1 /*
2 * Copyright (c) 2022, Red Hat, Inc. 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 "jni.h"
26 #include "jvm.h"
27 #include "classfile/javaClasses.inline.hpp"
28 #include "gc/shared/collectedHeap.hpp"
29 #include "oops/arrayOop.hpp"
30 #include "oops/instanceKlass.inline.hpp"
31 #include "oops/oop.inline.hpp"
32 #include "oops/oopsHierarchy.hpp"
33 #include "runtime/interfaceSupport.inline.hpp"
34 #include "runtime/jniHandles.inline.hpp"
35 #include "runtime/os.hpp"
36 #include "runtime/orderAccess.hpp"
37 #include "utilities/macros.hpp"
38
39 #include OS_CPU_HEADER_INLINE(os)
40
41 /**
42 * Implementation of the net.shipilev.Magic
43 */
44
45 JVM_ENTRY(static jlong, NetShipilevMagic_timestamp(JNIEnv *env, jclass cls)) {
46 #if defined(X86) && !defined(ZERO)
47 return os::rdtsc();
48 #else
49 return -1;
50 #endif
51 } JVM_END
52
53 JVM_ENTRY(static jlong, NetShipilevMagic_timestamp_serial(JNIEnv *env, jclass cls)) {
54 #if defined(X86) && !defined(ZERO)
55 // Rely on rdtscp intrinsic to make the right thing
56 // serialization-wise. In these fallback/interpreter paths,
57 // just bite the bullet and do the fence.
58 OrderAccess::fence();
59 return os::rdtsc();
60 #else
61 return -1;
62 #endif
63 } JVM_END
64
65 JVM_ENTRY(jlong, NetShipilevMagic_sizeOf(JNIEnv *env, jclass cls, jobject obj))
66 assert(obj != nullptr, "object must not be null");
67
68 oop o = JNIHandles::resolve_non_null(obj);
69 return o->size()*HeapWordSize;
70 JVM_END
71
72 JVM_ENTRY(jlong, NetShipilevMagic_addressOf(JNIEnv *env, jclass cls, jobject obj))
73 assert(obj != nullptr, "object must not be null");
74
75 oop o = JNIHandles::resolve_non_null(obj);
76 return cast_from_oop<jlong>(o);
77 JVM_END
78
79 JVM_ENTRY(jlong, NetShipilevMagic_fieldOffsetOf(JNIEnv *env, jclass cls, jobject field))
80 assert(field != nullptr, "field must not be null");
81
82 oop f = JNIHandles::resolve_non_null(field);
83 oop m = java_lang_reflect_Field::clazz(f);
84 Klass* k = java_lang_Class::as_Klass(m);
85 int slot = java_lang_reflect_Field::slot(f);
86
87 return InstanceKlass::cast(k)->field_offset(slot);
88 JVM_END
89
90 JVM_ENTRY(jlong, NetShipilevMagic_fieldSizeOf(JNIEnv *env, jclass cls, jobject field))
91 assert(field != nullptr, "field must not be null");
92
93 oop f = JNIHandles::resolve_non_null(field);
94 oop m = java_lang_reflect_Field::clazz(f);
95 Klass* k = java_lang_Class::as_Klass(m);
96 int slot = java_lang_reflect_Field::slot(f);
97
98 Symbol* sig = InstanceKlass::cast(k)->field_signature(slot);
99 switch (sig->char_at(0)) {
100 case JVM_SIGNATURE_CLASS :
101 case JVM_SIGNATURE_ARRAY : return type2aelembytes(T_OBJECT);
102 case JVM_SIGNATURE_BYTE : return type2aelembytes(T_BYTE);
103 case JVM_SIGNATURE_CHAR : return type2aelembytes(T_CHAR);
104 case JVM_SIGNATURE_FLOAT : return type2aelembytes(T_FLOAT);
105 case JVM_SIGNATURE_DOUBLE : return type2aelembytes(T_DOUBLE);
106 case JVM_SIGNATURE_INT : return type2aelembytes(T_INT);
107 case JVM_SIGNATURE_LONG : return type2aelembytes(T_LONG);
108 case JVM_SIGNATURE_SHORT : return type2aelembytes(T_SHORT);
