
If `open_timeout` is specified together with `resolv_timeout` and `connect_timeout`, I propose that only `open_timeout` be used and the others be ignored. While it is possible to support combinations of `open_timeout`, `resolv_timeout`, and `connect_timeout`, doing so would require defining which timeout takes precedence in which situations. In this case, I believe it is more valuable to keep the behavior simple and easy to understand, rather than supporting more complex use cases.
If this proposal is accepted, I also plan to extend `open_timeout` support to `TCPSocket.new`.
While the long-term future of `resolv_timeout` and `connect_timeout` may warrant further discussion, I believe the immediate priority is to offer a straightforward way to specify an overall timeout.
[Outcome]
If `open_timeout` is also supported by `TCPSocket.new`, users would be able to manage total connection timeouts directly in `Net::HTTP#connect` without relying on `Timeout.timeout`.
https://github.com/ruby/ruby/blob/aa0f689bf45352c4a592e7f1a044912c40435266/lib/net/http.rb#L1657
---
* Raise an exception if it is specified together with other timeout options
> If open_timeout is specified together with resolv_timeout and connect_timeout, I propose that only open_timeout be used and the others be ignored.
Since this approach may be unclear to users, I’ve decided to explicitly raise an `ArgumentError` if these options are specified together.
* Add doc
* Fix: open_timeout error should be raised even if there are still addresses that have not been tried
Allow Addrinfo objects to be shared among Ractors. Addrinfo objects are
already immutable, so I think it's safe for us to tag them as
RUBY_TYPED_FROZEN_SHAREABLE shareable too.
* Do not save ResolutionError if resolution succeeds for any address family
Socket with Happy Eyeballs Version 2 performs connection attempts and name resolution in parallel.
In the existing implementation, if a connection attempt failed for one address family while name resolution was still in progress for the other, and that name resolution later failed, the method would terminate with a name resolution error.
This behavior was intended to ensure that the final error reflected the most recent failure, potentially overriding an earlier error.
However, [Bug #21088](https://bugs.ruby-lang.org/issues/21088) made me realize that terminating with a name resolution error is unnatural when name resolution succeeded for at least one address family.
This PR modifies the behavior so that if name resolution succeeds for one address family, any name resolution error from the other is not saved.
This PR includes the following changes:
* Do not display select(2) as the system call that caused the raised error, as it is for internal processing
* Fix bug: Get errno with Socket::SO_ERROR in Windows environment with a workaround for tests not passing
* TCPSocket.new: Close resources in ensure
* TCPSocket.new: Remove unnecessary comments
* Socket.tcp: Make assert_separately in TestSocket more readable
* Socket.tcp: Returning instead of exiting
* Socket.tcp: Close resources in ensure
* Socket.tcp: Avoid test failures on hosts that only support IPv4
This change includes the following updates:
- Added an environment variable `RUBY_TCP_NO_FAST_FALLBACK` to control enabling/disabling fast_fallback
- Updated documentation and man pages
- Revised the implementation of Socket.tcp_fast_fallback= and Socket.tcp_fast_fallback, which previously performed dynamic name resolution of constants and variables. As a result, the following performance improvements were achieved:
(Case of 1000 executions of `TCPSocket.new` to the local host)
Rehearsal -----------------------------------------
before 0.031462 0.147946 0.179408 ( 0.249279)
after 0.031164 0.146839 0.178003 ( 0.346935)
-------------------------------- total: 0.178003sec
user system total real
before 0.027584 0.138712 0.166296 ( 0.233356)
after 0.025953 0.127608 0.153561 ( 0.237971)
To verify the behavior of HEv2, some tests were prepared. But unexpected failures occur in certain environments.
This happens in environments where "localhost" resolves only to an IPv4 address during tests that verify connections to IPv6.
For example, the following situation can occur:
- The server process is bound to ::1.
- The client socket always resolves "localhost" to 127.0.0.1 and attempts to connect to 127.0.0.1.
- Since no server is bound to 127.0.0.1, an ECONNREFUSED error is raised.
In such situations, the behavior of `TCPSocket.new` remains unchanged from before the introduction of HEv2.
