1 /*
   2  * Copyright (c) 1997, 2014, 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_VM_RUNTIME_JAVACALLS_HPP
  26 #define SHARE_VM_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.inline.hpp"
  33 #include "runtime/vmThread.hpp"
  34 #ifdef TARGET_ARCH_x86
  35 # include "jniTypes_x86.hpp"
  36 #endif
  37 #ifdef TARGET_ARCH_sparc
  38 # include "jniTypes_sparc.hpp"
  39 #endif
  40 #ifdef TARGET_ARCH_zero
  41 # include "jniTypes_zero.hpp"
  42 #endif
  43 #ifdef TARGET_ARCH_arm
  44 # include "jniTypes_arm.hpp"
  45 #endif
  46 #ifdef TARGET_ARCH_ppc
  47 # include "jniTypes_ppc.hpp"
  48 #endif
  49 
  50 // A JavaCallWrapper is constructed before each JavaCall and destructed after the call.
  51 // Its purpose is to allocate/deallocate a new handle block and to save/restore the last
  52 // Java fp/sp. A pointer to the JavaCallWrapper is stored on the stack.
  53 
  54 class JavaCallWrapper: StackObj {
  55   friend class VMStructs;
  56  private:
  57   JavaThread*      _thread;                 // the thread to which this call belongs
  58   JNIHandleBlock*  _handles;                // the saved handle block
  59   Method*          _callee_method;          // to be able to collect arguments if entry frame is top frame
  60   oop              _receiver;               // the receiver of the call (if a non-static call)
  61 
  62   JavaFrameAnchor  _anchor;                 // last thread anchor state that we must restore
  63 
  64   JavaValue*       _result;                 // result value
  65 
  66  public:
  67   // Construction/destruction
  68    JavaCallWrapper(methodHandle callee_method, Handle receiver, JavaValue* result, TRAPS);
  69   ~JavaCallWrapper();
  70 
  71   // Accessors
  72   JavaThread*      thread() const           { return _thread; }
  73   JNIHandleBlock*  handles() const          { return _handles; }
  74 
  75   JavaFrameAnchor* anchor(void)             { return &_anchor; }
  76 
  77   JavaValue*       result() const           { return _result; }
  78   // GC support
  79   Method*          callee_method()          { return _callee_method; }
  80   oop              receiver()               { return _receiver; }
  81   void             oops_do(OopClosure* f);
  82 
  83   bool             is_first_frame() const   { return _anchor.last_Java_sp() == NULL; }
  84 
  85 };
  86 
  87 
  88 // Encapsulates arguments to a JavaCall (faster, safer, and more convenient than using var-args)
  89 class JavaCallArguments : public StackObj {
  90  private:
  91   enum Constants {
  92    _default_size = 8    // Must be at least # of arguments in JavaCalls methods
  93   };
  94 
  95   intptr_t    _value_buffer [_default_size + 1];
  96   bool        _is_oop_buffer[_default_size + 1];
  97 
  98   intptr_t*   _value;
  99   bool*       _is_oop;
 100   int         _size;
 101   int         _max_size;
 102   bool        _start_at_zero;      // Support late setting of receiver
 103 
 104   void initialize() {
 105     // Starts at first element to support set_receiver.
