[PATCH] posix: Reimplement POSIX Key manager to use a red-black tree.

[Gedare Bloom]

Good work Zhongwei! This was a good effort and will be useful for many
in the future. I hope you can find other little RTEMS projects to work
on as your time and interest permits.

-Gedare

On Sun, Aug 4, 2013 at 8:23 PM, Ashi <ashi08104 at gmail.com> wrote:
> Here is the patch created by git format-patch.
>
> Cheers,
> Zhongwei
>
>
> On Sun, Aug 4, 2013 at 2:24 PM, Ashi <ashi08104 at gmail.com> wrote:
>>
>> Hi, All. The patch is updated according to Sebastian's comments.
>>
>> Cheers,
>> Zhongwei
>>
>>
>> On Fri, Aug 2, 2013 at 7:01 PM, Ashi <ashi08104 at gmail.com> wrote:
>>>
>>>
>>>
>>>
>>> On Fri, Aug 2, 2013 at 2:38 PM, Sebastian Huber
>>> <sebastian.huber at embedded-brains.de> wrote:
>>>>
>>>> On 2013-08-02 03:03, Ashi wrote:
>>>>>
>>>>>
>>>>>         +  /** This field points to parent freechain node */
>>>>>         +  POSIX_Keys_Freechain_node *fc_node_ptr;
>>>>>
>>>>>
>>>>>     I don't think we need this fc_node_ptr.
>>>>>
>>>>> Do you mean use a 'Container' macro instead?
>>>>
>>>>
>>>> Not necessarily, see below.
>>>>
>>>>>
>>>>>
>>>>>         +  /** This field is the POSIX key used as an rbtree key */
>>>>>         +  pthread_key_t key;
>>>>>         +  /** This field is the Thread id also used as an rbtree key
>>>>> */
>>>>>         +  Objects_Id thread_id;
>>>>>         +  /** This field points to the POSIX key value of specific
>>>>> thread */
>>>>>         +  void *value;
>>>>>         +}  POSIX_Keys_Rbtree_node;
>>>>>
>>>>>
>>>>>     I would call this POSIX_Keys_Key_value_pair.
>>>>>
>>>>>         +
>>>>>         +/**
>>>>>         + * @brief POSIX_Keys_Freechain is used in Freechain structure
>>>>>         + */
>>>>>         +typedef struct {
>>>>>         +    Freechain_Control super_fc;
>>>>>         +    size_t bump_count;
>>>>>         +} POSIX_Keys_Freechain;
>>>>>         +
>>>>>         +/**
>>>>>         + * @brief POSIX_Keys_Freechain_node is freechain node
>>>>>         + */
>>>>>         +struct POSIX_Keys_Freechain_node___struct {
>>>>>
>>>>>         +  Chain_Node ch_node;
>>>>>         +  POSIX_Keys_Rbtree_node rb_node;
>>>>>         +};
>>>>>
>>>>>
>>>>>     Why not use POSIX_Keys_Rbtree_node directly?
>>>>>
>>>>> Since every freechain node needs a Chain_Node in its first field. There
>>>>> is a
>>>>> Chain_Node in  POSIX_Keys_Rbtree_node, but it is used in each thread's
>>>>> key
>>>>> value chain. So I add a Chain_Node to POSIX_Keys_Rbtree_node.
>>>>
>>>>
>>>> The key value pairs on the free chain are unused, thus not part of other
>>>> data structures.  So basically you can cast an unused object to any type
>>>> provided it has enough storage.
>>>
>>> Cool! I see. I didn't realise the whole key value pairs is actually
>>> unused until it moves from Freechain to POSIX key value pair.
>>>>
>>>>
>>>>
>>>> --
>>>> Sebastian Huber, embedded brains GmbH
>>>>
>>>> Address : Dornierstr. 4, D-82178 Puchheim, Germany
>>>> Phone   : +49 89 189 47 41-16
>>>> Fax     : +49 89 189 47 41-09
>>>> E-Mail  : sebastian.huber at embedded-brains.de
>>>> PGP     : Public key available on request.
>>>>
>>>> Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.
>>>
>>>
>>
>