1 /*
2 * Copyright (c) 1997, 2019, 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 #ifndef SHARE_RUNTIME_JAVACALLS_HPP
26 #define SHARE_RUNTIME_JAVACALLS_HPP
27
28 #include "memory/allocation.hpp"
29 #include "oops/method.hpp"
30 #include "runtime/handles.hpp"
31 #include "runtime/javaFrameAnchor.hpp"
32 #include "runtime/thread.hpp"
33 #include "runtime/vmThread.hpp"
34 #include "utilities/macros.hpp"
35
36 #include CPU_HEADER(jniTypes)
37
38 // A JavaCallWrapper is constructed before each JavaCall and destructed after the call.
39 // Its purpose is to allocate/deallocate a new handle block and to save/restore the last
40 // Java fp/sp. A pointer to the JavaCallWrapper is stored on the stack.
41
42 class JavaCallWrapper: StackObj {
43 friend class VMStructs;
44 private:
45 JavaThread* _thread; // the thread to which this call belongs
46 JNIHandleBlock* _handles; // the saved handle block
47 Method* _callee_method; // to be able to collect arguments if entry frame is top frame
48 oop _receiver; // the receiver of the call (if a non-static call)
49
50 JavaFrameAnchor _anchor; // last thread anchor state that we must restore
51
52 JavaValue* _result; // result value
53
54 public:
55 // Construction/destruction
56 JavaCallWrapper(const methodHandle& callee_method, Handle receiver, JavaValue* result, TRAPS);
57 ~JavaCallWrapper();
58
59 // Accessors
60 JavaThread* thread() const { return _thread; }
61 JNIHandleBlock* handles() const { return _handles; }
62
63 JavaFrameAnchor* anchor(void) { return &_anchor; }
64
65 JavaValue* result() const { return _result; }
66 // GC support
67 Method* callee_method() { return _callee_method; }
68 oop receiver() { return _receiver; }
69 void oops_do(OopClosure* f);
70
71 bool is_first_frame() const { return _anchor.last_Java_sp() == NULL; }
72
73 };
74
75
76 // Encapsulates arguments to a JavaCall (faster, safer, and more convenient than using var-args)
77 class JavaCallArguments : public StackObj {
78 private:
79 enum Constants {
80 _default_size = 8 // Must be at least # of arguments in JavaCalls methods
81 };
82
83 intptr_t _value_buffer [_default_size + 1];
84 u_char _value_state_buffer[_default_size + 1];
85
86 intptr_t* _value;
87 u_char* _value_state;
88 int _size;
89 int _max_size;
90 bool _start_at_zero; // Support late setting of receiver
91 JVMCI_ONLY(nmethod* _alternative_target;) // Nmethod that should be called instead of normal target
92
93 void initialize() {
94 // Starts at first element to support set_receiver.
95 _value = &_value_buffer[1];
96 _value_state = &_value_state_buffer[1];
97
98 _max_size = _default_size;
99 _size = 0;
100 _start_at_zero = false;
101 JVMCI_ONLY(_alternative_target = NULL;)
102 }
103
104 // Helper for push_oop and the like. The value argument is a
105 // "handle" that refers to an oop. We record the address of the
106 // handle rather than the designated oop. The handle is later
107 // resolved to the oop by parameters(). This delays the exposure of
108 // naked oops until it is GC-safe.
109 template<typename T>
110 inline int push_oop_impl(T handle, int size) {
111 // JNITypes::put_obj expects an oop value, so we play fast and
112 // loose with the type system. The cast from handle type to oop
113 // *must* use a C-style cast. In a product build it performs a
114 // reinterpret_cast. In a debug build (more accurately, in a
115 // CHECK_UNHANDLED_OOPS build) it performs a static_cast, invoking
116 // the debug-only oop class's conversion from void* constructor.
117 JNITypes::put_obj((oop)handle, _value, size); // Updates size.
118 return size; // Return the updated size.
