🐛 修复了malloc的bug

This commit is contained in:
fslongjin 2022-05-07 14:14:11 +08:00
parent 37da6ef19e
commit a7596e6ff1
2 changed files with 24 additions and 14 deletions

View File

@ -12,9 +12,10 @@ int main()
put_string(tips_str, COLOR_GREEN, COLOR_BLACK);
printf("test printf: %s size: %d\n", string, sizeof(string));
/*
int fd = open(string, 0);
printf("fd=%d\n", fd);
/*
read(fd, buf, 128);
put_string(buf, COLOR_ORANGE, COLOR_BLACK);
@ -31,8 +32,9 @@ int main()
put_string(buf, COLOR_YELLOW, COLOR_BLACK);
close(fd);
*/
char* p = malloc(100);
printf("p=%lld\n", (uint64_t)p);
char *p = malloc(100);
*p = 'a';
printf("p=%lld\t*p=%c\n", (uint64_t)p, *p);
// *p = 'a';
/*
pid_t p = fork();

View File

@ -62,7 +62,7 @@ static malloc_mem_chunk_t *malloc_query_free_chunk_bf(uint64_t size)
malloc_mem_chunk_t *ptr = malloc_free_list;
malloc_mem_chunk_t *best = NULL;
printf("query size=%d", size);
while (ptr)
while (ptr != NULL)
{
printf("ptr->length=%#010lx\n", ptr->length);
if (ptr->length == size)
@ -73,14 +73,18 @@ static malloc_mem_chunk_t *malloc_query_free_chunk_bf(uint64_t size)
if (ptr->length > size)
{
printf("676767\n");
if (best == NULL)
best = ptr;
else if (best->length > ptr->length)
best = ptr;
printf("6rdf\n");
}
printf("ptr->next=%#018lx\n", ptr->next);
ptr = ptr->next;
}
printf("return best=%#018lx\n", (uint64_t)best);
return best;
}
@ -126,11 +130,11 @@ static int malloc_enlarge(int32_t size)
int64_t tmp = brk_managed_addr + size - brk_max_addr;
if (tmp > 0) // 现有堆空间不足
{
if (sbrk(tmp) != (-1))
brk_max_addr = brk((-1));
if (sbrk(tmp) != (void *)(-1))
brk_max_addr = brk((-2));
else
{
put_string("malloc_enlarge(): no_mem", COLOR_YELLOW, COLOR_BLACK);
put_string("malloc_enlarge(): no_mem\n", COLOR_YELLOW, COLOR_BLACK);
return -ENOMEM;
}
}
@ -263,6 +267,7 @@ static void *malloc_no_enlarge(ssize_t size)
return -ENOMEM; // 内存不足
}
found:;
// 分配空闲块
// 从空闲链表取出
if (ck->prev == NULL) // 当前是链表的第一个块
@ -278,7 +283,8 @@ found:;
// 当前块剩余的空间还能容纳多一个结点的空间,则分裂当前块
if (ck->length - size > sizeof(malloc_mem_chunk_t))
{
malloc_mem_chunk_t *new_ck = ((uint64_t)ck) + ck->length;
printf("new_ck = %#018lx\n", ((uint64_t)ck) + size);
malloc_mem_chunk_t *new_ck = ((uint64_t)ck) + size;
new_ck->length = ck->length - size;
new_ck->start_addr = (uint64_t)new_ck;
new_ck->prev = new_ck->next = NULL;
@ -286,7 +292,7 @@ found:;
ck->length = size;
malloc_insert_free_list(new_ck);
}
printf("12121212\n");
// 插入到已分配链表
// 直接插入到链表头符合LIFO
ck->prev = NULL;
@ -337,6 +343,8 @@ void *malloc(ssize_t size)
ck = malloc_query_free_chunk_bf(size);
}
found:;
printf("ck = %#018lx\n", (uint64_t)ck);
if (ck == NULL)
return -ENOMEM;
// 分配空闲块
@ -354,11 +362,11 @@ found:;
// 当前块剩余的空间还能容纳多一个结点的空间,则分裂当前块
if (ck->length - size > sizeof(malloc_mem_chunk_t))
{
malloc_mem_chunk_t *new_ck = ((uint64_t)ck) + ck->length;
malloc_mem_chunk_t *new_ck = ((uint64_t)ck) + size;
new_ck->length = ck->length - size;
new_ck->start_addr = (uint64_t)new_ck;
new_ck->prev = new_ck->next = NULL;
printf("new_ck=%#018lx, new_ck->length=%#010lx\n", (uint64_t)new_ck, new_ck->length);
ck->length = size;
malloc_insert_free_list(new_ck);
}