From f762232a12b9824a0efb331ba9da759f35845bf6 Mon Sep 17 00:00:00 2001 From: Martine Lenders Date: Fri, 6 Dec 2024 12:56:48 +0100 Subject: [PATCH] doc/static-vs-dynamic-memory: style and spelling fixes + updates To current status quo. --- doc/doxygen/src/static-vs-dynamic-memory.md | 42 ++++++++++----------- 1 file changed, 21 insertions(+), 21 deletions(-) diff --git a/doc/doxygen/src/static-vs-dynamic-memory.md b/doc/doxygen/src/static-vs-dynamic-memory.md index ade1e154a134..c4240dd879ba 100644 --- a/doc/doxygen/src/static-vs-dynamic-memory.md +++ b/doc/doxygen/src/static-vs-dynamic-memory.md @@ -1,29 +1,29 @@ -This page discusses the usage of memory on restricted devices -============================================================= +Static vs. Dynamic Memory +========================= -In your c program you have to decide where the memory you want to use comes from. -There are two ways to get memory in your c code: +In your C program you have to decide where the memory you want to use comes from. +There are two ways to get memory in your C code: -1. define static memory -2. use dynamic memory (call malloc/free to get memory from the heap) +1. Define static memory. +2. Use dynamic memory (call `malloc()`/`free()` to get memory from the heap). Both ways have some drawbacks which are listed here. -If you want to analyze the static memory consumption of your code you can use [otm](https://github.com/LudwigOrtmann/otm). +If you want to analyze the static memory consumption of your code you can use [otm](https://github.com/LudwigOrtmann/otm) or `make cosy`. -static memory +Static memory ------------- -* access the memory in one operation O(1) -> real time condition -* programmer needs to know the amount of memory on compile time - * leads to over and undersized buffers -* forces the programmer to think about the amount of need memory at compile time +* Access the memory in one operation O(1) ⇒ real time condition +* Programmer needs to know the amount of memory on compile time + * Leads to over and undersized buffers +* Forces the programmer to think about the amount of need memory at compile time -dynamic memory +Dynamic memory -------------- -* malloc and free are implemented in your libc (RIOT on ARM: newlib) - * run time behavior not predictable -* code can request the amount of memory it needs on run time -* on most platforms: the size of the heap is sizeof(RAM)-sizeof(static memory) - * if you reduce your usage of static memory your heap gets bigger -* on some platforms calling `free()` will not or not always make heap memory available again (see onetime_malloc() on MSP430 or the implementation of sbrk() for lpc2387) -* programmer needs to handle failed memory allocation calls at runtime -* static code analysis is unable to find errors regarding memory management \ No newline at end of file +* `malloc()` and `free()` are implemented in your `libc` (RIOT on ARM: `newlib`/`picolib`) + * Runtime behavior is not predictable +* Code can request the amount of memory it needs on runtime +* On most platforms: the size of the heap is `sizeof()-sizeof()` + * If you reduce your usage of static memory your heap gets bigger +* On some platforms calling `free()` will not or not always make heap memory available again (see @ref oneway_malloc on MSP430) +* Programmer needs to handle failed memory allocation calls at runtime +* Static code analysis is unable to find errors regarding memory management