The Less-Told Story of Socket Timeouts

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connect with timeout is too verbose: addr = Socket.pack_sockaddr_in(9418, "127.0.0.1") s = Socket.new(:AF_INET, :SOCK_STREAM, 0) begin s.connect_nonblock(addr) rescue Errno::EINPROGRESS IO.select(nil, [s], nil, 0.5) or raise Timeout::Error end 4UBSUBOPOCMPDLJOHDPOOFDUJPO 5JNFPVUJOTFD GSPNOPSNBMQFSTPO &SJD8POH IUUQTCVHTSVCZMBOHPSHJTTVFT "UJNFPVUGPSDPOOFDUJPOBUUFNQUT

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0.5, local_host: nil, local_port: nil) Or: TCPSocket.new(remote_host, remote_port, connect_timeout: 0.5) GSPNOPSNBMQFSTPO &SJD8POH IUUQTCVHTSVCZMBOHPSHJTTVFT "UJNFPVUGPSDPOOFDUJPOBUUFNQUT

8IZPOMZUIFDPOOFDUJPOXBTTVCKFDUUPUIFUJNFPVU BOEOPUOBNFSFTPMVUJPO Proposed API would be: TCPSocket.new(remote_host, remote_port, 
connect_timeout: 0.5, local_host: nil, local_port: nil) Or: TCPSocket.new(remote_host, remote_port, connect_timeout: 0.5) GSPNOPSNBMQFSTPO &SJD8POH IUUQTCVHTSVCZMBOHPSHJTTVFT "UJNFPVUGPSDPOOFDUJPOBUUFNQUT

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library for performing DNS-based name resolution. GSPNOPSNBMQFSTPO &SJD8POH IUUQTCVHTSVCZMBOHPSHJTTVFT

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-BZFSFE5JNFPVU%FTJHO 0CUBJOUIFEFTUJOBUJPO*1BEESFTTFTVTJOH UIFSFTPMWMJCSBSZ require "resolv" dns = Resolv::DNS.new dns.timeouts =
1 dns.getaddress("example.com") $MJFOU %/4TFSWFS 3FTPMWFUIFIPTUOBNFXJUISFTPMW 4FSWFS "OBNFSFTPMVUJPOUJNFPVU

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0.5, local_host: nil, local_port: nil) Or: TCPSocket.new(remote_host, remote_port, connect_timeout: 0.5) GSPNOPSNBMQFSTPO &SJD8POH IUUQTCVHTSVCZMBOHPSHJTTVFT

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resolv_timeout: 1)

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standard libraries. lib/net/http.rb 945 s = Timeout.timeout(@open_timeout, Net::OpenTimeout) { 946 begin 947 TCPSocket.open(conn_address, conn_port, @local_host, @local_port) 948 rescue => e 949 raise e, "Failed to open TCP connection to " + 950 "#{conn_address}:#{conn_port} (#{e.message})" 951 end 952 } GSPN(MBTT@TBHB .BTBLJ.BUTVTIJUB IUUQTCVHTSVCZMBOHPSHJTTVFT #BDLHSPVOE5JNFPVU)BOEMJOHJOOFUIUUQ 5IFUJNFPVUMJCSBSZTNFUIPE

GSPN(MBTT@TBHB .BTBLJ.BUTVTIJUB IUUQTCVHTSVCZMBOHPSHJTTVFT ※ The timeout library is a standard
library that forces an operation to be interrupted by raising an exception once a speci fi ed time has elapsed. Currently, we use Timeout in Net::HTTP and other standard libraries. lib/net/http.rb 945 s = Timeout.timeout(@open_timeout, Net::OpenTimeout) { 946 begin 947 TCPSocket.open(conn_address, conn_port, @local_host, @local_port) 948 rescue => e 949 raise e, "Failed to open TCP connection to " + 950 "#{conn_address}:#{conn_port} (#{e.message})" 951 end 952 } 5IFUJNFPVUMJCSBSZTNFUIPE #BDLHSPVOE5JNFPVU)BOEMJOHJOOFUIUUQ

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IUUQTCVHTSVCZMBOHPSHJTTVFT Socket.tcp supports connect_timeout, but Addrinfo.getaddrinfo doesn't support timeout. We need to use Timeout to wait name resolution. In this patch, Addrinfo.getaddrinfo support timeout and Socket.tcp accepts resolv_timeout. It uses getaddrinfo_a(3) if available, otherwise it uses Timeout. We can avoid thread creation to make a TCP connection if getaddrinfo_a(3) is available. ˞IUUQTHJUIVCDPNSVCZSVCZDPNNJUGDDBDFCDEBEB

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supports connect_timeout, but Addrinfo.getaddrinfo doesn't support timeout. We need to use Timeout to wait name resolution. In this patch, Addrinfo.getaddrinfo support timeout and Socket.tcp accepts resolv_timeout. It uses getaddrinfo_a(3) if available, otherwise it uses Timeout. We can avoid thread creation to make a TCP connection if getaddrinfo_a(3) is available.

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=> [#<Addrinfo: [****:****:****::***]:80 TCP (www.ruby-lang.org)>, ...] Socket.getaddrinfo("www.ruby-lang.org", 80) => [["AF_INET6", 80, "****:****:****::***", "****:****:****::***", 30, 1, 6], ...]

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※ 2020 Grant Accomplishment Report Happy Eyeballs Version 2 (RFC8305) support for Ruby’s socket library https://www.ruby.or.jp/grant/2020/matsushita_ fi nal_report.pdf

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3FTPMVUJPO%FBMBZ$POOFDUJPO"UUFNQU%FMBZ def self.tcp_with_fast_fallback( host, port, ..., connect_timeout: nil, resolv_timeout: nil
) # ... resolution_delay_expires_at = nil connection_attempt_delay_expires_at = nil # ... end *OUIFJNQMFNFOUBUJPO UIFTFEFMBZTBSFUSBDLFEVTJOH UIFWBSJBCMFTSFTPMVUJPO@EFMBZ@FYQJSFT@BUBOE DPOOFDUJPO@BUUFNQU@EFMBZ@FYQJSFT@BU 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC

3FTPMVUJPO%FBMBZ$POOFDUJPO"UUFNQU%FMBZ def self.tcp_with_fast_fallback( host, port, ..., connect_timeout: nil, resolv_timeout: nil
) # ... resolution_delay_expires_at = nil connection_attempt_delay_expires_at = nil # ... end #PUIBSFJOJUJBMJ[FEUPOJMBUUIFTUBSUPGUIFNFUIPE 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC

SFTPMW@UJNFPVUDPOOFDU@UJNFPVU *ODPOUSBTU SFTPMW@UJNFPVUBOEDPOOFDU@UJNFPVUXBJU VQUPBVTFSTQFDJ fi FEUJNFPVU %/4TFSWFS 4PDLFUUDQ 5$14PDLFUOFX 4FSWFS
SFTPMW@UJNFPVU *GUIFUJNFPVUFYQJSFT UIFXBJUJTUFSNJOBUFEBOEBOFSSPSJTSBJTFE "UUFNQUUPDPOOFDU 3FTPMWFUIFIPTUOBNF DPOOFDU@UJNFPVU

def self.tcp_with_fast_fallback( host, port, ..., connect_timeout: nil, resolv_timeout: nil )
# ... resolution_delay_expires_at = nil connection_attempt_delay_expires_at = nil user_specified_connect_timeout_at = nil # ... user_specified_resolv_timeout_at = resolv_timeout ? now + resolv_timeout : Float::INFINITY # ... end 5IFTFUJNFPVUTBSFUSBDLFEVTJOHUIFWBSJBCMFT VTFS@TQFDJ fi FE@SFTPMW@UJNFPVU@BUBOE VTFS@TQFDJ fi FE@DPOOFDU@UJNFPVU@BU SFTPMW@UJNFPVUDPOOFDU@UJNFPVU 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC

# ... resolution_delay_expires_at = nil connection_attempt_delay_expires_at = nil user_specified_connect_timeout_at = nil # ... user_specified_resolv_timeout_at = resolv_timeout ? now + resolv_timeout : Float::INFINITY # ... end VTFS@TQFDJ fi FE@DPOOFDU@UJNFPVU@BUJTJOJUJBMJ[FE UPOJMBUUIFTUBSUPGUIFNFUIPE SFTPMW@UJNFPVUDPOOFDU@UJNFPVU 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC

# ... resolution_delay_expires_at = nil connection_attempt_delay_expires_at = nil user_specified_connect_timeout_at = nil # ... user_specified_resolv_timeout_at = resolv_timeout ? now + resolv_timeout : Float::INFINITY # ... end *GSFTPMW@UJNFPVUJTTQFDJ fi FE VTFS@TQFDJ fi FE@SFTPMW@UJNFPVU@BUJTTFUUP JUTFYQJSBUJPOUJNF SFTPMW@UJNFPVUDPOOFDU@UJNFPVU 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC 5IFVTFSTQFDJ fi FEFYQJSBUJPOUJNF

