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author | Father Chrysostomos <sprout@cpan.org> | 2009-12-22 14:03:49 +0100 |
---|---|---|
committer | Rafael Garcia-Suarez <rgs@consttype.org> | 2009-12-22 14:03:49 +0100 |
commit | 27bca3226281a592aed848b7e68ea50f27381dac (patch) | |
tree | 1f612fa141096d89c960810e0933cfb4a4d6c644 /t/op/threads.t | |
parent | 0111a78fcc993bdfaa4b46112924c3a9751ecfa5 (diff) | |
download | perl-27bca3226281a592aed848b7e68ea50f27381dac.tar.gz |
[perl #70748] threads panic in del_backref
This was caused by change 34210/41fae7a, which simply reveals a bug that
already existed.
A sub returned from a thread brings a lot of baggage with it, including
some globs. There is this comment near the top of Perl_sv_dup in the
if(param->flags & CLONEf_JOIN_IN) block that reads:
/** don't clone stashes if they already exist **/
Then later on, under case SVt_PVGV:
/* Don't call sv_add_backref here as it's going to be
created as part of the magic cloning of the symbol
table. */
So what’s happening is that there is a glob with no back-reference in its
stash, which glob is sometimes freed after the stash, so it induces the
panic.
Diffstat (limited to 't/op/threads.t')
-rw-r--r-- | t/op/threads.t | 30 |
1 files changed, 23 insertions, 7 deletions
diff --git a/t/op/threads.t b/t/op/threads.t index 7985688e5c..c834d07524 100644 --- a/t/op/threads.t +++ b/t/op/threads.t @@ -16,7 +16,7 @@ BEGIN { exit 0; } - plan(15); + plan(17); } use strict; @@ -192,13 +192,11 @@ threads->new(sub {})->join; pass("undefing a typeglob doesn't cause a crash during cloning"); -TODO: { - no strict 'vars'; # Accessing $TODO from test.pl - local $TODO = 'perl #70748'; - # Test we don't get: # panic: del_backref during global destruction. -fresh_perl_is(<<'EOI', 'ok', { }, 'No del_backref panic'); +# when returning a non-closure sub from a thread and subsequently starting +# a new thread. +fresh_perl_is(<<'EOI', 'ok', { }, 'No del_backref panic [perl #70748]'); use threads; sub foo { return (sub { }); } my $bar = threads->create(\&foo)->join(); @@ -206,6 +204,24 @@ threads->create(sub { })->join(); print "ok"; EOI -} # TODO +# Another, more reliable test for the same del_backref bug: +fresh_perl_like( + <<' EOJ', qr/ok/, {}, 'No del_backref panic [perl #70748] (2)' + use threads; + push @bar, threads->create(sub{sub{}})->join() for 1...10; + print "ok"; + EOJ +); + +# Simple closure-returning test: At least this case works (though it +# leaks), and we don't want to break it. +fresh_perl_like(<<'EOJ', qr/^foo\n/, {}, 'returning a closure'); +use threads; +print create threads sub { + my $x = "foo\n"; + sub{sub{$x}} +}=>->join->()() + //"undef" +EOJ # EOF |