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 "precompiled.hpp"
26 #include "jni.h"
27 #include "jvm.h"
28 #include "classfile/javaClasses.inline.hpp"
29 #include "gc/shared/collectedHeap.hpp"
30 #include "oops/arrayOop.hpp"
31 #include "oops/instanceKlass.inline.hpp"
32 #include "oops/oop.inline.hpp"
33 #include "oops/oopsHierarchy.hpp"
34 #include "runtime/interfaceSupport.inline.hpp"
35 #include "runtime/jniHandles.inline.hpp"
36 #include "runtime/os.hpp"
37 #include "runtime/orderAccess.hpp"
38 #include "utilities/macros.hpp"
39
40 #include OS_CPU_HEADER_INLINE(os)
41
42 /**
43 * Implementation of the net.shipilev.Magic
44 */
45
46 JVM_ENTRY(static jlong, NetShipilevMagic_timestamp(JNIEnv *env, jclass cls)) {
47 #if defined(X86) && !defined(ZERO)
48 return os::rdtsc();
49 #else
50 return -1;
51 #endif
52 } JVM_END
53
54 JVM_ENTRY(static jlong, NetShipilevMagic_timestamp_serial(JNIEnv *env, jclass cls)) {
55 #if defined(X86) && !defined(ZERO)
56 // Rely on rdtscp intrinsic to make the right thing
57 // serialization-wise. In these fallback/interpreter paths,
58 // just bite the bullet and do the fence.
59 OrderAccess::fence();
60 return os::rdtsc();
61 #else
62 return -1;
63 #endif
64 } JVM_END
65
66 JVM_ENTRY(jlong, NetShipilevMagic_sizeOf(JNIEnv *env, jclass cls, jobject obj))
67 assert(obj != NULL, "object must not be NULL");
68
69 oop o = JNIHandles::resolve_non_null(obj);
70 return o->size()*HeapWordSize;
71 JVM_END
72
73 JVM_ENTRY(jlong, NetShipilevMagic_addressOf(JNIEnv *env, jclass cls, jobject obj))
74 assert(obj != NULL, "object must not be NULL");
75
76 oop o = JNIHandles::resolve_non_null(obj);
77 return cast_from_oop<jlong>(o);
78 JVM_END
79
80 JVM_ENTRY(jlong, NetShipilevMagic_fieldOffsetOf(JNIEnv *env, jclass cls, jobject field))
81 assert(field != NULL, "field must not be NULL");
82
83 oop f = JNIHandles::resolve_non_null(field);
84 oop m = java_lang_reflect_Field::clazz(f);
85 Klass* k = java_lang_Class::as_Klass(m);
86 int slot = java_lang_reflect_Field::slot(f);
87
88 return InstanceKlass::cast(k)->field_offset(slot);
89 JVM_END
90
91 JVM_ENTRY(jlong, NetShipilevMagic_fieldSizeOf(JNIEnv *env, jclass cls, jobject field))
92 assert(field != NULL, "field must not be NULL");
93
94 oop f = JNIHandles::resolve_non_null(field);
95 oop m = java_lang_reflect_Field::clazz(f);
96 Klass* k = java_lang_Class::as_Klass(m);
97 int slot = java_lang_reflect_Field::slot(f);
98
99 Symbol* sig = InstanceKlass::cast(k)->field_signature(slot);
100 switch (sig->char_at(0)) {
101 case JVM_SIGNATURE_CLASS :
102 case JVM_SIGNATURE_ARRAY : return type2aelembytes(T_OBJECT);
103 case JVM_SIGNATURE_BYTE : return type2aelembytes(T_BYTE);
104 case JVM_SIGNATURE_CHAR : return type2aelembytes(T_CHAR);
105 case JVM_SIGNATURE_FLOAT : return type2aelembytes(T_FLOAT);
106 case JVM_SIGNATURE_DOUBLE : return type2aelembytes(T_DOUBLE);
107 case JVM_SIGNATURE_INT : return type2aelembytes(T_INT);
108 case JVM_SIGNATURE_LONG : return type2aelembytes(T_LONG);
109 case JVM_SIGNATURE_SHORT : return type2aelembytes(T_SHORT);
110 case JVM_SIGNATURE_BOOLEAN : return type2aelembytes(T_BOOLEAN);
111 }
112
113 ShouldNotReachHere();
114 return 0;
115 JVM_END
116
117 class GetReferencedObjectsClosure : public BasicOopIterateClosure {
118 private:
119 objArrayOopDesc* const _result;
120 int _count;
121 public:
122 GetReferencedObjectsClosure(objArrayOopDesc* result) : _result(result), _count(0) {}
123
124 template <typename T> void do_oop_nv(T* p) {
125 oop o = HeapAccess<>::oop_load(p);
126 if (!CompressedOops::is_null(o)) {
127 _result->obj_at_put(_count++, o);
128 }
129 }
130
131 int count() { return _count; }
132
133 virtual void do_oop(oop* p) { do_oop_nv(p); }
134 virtual void do_oop(narrowOop* p) { do_oop_nv(p); }
135
136 // Don't use the oop verification code in the oop_oop_iterate framework.
