Docs: Add phase_9_79b_3_vm_vtable_thunks_and_pic.md\n- Plan to formalize TypeMeta+Thunk and upgrade PIC to poly\n- Diagnostics, risks, milestones, exit criteria, and Phase 10 readiness

src/runtime/cache_versions.rs

@@ -0,0 +1,30 @@
+//! Global cache version map for vtable/PIC invalidation
+
+use once_cell::sync::Lazy;
+use std::collections::HashMap;
+use std::sync::Mutex;
+
+static CACHE_VERSIONS: Lazy<Mutex<HashMap<String, u32>>> = Lazy::new(|| Mutex::new(HashMap::new()));
+
+/// Get current version for a cache label (default 0)
+pub fn get_version(label: &str) -> u32 {
+    let map = CACHE_VERSIONS.lock().unwrap();
+    *map.get(label).unwrap_or(&0)
+}
+
+/// Bump version for a cache label
+pub fn bump_version(label: &str) {
+    let mut map = CACHE_VERSIONS.lock().unwrap();
+    let e = map.entry(label.to_string()).or_insert(0);
+    *e = e.saturating_add(1);
+}
+
+/// Convenience: bump for multiple labels
+pub fn bump_many(labels: &[String]) {
+    let mut map = CACHE_VERSIONS.lock().unwrap();
+    for l in labels {
+        let e = map.entry(l.clone()).or_insert(0);
+        *e = e.saturating_add(1);
+    }
+}
+

src/runtime/mod.rs

@@ -20,6 +20,7 @@ pub use plugin_config::PluginConfig;
 pub use box_registry::{BoxFactoryRegistry, BoxProvider, get_global_registry};
 pub use plugin_loader_v2::{PluginLoaderV2, get_global_loader_v2, init_global_loader_v2};
 pub use plugin_loader_unified::{PluginHost, get_global_plugin_host, init_global_plugin_host, PluginLibraryHandle, PluginBoxType, MethodHandle};
+pub mod cache_versions;
 pub use unified_registry::{get_global_unified_registry, init_global_unified_registry, register_user_defined_factory};
 pub use nyash_runtime::{NyashRuntime, NyashRuntimeBuilder};
 // pub use plugin_box::PluginBox;  // legacy

src/runtime/plugin_loader_v2.rs

@@ -246,6 +246,16 @@ impl PluginBoxV2 {
                 eprintln!("Failed to load config: {}", e);
                 BidError::PluginError
             })?);
+        // Bump cache versions for all box types (config reload may change method layout)
+        if let Some(cfg) = self.config.as_ref() {
+            let mut labels: Vec<String> = Vec::new();
+            for (_lib, def) in &cfg.libraries {
+                for bt in &def.boxes {
+                    labels.push(format!("BoxRef:{}", bt));
+                }
+            }
+            crate::runtime::cache_versions::bump_many(&labels);
+        }
         Ok(())
     }
     
@@ -309,6 +319,8 @@ impl PluginBoxV2 {
             finalized: std::sync::atomic::AtomicBool::new(false),
         });
         self.singletons.write().unwrap().insert((lib_name.to_string(), box_type.to_string()), handle);
+        // bump version for this box type to invalidate caches
+        crate::runtime::cache_versions::bump_version(&format!("BoxRef:{}", box_type));
         Ok(())
     }