C语言内存池使用模型-2

static struct pfree *_pool_free(pool_t p, pool_cleanup_t f, void *arg)51Testing软件测试网ShL0Q+Rp*qZk
{51Testing软件测试网G8_3w
UgO
    struct pfree *ret;
7d?,p(blS0    while((ret = malloc(sizeof(struct pfree))) == NULL) sleep(1);
5sP^R(V0    ret->f = f;51Testing软件测试网 `+Ocfaj$`9B
    ret->arg = arg;51Testing软件测试网L5^;s5x+U|@ Hi7x+?
    ret->next = NULL;51Testing软件测试网u e{a5oY

    return ret;51Testing软件测试网5`ljL8\/m0x6I
}51Testing软件测试网-w1S5N0qh"C!i

|['bsu!|0static void _pool_cleanup_append(pool_t p, struct pfree *pf)
7`HR|/}2Z8V1E3~0{51Testing软件测试网#\\Cdt_)@:C]^
    struct pfree *cur;

    if(p->cleanup == NULL)51Testing软件测试网4k,P.|L_
    {
H|zAYw2u R0        p->cleanup = pf;
{u0}0Y;t.Ic0        p->cleanup_tail = pf;51Testing软件测试网X6a
S&I%lS3]%w
        return;
W)YW^g#n rwq[^3H0    }51Testing软件测试网Vp]|l)UAA

    cur = p->cleanup_tail;51Testing软件测试网3Ys"N:Vt"~
    cur->next = pf;
2Ee`6N @ _x0    p->cleanup_tail = pf;
cn/M%D$vW0}51Testing软件测试网+i-Q9Kj!B(kbH

void pool_free(pool_t p)51Testing软件测试网Qpc9p%D
{51Testing软件测试网cM@"I'Fm
    struct pfree *cur, *stub;

r
Ca4Y.WW0    if(p == NULL) return;51Testing软件测试网ud|m/~HN5S

    cur = p->cleanup;
W D}p};f^0    while(cur != NULL)51Testing软件测试网%Tf%G)Hl*m R5?
    {51Testing软件测试网3X@\[c$q
        (*cur->f)(cur->arg); // 这会释放用malloc分配的内存块和struct pheap结构所占用的内存。这就是前文的_pool_heap_free函数51Testing软件测试网`{2l~TA'u
 stub = cur->next;
$erhC"zq
[j0 free(cur);  // 释放pfree结构。
:TNRp+S6N#|w0 cur = stub;
-]TX!Fq$X*W0    }
GF:Sl4aHF5V0    free(p); //释放pool_struct结构所占用的内存。
xf MLQ#sV0}51Testing软件测试网s!K)UdZ!E

"BEAV'IlI0void *pool_malloc(pool_t p, int size)
$o"F YS3[P$w%u"R0{51Testing软件测试网b,qg$fBo-g P2j.Cv@
    void *block;51Testing软件测试网U$W-Z*Z:g6s[FJ

    if(p == NULL)
d^:iA:E,Xr-Ut0    {51Testing软件测试网-i1c m#Ju9|;se$d
        fprintf(stderr,"Memory Leak! [pmalloc received NULL pool, unable to track allocation, exiting]\n");
b'?"bfF2YC0        abort();51Testing软件测试网)Q,?\W}4JA&S5cR
    }

T8\:t%iQ d |0    if(p->heap == NULL || size > (p->heap->size / 2))
?Fs:u+{?{qTr0    {51Testing软件测试网(N
n"J2C"gD
        while((block = malloc(size)) == NULL) sleep(1);51Testing软件测试网q8]~,{[`%\ N
        p->size += size;51Testing软件测试网q5Ta]L
d[$E/Y,a._
        _pool_cleanup_append(p, _pool_free(p, _pool__free, block));51Testing软件测试网,rXoB ^,Vx!cH,iS
        return block;
VRS;b4h0    }

    if(size >= 4)
a0fW`4b4r:W wU0        while(p->heap->used&7) p->heap->used++; // 这一步是个对齐操作，如果已经使用的不是8的倍数，就会跳过，直到为8的倍数。

.AYr-^B F n0    if(size > (p->heap->size - p->heap->used))
*AcVM"q1Q6?Y0        p->heap = _pool_heap(p, p->heap->size);

#Ty'ZLM#X |0    block = (char *)p->heap->block + p->heap->used;
$e0V NJb@2dM SN0    p->heap->used += size; //已经使用部分增加，也会使得内存分配的偏移值指针增加。51Testing软件测试网w7r4W"j0Nl
    return block;51Testing软件测试网jK&@2h4M@}E^f
}