# ... resolution_delay_expires_at = nil connection_attempt_delay_expires_at = nil user_specified_connect_timeout_at = nil # ... user_specified_resolv_timeout_at = resolv_timeout ? now + resolv_timeout : Float::INFINITY # ... end 0UIFSXJTF JUJTTFUUP'MPBU*/'*/*5: UPNFBOXBJUJOEF fi OJUFMZ SFTPMW@UJNFPVUDPOOFDU@UJNFPVU 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC NFBOTJOEF fi OJUFMZ

%FUFSNJOJOHUIFOBNFSFTPMVUJPOUJNFPVU 0ODF*1WBOE*1WOBNFSFTPMVUJPOBSFTUBSUFEJO QBSBMMFM %/4TFSWFS 4FSWFS 4PDLFUUDQ 5$14PDLFUOFX 4FOE%/4RVFSZGPS*1W 4FOE%/4RVFSZGPS*1W

%FUFSNJOJOHUIFOBNFSFTPMVUJPOUJNFPVU JUXBJUTVOUJMFJUIFSPOFDPNQMFUFTPS PSVOUJMUIFFYQJSBUJPOUJNF %/4TFSWFS 4FSWFS 4PDLFUUDQ 5$14PDLFUOFX SFTPMW@UJNFPVU 8BJU 8BJUJOHGPSBO*1WPS*1W%/4SFTQPOTF
4FOE%/4RVFSZGPS*1W 4FOE%/4RVFSZGPS*1W

%FUFSNJOJOHUIFOBNFSFTPMVUJPOUJNFPVU ends_at = if resolution_store.any_addrinfos? resolution_delay_expires_at || connection_attempt_delay_expires_at else [
user_specified_resolv_timeout_at, user_specified_connect_timeout_at ].compact.max end 5IFFYQJSBUJPOUJNFJTEFUFSNJOFECZ UIFSFUVSOWBMVFPGUIJTDPOEJUJPOBMCSBODI 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC

user_specified_resolv_timeout_at, user_specified_connect_timeout_at ].compact.max end 5IFDPOEJUJPOJTXIFUIFSBOZ DBOEJEBUFEFTUJOBUJPOBEESFTTFTBSFBWBJMBCMF "OZDBOEJEBUFEFTUJOBUJPOBEESFTTFT 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC

user_specified_resolv_timeout_at, user_specified_connect_timeout_at ].compact.max end %VSJOHUIFJOJUJBMOBNFSFTPMVUJPO OPEFTUJOBUJPOBEESFTTJTLOPXOZFU TPFYFDVUJPOFOUFSTUIFMPXFSCSBODI 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC

%FUFSNJOJOHUIFOBNFSFTPMVUJPOUJNFPVU ends_at = if resolution_store.any_addrinfos? # ... else [ user_specified_resolv_timeout_at,
user_specified_connect_timeout_at ].compact.max end user_specified_resolv_timeout_at = resolv_timeout ? now + resolv_timeout : Float::INFINITY VTFS@TQFDJ fi FE@SFTPMW@UJNFPVU@BUJTTFUUP FJUIFSUIFFYQJSBUJPOUJNFPGSFTPMW@UJNFPVU PS'MPBU*/'*/*5: 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC

user_specified_resolv_timeout_at, user_specified_connect_timeout_at ].compact.max end user_specified_connect_timeout_at = nil VTFS@TQFDJ fi FE@DPOOFDU@UJNFPVU@BUSFNBJOT BUJUTJOJUJBMWBMVFPGOJM 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC

%FUFSNJOJOHUIFOBNFSFTPMVUJPOUJNFPVU ends_at = if resolution_store.any_addrinfos? # ... else [ user_specified_resolv_timeout_at,
user_specified_connect_timeout_at ].compact.max end "GUFSDPNQBDUJOHUIFBSSBZ VTFS@TQFDJ fi FE@SFTPMW@UJNFPVU@BUJTSFUVSOFE 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC user_specified_resolv_timeout_at = resolv_timeout ? now + resolv_timeout : Float::INFINITY

*UUIFOXBJUTVOUJMUIBUUJNF %FUFSNJOJOHUIFOBNFSFTPMVUJPOUJNFPVU %/4TFSWFS 4FSWFS 4PDLFUUDQ 5$14PDLFUOFX VTFS@TQFDJ fi FE@SFTPMW@UJNFPVU@BU 8BJU
8BJUJOHGPSBO*1WPS*1W%/4SFTQPOTF 4FOE%/4RVFSZGPS*1W 4FOE%/4RVFSZGPS*1W

*GOFJUIFSOBNFSFTPMVUJPOOPSUIFDPOOFDUJPODPNQMFUFT XJUIJOUIFTQFDJ fi FEUJNF BUJNPFVUFSSPSJTSBJTFE %/4TFSWFS 4PDLFUUDQ 5$14PDLFUOFX 4FSWFS %FUFSNJOJOHUIFOBNFSFTPMVUJPOUJNFPVU
$BODFMUIF*1W%/4RVFSZ $BODFMUIF*1W%/4RVFSZ VTFS@TQFDJ fi FE@SFTPMW@UJNFPVU@BU

*GUIFFYQJSBUJPOUJNFJT'MPBU*/'*/*5: UIFQSPDFTTXBJUTJOEF fi OJUFMZ %/4TFSWFS 4PDLFUUDQ 5$14PDLFUOFX 4FSWFS %FUFSNJOJOHUIFOBNFSFTPMVUJPOUJNFPVU
8BJU 8BJUJOEF fi OJUFMZGPSUIF%/4SFTQPOTF 4FOE%/4RVFSZGPS*1W 4FOE%/4RVFSZGPS*1W

"GUFSFJUIFSBEESFTTGBNJMZJTSFTPMWFE *G*1WOBNFSFTPMVUJPODPNQMFUFTXJUIJO UIFBMMPUUFEUJNF %/4TFSWFS 4PDLFUUDQ 5$14PDLFUOFX 4FSWFS 4FOE%/4RVFSZGPS*1W 4FOE%/4RVFSZGPS*1W 3FUVSOUIF*1W%/4SFTQPOTF
fi STU

BDPOOFDUJPOBUUFNQUJTTUBSUFEUPPOFPGUIFPCUBJOFE BEESFTTFT %/4TFSWFS 4PDLFUUDQ 5$14PDLFUOFX 4FSWFS "GUFSFJUIFSBEESFTTGBNJMZJTSFTPMWFE 4UBSUBDPOOFDUJPOBUUFNQUUP*1W 4FOE%/4RVFSZGPS*1W 4FOE%/4RVFSZGPS*1W
3FUVSOUIF*1W%/4SFTQPOTF fi STU 4UJMMXBJUJOHGPSUIF*1W%/4SFTQPOTF

*G*1WOBNFSFTPMVUJPODPNQMFUFTXJUIJO UIFBMMPUUFEUJNF 3FTPMVUJPO%FMBZNVTUCFXBJUFEGPS %/4TFSWFS 4PDLFUUDQ 5$14PDLFUOFX 4FSWFS "GUFSFJUIFSBEESFTTGBNJMZJTSFTPMWFE 4FOE%/4RVFSZGPS*1W 4FOE%/4RVFSZGPS*1W
3FUVSO*1W%/4SFTQPOTF fi STU 4UJMMXBJUJOHGPSUIF*1W%/4SFTQPOTF 3FTPMVUJPO%FMBZ 8BJUVQUPNTCFGPSF*1WDPOOFDUJPO

4PJUTFUTUIFFYQJSBUJPOUJNFEF fi OFECZUIFTQFDJ fi DBUJPO JOSFTPMVUJPO@EFMBZ@FYQJSFT@BU %/4TFSWFS 4PDLFUUDQ 5$14PDLFUOFX resolution_delay_expires_at
= now + RESOLUTION_DELAY "GUFSFJUIFSBEESFTTGBNJMZJTSFTPMWFE 4FOE%/4RVFSZGPS*1W 4FOE%/4RVFSZGPS*1W 3FUVSO*1W%/4SFTQPOTF fi STU 4UJMMXBJUJOHGPSUIF*1W%/4SFTQPOTF

ends_at = if resolution_store.any_addrinfos? resolution_delay_expires_at || connection_attempt_delay_expires_at else [ user_specified_resolv_timeout_at,
user_specified_connect_timeout_at ].compact.max end BOESFUVSOTUPUIJTDPOEJUJPOBMCSBODIBHBJO "GUFSFJUIFSBEESFTTGBNJMZJTSFTPMWFE 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC

user_specified_connect_timeout_at ].compact.max end 5IJTUJNF TJODFUIFSFBSFBMSFBEZ DBOEJEBUFEFTUJOBUJPOBEESFTTFT FYFDVUJPOFOUFSTUIFVQQFSCSBODI "GUFSFJUIFSBEESFTTGBNJMZJTSFTPMWFE 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC "OZDBOEJEBUFEFTUJOBUJPOBEESFTTFT

ends_at = if resolution_store.any_addrinfos? resolution_delay_expires_at || connection_attempt_delay_expires_at else # ...
end # When the resolved addresses are IPv4 addresses resolution_delay_expires_at = now + RESOLUTION_DELAY *GSFTPMVUJPO@EFMBZ@FYQJSFT@BUIBTBWBMVF UIBUWBMVFJTSFUVSOFE "GUFSFJUIFSBEESFTTGBNJMZJTSFTPMWFE 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC

*UUIFOXBJUTVOUJMUIBUUJNF %/4TFSWFS 4PDLFUUDQ 5$14PDLFUOFX 4FSWFS "GUFSFJUIFSBEESFTTGBNJMZJTSFTPMWFE 4FOE%/4RVFSZGPS*1W 4FOE%/4RVFSZGPS*1W 3FUVSO*1W%/4SFTQPOTF fi
STU 4UJMMXBJUJOHGPSUIF*1W%/4SFTQPOTF 3FTPMVUJPO%FMBZ 8BJUVQUPNTCFGPSF*1WDPOOFDUJPO

*G*1WOBNFSFTPMVUJPODPNQMFUFTPSUIFUJNFPVU FYQJSFT UIFXBJUFOET %/4TFSWFS 4PDLFUUDQ 5$14PDLFUOFX "GUFSFJUIFSBEESFTTGBNJMZJTSFTPMWFE 4FSWFS 3FTPMVUJPO%FMBZ 5IFUJNFPVUFYQJSFT
4FOE%/4RVFSZGPS*1W 4FOE%/4RVFSZGPS*1W 3FUVSO*1W%/4SFTQPOTF fi STU 4UJMMXBJUJOHGPSUIF*1W%/4SFTQPOTF

SFTPMVUJPO@EFMBZ@FYQJSFT@BUJTOPMPOHFSOFFEFE TPJUJTTFUUPOJM %/4TFSWFS 4PDLFUUDQ 5$14PDLFUOFX if expired?(now, resolution_delay_expires_at) resolution_delay_expires_at
= nil end "GUFSFJUIFSBEESFTTGBNJMZJTSFTPMWFE 4FOE%/4RVFSZGPS*1W 4FOE%/4RVFSZGPS*1W 3FUVSO*1W%/4SFTQPOTF fi STU 4UJMMXBJUJOHGPSUIF*1W%/4SFTQPOTF

BOETUBSUTBDPOOFDUJPOBUUFNQUUP POFPGUIFPCUBJOFEBEESFTTFT %/4TFSWFS 4PDLFUUDQ 5$14PDLFUOFX 4FSWFS "GUFSFJUIFSBEESFTTGBNJMZJTSFTPMWFE 4FOE%/4RVFSZGPS*1W 4FOE%/4RVFSZGPS*1W 3FUVSO*1W%/4SFTQPOTF
fi STU 4UJMMXBJUJOHGPSUIF*1W%/4SFTQPOTF 4UBSUBDPOOFDUJPOBUUFNQUUP*1W

8BJUGPSUIFDPOOFDUJPOUPCFFTUBCMJTIFE 0ODFBDPOOFDUJPOBUUFNQUIBTTUBSUFE JUUIFOOFFETUPXBJUGPS$POOFDUJPO"UUFNQU%FMBZ %/4TFSWFS 4PDLFUUDQ 5$14PDLFUOFX 4FSWFS 4UBSUBDPOOFDUJPOBUUFNQUUP*1W 8BJUVQUPNTCFGPSFOFYUDPOOFDUJPO
4FOE%/4RVFSZGPS*1W 4FOE%/4RVFSZGPS*1W 3FUVSO*1W%/4SFTQPOTF fi STU 4UJMMXBJUJOHGPSUIF*1W%/4SFTQPOTF $POOFDUJPO"UUFNQU%FMBZ

4PJUTFUTUIFFYQJSBUJPOUJNFEF fi OFECZUIFTQFDJ fi DBUJPO JODPOOFDUJPO@BUUFNQU@EFMBZ@FYQJSFT@BU %/4TFSWFS 4PDLFUUDQ 5$14PDLFUOFX connection_attempt_delay_expires_at
= now + CONNECTION_ATTEMPT_DELAY 4FSWFS 8BJUGPSUIFDPOOFDUJPOUPCFFTUBCMJTIFE 4UBSUBDPOOFDUJPOBUUFNQUUP*1W 4FOE%/4RVFSZGPS*1W 4FOE%/4RVFSZGPS*1W 3FUVSO*1W%/4SFTQPOTF fi STU 4UJMMXBJUJOHGPSUIF*1W%/4SFTQPOTF

user_specified_connect_timeout_at ].compact.max end BOESFUVSOUPUIFCSBODI 8BJUGPSUIFDPOOFDUJPOUPCFFTUBCMJTIFE 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC

user_specified_connect_timeout_at ].compact.max end *GBOZDBOEJEBUFEFTUJOBUJPOBEESFTTFTBSF TUJMMBWBJMBCMF FYFDVUJPOFOUFSTUIFVQQFSCSBODI 8BJUGPSUIFDPOOFDUJPOUPCFFTUBCMJTIFE 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC "OZDBOEJEBUFEFTUJOBUJPOBEESFTTFT

user_specified_connect_timeout_at ].compact.max end .VTUCFOJM BOESFUVSOTDPOOFDUJPO@BUUFNQU@EFMBZ@FYQJSFT@BU 8BJUGPSUIFDPOOFDUJPOUPCFFTUBCMJTIFE connection_attempt_delay_expires_at = now + CONNECTION_ATTEMPT_DELAY 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC

0ODF$POOFDUJPO"UUFNQU%FMBZUJNFPVUFYQJSFT BDPOOFDUJPOBUUFNQUDBOCFTUBSUFEUPUIFOFYUBEESFTT %/4TFSWFS 4PDLFUUDQ 5$14PDLFUOFX 4FSWFS 8BJUGPSUIFDPOOFDUJPOUPCFFTUBCMJTIFE 4FOE%/4RVFSZGPS*1W 4FOE%/4RVFSZGPS*1W
3FUVSO*1W%/4SFTQPOTF fi STU 4UJMMXBJUJOHGPSUIF*1W%/4SFTQPOTF "GUFSNT TUBSUBOPUIFSBUUFNQU 4UBSUBDPOOFDUJPOBUUFNQUUP*1W

5IJTJTSFQFBUFEFWFSZNTVOUJMOPBEESFTTFTSFNBJO %/4TFSWFS 4PDLFUUDQ 5$14PDLFUOFX 4FSWFS 8BJUGPSUIFDPOOFDUJPOUPCFFTUBCMJTIFE 4FOE%/4RVFSZGPS*1W 4FOE%/4RVFSZGPS*1W 3FUVSO*1W%/4SFTQPOTF fi
STU 4UJMMXBJUJOHGPSUIF*1W%/4SFTQPOTF "GUFSNT TUBSUBOPUIFSBUUFNQU 4UBSUBDPOOFDUJPOBUUFNQUUP*1W "GUFSNT TUBSUBOPUIFSBUUFNQU

if resolution_store.empty_addrinfos? user_specified_connect_timeout_at = connect_timeout ? now + connect_timeout :
Float::INFINITY end 0ODFBDPOOFDUJPOBUUFNQUIBTCFFOTUBSUFEGPS UIFMBTUEFTUJOBUJPOBEESFTT BWBMVFJTBTTJHOFEUP VTFS@TQFDJ fi FE@DPOOFDU@UJNFPVU@BU 8BJUGPSOBNFSFTPMVUJPOPSDPOOFDUJPO 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC

Float::INFINITY end *GDPOOFDU@UJNFPVUJTTQFDJ fi FE VTFS@TQFDJ fi FE@DPOOFDU@UJNFPVU@BUJTTFUUP JUTFYQJSBUJPOUJNF 8BJUGPSOBNFSFTPMVUJPOPSDPOOFDUJPO 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC 5IFVTFSTQFDJ fi FEFYQJSBUJPOUJNF

Float::INFINITY end 0UIFSXJTF JUJTTFUUP'MPBU*/'*/*5: UPNFBOXBJUJOEF fi OJUFMZ 8BJUGPSOBNFSFTPMVUJPOPSDPOOFDUJPO 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC NFBOTJOEF fi OJUFMZ

