Re: SGCL - Garbage Collector for C++

From:
"Sebastian Nibisz" <EBA_K@poczta.onet.pl>
Newsgroups:
comp.lang.c++.moderated
Date:
Thu, 6 Mar 2008 10:42:20 CST
Message-ID:
<fqon50$aec$1@inews.gazeta.pl>

How could I use your smart-pointer interface to do something like this:

_____________________________________________________________
/* assume this is all garbage collected */

struct llnode {
 llnode* next;
 void* state;
};

static llnode* volatile g_list = 0;

int list_push(void* const state) {
 llnode* const _this = gc_malloc(sizeof(*_this));
 if (_this) {
   _this->state = state;
   do {
     cmp = g_list;
     _this->next = cmp;
   } while (CASPTR_RELEASE(&g_list, cmp, _this));
   return 0;
 }
 return ENOMEM;
}

llnode* list_pop() {
 void* state;
 llnode* cmp;
 do {
   if (! (cmp = g_list)) {
     return 0;
   }
 } while (CASPTR_ACQUIRE(&g_list, cmp, cmp->next));
 state = cmp->state;
 cmp = 0;
 return state;
}
_____________________________________________________________

Since I am using GC, there is no ABA problem, and everything gets cleaned
up. What I am most interested in is how this would look with your smart
pointer interface?


//----------------------------------------------------------
struct node
{
    node(const gc<node>& n, void* s) : next(n), state(s)
    {
    }
    gc<node> next;
    void* state;
};

static gc<node> g_list;
static Sgcl::Mutex g_lmutex;

void list_push(void* state) throw(std::bad_alloc)
{
    Sgcl::AutoLock l(g_lmutex);
    g_list = gcnew node(g_list, state);
}

void* list_pop()
{
    Sgcl::AutoLock l(g_lmutex);
    if (g_list)
    {
        void* state = g_list->state;
        g_list = g_list->next;
        return state;
    }
    else return 0;
}
//----------------------------------------------------------

rgds
Sebastian Nibisz

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