(The failures occur because tests explicitly binding to ::1 were added to verify HEv2 behavior.)
This change ensures that the affected tests are skipped in environments of this kind.
* Do not save the last_error if there are no sockets waiting to be connected
In this implementation, the results of both name resolution and connection attempts are awaited using select(2).
When it returned, the implementation attempted to check for connections even if there were no sockets currently attempting to connect, treating the absence of connected sockets as a connection failure.
With this fix, it will no longer check for connections when there are no sockets waiting to be connected.
Additionally, the following minor fixes have been made:
* Handle failure of getsockopt(2) and removed unnecessary continue in the loop
* Tweak: Use common API to check in_progress_fds
* Safely call TCPServer.new in test
* Set empty writefds when there is no socket waiting to be connected
* Enable fast_fallback option
* Disable HEv2 tests temporarily
To suppress error log output in CI.
They should have been DISABLE in PR #12070.
---
Additionally, the following fixes have been made:
- Remove unnecessary `assert_separately` from the related tests
* Introduction of Happy Eyeballs Version 2 (RFC8305) in TCPSocket.new
This is an implementation of Happy Eyeballs version 2 (RFC 8305) in `TCPSocket.new`.
See https://github.com/ruby/ruby/pull/11653
1. Background
Prior to this implementation, I implemented Happy Eyeballs Version 2 (HEv2) for `Socket.tcp` in https://github.com/ruby/ruby/pull/9374.
HEv2 is an algorithm defined in [RFC 8305](https://datatracker.ietf.org/doc/html/rfc8305), aimed at improving network connectivity.
For more details on the specific cases that HEv2 helps, please refer to https://bugs.ruby-lang.org/issues/20108.
2. Proposal & Outcome
This proposal implements the same HEv2 algorithm in `TCPSocket.new`.
Since `TCPSocket.new` is used more widely than `Socket.tcp`, this change is expected to broaden the impact of HEv2's benefits.
Like `Socket.tcp`, I have also added `fast_fallback` keyword argument to `TCPSocket.new`.
This option is set to true by default, enabling the HEv2 functionality.
However, users can explicitly set it to false to disable HEv2 and use the previous behavior of `TCPSocket.new`.
It should be noted that HEv2 is enabled only in environments where pthreads are available.
This specification follows the approach taken in https://bugs.ruby-lang.org/issues/19965 , where name resolution can be interrupted.
(In environments where pthreads are not available, the `fast_fallback` option is ignored.)
3. Performance
Below is the benchmark of 100 requests to `www.ruby-lang.org` with the fast_fallback option set to true and false, respectively.
While there is a slight performance degradation when HEv2 is enabled, the degradation is smaller compared to that seen in `Socket.tcp`.
```
~/s/build ❯❯❯ ../install/bin/ruby ../ruby/test.rb
Rehearsal --------------------------------------------------------
fast_fallback: true 0.017588 0.097045 0.114633 ( 1.460664)
fast_fallback: false 0.014033 0.078984 0.093017 ( 1.413951)
----------------------------------------------- total: 0.207650sec
user system total real
fast_fallback: true 0.020891 0.124054 0.144945 ( 1.473816)
fast_fallback: false 0.018392 0.110852 0.129244 ( 1.466014)
```
* Update debug prints
Co-authored-by: Nobuyoshi Nakada <nobu.nakada@gmail.com>
* Remove debug prints
* misc
* Disable HEv2 in Win
* Raise resolution error with hostname resolution
* Fix to handle errors
* Remove warnings
* Errors that do not need to be handled
* misc
* Improve doc
* Fix bug on cancellation
* Avoid EAI_ADDRFAMILY for resolving IPv6
* Follow upstream
* misc
* Refactor connection_attempt_fds management
- Introduced allocate_connection_attempt_fds and reallocate_connection_attempt_fds for improved memory allocation of connection_attempt_fds
- Added remove_connection_attempt_fd to resize connection_attempt_fds dynamically.
- Simplified the in_progress_fds function to only check the size of connection_attempt_fds.