109 case JVM_SIGNATURE_BOOLEAN : return type2aelembytes(T_BOOLEAN);
110 }
111
112 ShouldNotReachHere();
113 return 0;
114 JVM_END
115
116 class GetReferencedObjectsClosure : public BasicOopIterateClosure {
117 private:
118 objArrayOopDesc* const _result;
119 int _count;
120 public:
121 GetReferencedObjectsClosure(objArrayOopDesc* result) : _result(result), _count(0) {}
122
123 template <typename T> void do_oop_nv(T* p) {
124 oop o = HeapAccess<>::oop_load(p);
125 if (!CompressedOops::is_null(o)) {
126 _result->obj_at_put(_count++, o);
127 }
128 }
129
130 int count() { return _count; }
131
132 virtual void do_oop(oop* p) { do_oop_nv(p); }
133 virtual void do_oop(narrowOop* p) { do_oop_nv(p); }
134 };
135
136 JVM_ENTRY(jint, NetShipilevMagic_getReferencedObjects(JNIEnv *env, jclass cls, jobject obj_ref, jobjectArray ref_buf_ref))
137 oop obj = JNIHandles::resolve_non_null(obj_ref);
138 objArrayOop ref_buf = objArrayOop(JNIHandles::resolve_non_null(ref_buf_ref));
139
140 assert(Universe::heap()->is_in(obj), "object should be in heap: " PTR_FORMAT, p2i(obj));
141 assert(Universe::heap()->is_in(ref_buf), "ref buf should be in heap: " PTR_FORMAT, p2i(ref_buf));
142
143 InstanceKlass* k = InstanceKlass::cast(obj->klass());
144
145 int count = 0;
146 {
147 InstanceKlass* ik = k;
148 while (ik != nullptr) {
149 count += ik->nonstatic_oop_field_count();
150 ik = ik->super();
151 }
152 }
153
154 if (count == 0) {
155 return 0;
156 }
157
158 if (count > ref_buf->length()) {
159 return -1;
160 }
161
162 GetReferencedObjectsClosure cl(ref_buf);
163
164 #ifdef _LP64
165 if (UseCompressedOops) {
166 k->oop_oop_iterate<narrowOop>(obj, &cl);
167 } else
168 #endif
169 {
170 k->oop_oop_iterate<oop>(obj, &cl);
171 }
172
173 return cl.count();
174 JVM_END
175
176 /// JVM_RegisterUnsafeMethods
177
178 #define CC (char*) /*cast a literal from (const char*)*/
179 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
180
181 #define LANG "Ljava/lang/"
182
183 #define OBJ LANG "Object;"
184 #define CLS LANG "Class;"
185 #define FLD LANG "reflect/Field;"
186
187 static JNINativeMethod net_shipilev_Magic_methods[] = {
188 {CC "timestamp", CC "()J", FN_PTR(NetShipilevMagic_timestamp)},
189 {CC "timestampSerial", CC "()J", FN_PTR(NetShipilevMagic_timestamp_serial)},
190 {CC "sizeOf0", CC "(" OBJ ")J", FN_PTR(NetShipilevMagic_sizeOf)},
191 {CC "addressOf0", CC "(" OBJ ")J", FN_PTR(NetShipilevMagic_addressOf)},
192 {CC "getReferencedObjects", CC "(" OBJ "[" OBJ ")I", FN_PTR(NetShipilevMagic_getReferencedObjects)},
193 {CC "fieldOffsetOf0", CC "(" FLD ")J", FN_PTR(NetShipilevMagic_fieldOffsetOf)},
194 {CC "fieldSizeOf0", CC "(" FLD ")J", FN_PTR(NetShipilevMagic_fieldSizeOf)},
195 };
196
197 #undef LANG
198 #undef OBJ
199 #undef CLS
200 #undef FLD
201
202 #undef CC
203 #undef FN_PTR
204
205 JVM_ENTRY(void, JVM_RegisterNetShipilevMagicMethods(JNIEnv *env, jclass cls)) {
206 ThreadToNativeFromVM ttnfv(thread);
207
208 int ok = env->RegisterNatives(cls, net_shipilev_Magic_methods, sizeof(net_shipilev_Magic_methods)/sizeof(JNINativeMethod));
209 guarantee(ok == 0, "register net.shipilev.Magic natives");
210 } JVM_END