hot reloading mule

src/mule/mule_hotload_main.c

@@ -0,0 +1,48 @@
+#include <stdint.h>
+#include <windows.h>
+
+int main(int argc, char **argv)
+{
+  int lib_loaded = 0;
+  HANDLE lib = {0};
+  FILETIME lib_last_filetime = {0};
+  int (*get_number)(void) = 0;
+  for(;;)
+  {
+    //- rjf: hot-load dll
+    {
+      HANDLE file = CreateFileA("mule_hotload_module.dll", GENERIC_READ, FILE_SHARE_READ, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
+      FILETIME modified = {0};
+      if(GetFileTime(file, 0, 0, &modified) &&
+         CompareFileTime(&lib_last_filetime, &modified) == -1)
+      {
+        for(int reloaded = 0; !reloaded;)
+        {
+          if(lib_loaded)
+          {
+            FreeLibrary(lib);
+            lib_loaded = 0;
+          }
+          BOOL copy_worked = CopyFile("mule_hotload_module.dll", "mule_hotload_module_temp.dll", 0);
+          lib = LoadLibraryA("mule_hotload_module_temp.dll");
+          if(lib != INVALID_HANDLE_VALUE)
+          {
+            reloaded = 1;
+            lib_last_filetime = modified;
+            get_number = (int(*)(void))GetProcAddress(lib, "get_number");
+            lib_loaded = 1;
+          }
+        }
+      }
+      CloseHandle(file);
+    }
+    int number = get_number();
+    printf("got a number: %i\n", number);
+    if(number == 0)
+    {
+      break;
+    }
+    Sleep(1000);
+  }
+  return 0;
+}

src/mule/mule_hotload_module_main.c

@@ -0,0 +1,13 @@
+__declspec(dllexport) int
+get_number(void)
+{
+  int sum = 0;
+  for(int i = 0; i < 100; i += 1)
+  {
+    sum += i;
+    sum += i;
+    sum += 1;
+  }
+  sum = 0;
+  return sum;
+}