* Rename do_pthread_create to raddrinfo_pthread_create to avoid conflicting
---------
Co-authored-by: Nobuyoshi Nakada <nobu.nakada@gmail.com>
Some packaging systems that include support for running tests,
such as OpenBSD's, do not allow outbound network connections
during testing for security reasons. EACCES is the error raised by
OpenBSD in this case.
* Introduction of Happy Eyeballs Version 2 (RFC8305) in Socket.tcp
This is an implementation of Happy Eyeballs version 2 (RFC 8305) in Socket.tcp.
[Background]
Currently, `Socket.tcp` synchronously resolves names and makes connection attempts with `Addrinfo::foreach.`
This implementation has the following two problems.
1. In name resolution, the program stops until the DNS server responds to all DNS queries.
2. In a connection attempt, while an IP address is trying to connect to the destination host and is taking time, the program stops, and other resolved IP addresses cannot try to connect.
[Proposal]
"Happy Eyeballs" ([RFC 8305](https://datatracker.ietf.org/doc/html/rfc8305)) is an algorithm to solve this kind of problem. It avoids delays to the user whenever possible and also uses IPv6 preferentially.
I implemented it into `Socket.tcp` by using `Addrinfo.getaddrinfo` in each thread spawned per address family to resolve the hostname asynchronously, and using `Socket::connect_nonblock` to try to connect with multiple addrinfo in parallel.
[Outcome]
This change eliminates a fatal defect in the following cases.
Case 1. One of the A or AAAA DNS queries does not return
---
require 'socket'
class Addrinfo
class << self
# Current Socket.tcp depends on foreach
def foreach(nodename, service, family=nil, socktype=nil, protocol=nil, flags=nil, timeout: nil, &block)
getaddrinfo(nodename, service, Socket::AF_INET6, socktype, protocol, flags, timeout: timeout)
.concat(getaddrinfo(nodename, service, Socket::AF_INET, socktype, protocol, flags, timeout: timeout))
.each(&block)
end
def getaddrinfo(_, _, family, *_)
case family
when Socket::AF_INET6 then sleep
when Socket::AF_INET then [Addrinfo.tcp("127.0.0.1", 4567)]
end
end
end
end
Socket.tcp("localhost", 4567)
---
Because the current `Socket.tcp` cannot resolve IPv6 names, the program stops in this case. It cannot start to connect with IPv4 address.
Though `Socket.tcp` with HEv2 can promptly start a connection attempt with IPv4 address in this case.
Case 2. Server does not promptly return ack for syn of either IPv4 / IPv6 address family
---
require 'socket'
fork do
socket = Socket.new(Socket::AF_INET6, :STREAM)
socket.setsockopt(:SOCKET, :REUSEADDR, true)
socket.bind(Socket.pack_sockaddr_in(4567, '::1'))
sleep
socket.listen(1)
connection, _ = socket.accept
connection.close
socket.close
end
fork do
socket = Socket.new(Socket::AF_INET, :STREAM)
socket.setsockopt(:SOCKET, :REUSEADDR, true)
socket.bind(Socket.pack_sockaddr_in(4567, '127.0.0.1'))
socket.listen(1)
connection, _ = socket.accept
connection.close
socket.close
end
Socket.tcp("localhost", 4567)
---
The current `Socket.tcp` tries to connect serially, so when its first name resolves an IPv6 address and initiates a connection to an IPv6 server, this server does not return an ACK, and the program stops.
Though `Socket.tcp` with HEv2 starts to connect sequentially and in parallel so a connection can be established promptly at the socket that attempted to connect to the IPv4 server.
In exchange, the performance of `Socket.tcp` with HEv2 will be degraded.
---
100.times { Socket.tcp("www.ruby-lang.org", 80) }
---
This is due to the addition of the creation of IO objects, Thread objects, etc., and calls to `IO::select` in the implementation.
* Avoid NameError of Socket::EAI_ADDRFAMILY in MinGW
* Support Windows with SO_CONNECT_TIME
* Improve performance
I have additionally implemented the following patterns:
- If the host is single-stack, name resolution is performed in the main thread. This reduces the cost of creating threads.
