void* cmemalloc::palloc_block(size_t size)
{
u_char* m;
size_t psize;
mem_data* d, *p, *current;
psize = (size_t) (m_d->end - (u_char*) m_d);
m = (u_char*)malloc(psize);
if (m == NULL) {
return NULL;
}
d = (mem_data*)m;
d->end = m + psize;
d->next = NULL;
d->failed = 0;
m += sizeof(mem_data);
m = mem_align_ptr(m, MEM_ALIGNMENT);
d->last = m + size;
current = m_cur;
for (p = m_cur; p->next; p = p->next) {
if (p->failed++ > 4) {
current = p->next;
}
}
p->next = d;
m_cur = current ? current : d;
return m;
}
void *fms_mem_alloc(fms_mem_pool *mem_pool, fms_u32 data_size) {
struct rb_node *pos = mem_pool->free_blocks.rb_node;
fms_mem_block *block = NULL;
struct rb_node *best_fit = NULL;
fms_u32 block_data_size = 0;
data_size = mem_align_ptr(data_size, 4);//²»¼ÓÕâÒ»¾ä¾Í¶Î´íÎóå why ?½¨Òé×öÒ»´ÎµØÖ·¸ú×Ù²âÊÔ
//printf("@@@@@@@@@@fms_mem_alloc:datasize=%u\n", data_size);
while (pos) {
block = rb_entry(pos, fms_mem_block, rb_node);
//printf("lorent 1, need %u[%u]\n", data_size, block->data_size);
block_data_size = block->data_size;
if (data_size < block->data_size) {
best_fit = pos;
pos = pos->rb_left;
} else if (data_size > block->data_size) {
pos = pos->rb_right;
} else {
best_fit = pos;
break;
}
}
if (best_fit == NULL) {
//ûÓзûºÏ´óСµÄÄÚ´æ¿é£¬ÄÇôÐèÒªÔÙ´ÎÀ©Õ¹ÄÚ´æ³Ø£¬Ò»°ã²»»á·¢Éú´ËÖÖÇé¿ö
printf("mem_pool no space\n");
}
if (NULL == pos) { //ûÓÐÕÒµ½¸ÕºÃ·ûºÏµÄÄÚ´æ¿é pos != best_fit
block = rb_entry(best_fit, fms_mem_block, rb_node);
//printf("lorent 2, find %u\n", block->data_size);
block_data_size = block->data_size;
//ÕâÀïÓиöÒþ²ØÌõ¼þ block->data_size > data_size
if (data_size + sizeof(fms_mem_block) > block->data_size) {
/* no room for other buffers */
} else {
//printf("lroent 2-1, cut %u->%u\n", block->data_size, data_size);
block->data_size = data_size;//²Ã¼ô´óС
}
}
//printf("lorent 3\n");
rb_erase(best_fit, &mem_pool->free_blocks);
//printf("lorent 3-1\n");
mem_block_insert_allocated(mem_pool, block);
block->free = FMS_FALSE;
if (block->data_size != block_data_size) { //²Ã¼ô
fms_mem_block *new_block = (fms_mem_block *)((fms_u8 *)block->data + block->data_size);
new_block->data_size = block_data_size - block->data_size - sizeof(fms_mem_block);
//printf("lorent 4, new block size=%u\n", new_block->data_size );
new_block->id = mem_pool->block_id;//Ìرð×¢Òâ²Ã¼ô³öÀ´µÄBlockµÄIDÊÇÏàͬµÄ
new_block->free = FMS_TRUE;
list_add(&new_block->entry, &block->entry);//ÕâÀï¿ÉÄÜ»á³ö´í?list_addµÄ¹¦ÄÜ
mem_block_insert_free(mem_pool, new_block);
}
//printf("lorent 5\n");
return (void *)block->data;
}
void* cmemalloc::palloc(size_t size)
{
u_char* m;
mem_data* p;
if (size <= m_max) {
p = m_cur;
do {
m = mem_align_ptr(p->last, MEM_ALIGNMENT);
if ((size_t) (p->end - m) >= size) {
p->last = m + size;
return m;
}
p = p->next;
}while(p);
return palloc_block(size);
}
return palloc_large(size);
}
