Book Image

Linux System Programming Techniques

By : Jack-Benny Persson
Book Image

Linux System Programming Techniques

By: Jack-Benny Persson

Overview of this book

Linux is the world's most popular open source operating system (OS). Linux System Programming Techniques will enable you to extend the Linux OS with your own system programs and communicate with other programs on the system. The book begins by exploring the Linux filesystem, its basic commands, built-in manual pages, the GNU compiler collection (GCC), and Linux system calls. You'll then discover how to handle errors in your programs and will learn to catch errors and print relevant information about them. The book takes you through multiple recipes on how to read and write files on the system, using both streams and file descriptors. As you advance, you'll delve into forking, creating zombie processes, and daemons, along with recipes on how to handle daemons using systemd. After this, you'll find out how to create shared libraries and start exploring different types of interprocess communication (IPC). In the later chapters, recipes on how to write programs using POSIX threads and how to debug your programs using the GNU debugger (GDB) and Valgrind will also be covered. By the end of this Linux book, you will be able to develop your own system programs for Linux, including daemons, tools, clients, and filters.
Table of Contents (14 chapters)

Debugging programs with multiple threads

It's possible to view threads in a program using GBD and also to jump between threads. Knowing how to jump between the threads in a program will make threaded programs easier to debug. Writing threaded programs can be hard, but with GDB it's easier to make sure they are working correctly.

Getting ready

In this recipe, we'll use the first-threaded.c program from Chapter 11, Using Threads in Your Programs. There's a copy of the source code in this chapter's GitHub directory.

You'll also need the GCC compiler.

How to do it…

In this recipe, we'll look at the threads from the first-threaded.c program using GDB:

  1. Let's start by compiling the program:
    $> gcc -g -Wall -Wextra -pedantic -std=c99 \
    > first-threaded.c -o first-threaded -lpthread
  2. Before we run the program through the debugger, let's first run it to recap how the program works:
    $> ./first-threaded 990233331...