What Does Stack Frame Mean?
A stack frame is a memory management technique used in some programming languages for generating and eliminating temporary variables. In other words, it can be considered the collection of all information on the stack pertaining to a subprogram call. Stack frames are only existent during the runtime process. Stack frames help programming languages in supporting recursive functionality for subroutines.
A stack frame also known as an activation frame or activation record.
Techopedia Explains Stack Frame
A stack frame is comprised of:
- Local variables
- Saved copies of registers modified by subprograms that could need restoration
- Argument parameters
- Return address
An individual stack frame has space for actual parameters, temporary locations, local variables and calling subroutine information. When the specific routines calling these parameters, locations or variables have completed execution, the relevant stack frame is eliminated from the stack. The order of packing information in the stack frame in most cases is independent of the specifications of the programming language.
One of the salient features of the stack frame is that for a specific subprogram, the size of the stack frame is fixed. In order for a programming language to use a stack frame, a program counter and a thread must be available with two pointers: the base pointer and the stack pointer. The base pointer always points to the top of the frame, whereas the stack pointer points to the top of the stack. The program counter helps in pointing to the next executable instruction. A stack frame for a given procedure has all the relevant information for saving and restoring the state of the specific procedure.