![]() ![]() Line 18: The main function's stack frame is popped from the stack, and all local variables ( value and ptr) are deallocated. Line 17: The main function returns 0, signaling successful execution. However, we will not discuss dangling pointers in detail for this essential discussion. After this line, ptr becomes a dangling pointer because it still holds the address 0x1000, but that memory has been deallocated. Line 15: The memory allocated on the heap at address 0x1000 is deallocated using the delete keyword. Line 12: The value stored at the memory location pointed to by ptr ( 42) is printed to the console. Line 11: The integer value 42 is assigned to the memory location pointed to by ptr (heap address 0x1000). The address of the allocated heap memory (0x1000) is stored in the pointer. Let's assume the address of this new memory on the heap to be 0x1000. Line 8: A pointer variable ptr is allocated the dynamically created memory for a single integer on the heap using the new keyword. Line 5: A local variable value on the stack frame is assigned the value 42. Line 3: The function main is called, and a new stack frame is created for it. We're only discussing the stack and heap segments here. Although we're focusing on C++, the explanation also holds true for Python and Java. In the following explanation, we'll go over how heap and stack change after running each important line of code. Note: In Java and Python, garbage collection takes care of memory deallocation automatically, eliminating the need for manual memory release, as seen in C++. However, Python and Java manage memory deallocation automatically through garbage collection, eliminating the need for manual intervention. In C++, it's necessary to manually release the memory allocated on the heap using the delete keyword. The value stored on the heap is then printed. This is done by using a pointer or reference variable that resides in stack memory:Ī list with a single element ptr in Python. In these code examples, the goal is to store the value 42 in heap memory, which is a more permanent and flexible storage space. Here are some key aspects to consider about stack memory: Line 20: The main function's stack frame is popped from the stack, and all local variables ( x and result) are deallocated. Line 19: The main function returns 0, signaling successful execution. ![]() Line 17: The value stored in the result variable (i.e., 15) is printed to the console using std::cout. Line 15: The local variable result on the stack frame of the main function is assigned the returned value (i.e., 15). Line 8: The add function's stack frame is popped from the stack, and all local variables ( a, b, and sum) are deallocated. Line 7: The sum variable's value (i.e., 15) is returned to the caller. Line 6: The local variable sum is assigned the value of a + b (i.e., 5 + 10). Variables a and b are assigned the values of x and 10, respectively. The control is transferred to the add function with local variables. Line 4: A new stack frame is created for the add function. Line 15: The add the function is called with the arguments x and 10. Line 12: The local variable x is assigned the value 5. Line 10: The program starts with the main function, and a new stack frame is created for it. Here is the explanation of the C++ code in the order of execution: We're only discussing the stack segment here. Although we're focusing on C++, the explanation for Python and Java also holds. In the following explanation, we'll go over how the heap and stack change after running each important line of code. Once the add function returns, the stack is popped, removing the function call and associated data, and we can print the result. The function call and its arguments and return address are placed on the stack. ![]() Then, we call the add function with x and 10 as arguments. This variable is also stored in stack memory. In the main function (or top-level script for Python), we create another local variable x and assign it the value 5. Inside the add function, we created a local variable called sum to store the result. This function takes two parameters as input integers and returns their sum. In the codes instances above, we created a function called add. This memory is created on the stack segment. The stack frame stores information related to local variables, parameters, and the return address of the function. A block of memory called a stack frame is created when a function is called. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |