Autosave: 2024-04-20 13:20:05

zk/Heap_memory.md

@@ -0,0 +1,10 @@
+---
+id: 18bl
+title: Heap_memory
+tags: []
+created: Saturday, April 20, 2024
+---
+
+# Heap_memory
+
+## Related notes

zk/Stack_memory.md

@@ -7,8 +7,18 @@ created: Tuesday, April 16, 2024
 
 # Stack memory
 
-Along with heap memory, programs make use of _stack memory_ during the runtime
-of programs.
+## Summary
+
+- Along with heap memory, programs make use of _stack memory_ during the runtime
+  of programs.
+
+- Specifically used to keep track of memory used during function executions
+  within a given scope: control flow, local variables, returned value.
+
+- Uses a LIFO data-structure
+
+- Best suited for small-sized singular values rather than large or complex data
+  types
 
 ## Stack memory
 
@@ -25,6 +35,30 @@ from the top down.
 
 A **stack pointer** is used to manage the items in the stack. This value is
 stored in a [[CPU_architecture#registers|register]] and its value is the memory
-address of the item currently on the top of the stack.
+address of the item currently on the top of the stack. Note: _not_ the value
+itself, the _address_ of the value.
+
+When a new value is added to the top of the stack, the pointer's value is
+adjusted to increase the size of the stack and make room for the new value. So
+this will be a new memory address for the latest item. When an item is removed,
+the reverse happens. The previously top address is cleared and the pointer
+points to the new top item.
+
+### Role in program execution
+
+1. Function call management: a stack records the key information pertaining to
+   the execution of a function: parameters, local variables, the location of the
+   address for the returned value.
+
+2. Local variable storage: storing the variables local to a function's scope and
+   removing them once the function returns, avoiding
+   [[Memory_leaks|memory leaks]]
+
+3. Control flow: record from where a function is called and where its return
+   value should be stored, meaning the right value is always returned no matter
+   how nested it is.
+
+4. Recursion: individuating each call of a function that calls itself and its
+   given step to avoid infinite loops
 
 ## Related notes