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| author | Dave Mitchell <davem@fdisolutions.com> | 2007-11-02 23:59:27 +0000 |
|---|---|---|
| committer | Dave Mitchell <davem@fdisolutions.com> | 2007-11-02 23:59:27 +0000 |
| commit | 33de8e4aff58f134481d1a594f7a9734709d8ea5 (patch) | |
| tree | 1663710b3c2995ad948cc332faebd0cf0797d457 /pod/perlmod.pod | |
| parent | be61d08ee327e91edc6bb39a13e0138e0eed393a (diff) | |
| download | perl-33de8e4aff58f134481d1a594f7a9734709d8ea5.tar.gz | |
[perl #47045] CLONE_SKIP doesn't result in undef copies
clarify the documentation on CLONE_SKIP, and ensure that the
undef value has all its flags cleared
p4raw-id: //depot/perl@32213
Diffstat (limited to 'pod/perlmod.pod')
| -rw-r--r-- | pod/perlmod.pod | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/pod/perlmod.pod b/pod/perlmod.pod index 53f3d21c65..63f0be9d2c 100644 --- a/pod/perlmod.pod +++ b/pod/perlmod.pod @@ -581,6 +581,9 @@ Like C<CLONE>, C<CLONE_SKIP> is called once per package; however, it is called just before cloning starts, and in the context of the parent thread. If it returns a true value, then no objects of that class will be cloned; or rather, they will be copied as unblessed, undef values. +For example: if in the parent there are two references to a single blessed +hash, then in the child there will be two references to a single undefined +scalar value instead. This provides a simple mechanism for making a module threadsafe; just add C<sub CLONE_SKIP { 1 }> at the top of the class, and C<DESTROY()> will be now only be called once per object. Of course, if the child thread needs |