0OUPQPGUIBU JUXBJUTGPSPOFPGUIFGPMMPXJOH ɹɹVOUJMBOZPGUIFDPOOFDUJPOBUUFNQUTJTFTUBCMJTIFE ɹɹVOUJMUIFPUIFSOBNFSFTPMVUJPODPNQMFUFT JGJUIBTOPUZFUDPNQMFUFE ɹɹVOUJMUIFFYQJSBUJPOUJNF %/4TFSWFS 4PDLFUUDQ 5$14PDLFUOFX
4FSWFS 8BJUGPSOBNFSFTPMVUJPOPSDPOOFDUJPO 8BJUJOHGPSUIFPUIFS%/4SFTQPOTF 8BJUJOHGPSUIFDPOOFDUJPOFTUBCMJTIFE

user_specified_connect_timeout_at ].compact.max end 5PEPUIBU JUSFUVSOTUPUIFCSBODI 4JODFUIFSFBSFOPDBOEJEBUFEFTUJOBUJPOBEESFTTFT MFGU FYFDVUJPOFOUFSTUIFMPXFSCSBODI 8BJUGPSOBNFSFTPMVUJPOPSDPOOFDUJPO 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC "OZDBOEJEBUFEFTUJOBUJPOBEESFTTFT

ends_at = if resolution_store.any_addrinfos? # ... else [ user_specified_resolv_timeout_at, user_specified_connect_timeout_at
].compact.max end BOESFUVSOTXIJDIFWFSJTHSFBUFS VTFS@TQFDJ fi FE@SFTPMW@UJNFPVU@BUPS VTFS@TQFDJ fi FE@DPOOFDU@UJNFPVU@BU user_specified_resolv_timeout_at = resolv_timeout ? now + resolv_timeout : Float::INFINITY user_specified_connect_timeout_at = connect_timeout ? now + connect_timeout : Float::INFINITY 8BJUGPSOBNFSFTPMVUJPOPSDPOOFDUJPO 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC

*UUIFOXBJUTVOUJMUIBUUJNF %FUFSNJOJOHUIFOBNFSFTPMVUJPOUJNFPVU %/4TFSWFS 4FSWFS 4PDLFUUDQ 5$14PDLFUOFX VTFS@TQFDJ fi FE@DPOOFDU@UJNFPVU@BU PSVTFS@TQFDJ
fi FE@SFTPMW@UJNFPVU@BU 8BJUJOHGPSBDPOOFDUJPOFTUBCMJTIFE 8BJUJOHGPSUIFPUIFS%/4SFTQPOTF

*GOFJUIFSOBNFSFTPMVUJPOOPSUIFDPOOFDUJPODPNQMFUFT XJUIJOUIFTQFDJ fi FEUJNF BUJNFPVUFSSPSJTSBJTFE %/4TFSWFS 4PDLFUUDQ 5$14PDLFUOFX 4FSWFS 8BJUGPSOBNFSFTPMVUJPOPSDPOOFDUJPO
$BODFMUIFSFNBJOJOH%/4RVFSZ $BODFMUIFBUUFNQUT VTFS@TQFDJ fi FE@DPOOFDU@UJNFPVU@BU PSVTFS@TQFDJ fi FE@SFTPMW@UJNFPVU@BU

*GUIFFYQJSBUJPOUJNFJT'MPBU*/'*/*5: UIFQSPDFTTXBJUTJOEF fi OJUFMZ %/4TFSWFS 4PDLFUUDQ 5$14PDLFUOFX 4FSWFS 8BJUGPSOBNFSFTPMVUJPOPSDPOOFDUJPO
8BJUJOHGPSUIFPUIFS%/4SFTQPOTF 8BJUJOHGPSBDPOOFDUJPOFTUBCMJTIFE

*GUIFOBNFSFTPMVUJPOGPSUIFPUIFSBEESFTTGBNJMZ DPNQMFUFTXJUIJOUIFXBJUQFSJPE 8IFOBMMOBNFSFTPMVUJPOJTDPNQMFUF %/4TFSWFS 4PDLFUUDQ 5$14PDLFUOFX 4FSWFS SFTPMW@UJNFPVU DPOOFDU@UJNFPVU 3FUVSOUIFPUIFS%/4SFTQPOTF
8BJUJOHGPSBDPOOFDUJPOFTUBCMJTIFE

8IFOBMMOBNFSFTPMVUJPOJTDPNQMFUF if resolution_store.resolved?(:ipv4) if resolution_store.resolved?(:ipv6) # ... user_specified_resolv_timeout_at = nil
end # ... end VTFS@TQFDJ fi FE@SFTPMW@UJNFPVU@BUJT OPMPOHFSOFFEFE TPJUJTTFUUPOJM 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC

"GUFSUIBU JUTUBSUTDPOOFDUJPOBUUFNQUTUP UIFSFNBJOJOHSFTPMWFEBEESFTTFTFWFSZNT $POUJOVFTUBSUJOHDPOOFDUJPOBUUFNQUT 4PDLFUUDQ 5$14PDLFUOFX 4FSWFS "GUFSNT TUBSUBOPUIFSBUUFNQU 4UBSUBDPOOFDUJPOBUUFNQU
"GUFSNT TUBSUBOPUIFSBUUFNQU

$POUJOVFTUBSUJOHDPOOFDUJPOBUUFNQUT if resolution_store.empty_addrinfos? user_specified_connect_timeout_at = connect_timeout ? now + connect_timeout
: Float::INFINITY end 0ODFBDPOOFDUJPOBUUFNQUIBTCFFOTUBSUFEGPS UIFMBTUBEESFTT VTFS@TQFDJ fi FE@DPOOFDU@UJNFPVU@BUJTTFUBHBJO 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC

user_specified_connect_timeout_at ].compact.max end 5IJTJTUIFOUBLFOBTUIFFYQJSBUJPOUJNF user_specified_connect_timeout_at = connect_timeout ? now + connect_timeout : Float::INFINITY $POUJOVFTUBSUJOHDPOOFDUJPOBUUFNQUT 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC user_specified_resolv_timeout_at = nil

*UUIFOXBJUTVOUJMBOZPGUIFDPOOFDUJPOBUUFNQUTJT FTUBCMJTIFE PSVOUJMUIFFYQJSBUJPOUJNF $POUJOVFXBJUJOHGPSBDPOOFDUJPOFTUBCMJTIFE 4PDLFUUDQ 5$14PDLFUOFX 8BJUJOHGPSBDPOOFDUJPOFTUBCMJTIFE 4FSWFS

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DPOOFDU@UJNFPVU

*GUIFFYQJSBUJPOUJNFJT'MPBU*/'*/*5: UIFQSPDFTTXBJUTJOEF fi OJUFMZ $POUJOVFXBJUJOHGPSBDPOOFDUJPOFTUBCMJTIFE 4PDLFUUDQ 5$14PDLFUOFX 4FSWFS 8BJUJOHGPSBDPOOFDUJPOFTUBCMJTIFE

GBTU@GBMMCBDLJTFOBCMFECZEFGBVMU CVUJUDBOCFEJTBCMFEJOUIFTFUUJOHT 8IFOGBTU@GBMMCBDLJTEJTBCMFE UIFJNQMFNFOUBUJPOTPG4PDLFUUDQ BOE5$14PDLFUOFXSFNBJOVODIBOHFEGSPNUIPTFJO3VCZ # An argument to
the method Socket.tcp(host, port, fast_fallback: false) TCPSocket.new(host, port, fast_fallback: false) # An accessor method on the Socket class Socket.tcp_fast_fallback = false # An environment variable TCP_NO_FAST_FALLBACK = 1

/PX MFU`TSFUVSOUPUIFQSFTFOU UIF3VCZEFWFMPQNFOUFSB

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Timeout in Net::HTTP and other standard libraries. lib/net/http.rb 945 s = Timeout.timeout(@open_timeout, Net::OpenTimeout) { 946 begin 947 TCPSocket.open(conn_address, conn_port, @local_host, @local_port) 948 rescue => e 949 raise e, "Failed to open TCP connection to " + 950 "#{conn_address}:#{conn_port} (#{e.message})" 951 end 952 } 5IFUJNFPVUMJCSBSZTNFUIPE

5IFUJNFPVUMJCSBSZXJUI3BDUPS 3VCZ require "timeout" r = Ractor.new do Timeout.timeout(1) do
sleep 2 end end r.take )PXFWFS BTPG3VCZ UIFUJNFPVUMJCSBSZEJEOPUXPSLXFMM XJUI3BDUPS 6TJOHJUJOTJEFBOPONBJO3BDUPSXPVMESBJTFBOFSSPS # => Ractor::IsolationError can not access non-shareable objects in constant Timeout::State::GLOBAL_STATE by non-main ractor.

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$BODFMUIF*1WBUUFNQU SFTPMW@UJNFPVUNT

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4FSWFS 5IFPWFSBMMUJNFPVUNT $BODFMUIF*1WBUUFNQU $BODFMUIF*1W%/4RVFSZ SFTPMW@UJNFPVUNT

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0CUBJOUXPBEESFTTFT" # DPOOFDU@UJNFPVUNT

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DPOOFDU@UJNFPVUNT

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DPOOFDU@UJNFPVUNT

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FH8IFO$POOFDUJPO"UUFNQU%FMBZPDDVST $BODFMUIFDPOOFDUJPOUP# $BODFMUIFDPOOFDUJPOUP" 5IFPWFSBMMUJNFPVUNT NT DPOOFDU@UJNFPVUNT

5IFTFBSFUIFEJ ff i DVMUJFTPGUJNFPVUIBOEMJOH XJUIGBTU@GBMMCBDL

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4UBSUBOFXDPOOFDUJPOBUUFNQU 4PDLFUUDQ 5$14PDLFUOFX

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5IFPWFSBMMUJNFPVUNTʷ 4PDLFUUDQ 5$14PDLFUOFX

5IJTTIPXTUIBUFWFOJGCPUISFTPMW@UJNFPVUBOE DPOOFDU@UJNFPVUBSFVTFE UIFZTUJMMDBOOPUSFQMBDFUIFUJNFPVUMJCSBSZ

"EEPQFO@UJNFPVUBTPWFSBMMUJNFPVUPQUJPOGPS4PDLFUUDQ 5PBEESFTTUIJT PQFO@UJNFPVUXBTQSPQPTFEGPS3VCZ -JLFUIFUJNFPVUMJCSBSZ NBOBHFTUIFUJNFPVUGSPN OBNFSFTPMVUJPOUPDPOOFDUJPOFTUBCMJTINFOU GSPNTIJPJNN .JTBLJ4IJPJ IUUQTCVHTSVCZMBOHPSHJTTVFT

BOPQFO@UJNFPVULFZXPSEBSHVNFOU 8IFOUIFNFUIPEJTDBMMFEXJUIPQFO@UJNFPVU TQFDJ fi FE 4PDLFUUDQ 5$14PDLFUOFX 4FSWFS %/4TFSWFS Socket.tcp("ruby-lang.org",
80, open_timeout: 1) PQFO@UJNFPVU "UUFNQUUPDPOOFDU 3FTPMWFUIFIPTUOBNF

BOPQFO@UJNFPVULFZXPSEBSHVNFOU JGUIFDPOOFDUJPOUPUIFTFSWFSJTOPUFTUBCMJTIFE XJUIJOUIFTQFDJ fi FEUJNF 4PDLFUUDQ 5$14PDLFUOFX 4FSWFS %/4TFSWFS Socket.tcp("ruby-lang.org",
80, open_timeout: 1) "UUFNQUUPDPOOFDU 3FTPMWFUIFIPTUOBNF PQFO@UJNFPVU

BOPQFO@UJNFPVULFZXPSEBSHVNFOU BUJNFPVUFSSPSJTSBJTFE 4PDLFUUDQ 5$14PDLFUOFX 4FSWFS %/4TFSWFS Socket.tcp("ruby-lang.org", 80, open_timeout: 1)
$BODFMUPDPOOFDU $BODFMUPSFTPMWFUIFIPTUOBNF PQFO@UJNFPVU

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80, open_timeout: 1) $BODFMUPDPOOFDU $BODFMUPSFTPMWFUIFIPTUOBNF PQFO@UJNFPVU

'JSTU XFOFFEUPDPOTJEFSIPXPQFO@UJNFPVU SFMBUFTUPUIFFYJTUJOHUJNFPVUPQUJPOT 8IFOPQFO@UJNFPVUJTVTFEXJUI SFTPMW@UJNFPVUBOEPSDPOOFDU@UJNFPVU JOXIBUDBTFT BOEXIJDIUJNFPVUTIPVMEUBLFQSFDFEFODF 6TJOHPQFO@UJNFPVUBOEPUIFSUJNFPVUPQUJPOTUPHFUIFS

'JSTU XFOFFEUPDPOTJEFSIPXPQFO@UJNFPVU SFMBUFTUPUIFFYJTUJOHUJNFPVUPQUJPOT 8IFOPQFO@UJNFPVUJTVTFEXJUI SFTPMW@UJNFPVUBOEPSDPOOFDU@UJNFPVU JOXIBUDBTFT BOEXIJDIUJNFPVUTIPVMEUBLFQSFDFEFODF 5PPDPNQMFY 6TJOHPQFO@UJNFPVUBOEPUIFSUJNFPVUPQUJPOTUPHFUIFS

/PUVTJOHPQFO@UJNFPVUBOEPUIFSUJNFPVUPQUJPOTUPHFUIFS def self.tcp( host, port, ..., connect_timeout: nil, resolv_timeout: nil,
open_timeout: nil, ..., & ) if open_timeout && (connect_timeout || resolv_timeout) raise ArgumentError, "Cannot specify open_timeout along with connect_timeout or resolv_timeout" end # ... end *GPQFO@UJNFPVUJTTQFDJ fi FEUPHFUIFSXJUI BOPUIFSUJNFPVUBSHVNFOU JUJTUSFBUFEBTJOWBMJEBOE BO"SHVNFOU&SSPSJTSBJTFE 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC .VTUCFSBJTFE "EEFE

PQFO@UJNFPVUXJUIGBTU@GBMMCBDL ends_at = if resolution_store.any_addrinfos? resolution_delay_expires_at || connection_attempt_delay_expires_at else [
user_specified_resolv_timeout_at, user_specified_connect_timeout_at ].compact.max end /FYU XFOFFEUPDPOTJEFSIPXUPNBLFGBTU@GBMMCBDL XPSLXJUIGBTU@GBMMCBDL 5IJTJTUIFDPEFBTPG3VCZ 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC *O3VCZ

user_specified_connect_timeout_at ].compact.max end *GUIFSFBSFDBOEJEBUFEFTUJOBUJPOBEESFTTFT JUSFUVSOTUIFUJNFXIFOUIFOFYUDPOOFDUJPOBUUFNQU DBOCFTUBSUFE PQFO@UJNFPVUXJUIGBTU@GBMMCBDL "OZDBOEJEBUFEFTUJOBUJPOBEESFTTFT 3FUVSOTXIFOUPTUBSUUIFOFYUDPOOFDUJPOBUUFNQU 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC *O3VCZ

user_specified_connect_timeout_at ].compact.max end 0UIFSXJTF JUSFUVSOTUIFUJNF XIFOBUJNFPVUFSSPSTIPVMECFSBJTFE PQFO@UJNFPVUXJUIGBTU@GBMMCBDL 3FUVSOTXIFOUPSBJTFBUJNFPVUFSSPS "OZDBOEJEBUFEFTUJOBUJPOBEESFTTFT 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC *O3VCZ

user_specified_connect_timeout_at ].compact.max end 8JUIPQFO@UJNFPVU BUJNFPVUFSSPSOFFETUPCFSBJTFE BUUIFTQFDJ fi FEUJNFSFHBSEMFTTPGXIFUIFSUIFSFBSF BOZDBOEJEBUFEFTUJOBUJPOBEESFTTFT PQFO@UJNFPVUXJUIGBTU@GBMMCBDL "OZDBOEJEBUFEFTUJOBUJPOBEESFTTFT 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC *O3VCZ

def self.tcp_with_fast_fallback( host, port, ..., connect_timeout: nil, resolv_timeout: nil, open_timeout:
nil, ) # ... resolution_delay_expires_at = nil connection_attempt_delay_expires_at = nil user_specified_connect_timeout_at = nil user_specified_open_timeout_at = open_timeout ? now + open_timeout : nil # ... end 8JUIUIJTJONJOE JOUIFNPEJ fi FEDPEF BWBMVFJTBTTJHOFEUPVTFS@TQFDJ fi FE@PQFO@UJNFPVU@BU BUUIFTUBSUPGUIFNFUIPE PQFO@UJNFPVUXJUIGBTU@GBMMCBDL 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC *O3VCZ

nil, ) # ... resolution_delay_expires_at = nil connection_attempt_delay_expires_at = nil user_specified_connect_timeout_at = nil user_specified_open_timeout_at = open_timeout ? now + open_timeout : nil # ... end *GPQFO@UJNFPVUJTDPO fi HVSFE UIFWBSJBCMFJTTFUUPUIFUJNFXIFOPQFO@UJNFPVU XJMMFYQJSF PQFO@UJNFPVUXJUIGBTU@GBMMCBDL 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC *O3VCZ

