Where is the block size recorded in the Release version after allocating memory to a pointer?

tttt2222

Where is the release version of the allocated block management information such as the block size after allocating memory to a pointer?
    

    Recently, when I deeply analyzed the C ++ problem, I encountered a problem that could not be solved. That is, the use of heap management after C ++ program compilation is not the same as the Debug version. The Debug version is easy to understand, but how does the Release version manage it? The Debug version stores a double linked list structure in the first 32 bytes of the memory block. One member of this structure is the size of the memory block. But where is the Release version? Run the following version of the Release version of the program without knowing what it is? Which prawn can confuse me?
main ()
{
    int * pInt = new int [2];
    for (int i = 1; i <= 8; i ++)
    {
        printf ("% x\n", * (pInt-i)); // Print out the first 32 bytes of memory in Pint
    }
. ． ． ． ．
. ． ． ． ．
}
Debug version shows the result is
fdfdfdfd
33
1
8 // Memory block size
0
0
372a80 // Next block address
3729f0 // Previous block address

But the Release version is executed like this
180764
230004
0
0
abababab
abababab
baad0a00
ffffffff
The memory block size is not there at all, where will it be stored? Still do not need to record? How to collect it when released without recording?
What is in the first 32 bytes of Pint?

julines

Don't understand

shihuizi

Records are definitely needed, otherwise how to know the length.
Or the way is different: use tables to store?

hzxszmh

Doesn't seem to be recorded

lklklk

The operating system records and recycles itself.In fact, the first address of each thing on the heap will record its allocated size, the ID of the application program assigned to it, and the operating system said that the landlord will go to tuition.

tttt2222

lklklk(Learn C ++ without getting tired)
The operating system records and recycles itself? Don't say so general, each process should record the usage of its own memory block. The operating system records which memory pages (ie blocks) the process uses! As for the operating system in the memory page, it doesn't matter.

vincent119

Under VC Release, each program and each dll use _crtHeap to manage the heap. _CrtHeap is a global handle.
_crtheap = HeapCreate () initialization,
HeapAlloc (_crtheap, 0, size);
retval = HeapFree (_crtheap, 0, pBlock);
I do n’t know deeply, you can track the execution of new and delete

mingliang261

What LZ is talking about is a special case. In theory, the memory applied for does not include the size for the upper layer;
Operating system internal records