119 }
120
121 public:
122 JavaCallArguments() { initialize(); }
123
124 JavaCallArguments(Handle receiver) {
125 initialize();
126 push_oop(receiver);
127 }
128
129 JavaCallArguments(int max_size) {
130 if (max_size > _default_size) {
131 _value = NEW_RESOURCE_ARRAY(intptr_t, max_size + 1);
132 _value_state = NEW_RESOURCE_ARRAY(u_char, max_size + 1);
133
134 // Reserve room for potential receiver in value and state
135 _value++;
136 _value_state++;
137
138 _max_size = max_size;
139 _size = 0;
140 _start_at_zero = false;
141 JVMCI_ONLY(_alternative_target = NULL;)
142 } else {
143 initialize();
144 }
145 }
146
147 #if INCLUDE_JVMCI
148 void set_alternative_target(nmethod* target) {
149 _alternative_target = target;
150 }
151
152 nmethod* alternative_target() {
153 return _alternative_target;
154 }
155 #endif
156
157 // The possible values for _value_state elements.
158 enum {
159 value_state_primitive,
160 value_state_oop,
161 value_state_handle,
162 value_state_jobject,
163 value_state_limit
164 };
165
166 inline void push_oop(Handle h) {
167 _value_state[_size] = value_state_handle;
168 _size = push_oop_impl(h.raw_value(), _size);
169 }
170
171 inline void push_jobject(jobject h) {
172 _value_state[_size] = value_state_jobject;
173 _size = push_oop_impl(h, _size);
174 }
175
176 inline void push_int(int i) {
177 _value_state[_size] = value_state_primitive;
178 JNITypes::put_int(i, _value, _size);
179 }
180
181 inline void push_double(double d) {
182 _value_state[_size] = value_state_primitive;
183 _value_state[_size + 1] = value_state_primitive;
184 JNITypes::put_double(d, _value, _size);
185 }
186
187 inline void push_long(jlong l) {
188 _value_state[_size] = value_state_primitive;
189 _value_state[_size + 1] = value_state_primitive;
190 JNITypes::put_long(l, _value, _size);
191 }
192
193 inline void push_float(float f) {
194 _value_state[_size] = value_state_primitive;
195 JNITypes::put_float(f, _value, _size);
196 }
197
198 // receiver
199 Handle receiver() {
200 assert(_size > 0, "must at least be one argument");
201 assert(_value_state[0] == value_state_handle,
202 "first argument must be an oop");
203 assert(_value[0] != 0, "receiver must be not-null");
204 return Handle((oop*)_value[0], false);
205 }
206
207 void set_receiver(Handle h) {
208 assert(_start_at_zero == false, "can only be called once");
209 _start_at_zero = true;
210 _value_state--;
211 _value--;
212 _size++;
213 _value_state[0] = value_state_handle;
214 push_oop_impl(h.raw_value(), 0);
215 }
216
217 // Converts all Handles to oops, and returns a reference to parameter vector
218 intptr_t* parameters() ;
219 int size_of_parameters() const { return _size; }
220
221 // Verify that pushed arguments fits a given method
222 void verify(const methodHandle& method, BasicType return_type);
223 };
224
225 // All calls to Java have to go via JavaCalls. Sets up the stack frame
226 // and makes sure that the last_Java_frame pointers are chained correctly.
227 //
228
229 class JavaCalls: AllStatic {
230 static void call_helper(JavaValue* result, const methodHandle& method, JavaCallArguments* args, TRAPS);
231 public:
232 // call_special
233 // ------------
234 // The receiver must be first oop in argument list
235 static void call_special(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS);
236
237 static void call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, TRAPS); // No args
238 static void call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS);
239 static void call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS);
240
241 // virtual call
242 // ------------
243
244 // The receiver must be first oop in argument list
245 static void call_virtual(JavaValue* result, Klass* spec_klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS);
246
247 static void call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, TRAPS); // No args
248 static void call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS);
249 static void call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS);
250
251 // Static call
252 // -----------
253 static void call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS);
254
255 static void call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, TRAPS);
256 static void call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS);
257 static void call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS);
258 static void call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, Handle arg3, TRAPS);
259
260 // Allocate instance + invoke constructor. This is equivalent to "new Klass(args ...)" expression in Java code.
261 static Handle construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, JavaCallArguments* args, TRAPS);
262
263 static Handle construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, TRAPS);
264 static Handle construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, Handle arg1, TRAPS);
265 static Handle construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, Handle arg1, Handle arg2, TRAPS);
266
267 // Low-level interface
268 static void call(JavaValue* result, const methodHandle& method, JavaCallArguments* args, TRAPS);
269 };
270
271 #endif // SHARE_RUNTIME_JAVACALLS_HPP