1 /*
   2  * Copyright (c) 1997, 2017, 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_CODE_COMPILEDIC_HPP
  26 #define SHARE_VM_CODE_COMPILEDIC_HPP
  27 
  28 #include "interpreter/linkResolver.hpp"
  29 #include "oops/compiledICHolder.hpp"
  30 #ifdef TARGET_ARCH_x86
  31 # include "nativeInst_x86.hpp"
  32 #endif
  33 #ifdef TARGET_ARCH_sparc
  34 # include "nativeInst_sparc.hpp"
  35 #endif
  36 #ifdef TARGET_ARCH_zero
  37 # include "nativeInst_zero.hpp"
  38 #endif
  39 #ifdef TARGET_ARCH_arm
  40 # include "nativeInst_arm.hpp"
  41 #endif
  42 #ifdef TARGET_ARCH_ppc
  43 # include "nativeInst_ppc.hpp"
  44 #endif
  45 
  46 //-----------------------------------------------------------------------------
  47 // The CompiledIC represents a compiled inline cache.
  48 //
  49 // In order to make patching of the inline cache MT-safe, we only allow the following
  50 // transitions (when not at a safepoint):
  51 //
  52 //
  53 //         [1] --<--  Clean -->---  [1]
  54 //            /       (null)      \
  55 //           /                     \      /-<-\
  56 //          /          [2]          \    /     \
  57 //      Interpreted  ---------> Monomorphic     | [3]
  58 //  (CompiledICHolder*)            (Klass*)     |
  59 //          \                        /   \     /
  60 //       [4] \                      / [4] \->-/
  61 //            \->-  Megamorphic -<-/
  62 //              (CompiledICHolder*)
  63 //
  64 // The text in parentheses () refers to the value of the inline cache receiver (mov instruction)
  65 //
  66 // The numbers in square brackets refer to the kind of transition:
  67 // [1]: Initial fixup. Receiver it found from debug information
  68 // [2]: Compilation of a method
  69 // [3]: Recompilation of a method (note: only entry is changed. The Klass* must stay the same)
  70 // [4]: Inline cache miss. We go directly to megamorphic call.
  71 //
  72 // The class automatically inserts transition stubs (using the InlineCacheBuffer) when an MT-unsafe
  73 // transition is made to a stub.
  74 //
  75 class CompiledIC;
  76 class ICStub;
  77 
  78 class CompiledICInfo : public StackObj {
  79  private:
  80   address _entry;              // entry point for call
  81   void*   _cached_value;         // Value of cached_value (either in stub or inline cache)
  82   bool    _is_icholder;          // Is the cached value a CompiledICHolder*
  83   bool    _is_optimized;       // it is an optimized virtual call (i.e., can be statically bound)
  84   bool    _to_interpreter;     // Call it to interpreter
  85   bool    _release_icholder;
  86  public:
  87   address entry() const        { return _entry; }
  88   Metadata*    cached_metadata() const         { assert(!_is_icholder, ""); return (Metadata*)_cached_value; }
  89   CompiledICHolder*    claim_cached_icholder() {
  90     assert(_is_icholder, "");
  91     assert(_cached_value != NULL, "must be non-NULL");
  92     _release_icholder = false;
  93     CompiledICHolder* icholder = (CompiledICHolder*)_cached_value;
  94     icholder->claim();
  95     return icholder;
  96   }
  97   bool    is_optimized() const { return _is_optimized; }
  98   bool         to_interpreter() const  { return _to_interpreter; }
  99 
 100   void set_compiled_entry(address entry, Klass* klass, bool is_optimized) {
 101     _entry      = entry;
 102     _cached_value = (void*)klass;
 103     _to_interpreter = false;
 104     _is_icholder = false;
 105     _is_optimized = is_optimized;
 106     _release_icholder = false;
 107   }
 108 
 109   void set_interpreter_entry(address entry, Method* method) {
 110     _entry      = entry;
 111     _cached_value = (void*)method;
 112     _to_interpreter = true;
 113     _is_icholder = false;
 114     _is_optimized = true;
 115     _release_icholder = false;
 116   }
 117 
 118   void set_icholder_entry(address entry, CompiledICHolder* icholder) {
 119     _entry      = entry;
 120     _cached_value = (void*)icholder;
 121     _to_interpreter = true;
 122     _is_icholder = true;
 123     _is_optimized = false;
 124     _release_icholder = true;
 125   }
 126 
 127   CompiledICInfo(): _entry(NULL), _cached_value(NULL), _is_icholder(false),
 128                     _to_interpreter(false), _is_optimized(false), _release_icholder(false) {
 129   }
 130   ~CompiledICInfo() {
 131     // In rare cases the info is computed but not used, so release any
 132     // CompiledICHolder* that was created
 133     if (_release_icholder) {
 134       assert(_is_icholder, "must be");
 135       CompiledICHolder* icholder = (CompiledICHolder*)_cached_value;
 136       icholder->claim();
 137       delete icholder;
 138     }
 139   }
 140 };
 141 
 142 class CompiledIC: public ResourceObj {
 143   friend class InlineCacheBuffer;
 144   friend class ICStub;
 145 
 146 
 147  private:
 148   NativeCall*   _ic_call;       // the call instruction
 149   NativeMovConstReg* _value;    // patchable value cell for this IC
 150   bool          _is_optimized;  // an optimized virtual call (i.e., no compiled IC)
 151 
 152   CompiledIC(nmethod* nm, NativeCall* ic_call);
 153   CompiledIC(RelocIterator* iter);
 154 
 155   void initialize_from_iter(RelocIterator* iter);
 156 
 157   static bool is_icholder_entry(address entry);
 158 
 159   // low-level inline-cache manipulation. Cannot be accessed directly, since it might not be MT-safe
 160   // to change an inline-cache. These changes the underlying inline-cache directly. They *newer* make
 161   // changes to a transition stub.