- If an IP address is specified, name resolution is performed in the main thread. This also reduces the cost of creating threads.
- If only one IP address is resolved, connect is executed in blocking mode. This reduces the cost of calling IO::select.
Also, I have added a fast_fallback option for users who wish not to use HE.
Here are the results of each performance test.
```ruby
require 'socket'
require 'benchmark'
HOSTNAME = "www.ruby-lang.org"
PORT = 80
ai = Addrinfo.tcp(HOSTNAME, PORT)
Benchmark.bmbm do |x|
x.report("Domain name") do
30.times { Socket.tcp(HOSTNAME, PORT).close }
end
x.report("IP Address") do
30.times { Socket.tcp(ai.ip_address, PORT).close }
end
x.report("fast_fallback: false") do
30.times { Socket.tcp(HOSTNAME, PORT, fast_fallback: false).close }
end
end
```
```
user system total real
Domain name 0.015567 0.032511 0.048078 ( 0.325284)
IP Address 0.004458 0.014219 0.018677 ( 0.284361)
fast_fallback: false 0.005869 0.021511 0.027380 ( 0.321891)
````
And this is the measurement result when executed in a single stack environment.
```
user system total real
Domain name 0.007062 0.019276 0.026338 ( 1.905775)
IP Address 0.004527 0.012176 0.016703 ( 3.051192)
fast_fallback: false 0.005546 0.019426 0.024972 ( 1.775798)
```
The following is the result of the run on Ruby 3.3.0.
(on Dual stack environment)
```
user system total real
Ruby 3.3.0 0.007271 0.027410 0.034681 ( 0.472510)
```
(on Single stack environment)
```
user system total real
Ruby 3.3.0 0.005353 0.018898 0.024251 ( 1.774535)
```
* Do not cache `Socket.ip_address_list`
As mentioned in the comment at https://github.com/ruby/ruby/pull/9374#discussion_r1482269186, caching Socket.ip_address_list does not follow changes in network configuration.
But if we stop caching, it becomes necessary to check every time `Socket.tcp` is called whether it's a single stack or not, which could further degrade performance in the case of a dual stack.
From this, I've changed the approach so that when a domain name is passed, it doesn't check whether it's a single stack or not and resolves names in parallel each time.
The performance measurement results are as follows.
require 'socket'
require 'benchmark'
HOSTNAME = "www.ruby-lang.org"
PORT = 80
ai = Addrinfo.tcp(HOSTNAME, PORT)
Benchmark.bmbm do |x|
x.report("Domain name") do
30.times { Socket.tcp(HOSTNAME, PORT).close }
end
x.report("IP Address") do
30.times { Socket.tcp(ai.ip_address, PORT).close }
end
x.report("fast_fallback: false") do
30.times { Socket.tcp(HOSTNAME, PORT, fast_fallback: false).close }
end
end
user system total real
Domain name 0.004085 0.011873 0.015958 ( 0.330097)
IP Address 0.000993 0.004400 0.005393 ( 0.257286)
fast_fallback: false 0.001348 0.008266 0.009614 ( 0.298626)
* Wait forever if fallback addresses are unresolved, unless resolv_timeout
Changed from waiting only 3 seconds for name resolution when there is no fallback address available, to waiting as long as there is no resolv_timeout.
This is in accordance with the current `Socket.tcp` specification.
* Use exact pattern to match IPv6 address format for specify address family
When making an outgoing TCP or UDP connection, set AI_ADDRCONFIG in the
hints we send to getaddrinfo(3) (if supported). This will prompt the
resolver to _NOT_ issue A or AAAA queries if the system does not
actually have an IPv4 or IPv6 address (respectively).
This makes outgoing connections marginally more efficient on
non-dual-stack systems, since we don't have to try connecting to an
address which can't possibly work.
More importantly, however, this works around a race condition present
in some older versions of glibc on aarch64 where it could accidently
send the two outgoing DNS queries with the same DNS txnid, and get
confused when receiving the responses. This manifests as outgoing
connections sometimes taking 5 seconds (the DNS timeout before retry) to
be made.
Fixes#19144
