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 thread() const60 JavaThread* thread() const { return _thread; } handles() const61 JNIHandleBlock* handles() const { return _handles; } 62 anchor(void)63 JavaFrameAnchor* anchor(void) { return &_anchor; } 64 result() const65 JavaValue* result() const { return _result; } 66 // GC support callee_method()67 Method* callee_method() { return _callee_method; } receiver()68 oop receiver() { return _receiver; } 69 void oops_do(OopClosure* f); 70 is_first_frame() const71 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 JVMCI_ONLY(nmethod * _alternative_target;)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> push_oop_impl(T handle,int size)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: JavaCallArguments()122 JavaCallArguments() { initialize(); } 123 JavaCallArguments(Handle receiver)124 JavaCallArguments(Handle receiver) { 125 initialize(); 126 push_oop(receiver); 127 } 128 JavaCallArguments(int max_size)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 set_alternative_target(nmethod * target)148 void set_alternative_target(nmethod* target) { 149 _alternative_target = target; 150 } 151 alternative_target()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 push_oop(Handle h)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 push_jobject(jobject h)171 inline void push_jobject(jobject h) { 172 _value_state[_size] = value_state_jobject; 173 _size = push_oop_impl(h, _size); 174 } 175 push_int(int i)176 inline void push_int(int i) { 177 _value_state[_size] = value_state_primitive; 178 JNITypes::put_int(i, _value, _size); 179 } 180 push_double(double d)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 push_long(jlong l)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 push_float(float f)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 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 set_receiver(Handle h)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() ; size_of_parameters() const219 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 272