Hello Sergei!
Thanks for a fast response.
I'll give you the answers to the point, and later will get to the fixes that you mentioned.
Hi, Nikita,
Despite the commit has in the title, comments below apply to four
commits:
$ git log --oneline 7d5165894282^..0f6fd23e1604
0f6fd23e160 cleanup: add new(thd) to Sql_alloc and Item
e0afb5f08b5 cleanup: further replace thd->alloc() with operator new
8daea2e14b2 cleanup: add operator new(size_t, const THD*) for single-object allocations
7d516589428 cleanup: add operator new[](size_t, const THD*)
On Dec 06, Nikita Malyavin wrote:
> diff --git a/sql/sql_class.h b/sql/sql_class.h
> index aff02df69ec..299c8298606 100644
> --- a/sql/sql_class.h
> +++ b/sql/sql_class.h
> @@ -1279,11 +1279,5 @@ class Query_arena
> { return state == STMT_CONVENTIONAL_EXECUTION; }
>
> template <typename T=char>
> - inline T* alloc(size_t size) const
> - {
> - return (T*)alloc_root(mem_root, sizeof(T)*size);
> - }
> -
> - template <typename T=char>
> inline T* calloc(size_t size) const
Hmm, you didn't remove thd->calloc<>()
Well, I could do that, the calloc analogue looks like
new (thd) char[size] ();
Note the brackets before the semicolon -- they force zero
initialization for scalar types, as well as for POD types:
new (thd) pod_t[size] ();
As far as I understand, it forces calling a default constructor
of a POD type or a scalar, which is a zero initialization.
For non-POD types, the default constructor is always called.
But I thought that maybe it can be found too odious for our developer community ☺️
So I decided to see how it goes with single THD:alloc() first:)
> - static void *operator new[](size_t size) throw ()
> + static void *operator new[](size_t size) noexcept
> {
> return thd_alloc(_current_thd(), size);
> }
> - static void *operator new[](size_t size, MEM_ROOT *mem_root) throw ()
> +
> + static void *operator new[](size_t size, const THD *thd) noexcept;
> + static void *operator new(size_t size, const THD *thd) noexcept;
> +
> + static void *operator new[](size_t size, MEM_ROOT *mem_root) noexcept
> { return alloc_root(mem_root, size); }
> - static void *operator new(size_t size, MEM_ROOT *mem_root) throw()
> + static void *operator new(size_t size, MEM_ROOT *mem_root) noexcept
> { return alloc_root(mem_root, size); }
> static void operator delete(void *ptr, size_t size) { TRASH_FREE(ptr, size); }
> static void operator delete(void *, MEM_ROOT *){}
> diff --git a/sql/sql_class.cc b/sql/sql_class.cc
> index 7847389dabc..37869da63ae 100644
> --- a/sql/sql_class.cc
> +++ b/sql/sql_class.cc
> @@ -8831,3 +8831,46 @@ LEX_CSTRING make_string(THD *thd, const char *start_ptr,
> size_t length= end_ptr - start_ptr;
> return {strmake_root(thd->mem_root, start_ptr, length), length};
> }
> +void* operator new(size_t size, const Query_arena *thd) noexcept
> +{
> + return alloc_root(thd->mem_root, size);
> +}
> +
> +void operator delete[](void *ptr, const Query_arena *thd) noexcept
> +{}
> +
> +void operator delete(void *ptr, const Query_arena *thd) noexcept
> +{}
if you put them into sql_class.h - will they be inlined?
Apparently, one can't put a global operator new/delete definition into a header:
then a linker finds duplicates:(
I didn't find a solution for that. But I'm sure it'll be inlined with -flto and O1 or O2.
Yours truly,
Nikita Malyavin