 106     _value    = &_value_buffer[1];
 107     _is_oop   = &_is_oop_buffer[1];
 108 
 109     _max_size = _default_size;
 110     _size = 0;
 111     _start_at_zero = false;
 112   }
 113 
 114  public:
 115   JavaCallArguments() { initialize(); }
 116 
 117   JavaCallArguments(Handle receiver) {
 118     initialize();
 119     push_oop(receiver);
 120   }
 121 
 122   JavaCallArguments(int max_size) {
 123     if (max_size > _default_size) {
 124       _value  = NEW_RESOURCE_ARRAY(intptr_t, max_size + 1);
 125       _is_oop = NEW_RESOURCE_ARRAY(bool, max_size + 1);
 126 
 127       // Reserve room for potential receiver in value and is_oop
 128       _value++; _is_oop++;
 129 
 130       _max_size = max_size;
 131       _size = 0;
 132       _start_at_zero = false;
 133     } else {
 134       initialize();
 135     }
 136   }
 137 
 138   inline void push_oop(Handle h)    { _is_oop[_size] = true;
 139                                JNITypes::put_obj((oop)h.raw_value(), _value, _size); }
 140 
 141   inline void push_int(int i)       { _is_oop[_size] = false;
 142                                JNITypes::put_int(i, _value, _size); }
 143 
 144   inline void push_double(double d) { _is_oop[_size] = false; _is_oop[_size + 1] = false;
 145                                JNITypes::put_double(d, _value, _size); }
 146 
 147   inline void push_long(jlong l)    { _is_oop[_size] = false; _is_oop[_size + 1] = false;
 148                                JNITypes::put_long(l, _value, _size); }
 149 
 150   inline void push_float(float f)   { _is_oop[_size] = false;
 151                                JNITypes::put_float(f, _value, _size); }
 152 
 153   // receiver
 154   Handle receiver() {
 155     assert(_size > 0, "must at least be one argument");
 156     assert(_is_oop[0], "first argument must be an oop");
 157     assert(_value[0] != 0, "receiver must be not-null");
 158     return Handle((oop*)_value[0], false);
 159   }
 160 
 161   void set_receiver(Handle h) {
 162     assert(_start_at_zero == false, "can only be called once");
 163     _start_at_zero = true;
 164     _is_oop--;
 165     _value--;
 166     _size++;
 167     _is_oop[0] = true;
 168     _value[0] = (intptr_t)h.raw_value();
 169   }
 170 
 171   // Converts all Handles to oops, and returns a reference to parameter vector
 172   intptr_t* parameters() ;
 173   int   size_of_parameters() const { return _size; }
 174 
 175   // Verify that pushed arguments fits a given method
 176   void verify(methodHandle method, BasicType return_type, Thread *thread);
 177 };
 178 
 179 // All calls to Java have to go via JavaCalls. Sets up the stack frame
 180 // and makes sure that the last_Java_frame pointers are chained correctly.
 181 //
 182 
 183 class JavaCalls: AllStatic {
 184   static void call_helper(JavaValue* result, methodHandle* method, JavaCallArguments* args, TRAPS);
 185  public:
 186   // call_special
 187   // ------------
 188   // The receiver must be first oop in argument list
 189   static void call_special(JavaValue* result, KlassHandle klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS);
 190 
 191   static void call_special(JavaValue* result, Handle receiver, KlassHandle klass, Symbol* name, Symbol* signature, TRAPS); // No args
 192   static void call_special(JavaValue* result, Handle receiver, KlassHandle klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS);
 193   static void call_special(JavaValue* result, Handle receiver, KlassHandle klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS);
 194 
 195   // virtual call
 196   // ------------
 197 
 198   // The receiver must be first oop in argument list
 199   static void call_virtual(JavaValue* result, KlassHandle spec_klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS);
 200 
 201   static void call_virtual(JavaValue* result, Handle receiver, KlassHandle spec_klass, Symbol* name, Symbol* signature, TRAPS); // No args
 202   static void call_virtual(JavaValue* result, Handle receiver, KlassHandle spec_klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS);
 203   static void call_virtual(JavaValue* result, Handle receiver, KlassHandle spec_klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS);
 204 
 205   // Static call
 206   // -----------
 207   static void call_static(JavaValue* result, KlassHandle klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS);
 208 
 209   static void call_static(JavaValue* result, KlassHandle klass, Symbol* name, Symbol* signature, TRAPS);
 210   static void call_static(JavaValue* result, KlassHandle klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS);
 211   static void call_static(JavaValue* result, KlassHandle klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS);
 212 
 213   // Low-level interface
 214   static void call(JavaValue* result, methodHandle method, JavaCallArguments* args, TRAPS);
 215 };
 216 
 217 #endif // SHARE_VM_RUNTIME_JAVACALLS_HPP