Shatter JvmRefBase and ThreadGuard into separate files.

This change has no effect.

PiperOrigin-RevId: 595901454

BUILD

@@ -39,6 +39,7 @@ cc_library(
         "//implementation:corpus_tag",
         "//implementation:default_class_loader",
         "//implementation:field",
+        "//implementation:find_class_fallback",
         "//implementation:forward_declarations",
         "//implementation:global_class_loader",
         "//implementation:global_object",

class_defs/BUILD

@@ -19,6 +19,7 @@ cc_library(
         "//:jni_dep",
         "//implementation:array",
         "//implementation:class",
+        "//implementation:constructor",
         "//implementation:method",
         "//implementation:params",
         "//implementation:return",

class_defs/java_lang_classes.h

@@ -19,6 +19,7 @@
 
 #include "implementation/array.h"
 #include "implementation/class.h"
+#include "implementation/constructor.h"
 #include "implementation/method.h"
 #include "implementation/params.h"
 #include "implementation/return.h"
@@ -27,23 +28,30 @@
 namespace jni {
 
 // clang-format off
-inline constexpr Class kJavaLangClass{"java/lang/Class"};
 
-inline constexpr Class kJavaLangObject{"java/lang/Object"};
+inline constexpr Class kJavaLangClass{
+  "java/lang/Class",
+  Method{"getClassLoader", Return{ Class { "java/lang/ClassLoader" } }, Params{}},
+};
+
+inline constexpr Class kJavaLangObject{
+  "java/lang/Object",
+  Method{"getClass", Return{kJavaLangClass}, Params{}},
+};
 
 inline constexpr Class kJavaLangClassLoader{
-    "java/lang/ClassLoader",
-    Method{"loadClass", Return{kJavaLangClass}, Params<jstring>{}},
-    Method{"toString", Return{jstring{}}, Params<>{}},
+  "java/lang/ClassLoader",
+  Method{"loadClass", Return{kJavaLangClass}, Params<jstring>{}},
+  Method{"toString", Return{jstring{}}, Params<>{}},
 };
 
 static constexpr Class kJavaLangString{
-    "java/lang/String",
+  "java/lang/String",
 
-    Constructor{jstring{}},
-    Constructor{Array{jbyte{}}},
+  Constructor{jstring{}},
+  Constructor{Array{jbyte{}}},
 
-    Method{"toString", Return{jstring{}}, Params<>{}},
+  Method{"toString", Return{jstring{}}, Params<>{}},
 };
 // clang-format on
 

implementation/BUILD

@@ -233,7 +233,6 @@ cc_library(
         ":global_object",
         ":id",
         ":jni_type",
-        ":jvm_ref",
         ":local_object",
         ":local_string",
         ":method",
@@ -390,6 +389,19 @@ cc_library(
     ],
 )
 
+cc_library(
+    name = "find_class_fallback",
+    hdrs = ["find_class_fallback.h"],
+    deps = [
+        ":default_class_loader",
+        ":global_class_loader",
+        ":local_object",
+        ":promotion_mechanics_tags",
+        "//:jni_dep",
+        "//implementation/jni_helper",
+    ],
+)
+
 cc_library(
     name = "forward_declarations",
     hdrs = ["forward_declarations.h"],
@@ -407,6 +419,7 @@ cc_library(
     deps = [
         ":class_loader",
         ":class_loader_ref",
+        ":default_class_loader",
         ":jvm",
         ":promotion_mechanics",
         "//:jni_dep",
@@ -533,6 +546,18 @@ cc_library(
     ],
 )
 
+cc_test(
+    name = "jvm_test",
+    srcs = ["jvm_test.cc"],
+    deps = [
+        "//:jni_bind",
+        "//:jni_test",
+        "//implementation/jni_helper",
+        "//implementation/jni_helper:jni_env",
+        "@googletest//:gtest_main",
+    ],
+)
+
 cc_library(
     name = "jvm_ref",
     hdrs = ["jvm_ref.h"],
@@ -543,25 +568,38 @@ cc_library(
         ":default_class_loader",
         ":field_ref",
         ":forward_declarations",
+        ":global_class_loader",
         ":jni_type",
         ":jvm",
-        ":method_ref",
+        ":jvm_ref_base",
+        ":promotion_mechanics_tags",
         ":ref_storage",
+        ":thread_guard",
         "//:jni_dep",
+        "//class_defs:java_lang_classes",
+        "//implementation/jni_helper",
         "//implementation/jni_helper:lifecycle_object",
         "//metaprogramming:double_locked_value",
         "//metaprogramming:function_traits",
     ],
 )
 
