thevar1able/ClickHouse
1
0
Fork 0
mirror of https://github.com/ClickHouse/ClickHouse.git synced 2024-11-24 00:22:29 +00:00
Code Issues Packages Projects Releases Wiki Activity

Modified comment [#CLICKHOUSE-2]

Browse Source
This commit is contained in:
Alexey Milovidov 2018-03-05 21:26:43 +03:00
parent 28b46655db
commit ff822f5d81
1 changed files with 6 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
dbms/src/Common/COWPtr.h
View File

@ -66,6 +66,12 @@
* In contrast, COWPtr is intended for the cases when you need to share states of large objects, * In contrast, COWPtr is intended for the cases when you need to share states of large objects,
* (when you usually will use std::shared_ptr) but you also want precise control over modification * (when you usually will use std::shared_ptr) but you also want precise control over modification
* of this shared state. * of this shared state.
*
* Caveats:
* - after a call to 'mutate' method, you can still have a reference to immutable ptr somewhere
* and it can still become shared. Also it would be better to make 'mutate' method rvalue-qualified.
* - as 'mutable_ptr' should be unique, it's refcount is redundant - probably it would be better
* to use std::unique_ptr for it, but see above.
*/ */
template <typename Derived> template <typename Derived>
class COWPtr : public boost::intrusive_ref_counter<Derived> class COWPtr : public boost::intrusive_ref_counter<Derived>