nil, ) # ... resolution_delay_expires_at = nil connection_attempt_delay_expires_at = nil user_specified_connect_timeout_at = nil user_specified_open_timeout_at = open_timeout ? now + open_timeout : nil # ... end 0UIFSXJTF JUJTTFUUPOJM PQFO@UJNFPVUXJUIGBTU@GBMMCBDL 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC *O3VCZ

ends_at = if resolution_store.any_addrinfos? /FYUJTBDIBOHFUPUIFDPOEJUJPOBMCSBODIUIBU SFUVSOTUIFFYQJSBUJPOUJNF 8IFOUIFSFBSFDBOEJEBUFEFTUJOBUJPOBEESFTTFT PQFO@UJNFPVUXJUIGBTU@GBMMCBDL 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC "OZDBOEJEBUFEFTUJOBUJPOBEESFTTFT
*O3VCZ

ends_at = if resolution_store.any_addrinfos? [(resolution_delay_expires_at || connection_attempt_delay_expires_at), UIFFYQJSBUJPOUJNFGPS3FTPMVUJPO%FMBZPS $POOFDUJPO"UUFNQU%FMBZJTDPNQBSFE PQFO@UJNFPVUXJUIGBTU@GBMMCBDL
'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC *O3VCZ

ends_at = if resolution_store.any_addrinfos? [(resolution_delay_expires_at || connection_attempt_delay_expires_at), user_specified_open_timeout_at].compact.min XJUIUIFFYQJSBUJPOUJNFGPSPQFO@UJNFPVU
PQFO@UJNFPVUXJUIGBTU@GBMMCBDL user_specified_open_timeout_at = open_timeout ? now + open_timeout : nil 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC *O3VCZ

ends_at = if resolution_store.any_addrinfos? [(resolution_delay_expires_at || connection_attempt_delay_expires_at), user_specified_open_timeout_at].compact.min XJUIUIFFYQJSBUJPOUJNFGPSPQFO@UJNFPVU
BOEUIFFBSMJFSPOFJTSFUVSOFE PQFO@UJNFPVUXJUIGBTU@GBMMCBDL 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC user_specified_open_timeout_at = open_timeout ? now + open_timeout : nil *O3VCZ

ends_at = if resolution_store.any_addrinfos? [(resolution_delay_expires_at || connection_attempt_delay_expires_at), user_specified_open_timeout_at].compact.min # ...
end if expired?(now, user_specified_open_timeout_at) raise(IO::TimeoutError, "user specified timeout for #{host}:#{port}") end *GUIFPQFO@UJNFPVUFYQJSBUJPOUJNFIBT BMSFBEZQBTTFEXIFOUIFXBJUFOET BUJNFPVUFSSPSJTSBJTFE PQFO@UJNFPVUXJUIGBTU@GBMMCBDL 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC .VTUCFSBJTFE *O3VCZ

ends_at = if resolution_store.any_addrinfos? [(resolution_delay_expires_at || connection_attempt_delay_expires_at), user_specified_open_timeout_at].compact.min *GPQFO@UJNFPVUJTOPUTQFDJ fi
FE UIFWBMVFPGVTFS@TQFDJ fi FE@PQFO@UJNFPVU@BUJTOJM PQFO@UJNFPVUXJUIGBTU@GBMMCBDL 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC user_specified_open_timeout_at = open_timeout ? now + open_timeout : nil *O3VCZ

ends_at = if resolution_store.any_addrinfos? [(resolution_delay_expires_at || connection_attempt_delay_expires_at), user_specified_open_timeout_at].compact.min *OUIBUDBTF BTCFGPSF
UIFSFUVSOWBMVFJT UIFFYQJSBUJPOUJNFGPSFJUIFS3FTPMVUJPO%FMBZ PS$POOFDUJPO"UUFNQU%FMBZ PQFO@UJNFPVUXJUIGBTU@GBMMCBDL 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC 3FUVSOTXIFOUPTUBSUUIFOFYUDPOOFDUJPOBUUFNQU *O3VCZ

ends_at = if resolution_store.any_addrinfos? [(resolution_delay_expires_at || connection_attempt_delay_expires_at), user_specified_open_timeout_at].compact.min *GUIFSFBSFOPDBOEJEBUFEFTUJOBUJPOBEESFTTFT PQFO@UJNFPVUXJUIGBTU@GBMMCBDL
'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC "OZDBOEJEBUFEFTUJOBUJPOBEESFTTFT *O3VCZ

ends_at = if resolution_store.any_addrinfos? [(resolution_delay_expires_at || connection_attempt_delay_expires_at), user_specified_open_timeout_at].compact.min elsif user_specified_open_timeout_at
JGPQFO@UJNFPVUJTTQFDJ fi FE JUJTUIFPOMZUJNFPVUUIBUDBODBVTFBUJNFPVUFSSPS PQFO@UJNFPVUXJUIGBTU@GBMMCBDL 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC *O3VCZ

user_specified_open_timeout_at else # ... end 4PUIFSFUVSOWBMVFJTTJNQMZ VTFS@TQFDJ fi FE@PQFO@UJNFPVU@BU PQFO@UJNFPVUXJUIGBTU@GBMMCBDL 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC user_specified_open_timeout_at = open_timeout ? now + open_timeout : nil *O3VCZ

user_specified_open_timeout_at else [ user_specified_resolv_timeout_at, user_specified_connect_timeout_at ].compact.max end *GVTFS@TQFDJ fi FE@PQFO@UJNFPVU@BUJTOJM JUGBMMTCBDLUPUIFPUIFSVTFSTQFDJ fi FEUJNFPVUWBMVFT 5IJTNBJOUBJOTUIFCFIBWJPSCFGPSFUIFDIBOHF PQFO@UJNFPVUXJUIGBTU@GBMMCBDL 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC nil *O3VCZ

user_specified_open_timeout_at else [ user_specified_resolv_timeout_at, user_specified_connect_timeout_at ].compact.max end 8JUIUIJT PQFO@UJNFPVUJTOPXDPNQMFUF XIFOGBTU@GBMMCBDLJTFOBCMFE PQFO@UJNFPVUXJUIGBTU@GBMMCBDL 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC *O3VCZ

/FYU MFUTBMTPMPPLBUUIFJNQMFNFOUBUJPO XIFOGBTU@GBMMCBDLJTEJTBCMFE

8IFOGBTU@GBMMCBDLJTEJTBCMFE 4PDLFUUDQBOE5$14PDLFUOFXQFSGPSNOBNFSFTPMVUJPO fi STU BOEUIFOTUBSUDPOOFDUJPOBUUFNQUT 4FSWFS 4PDLFUUDQ 5$14PDLFUOFX
%/4TFSWFS PQFO@UJNFPVUXJUIPVUGBTU@GBMMCBDL "UUFNQUUPDPOOFDU 3FTPMWFUIFIPTUOBNF

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PQFO@UJNFPVU PQFO@UJNFPVU

0GUIFTF GPSUIFOBNFSFTPMVUJPOUJNFPVU UIFFYJTUJOHJNQMFNFOUBUJPODBOCFVTFEBTJT 4FSWFS 4PDLFUUDQ 5$14PDLFUOFX %/4TFSWFS PQFO@UJNFPVUXJUIPVUGBTU@GBMMCBDL 3FTPMWFUIFIPTUOBNF
PQFO@UJNFPVU

def self.tcp_without_fast_fallback( host, port, ..., connect_timeout: nil, resolv_timeout: nil, )
# ... Addrinfo.foreach(host, port, nil, :STREAM, timeout: resolv_timeout) {|ai| # ... } # ... end 5IJTJTUIF3VCZJNQMFNFOUBUJPO XIFOGBTU@GBMMCBDLJTEJTBCMFE PQFO@UJNFPVUXJUIPVUGBTU@GBMMCBDL *O3VCZ 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC

def self.tcp_without_fast_fallback( host, port, ..., connect_timeout: nil, resolv_timeout: nil, )
# ... Addrinfo.foreach(host, port, nil, :STREAM, timeout: resolv_timeout) {|ai| # ... } # ... end 5IFSFNBJOJOHUJNFVOUJMSFTPMW@UJNFPVUFYQJSFTJT BMSFBEZQBTTFEUPUIFNFUIPEPSGVODUJPOUIBU QFSGPSNTOBNFSFTPMVUJPOBTUIFUJNFPVUEVSBUJPO PQFO@UJNFPVUXJUIPVUGBTU@GBMMCBDL 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC "EESJOGPGPSFBDIDBMMT"EESJOGPHFUBEESJOGP JOUFSOBMMZXJUIUJNFPVU *O3VCZ

def self.tcp_without_fast_fallback( host, port, ..., connect_timeout: nil, resolv_timeout: nil, open_timeout:
nil ) # ... timeout = open_timeout ? open_timeout : resolv_timeout starts_at = current_clock_time Addrinfo.foreach(host, port, nil, :STREAM, timeout: timeout) {|ai| # ... } # ... end JGPQFO@UJNFPVUJTTQFDJ fi FE JUTWBMVFDBOCFQBTTFE BTUIFUJNFPVUWBMVFJOTUFBEPGSFTPMW@UJNFPVU TP UIBUOBNFSFTPMVUJPOUJNFTPVUBUUIFTQFDJ fi FEUJNF PQFO@UJNFPVUXJUIPVUGBTU@GBMMCBDL 6TFPQFO@UJNFPVUJOTUFBEPGSFTPMW@UJNFPVU 'PS4PDLFUUDQIUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC *O3VCZ "EEFE

3FBMMZ

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"TPG3VCZ

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"1*POMZ "1*POMZ 3VCZ !? !?

