Segmentation fault using https in multi-threaded environment

[relonger]

use HTTP::UserAgent;

await (for 1..10 { start {
   my $ua = HTTP::UserAgent.new(useragent => 'ie_w7_64', :throw-exceptions);
   my $res = $ua.get("https://github.com");
   #my $res = $ua.get("http://polyglot.by/");
   say $res.status-line;
} })

generates:

moar(9200,0x700013399000) malloc: *** error for object 0x7fb4072eeb30: pointer being realloc'd was not allocated
*** set a breakpoint in malloc_error_break to debug
moar(9200,0x700012393000) malloc: *** error for object 0x7fb4072eebb0: incorrect checksum for freed object - object was probably modified after being freed.
*** set a breakpoint in malloc_error_break to debug
[1]    9200 abort      perl6 useragent-concurr.p6

or just:

[1]    9186 segmentation fault  perl6 useragent-concurr.p6

using HTTP is fine, so problem is somewhere in IO::Socket::SSL

my versions:

perl6 -v
This is Rakudo Star version 2018.01 built on MoarVM version 2018.01
implementing Perl 6.c.

Darwin WanMini.local 17.4.0 Darwin Kernel Version 17.4.0: Sun Dec 17 09:19:54 PST 2017; root:xnu-4570.41.2~1/RELEASE_X86_64 x86_64

[AlexDaniel]

I got segmentation fault even when I had no IO::Socket::SSL installed. Interesting.

[AlexDaniel]

Not reproducible on whateverable, which is even more interesting. FWIW another simple SEGV: rakudo/rakudo#1202

[AlexDaniel]

Also, FWIW, pretty much any segfault is a rakudobug. So please submit a rakudo ticket once there's more info (e.g. caught under gdb or golfed down significantly).

[relonger]

Overriding get-connection, surrounding it with lock, and using my UserAgent2 instead of UserAgent seems to solve the problem.

package HTTP {
   our $https_lock = Lock.new;
   class UserAgent2 is HTTP::UserAgent {
      multi method get-connection(HTTP::Request $request, Str $host, Int $port?) {
         {
            $https_lock.lock;
            LEAVE $https_lock.unlock;
            return callsame;
         }
      }
   }
}

[briandfoy]

https://rt.perl.org/Public/Bug/Display.html?id=133057