목차
Stack data structure
A stack is a data structure in which last-in data is firstly popped out ○ We call it Last In First Out (LIFO)
Function call stack
Lots of programming language runtimes utilizes a call stack to manage function calls ○ A call stack is a stack that stores functions’ local data ○ When calling a function, the callee function data is pushed onto the call stack ○ When returning a function, the function data is popped out from the call stack
Stack memeory allocation
Local data is allocated on the call stack ○ Parameters, local variables, local objects and arrays, … ○ The size of memory to be allocated is known to compiler ○ Whenever a function is called, its variables get memory allocated on the stack ○ Whenever the function call is over, the memory for the variables is deallocated ■ Don’t need to consider memory alloc/dealloc of stack variables
Heap memory allocation
Memory is allocated on a heap ○ Call it dynamic memory allocation ○ The size of memory to be allocated is calculated at runtime ○ The allocated memory is valid for long-time before deallocating it ■ Need to explicitly alloc/dealloc memory ■ Be careful to avoid memory leak or dangling pointer errors
=> Node* n = new Node(3) : 3이라는 값을 넣은 Node가 heap에 생기고 그 주소가 foo로 옴
* new Node는 클래스니까 생성자를 부르는거임 heap 안에 오브젝트를 만들어서 그 공간을 주는건데
malloc은 그냥 heap 안에 특정 크기만큼만 두는거임
뭔소리야
deallocation : free(), delete ..
Dynamic allocation with new keyword
A keyword new is used to allocate memory in C++ ○ Basically, it works as the same as malloc ○ But, it creates an object and invokes its constructor as well ○ It is paired with delete keyword ■ it works as the same as free ■ But, it deletes an object and invokes its destructor as well