clean up reload logic

1 files changed, 46 insertions, 0 deletions

diff --git a/src/reload.rs b/src/reload.rs
new file mode 100644
index 0000000..effc8fd
--- /dev/null
+++ b/src/reload.rs
@@ -0,0 +1,46 @@
+use std::{
+    env,
+    ffi::CString,
+    io::Write,
+    panic, ptr,
+    sync::atomic::{AtomicBool, Ordering},
+};
+
+static RELOAD: AtomicBool = AtomicBool::new(false);
+
+pub fn begin_reload() {
+    RELOAD.store(true, Ordering::SeqCst);
+    panic::resume_unwind(Box::new(42));
+}
+
+/// ONLY TO BE CALLED FROM MAIN WHEN NOT A SINGLE RESOURCE IS HELD
+pub unsafe fn continue_reload() {
+    if !RELOAD.load(Ordering::SeqCst) {
+        return;
+    }
+
+    eprintln!("reloading...");
+    let _ = std::io::stdout().lock().flush();
+
+    unsafe { exec() }
+
+    eprintln!("exec failed.");
+}
+
+unsafe fn exec() {
+    // path to this executable
+    let exe = env::current_exe()
+        .unwrap()
+        .to_string_lossy()
+        .replace(" (deleted)", "");
+    let exe_c = CString::new(exe).unwrap();
+
+    // argv
+    let args: Vec<CString> = env::args().map(|a| CString::new(a).unwrap()).collect();
+    let mut argv: Vec<*const libc::c_char> = args.iter().map(|a| a.as_ptr()).collect();
+    argv.push(ptr::null());
+
+    unsafe {
+        libc::execv(exe_c.as_ptr(), argv.as_ptr());
+    }
+}