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Re: Fix hashtable node deallocation


Still waiting for this (I hope) last fix before gcc 9 release...

We could perhaps make:
      _Pointer_adapter(element_type* __arg = 0)

explicit to find out if there are other places where we miss to properly call pointer_traits<>::pointer_to. But I aren't sure we can do it in this extension and I haven't tried yet.

François

On 12/16/18 2:16 PM, François Dumont wrote:
Gentle reminder, we still have this issue pending.

    * include/bits/hashtable_policy.h
(_Hashtable_alloc<>::_M_deallocate_node_ptr(__node_type*)): New.
    (_Hashtable_alloc<>::_M_deallocate_node(__node_type*)): Use latter.
(_ReuseOrAllocNode<>::operator<_Arg>()(_Arg&&)): Likewise.
    * libstdc++-v3/testsuite/util/testsuite_allocator.h
    (CustomPointerAlloc<>::allocate(size_t, pointer)): Replace by...
    (CustomPointerAlloc<>::allocate(size_t, const_void_pointer)): ...this.

François

On 11/29/18 7:08 AM, François Dumont wrote:
I am unclear about this patch, is it accepted ?


On 11/19/18 10:19 PM, François Dumont wrote:
On 11/19/18 1:34 PM, Jonathan Wakely wrote:
On 10/11/18 22:40 +0100, François Dumont wrote:
While working on a hashtable enhancement I noticed that we are not using the correct method to deallocate node if the constructor throws in _ReuseOrAllocNode operator(). I had to introduce a new _M_deallocate_node_ptr for that as node value shall not be destroy again.

I also check other places and noticed that a __node_type destructor call was missing.

That's intentional. The type has a trivial destructor, so its storage
can just be reused, we don't need to destroy it.


Ok, do you want to also remove the other call to ~__node_type() then ?

Here is the updated patch and the right ChangeLog entry:

    * include/bits/hashtable_policy.h
(_Hashtable_alloc<>::_M_deallocate_node_ptr(__node_type*)): New.
(_Hashtable_alloc<>::_M_deallocate_node(__node_type*)): Use latter.
(_ReuseOrAllocNode<>::operator<_Arg>()(_Arg&&)): Likewise.
    (_Hashtable_alloc<>::_M_allocate_node): Add ~__node_type call.
    * libstdc++-v3/testsuite/util/testsuite_allocator.h
    (CustomPointerAlloc<>::allocate(size_t, pointer)): Replace by...
    (CustomPointerAlloc<>::allocate(size_t, const_void_pointer)): ...this.
    * testsuite/23_containers/unordered_set/allocator/ext_ptr.cc: Add
    check.

Ok to commit ?

François





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