+cc_library(
+    name = "jvm_ref_base",
+    hdrs = ["jvm_ref_base.h"],
+    deps = [
+        ":forward_declarations",
+        "//:jni_dep",
+    ],
+)
+
 cc_test(
-    name = "jvm_test",
-    srcs = ["jvm_test.cc"],
+    name = "jvm_ref_test",
+    srcs = ["jvm_ref_test.cc"],
     deps = [
+        ":jvm_ref",
         "//:jni_bind",
         "//:jni_test",
-        "//implementation/jni_helper",
-        "//implementation/jni_helper:jni_env",
         "@googletest//:gtest_main",
     ],
 )
@@ -658,6 +696,7 @@ cc_library(
         ":class",
         ":class_loader",
         ":class_loader_ref",
+        ":default_class_loader",
         ":forward_declarations",
         ":jvm",
         ":jvm_ref",
@@ -679,7 +718,6 @@ cc_library(
         ":forward_declarations",
         ":jni_type",
         ":jvm",
-        ":jvm_ref",
         ":object_ref",
         ":promotion_mechanics",
         ":promotion_mechanics_tags",
@@ -851,7 +889,6 @@ cc_library(
         ":default_class_loader",
         ":field_ref",
         ":jni_type",
-        ":jvm_ref",
         ":method_ref",
         ":method_selection",
         ":proxy",
@@ -1175,6 +1212,28 @@ cc_test(
     ],
 )
 
+cc_library(
+    name = "thread_guard",
+    hdrs = ["thread_guard.h"],
+    deps = [
+        ":forward_declarations",
+        ":jvm_ref_base",
+        "//:jni_dep",
+        "//metaprogramming:function_traits",
+    ],
+)
+
+cc_test(
+    name = "thread_guard_test",
+    srcs = ["thread_guard_test.cc"],
+    deps = [
+        ":thread_guard",
+        "//:jni_bind",
+        "//:jni_test",
+        "@googletest//:gtest_main",
+    ],
+)
+
 cc_library(
     name = "void",
     hdrs = ["void.h"],

implementation/class_loader_ref.h

@@ -26,7 +26,6 @@
 #include "implementation/jni_helper/jni_env.h"
 #include "implementation/jni_helper/lifecycle_object.h"
 #include "implementation/jni_type.h"
-#include "implementation/jvm_ref.h"
 #include "implementation/local_object.h"
 #include "implementation/local_string.h"
 #include "implementation/method.h"
@@ -64,10 +63,6 @@ class ClassLoaderRef : public ClassLoaderImpl<lifecycleType> {
   using Base = ClassLoaderImpl<lifecycleType>;
   using Base::Base;
 
-  static_assert(class_loader_v_ != kDefaultClassLoader,
-                "Custom class loaders should not use the default class loader,"
-                "objects will automatically use the default.");
-
   template <const auto& class_v, typename... Params>
   [[nodiscard]] auto BuildLocalObject(Params&&... params) {
     using JniClassT = JniT<jobject, class_v>;

