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

[Ashi]

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<sebastian.huber at embedded-brains.de>
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>
> Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.
>
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