It happens internally in the perl code, which is guaranteed to be thread safe
||= happens in Perl code, yet it's not thread safe for shared variables.
You may say that's because it's the user requesting a change the variable, but that's the case for all the examples I showed too.
Now, tye and BrowserUk say the shared SV is appropriately locked internally when updated (and I believe it to be true), so that eliminates the potential problems I posited, so the point is simply that your guarantee is worthless as formulated.
That's probably because you pulled the guarantee out of this air. When I looked this up some time ago, I couldn't find any documentation on this. A very quick look still shows nothing. This is why I prompted for replies on the subject.
Update: Added everything after first line.
Update: Added "for shared variables" in response to reply.
Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
Read Where should I post X? if you're not absolutely sure you're posting in the right place.
Please read these before you post! —
Posts may use any of the Perl Monks Approved HTML tags:
You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
- a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
Link using PerlMonks shortcuts! What shortcuts can I use for linking?
See Writeup Formatting Tips and other pages linked from there for more info.
| & || & |
| < || < |
| > || > |
| [ || [ |
| ] || ] ||