implementation/find_class_fallback.h

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef JNI_BIND_IMPLEMENTATION_FIND_CLASS_FALLBACK_H_
+#define JNI_BIND_IMPLEMENTATION_FIND_CLASS_FALLBACK_H_
+
+#include "implementation/default_class_loader.h"
+#include "implementation/global_class_loader.h"
+#include "implementation/jni_helper/jni_helper.h"
+#include "implementation/local_object.h"
+#include "implementation/promotion_mechanics_tags.h"
+#include "jni_dep.h"
+
+namespace jni {
+
+// This is currently using JNI Bind itself and so cannot be directly included.
+// By delaying linkage for this we can use a bootstrapped JNI Bind. This could
+// be rewritten in porcelain JNI, but this flow ought to be only on
+// secondary threads with previously unused `jclass`'s (which is mostly rare),
+// and this is simpler to reason about than porcelain JNI.
+inline jclass FindClassFallback(const char* class_name) {
+  // The loader will be primed by the JVM, however, it needs to be accessible
+  // from the jni_helper layer. See `JvmRef` for how this is primed.
+  GlobalClassLoader<kDefaultClassLoader> loader{AdoptGlobal{},
+                                                FallbackLoader()};
+
+  jni::LocalObject loaded_class = loader("loadClass", class_name);
+  jclass ret{static_cast<jclass>(static_cast<jobject>(loaded_class.Release()))};
+
+  loader.Release();
+
+  return ret;
+}
+
+}  // namespace jni
+
+#endif  // JNI_BIND_IMPLEMENTATION_FIND_CLASS_FALLBACK_H_

implementation/forward_declarations.h

@@ -65,6 +65,10 @@ template <LifecycleType lifecycleType, const auto& jvm_v_,
           const auto& class_loader_v_>
 class ClassLoaderRef;
 
+// Jvm.
+template <const auto& jvm_v_>
+class JvmRef;
+
 // Thread Guards.
 class ThreadGuard;
 class ThreadLocalGuardDestructor;

implementation/global_class_loader.h

@@ -20,14 +20,16 @@
 #include "class_defs/java_lang_classes.h"
 #include "implementation/class_loader.h"
 #include "implementation/class_loader_ref.h"
+#include "implementation/default_class_loader.h"
 #include "implementation/jni_helper/lifecycle_object.h"
 #include "implementation/jvm.h"
 #include "implementation/promotion_mechanics.h"
 #include "jni_dep.h"
 
 namespace jni {
 
-template <const auto& class_loader_v_, const auto& jvm_v_ = kDefaultJvm>
+template <const auto& class_loader_v_ = kDefaultClassLoader,
+          const auto& jvm_v_ = kDefaultJvm>
 class GlobalClassLoader
     : public ClassLoaderRef<LifecycleType::GLOBAL, class_loader_v_, jvm_v_> {
  public:

implementation/jni_helper/BUILD

@@ -18,6 +18,7 @@ cc_library(
     hdrs = ["field_value.h"],
     deps = [
         ":jni_env",
+        ":trace",
         "//:jni_dep",
     ],
 )
@@ -27,6 +28,7 @@ cc_library(
     hdrs = ["jni_array_helper.h"],
     deps = [
         ":jni_env",
+        ":trace",
         "//:jni_dep",
     ],
 )
@@ -55,6 +57,7 @@ cc_library(
     hdrs = ["jni_helper.h"],
     deps = [
         ":jni_env",
+        ":trace",
         "//:jni_dep",
     ],
 )
@@ -95,6 +98,7 @@ cc_library(
     hdrs = ["invoke.h"],
     deps = [
         ":jni_env",
+        ":trace",
         "//:jni_dep",
     ],
 )
@@ -118,6 +122,7 @@ cc_library(
     deps = [
         ":invoke",
         ":jni_env",
+        ":trace",
         "//:jni_dep",
     ],
 )
@@ -127,6 +132,7 @@ cc_library(
     hdrs = ["lifecycle.h"],
     deps = [
         ":jni_env",
+        ":trace",
         "//:jni_dep",
     ],
 )
@@ -135,9 +141,8 @@ cc_library(
     name = "lifecycle_object",
     hdrs = ["lifecycle_object.h"],
     deps = [
-        ":jni_env",
         ":lifecycle",
-        "//:jni_dep",
+        ":trace",
     ],
 )
 
@@ -158,6 +163,7 @@ cc_library(
     deps = [
         ":lifecycle",
         ":lifecycle_object",
+        ":trace",
     ],
 )
 
@@ -178,6 +184,12 @@ cc_library(
     deps = [
         ":field_value_getter",
         ":jni_env",
+        ":trace",
         "//:jni_dep",
     ],
 )
+
+cc_library(
+    name = "trace",
+    hdrs = ["trace.h"],
+)