cj1128/hot-reload-c

Hot Reload C

A simple SDL2 program to demonstrate how to hot reload C.

demo.mp4

Build

This program can be built on MacOS and Linux.

First you need to install SDL2:

• MacOS: brew install sdl2
• Linux: Check your package manager, e.g. on Manjaro, pacman -S sdl2

Then clone the code and build

$ git clone ... && cd ...
$ make run
# while the program is running, modify render.c and rebuild
$ make build
# and then the program will be hot reloaded 🚀

Idea

The main idea behind this is Shared Library a.k.a Dynamic Loaded Library.

We compile the render logic into a separate shared library and load it in main program dynamically via these apis:

• dlopen
• dlclose
• dlsym

So while the main program is running, we can rebuild our render library to hot load the main program.

Google dynamic linking for more details.

hot-reload-c's Issues

每次都reload so

为什么每次都要reload so？使用signal触发动态库的更新可以么

不考虑把 LoadCode/UnloadCode 放到 while 外面吗

hot-reload-c/src/main.c

Line 127 in e4ffe79

LoadCode(&code);

放在外面主循环里运行的代码得不到更新，也就不能热重载了😂

放在外面主循环里运行的代码得不到更新，也就不能热重载了😂

Originally posted by @cj1128 in #1 (comment)

可以通过 signal 触发 reload render.dylib
main.c 里面注册一个 signal(SIGUSR1, reload)
每次 build 完就给进程发一个 signal
ps -ef | grep dist/main.out| grep -v grep| awk '{print $2}'|xargs kill -s SIGUSR1