-FUTSFXJOEUIFDMPDLBOEMPPLCBDLPOUIFEFWFMPQNFOU MFBEJOHVQUP3VCZ UJNFPVU "EESJOGPHFUBEESJOGP DPOOFDU@UJNFPVU SFTPMW@UJNFPVU PQFO@UJNFPVU 4PDLFUUDQ5$14PDLFUOFX XJUIPVUGBTU@GBMMCBDL 4PDLFUUDQ5$14PDLFUOFX
XJUIGBTU@GBMMCBDL "1*POMZ "1*POMZ 3VCZ

*O3VCZ UIFJNQMFNFOUBUJPOPGOBNFSFTPMVUJPOUJNFPVUT XBTOPUBEPQUFE BOEPOMZUIF"1*XBTBEEFE UJNFPVU "EESJOGPHFUBEESJOGP DPOOFDU@UJNFPVU SFTPMW@UJNFPVU PQFO@UJNFPVU "1*POMZ
4PDLFUUDQ5$14PDLFUOFX "1*POMZ 3VCZ

*O3VCZ XIJMFJNQSPWFNFOUTXFSFNBEFUPBMMPXOBNFSFTPMVUJPO UPCFJOUFSSVQUFE OBNFSFTPMVUJPOUJNFPVUTXFSFOPUJNQMFNFOUFE UJNFPVU "EESJOGPHFUBEESJOGP DPOOFDU@UJNFPVU SFTPMW@UJNFPVU PQFO@UJNFPVU "1*POMZ
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4PDLFUUDQ5$14PDLFUOFX XJUIPVUGBTU@GBMMCBDL 4PDLFUUDQ5$14PDLFUOFX XJUIGBTU@GBMMCBDL "1*POMZ "1*POMZ 3VCZ

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4PDLFUUDQ ➡︎ "EESJOGPHFUBEESJOGP ➡︎ BEESJOGP@T@HFUBEESJOGP ɹ ➡︎ BEESJOGP@MJTU@OFX
ɹ ➡︎ DBMM@HFUBEESJOGP ɹɹ ➡︎ STPDL@HFUBEESJOGP "EESJOGPHFUBEESJOGPDBMMT STPDL@HFUBEESJOGP JOUFSOBMMZ 8IBUJTIBQQFOJOHXJUIUIFOBNFSFTPMVUJPOUJNFPVUT

ɹ ➡︎ DBMM@HFUBEESJOGP ɹɹ ➡︎ STPDL@HFUBEESJOGP 5$14PDLFUOFXDBMMT STPDL@HFUBEESJOGP JOUFSOBMMZ UPP 8IBUJTIBQQFOJOHXJUIUIFOBNFSFTPMVUJPOUJNFPVUT 5$14PDLFUOFX ➡︎ 5$14PDLFUJOJUJBMJ[F ➡︎ STPDL@JOJU@JOFUTPDL ɹ ➡︎ JOJU@JOFUTPDL@JOUFSOBM ɹ ➡︎ STPDL@BEESJOGP ɹ ➡︎ STPDL@HFUBEESJOGP

ɹ ➡︎ DBMM@HFUBEESJOGP ɹɹ ➡︎ STPDL@HFUBEESJOGP 8IBUUIFZIBWFJODPNNPO JTUIFDBMMUPSTPDL@HFUBEESJOGP DPNNPO 8IBUJTIBQQFOJOHXJUIUIFOBNFSFTPMVUJPOUJNFPVUT 5$14PDLFUOFX ➡︎ 5$14PDLFUJOJUJBMJ[F ➡︎ STPDL@JOJU@JOFUTPDL ɹ ➡︎ JOJU@JOFUTPDL@JOUFSOBM ɹ ➡︎ STPDL@BEESJOGP ɹ ➡︎ STPDL@HFUBEESJOGP

static struct rb_addrinfo * call_getaddrinfo( VALUE node, VALUE service, VALUE
family, VALUE socktype, VALUE protocol, VALUE flags, int socktype_hack, VALUE timeout ) { // ... } 5IFDPEFUIBUDBMMTSTPDL@HFUBEESJOGP 8IBUJTIBQQFOJOHXJUIUIFOBNFSFTPMVUJPOUJNFPVUT IUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUSBEESJOGPD *O3VCZ

family, VALUE socktype, VALUE protocol, VALUE flags, int socktype_hack, VALUE timeout ) { // ... } 5IFDPEFUIBUDBMMTSTPDL@HFUBEESJOGP BMSFBEZUBLFTUIFVTFSTQFDJ fi FEUJNFPVUWBMVF BTBOBSHVNFOU 8IBUJTIBQQFOJOHXJUIUIFOBNFSFTPMVUJPOUJNFPVUT 5IFVTFSTQFDJ fi FEUJNFPVUWBMVF IUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUSBEESJOGPD *O3VCZ

family, VALUE socktype, VALUE protocol, VALUE flags, int socktype_hack, VALUE timeout ) { // ... res = rsock_getaddrinfo(node, service, &hints, socktype_hack); // ... } #VUJOGBDU JUXBTOPUCFJOHQBTTFEUPSTPDL@HFUBEESJOGP 8IBUJTIBQQFOJOHXJUIUIFOBNFSFTPMVUJPOUJNFPVUT 5IFWBMVFJTOPUQBTTFE 5IFVTFSTQFDJ fi FEUJNFPVUWBMVF IUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUSBEESJOGPD *O3VCZ

struct rb_addrinfo* rsock_getaddrinfo( VALUE host, VALUE port, struct addrinfo *hints,
int socktype_hack ) { // ... } "OEPOUIFSTPDL@HFUBEESJOGP TJEF UIFSFXBTOP QBSBNFUFSGPSSFDFJWJOHUIFWBMVF5IFVTFSTQFDJ fi FE UJNFPVUWBMVFTJNQMZWBOJTIFEBUUIJTQPJOU 5IFVTFSTQFDJ fi FEUJNFPVUWBMVFDBOOPUCFQBTTFE 8IBUJTIBQQFOJOHXJUIUIFOBNFSFTPMVUJPOUJNFPVUT IUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUSBEESJOGPD *O3VCZ

'JYUIFOBNFSFTPMVUJPOUJNFPVUT struct rb_addrinfo* rsock_getaddrinfo( VALUE host, VALUE port, struct addrinfo
*hints, int socktype_hack VALUE timeout ) { // ... } 4P STPDL@HFUBEESJOGP XBTDIBOHFEUPSFDFJWF UIFVTFSTQFDJ fi FEUJNFPVUWBMVFBTXFMM "EEFE IUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUSBEESJOGPD *O3VCZ

struct rb_addrinfo* rsock_getaddrinfo( VALUE host, VALUE port, struct addrinfo *hints,
int socktype_hack VALUE timeout ) { // ... int t = NIL_P(timeout) ? -1 : rsock_value_timeout_to_msec(timeout); error = rb_getaddrinfo(hostp, portp, hints, &ai, t); // ... } *UUIFOQBTTFTUIBUWBMVFGVSUIFSEPXOUP UIFGVODUJPOJUDBMMTJOUFSOBMMZ 'JYUIFOBNFSFTPMVUJPOUJNFPVUT IUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUSBEESJOGPD "EEFE *O3VCZ

static void * wait_getaddrinfo(void *ptr) { // ... long msec
= arg->timeout; if (msec == 0) { arg->cancelled = 1; arg->timedout = 1; } else if (msec > 0) { rb_native_cond_timedwait(&arg->cond, &arg->lock, msec); if (!arg->done) { arg->cancelled = 1; arg->timedout = 1; } // ... } // ... } 8IFOXBJUJOHGPSOBNFSFTPMVUJPO JUOPXUFSNJOBUFTUIFXBJUBGUFSUIFTQFDJ fi FEUJNF JGBUJNFPVUWBMVFJTHJWFO 'JYUIFOBNFSFTPMVUJPOUJNFPVUT 8BJUVOUJMUIFOBNFSFTPMVUJPOUJNFPVUFYQJSFT 5IFVTFSTQFDJ fi FEUJNFPVUWBMVF IUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUSBEESJOGPD *O3VCZ

