[getdns-api] Custom memory management functions again

[Wiley, Glen]

An of course I see that you included this in your original note (it pays
to scroll)...
-- 
Glen Wiley
KK4SFV

Sr. Engineer
The Hive, Verisign, Inc.




On 11/20/13 4:23 PM, "Wiley, Glen" <gwiley at verisign.com> wrote:

>Wouter had suggested adding a void* userarg to
>getdns_context_set_memory_functions() which I think may come in handy for
>folks that are taking things far enough to provide their own allocators.
>His suggested function signature would be:
>
>void getdns_context_set_memory_functions(getdns_context_t context,
>    void *(*malloc)(void *userarg, size_t sz),
>    void *(*realloc)(void *userarg, void *ptr, size_t sz),
>    void (*free)(void *userarg, void *ptr),
>    void *userarg);
>
>
>
>-- 
>Glen Wiley
>KK4SFV
>
>Sr. Engineer
>The Hive, Verisign, Inc.
>
>
>
>
>On 11/20/13 10:00 AM, "Willem Toorop" <willem at nlnetlabs.nl> wrote:
>
>>From talking to people involved in the getdns-api design at the IETF-88,
>>we learned that custom memory functions configured per context are an
>>essential part of the design.  They really did *not* want custom memory
>>functions to be global.  They did agree that setting all memory
>>functions in one go is the better method.
>>
>>We propose to replace getdns_context_set_allocator,
>>getdns_context_set_reallocator and getdns_context_set_deallocator with
>>the following signature for setting them:
>>
>>getdns_return_t
>>getdns_context_set_memory_functions(getdns_context_t context,
>>    void *(*malloc) (size_t),
>>    void *(*realloc) (void *, size_t),
>>    void (*free) (void *)
>>    );
>>
>>Now the creation of the context itself should also be possible with
>>those custom memory function.  Therefore I propose to have this extra
>>context constructor:
>>
>>getdns_return_t
>>getdns_context_create_with_memory_functions(
>>    getdns_context_t * context,
>>    int set_from_os,
>>    void *(*malloc) (size_t),
>>    void *(*realloc) (void *, size_t),
>>    void (*free) (void *)
>>    );
>>
>>Dicts and lists that were generated as a result of actions done by the
>>library will inherit the custom memory functions from the context.
>>
>>But the user is able to create dicts and lists on its own. We propose to
>>add the following signatures to facilitate creation of dicts and lists
>>by the user with custom memory functions:
>>
>>struct getdns_list *
>>getdns_list_create_with_context(getdns_context_t context);
>>
>>struct getdns_list *
>>getdns_list_create_with_memory_functions(
>>    void *(*malloc) (size_t),
>>    void *(*realloc) (void *, size_t),
>>    void (*free) (void *));
>>
>>struct getdns_dict *
>>getdns_dict_create_with_context(getdns_context_t context);
>>
>>struct getdns_dict *
>>getdns_dict_create_with_memory_functions(
>>    void *(*malloc) (size_t),
>>    void *(*realloc) (void *, size_t),
>>    void (*free) (void *));
>>
>>
>>Now custom memory functions might be even more useful if they have the
>>possibility to have state (i.e. the region with Region-based memory
>>management etc.).  This is best accomplished with a "user argument" that
>>will be passed to the custom memory management functions.
>>We propose four more API functions to allow for this:
>>
>>void
>>getdns_context_set_extended_memory_functions(getdns_context_t context,
>>    void *userarg,
>>    void *(*malloc)(void *userarg, size_t sz),
>>    void *(*realloc)(void *userarg, void *ptr, size_t sz),
>>    void (*free)(void *userarg, void *ptr));
>>
>>getdns_return_t
>>getdns_context_create_with_extended_memory_functions(
>>    getdns_context_t * context,
>>    int set_from_os,
>>    void *userarg,
>>    void *(*malloc) (void *userarg, size_t),
>>    void *(*realloc) (void *userarg, void *, size_t),
>>    void (*free) (void *userarg, void *)
>>    );
>>
>>struct getdns_list *
>>getdns_list_create_with_extended_memory_functions(
>>    void *userarg,
>>    void *(*malloc) (void *userarg, size_t),
>>    void *(*realloc) (void *userarg, void *, size_t),
>>    void (*free) (void *userarg, void *));
>>
>>
>>struct getdns_dict *
>>getdns_dict_create_with_extended_memory_functions(
>>    void *userarg,
>>    void *(*malloc) (void *userarg, size_t),
>>    void *(*realloc) (void *userarg, void *, size_t),
>>    void (*free) (void *userarg, void *));
>>
>>
>>What do you think? Is it too much? Should we choose one type of custom
>>memory functions and if so, which one (extended or not)? Should we hide
>>the dict_create_* and list_create_* functions?
>>
>>-- Willem
>>_______________________________________________
>>getdns-api mailing list
>>getdns-api at vpnc.org
>
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