src/hotspot/share/classfile/modules.cpp

@@ -277,11 +277,10 @@
    }
  }
  
  void Modules::define_module(Handle module, jboolean is_open, jstring version,
                              jstring location, jobjectArray packages, TRAPS) {
-   check_cds_restrictions(CHECK);
    ResourceMark rm(THREAD);
  
    if (module.is_null()) {
      THROW_MSG(vmSymbols::java_lang_NullPointerException(), "Null module object");
    }

@@ -299,10 +298,13 @@
    }
  
    // Resolve packages
    objArrayHandle packages_h(THREAD, objArrayOop(JNIHandles::resolve(packages)));
    int num_packages = (packages_h.is_null() ? 0 : packages_h->length());
+   if (strncmp(module_name, "jdk.proxy", 9) != 0) {
+     check_cds_restrictions(Handle(), Handle(), CHECK);
+   }
  
    // Special handling of java.base definition
    if (strcmp(module_name, JAVA_BASE_NAME) == 0) {
      assert(is_open == JNI_FALSE, "java.base module cannot be open");
      define_javabase_module(module, version, location, packages_h, num_packages, CHECK);

@@ -736,18 +738,35 @@
    assert(Arguments::get_property("java.system.class.loader") == nullptr,
             "archived full module should have been disabled if -Djava.system.class.loader is specified");
    ClassLoaderDataShared::restore_java_system_loader_from_archive(system_loader_data);
  }
  
- void Modules::check_cds_restrictions(TRAPS) {
+ void Modules::check_cds_restrictions(Handle module1, Handle module2, TRAPS) {
    if (CDSConfig::is_dumping_full_module_graph() && Universe::is_module_initialized()) {
-     THROW_MSG(vmSymbols::java_lang_UnsupportedOperationException(),
-               "During -Xshare:dump, module system cannot be modified after it's initialized");
+     if (CDSConfig::is_dumping_dynamic_proxies() && (is_dynamic_proxy_module(module1) || is_dynamic_proxy_module(module2))) {
+       // The only the we allow is to add or modify the jdk.proxy?? modules that are used for dynamic proxies.
+     } else {
+       THROW_MSG(vmSymbols::java_lang_UnsupportedOperationException(),
+                 "During -Xshare:dump, module system cannot be modified after it's initialized");
+     }
    }
  }
+ 
  #endif // INCLUDE_CDS_JAVA_HEAP
  
+ bool Modules::is_dynamic_proxy_module(Handle module) {
+   if (!module.is_null()) {
+     ModuleEntry* module_entry = java_lang_Module::module_entry(module());
+     return is_dynamic_proxy_module(module_entry);
+   }
+   return false;
+ }
+ 
+ bool Modules::is_dynamic_proxy_module(ModuleEntry* module_entry) {
+   return (module_entry != nullptr && module_entry->is_named() && module_entry->name()->starts_with("jdk.proxy"));
+ }
+ 
  void Modules::set_bootloader_unnamed_module(Handle module, TRAPS) {
    ResourceMark rm(THREAD);
  
    if (module.is_null()) {
      THROW_MSG(vmSymbols::java_lang_NullPointerException(), "Null module object");

@@ -781,11 +800,11 @@
    // Store pointer to the ModuleEntry in the unnamed module's java.lang.Module object.
    java_lang_Module::set_module_entry(module(), unnamed_module);
  }
  
  void Modules::add_module_exports(Handle from_module, jstring package_name, Handle to_module, TRAPS) {
-   check_cds_restrictions(CHECK);
+   check_cds_restrictions(from_module, to_module, CHECK);
  
    if (package_name == nullptr) {
      THROW_MSG(vmSymbols::java_lang_NullPointerException(),
                "package is null");
    }

@@ -849,20 +868,20 @@
  }
  
  
  void Modules::add_module_exports_qualified(Handle from_module, jstring package,
                                             Handle to_module, TRAPS) {
-   check_cds_restrictions(CHECK);
+   check_cds_restrictions(from_module, to_module, CHECK);
    if (to_module.is_null()) {
      THROW_MSG(vmSymbols::java_lang_NullPointerException(),
                "to_module is null");
    }
    add_module_exports(from_module, package, to_module, CHECK);
  }
  
  void Modules::add_reads_module(Handle from_module, Handle to_module, TRAPS) {
-   check_cds_restrictions(CHECK);
+   check_cds_restrictions(from_module, to_module, CHECK);
    if (from_module.is_null()) {
      THROW_MSG(vmSymbols::java_lang_NullPointerException(),
                "from_module is null");
    }
  

@@ -964,11 +983,11 @@
    return nullptr;
  }
  
  // Export package in module to all unnamed modules.
  void Modules::add_module_exports_to_all_unnamed(Handle module, jstring package_name, TRAPS) {
-   check_cds_restrictions(CHECK);
+   check_cds_restrictions(Handle(), module, CHECK);
    if (module.is_null()) {
      THROW_MSG(vmSymbols::java_lang_NullPointerException(),
                "module is null");
    }
    if (package_name == nullptr) {