137 debug_only(virtual bool should_verify_oops() { return false; })
138 };
139
140 JVM_ENTRY(jint, NetShipilevMagic_getReferencedObjects(JNIEnv *env, jclass cls, jobject obj_ref, jobjectArray ref_buf_ref))
141 oop obj = JNIHandles::resolve_non_null(obj_ref);
142 objArrayOop ref_buf = objArrayOop(JNIHandles::resolve_non_null(ref_buf_ref));
143
144 assert(Universe::heap()->is_in(obj), "object should be in heap: " PTR_FORMAT, p2i(obj));
145 assert(Universe::heap()->is_in(ref_buf), "ref buf should be in heap: " PTR_FORMAT, p2i(ref_buf));
146
147 InstanceKlass* k = InstanceKlass::cast(obj->klass());
148
149 int count = 0;
150 {
151 InstanceKlass* ik = k;
152 while (ik != NULL) {
153 count += ik->nonstatic_oop_field_count();
154 ik = ik->superklass();
155 }
156 }
157
158 if (count == 0) {
159 return 0;
160 }
161
162 if (count > ref_buf->length()) {
163 return -1;
164 }
165
166 GetReferencedObjectsClosure cl(ref_buf);
167
168 #ifdef _LP64
169 if (UseCompressedOops) {
170 k->oop_oop_iterate<narrowOop>(obj, &cl);
171 } else
172 #endif
173 {
174 k->oop_oop_iterate<oop>(obj, &cl);
175 }
176
177 return cl.count();
178 JVM_END
179
180 /// JVM_RegisterUnsafeMethods
181
182 #define CC (char*) /*cast a literal from (const char*)*/
183 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
184
185 #define LANG "Ljava/lang/"
186
187 #define OBJ LANG "Object;"
188 #define CLS LANG "Class;"
189 #define FLD LANG "reflect/Field;"
190
191 static JNINativeMethod net_shipilev_Magic_methods[] = {
192 {CC "timestamp", CC "()J", FN_PTR(NetShipilevMagic_timestamp)},
193 {CC "timestampSerial", CC "()J", FN_PTR(NetShipilevMagic_timestamp_serial)},
194 {CC "sizeOf0", CC "(" OBJ ")J", FN_PTR(NetShipilevMagic_sizeOf)},
195 {CC "addressOf0", CC "(" OBJ ")J", FN_PTR(NetShipilevMagic_addressOf)},
196 {CC "getReferencedObjects", CC "(" OBJ "[" OBJ ")I", FN_PTR(NetShipilevMagic_getReferencedObjects)},
197 {CC "fieldOffsetOf0", CC "(" FLD ")J", FN_PTR(NetShipilevMagic_fieldOffsetOf)},
198 {CC "fieldSizeOf0", CC "(" FLD ")J", FN_PTR(NetShipilevMagic_fieldSizeOf)},
199 };
200
201 #undef LANG
202 #undef OBJ
203 #undef CLS
204 #undef FLD
205
206 #undef CC
207 #undef FN_PTR
208
209 JVM_ENTRY(void, JVM_RegisterNetShipilevMagicMethods(JNIEnv *env, jclass cls)) {
210 ThreadToNativeFromVM ttnfv(thread);
211
212 int ok = env->RegisterNatives(cls, net_shipilev_Magic_methods, sizeof(net_shipilev_Magic_methods)/sizeof(JNINativeMethod));
213 guarantee(ok == 0, "register net.shipilev.Magic natives");
214 } JVM_END