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3FTPMWFUIFIPTUOBNF PQFO@UJNFPVU

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starts_at = current_clock_time Addrinfo.foreach(host, port, nil, :STREAM, timeout:) {|ai| #
... timeout = if open_timeout t = open_timeout - (current_clock_time - starts_at) t.negative? ? 0 : t # ... end # ... } 4P CFGPSFTUBSUJOHUIFDPOOFDUJPOBUUFNQU JUPCUBJOTUIFSFNBJOJOHUJNFVOUJM PQFO@UJNFPVUFYQJSFT PQFO@UJNFPVUXJUIPVUGBTU@GBMMCBDL IUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC 5IFSFNBJOJOHUJNFVOUJMPQFO@UJNFPVUFYQJSFT

... timeout = if open_timeout t = open_timeout - (current_clock_time - starts_at) t.negative? ? 0 : t # ... end sock = local_addr ? ai.connect_from(local_addr, timeout: timeout) : ai.connect(timeout: timeout) # ... } BOEQBTTFTJUBTUIFUJNFPVUEVSBUJPO GPSUIFDPOOFDUJPOBUUFNQU PQFO@UJNFPVUXJUIPVUGBTU@GBMMCBDL IUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC 8BJUVOUJMUIFUJNFPVUFYQJSFT 5IFSFNBJOJOHUJNFVOUJMPQFO@UJNFPVUFYQJSFT

... timeout = if open_timeout t = open_timeout - (current_clock_time - starts_at) t.negative? ? 0 : t # ... end sock = local_addr ? ai.connect_from(local_addr, timeout: timeout) : ai.connect(timeout: timeout) # ... } *GUIBUDPOOFDUJPOBUUFNQUGBJMT UIFSFNBJOJOHUJNFJT VQEBUFECFGPSFUIFOFYUDPOOFDUJPOBUUFNQUJTTUBSUFE PQFO@UJNFPVUXJUIPVUGBTU@GBMMCBDL IUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC 6QEBUFPOSFNBJOJOHUJNFVOUJMUJNFPVU

... timeout = if open_timeout t = open_timeout - (current_clock_time - starts_at) t.negative? ? 0 : t # ... end sock = local_addr ? ai.connect_from(local_addr, timeout: timeout) : ai.connect(timeout: timeout) # ... } 0ODFUIFSFNBJOJOHUJNFJTFYIBVTUFE BUJNFPVUFSSPSJTSBJTFE PQFO@UJNFPVUXJUIPVUGBTU@GBMMCBDL IUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC .VTUCFSBJTFE 6QEBUFPOSFNBJOJOHUJNFVOUJMUJNFPVU

... timeout = if open_timeout t = open_timeout - (current_clock_time - starts_at) t.negative? ? 0 : t else connect_timeout end sock = local_addr ? ai.connect_from(local_addr, timeout: timeout) : ai.connect(timeout: timeout) # ... } *GPQFO@UJNFPVUJTOPUTQFDJ fi FE UIFWBMVFPG DPOOFDU@UJNFPVUJTVTFEBTUIFDPOOFDUJPOUJNFPVU 5IJTNBJOUBJOTUIFCFIBWJPSCFGPSFUIFDIBOHF PQFO@UJNFPVUXJUIPVUGBTU@GBMMCBDL 8BJUVOUJMUIFUJNFPVUFYQJSFT PSJOEF fi OJUFMZ 5IFWBMVFTQFDJ fi FEGPSDPOOFDU@UJNFPVU PSOJM IUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC

... timeout = if open_timeout t = open_timeout - (current_clock_time - starts_at) t.negative? ? 0 : t else connect_timeout end sock = local_addr ? ai.connect_from(local_addr, timeout: timeout) : ai.connect(timeout: timeout) # ... } 8JUIUIJT PQFO@UJNFPVUJTBMTPDPNQMFUF XIFOGBTU@GBMMCBDLJTEJTBCMFE PQFO@UJNFPVUXJUIPVUGBTU@GBMMCBDL IUUQTHJUIVCDPNSVCZSVCZCMPCSVCZ@@FYUTPDLFUMJCTPDLFUSC

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3FQMBDF5JNFPVUUJNFPVUXJUI5$14PDLFUPQFO PQFO@UJNFPVU BQVMMSFRVFTUUPSFNPWFOFUIUUQ`TEFQFOEFODZ POUIFUJNFPVUMJCSBSZXBTDSFBUFECZ!PTZPZV CZPTZPZVIUUQTHJUIVCDPNSVCZOFUIUUQQVMM

3FNPWFOFUIUUQ`TEFQFOEFODZPOUIFUJNFPVUMJCSBSZ "GUFSEJTDVTTJPOPOIPXUPQSFTFSWFCBDLXBSEDPNQBUJCJMJUZ BOETFWFSBM fi YFT UIJTDIBOHFXBTJOUSPEVDFEJOUPOFUIUUQ BOEXBTVMUJNBUFMZSFMFBTFEBTOFUIUUQ CZPTZPZVIUUQTHJUIVCDPNSVCZOFUIUUQQVMM CZFSFHPOIUUQTHJUIVCDPNSVCZOFUQSPUPDPMQVMM CZFSFHPOIUUQTHJUIVCDPNSVCZOFUIUUQQVMM

3FNPWFOFUIUUQ`TEFQFOEFODZPOUIFUJNFPVUMJCSBSZ 5IJTSFTPMWFEBMPOHTUBOEJOHDPODFSOEBUJOHCBDLUP UIF3VCZEFWFMPQNFOUFSB GSPN(MBTT@TBHB .BTBLJ.BUTVTIJUB IUUQTCVHTSVCZMBOHPSHJTTVFT Currently, we use Timeout
in Net::HTTP and other standard libraries. lib/net/http.rb 945 s = Timeout.timeout(@open_timeout, Net::OpenTimeout) { 946 begin 947 TCPSocket.open(conn_address, conn_port, @local_host, @local_port) 948 rescue => e 949 raise e, "Failed to open TCP connection to " + 950 "#{conn_address}:#{conn_port} (#{e.message})" 951 end 952 } 5IFUJNFPVUMJCSBSZTNFUIPE

5IFUJNFPVUMJCSBSZXJUI3BDUPS 3VCZ require "timeout" r = Ractor.new do Timeout.timeout(1) do
sleep 2 end end r.take 'PSUIFSFDPSE UIFJTTVFCFUXFFO3BDUPSBOEUIFUJNFPVUMJCSBSZ UIBUMFEUPUIFJOUSPEVDUJPOPGPQFO@UJNFPVUXBTSFTPMWFE JO3VCZUISPVHIJNQSPWFNFOUTUP3BDUPS 5PEBZ UIFUJNFPVUMJCSBSZDBOCFVTFEJOTJEFBOPONBJO3BDUPS # => no exception in Ruby 4.0!

*ODMPTJOH

3VCZJOUSPEVDFEOFXGFBUVSFT TVDIBT3VCZ#PYBOE;+*5

"TUIFTFOFXGFBUVSFTBOEJNQSPWFNFOUTTIPX 3VCZJTDPOUJOVJOHUPFWPMWF /FXWFSTJPOTPG3VCZ QBDLFEXJUIOFXDIBOHFT BMXBZTFYDJUFVT

*OUIJTUBML XFFYQMPSFEUIFIJTUPSZPG UIFTPDLFUMJCSBSZUISPVHIUIFMFOTPGUJNFPVUT *UNBZOPUCFBTUPSZUIBUJTPGUFOUPME #VUUIJTGFBUVSFIBTBMTPFWPMWFEPWFSUJNF UISPVHIUIFF ff PSUTPG3VCZJTUTXIPDBSFEEFFQMZ JOFBDIFSBBOEBUFBDINPNFOU

5IJTTUPSZ UPP JTQBSUPG3VCZTIJTUPSZ

8JUIHSBUJUVEFUPUIF3VCZJTUTXIPIFMQFEXFBWFUIJTTUPSZ 5IF-FTT5PME4UPSZPG4PDLFU5JNFPVUT 4QFDJBMUIBOLTUP !OPSNBMQFSTPO !BLS !(MBTT@TBHB!LJST !ZBIPOEB !FVHFOFJVT !NBNF
!PTZPZV !OBSVTF !FSFHPOBOE3VCZDPNNVOJUZ

The Less-Told Story of Socket Timeouts

The Less-Told Story of Socket Timeouts

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