A. Jesse Jiryu Davis added the comment: NetBSD has a concurrency test for getaddrinfo, so I tried it on Mac to see if getaddrinfo is thread-safe here, too. It appears that it is thread-safe.
I copied NetBSD's getaddrinfo concurrency test "h_resolv.c" and the test's data file "d_mach" from src/tests/lib/libpthread in the NetBSD 7 source: http://cvsweb.netbsd.org/bsdweb.cgi/src/tests/lib/libpthread/ I've also attached these files to this ticket.* The test program h_resolv.c compiles fine on Mac OS X 10.10 with clang 7, and the test passes using the same parameters that the NetBSD test uses, resolving five host names on five threads: ./h_resolv -d -n 5 -h 5 d_mach There's even evidence that getaddrinfo is actually concurrent on my Mac: resolving 100 hostnames on 1 thread takes about 6 seconds, but using 100 threads take only 3 seconds. To test concurrency I ran this: sudo dscacheutil -flushcache sudo killall -HUP mDNSResponder time h_resolv -d -h 100 -n 1 d_mach sudo dscacheutil -flushcache sudo killall -HUP mDNSResponder time h_resolv -d -h 1 -n 100 d_mach Those sudo commands flush the Mac's DNS cache between runs. * I removed one unresolvable domain, "cnftp.bjpu.edu.cn", from the test file d_mach. That domain took 15 seconds to time out and made the rest of the timing irrelevant. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue25924> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
