diff options
| author | Marc Mutz <marc.mutz@qt.io> | 2022-04-04 18:00:36 +0200 |
|---|---|---|
| committer | Marc Mutz <marc.mutz@qt.io> | 2022-04-06 10:44:40 +0000 |
| commit | 2fb7c94f63ce783c7f36149791fe72e053933ece (patch) | |
| tree | 418bbff5f1d4681900298af1f4310a985d9b1564 /src/xml | |
| parent | ad26d6a18d024d55a1325295cefafc991dc08a79 (diff) | |
QDom: optimize an atomic read
By the time setNodeValue() gets its hands on the removed object, the
removeChild() function has already called removed->ref.deref(), which
performs an acquire fence if the ref-count drops to zero.
IOW: if removed->ref == 0 now, then an acquire fence has been
executed. If ref != 0, then we're not reaching into removed, so we
need no acquire.
Therefore, a relaxed load suffices (as opposed to the loadAcquire()
the implicit conversion operator performs).
Found by disabling QAtomic<T> -> T implicit conversions.
Change-Id: I367754fde0ad82db797161b5e94e2ebc08a90c0b
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Diffstat (limited to 'src/xml')
| -rw-r--r-- | src/xml/dom/qdom.cpp | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/xml/dom/qdom.cpp b/src/xml/dom/qdom.cpp index 603704f916..a36d4389e4 100644 --- a/src/xml/dom/qdom.cpp +++ b/src/xml/dom/qdom.cpp @@ -3625,7 +3625,7 @@ void QDomAttrPrivate::setNodeValue(const QString& v) t->ref.deref(); if (first) { auto removed = removeChild(first); - if (removed && !removed->ref) + if (removed && !removed->ref.loadRelaxed()) // removeChild() already deref()ed delete removed; } appendChild(t); |