include/salhelper/simplereferenceobject.hxx | 29 ++++++++++++++++++++++------
1 file changed, 23 insertions(+), 6 deletions(-)
New commits:
commit 914e79524cdd9c4176e6508d1401fb7dca6264e2
Author: Michael Meeks <michael.me...@collabora.com>
AuthorDate: Thu Oct 17 07:24:10 2024 +0200
Commit: Noel Grandin <noel.gran...@collabora.co.uk>
CommitDate: Mon Oct 21 09:47:28 2024 +0200
SimpleReferenceObject: add ability to staticize the ref-count.
Useful for when we allocate data at startup and want to share it
across multiple threads. Also potentiall useful for turning
extreme cases of ref-count wrap-around into a more benign leak.
Change-Id: I04e6a62dbd366d294d86ab72036c3498402357f0
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/175196
Tested-by: Jenkins CollaboraOffice <jenkinscollaboraoff...@gmail.com>
Reviewed-by: Noel Grandin <noel.gran...@collabora.co.uk>
diff --git a/include/salhelper/simplereferenceobject.hxx
b/include/salhelper/simplereferenceobject.hxx
index ac721ad3da98..59a2baf83bc6 100644
--- a/include/salhelper/simplereferenceobject.hxx
+++ b/include/salhelper/simplereferenceobject.hxx
@@ -60,20 +60,28 @@ namespace salhelper {
*/
class SALHELPER_DLLPUBLIC SimpleReferenceObject
{
+ static const size_t nStaticFlag = 0x80000000;
+
public:
SimpleReferenceObject(): m_nCount(0) {}
/** @attention
- The results are undefined if, for any individual instance of
- SimpleReferenceObject, the total number of calls to acquire() exceeds
- the total number of calls to release() by a platform dependent amount
- (which, hopefully, is quite large).
+ If, for any individual instance of SimpleReferenceObject, the total
+ number of calls to acquire() exceeds the total number of calls to
+ release() by 2^31 - the object will never subsequently be released.
*/
void acquire()
- { osl_atomic_increment(&m_nCount); }
+ {
+ if (!(m_nCount & nStaticFlag))
+ osl_atomic_increment(&m_nCount);
+ }
void release()
- { if (osl_atomic_decrement(&m_nCount) == 0) delete this; }
+ {
+ if (!(m_nCount & nStaticFlag) &&
+ osl_atomic_decrement(&m_nCount) == 0)
+ delete this;
+ }
/** see general class documentation
*/
@@ -95,6 +103,15 @@ public:
protected:
virtual ~SimpleReferenceObject() COVERITY_NOEXCEPT_FALSE;
+ /** mark reference count as not to be touched, and the
+ * related object as having an indefinite lifespan.
+ * NB. do not use if you have a non-empty destructor.
+ */
+ void staticize()
+ {
+ m_nCount |= nStaticFlag;
+ }
+
oslInterlockedCount m_nCount;
private:
