1 /*
2 * Copyright (c) 2020, 2026, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "classfile/javaClasses.inline.hpp"
26 #include "code/codeCache.hpp"
27 #include "code/vmreg.hpp"
28 #include "logging/logStream.hpp"
29 #include "memory/resourceArea.hpp"
30 #include "oops/oopCast.inline.hpp"
31 #include "oops/typeArrayOop.inline.hpp"
32 #include "prims/downcallLinker.hpp"
33 #include "prims/foreignGlobals.inline.hpp"
34 #include "runtime/interfaceSupport.inline.hpp"
35 #include "runtime/jniHandles.inline.hpp"
36
37 JNI_ENTRY(jlong, NEP_makeDowncallStub(JNIEnv* env, jclass _unused, jobject method_type, jobject jabi,
38 jobjectArray arg_moves, jobjectArray ret_moves,
39 jboolean needs_return_buffer, jint captured_state_mask,
40 jboolean needs_transition))
41 ResourceMark rm;
42 const ABIDescriptor abi = ForeignGlobals::parse_abi_descriptor(jabi);
43
44 oop type = JNIHandles::resolve(method_type);
45 refArrayOop arg_moves_oop = oop_cast<refArrayOop>(JNIHandles::resolve(arg_moves));
46 refArrayOop ret_moves_oop = oop_cast<refArrayOop>(JNIHandles::resolve(ret_moves));
47 int pcount = java_lang_invoke_MethodType::ptype_count(type);
48 int pslots = java_lang_invoke_MethodType::ptype_slot_count(type);
49 BasicType* basic_type = NEW_RESOURCE_ARRAY(BasicType, pslots);
50
51 GrowableArray<VMStorage> input_regs(pcount);
52 for (int i = 0, bt_idx = 0; i < pcount; i++) {
53 oop type_oop = java_lang_invoke_MethodType::ptype(type, i);
54 BasicType bt = java_lang_Class::as_BasicType(type_oop);
55 basic_type[bt_idx++] = bt;
56 oop reg_oop = arg_moves_oop->obj_at(i);
57 if (reg_oop != nullptr) {
58 input_regs.push(ForeignGlobals::parse_vmstorage(reg_oop));
59 }
60
61 if (bt == BasicType::T_DOUBLE || bt == BasicType::T_LONG) {
62 basic_type[bt_idx++] = T_VOID;
63 // we only need these in the basic type
64 // NativeCallingConvention ignores them, but they are needed
65 // for JavaCallingConvention
66 }
67 }
68
69
70 jint outs = ret_moves_oop->length();
71 GrowableArray<VMStorage> output_regs(outs);
72 oop type_oop = java_lang_invoke_MethodType::rtype(type);
73 BasicType ret_bt = java_lang_Class::primitive_type(type_oop);
74 for (int i = 0; i < outs; i++) {
75 // note that we don't care about long/double upper halfs here:
76 // we are NOT moving Java values, we are moving register-sized values
77 output_regs.push(ForeignGlobals::parse_vmstorage(ret_moves_oop->obj_at(i)));
78 }
79
80 RuntimeStub* stub = DowncallLinker::make_downcall_stub(basic_type, pslots, ret_bt, abi,
81 input_regs, output_regs,
82 needs_return_buffer, captured_state_mask,
83 needs_transition);
84 if (stub == nullptr) {
85 return 0;
86 }
87 return (jlong) stub->code_begin();
88 JNI_END
89
90 JNI_ENTRY(jboolean, NEP_freeDowncallStub(JNIEnv* env, jclass _unused, jlong invoker))
91 // safe to call without code cache lock, because stub is always alive
92 CodeBlob* cb = CodeCache::find_blob((char*) invoker);
93 if (cb == nullptr) {
94 return false;
95 }
96 RuntimeStub::free(cb->as_runtime_stub());
97 return true;
98 JNI_END
99
100 #define CC (char*) /*cast a literal from (const char*)*/
101 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
102 #define METHOD_TYPE "Ljava/lang/invoke/MethodType;"
103 #define ABI_DESC "Ljdk/internal/foreign/abi/ABIDescriptor;"
104 #define VM_STORAGE_ARR "[Ljdk/internal/foreign/abi/VMStorage;"
105
106 static JNINativeMethod NEP_methods[] = {
107 {CC "makeDowncallStub", CC "(" METHOD_TYPE ABI_DESC VM_STORAGE_ARR VM_STORAGE_ARR "ZIZ)J", FN_PTR(NEP_makeDowncallStub)},
108 {CC "freeDowncallStub0", CC "(J)Z", FN_PTR(NEP_freeDowncallStub)},
109 };
110
111 #undef METHOD_TYPE
112 #undef ABI_DESC
113 #undef VM_STORAGE_ARR
114
115 JNI_ENTRY(void, JVM_RegisterNativeEntryPointMethods(JNIEnv *env, jclass NEP_class))
116 ThreadToNativeFromVM ttnfv(thread);
117 int status = env->RegisterNatives(NEP_class, NEP_methods, sizeof(NEP_methods)/sizeof(JNINativeMethod));
118 guarantee(status == JNI_OK && !env->ExceptionCheck(),
119 "register jdk.internal.foreign.abi.NativeEntryPoint natives");
120 JNI_END