 162   void internal_set_ic_destination(address entry_point, bool is_icstub, void* cache, bool is_icholder);
 163   void set_ic_destination(ICStub* stub);
 164   void set_ic_destination(address entry_point) {
 165     assert(_is_optimized, "use set_ic_destination_and_value instead");
 166     internal_set_ic_destination(entry_point, false, NULL, false);
 167   }
 168   // This only for use by ICStubs where the type of the value isn't known
 169   void set_ic_destination_and_value(address entry_point, void* value) {
 170     internal_set_ic_destination(entry_point, false, value, is_icholder_entry(entry_point));
 171   }
 172   void set_ic_destination_and_value(address entry_point, Metadata* value) {
 173     internal_set_ic_destination(entry_point, false, value, false);
 174   }
 175   void set_ic_destination_and_value(address entry_point, CompiledICHolder* value) {
 176     internal_set_ic_destination(entry_point, false, value, true);
 177   }
 178 
 179   // Reads the location of the transition stub. This will fail with an assertion, if no transition stub is
 180   // associated with the inline cache.
 181   address stub_address() const;
 182   bool is_in_transition_state() const;  // Use InlineCacheBuffer
 183 
 184  public:
 185   // conversion (machine PC to CompiledIC*)
 186   friend CompiledIC* CompiledIC_before(nmethod* nm, address return_addr);
 187   friend CompiledIC* CompiledIC_at(nmethod* nm, address call_site);
 188   friend CompiledIC* CompiledIC_at(Relocation* call_site);
 189   friend CompiledIC* CompiledIC_at(RelocIterator* reloc_iter);
 190 
 191   // This is used to release CompiledICHolder*s from nmethods that
 192   // are about to be freed.  The callsite might contain other stale
 193   // values of other kinds so it must be careful.
 194   static void cleanup_call_site(virtual_call_Relocation* call_site);
 195   static bool is_icholder_call_site(virtual_call_Relocation* call_site);
 196 
 197   // Return the cached_metadata/destination associated with this inline cache. If the cache currently points
 198   // to a transition stub, it will read the values from the transition stub.
 199   void* cached_value() const;
 200   CompiledICHolder* cached_icholder() const {
 201     assert(is_icholder_call(), "must be");
 202     return (CompiledICHolder*) cached_value();
 203   }
 204   Metadata* cached_metadata() const {
 205     assert(!is_icholder_call(), "must be");
 206     return (Metadata*) cached_value();
 207   }
 208 
 209   address ic_destination() const;
 210 
 211   bool is_optimized() const   { return _is_optimized; }
 212 
 213   // State
 214   bool is_clean() const;
 215   bool is_megamorphic() const;
 216   bool is_call_to_compiled() const;
 217   bool is_call_to_interpreted() const;
 218 
 219   bool is_icholder_call() const;
 220 
 221   address end_of_call() { return  _ic_call->return_address(); }
 222 
 223   // MT-safe patching of inline caches. Note: Only safe to call is_xxx when holding the CompiledIC_ock
 224   // so you are guaranteed that no patching takes place. The same goes for verify.
 225   //
 226   // Note: We do not provide any direct access to the stub code, to prevent parts of the code
 227   // to manipulate the inline cache in MT-unsafe ways.
 228   //
 229   // They all takes a TRAP argument, since they can cause a GC if the inline-cache buffer is full.
 230   //
 231   void set_to_clean(bool in_use = true);
 232   void set_to_monomorphic(CompiledICInfo& info);
 233   void clear_ic_stub();
 234 
 235   // Returns true if successful and false otherwise. The call can fail if memory
 236   // allocation in the code cache fails.
 237   bool set_to_megamorphic(CallInfo* call_info, Bytecodes::Code bytecode, TRAPS);
 238 
 239   static void compute_monomorphic_entry(methodHandle method, KlassHandle receiver_klass,
 240                                         bool is_optimized, bool static_bound, CompiledICInfo& info, TRAPS);
 241 
 242   // Location
 243   address instruction_address() const { return _ic_call->instruction_address(); }
 244 
 245   // Misc
 246   void print()             PRODUCT_RETURN;
 247   void print_compiled_ic() PRODUCT_RETURN;
 248   void verify()            PRODUCT_RETURN;
 249 };
 250 
 251 inline CompiledIC* CompiledIC_before(nmethod* nm, address return_addr) {
 252   CompiledIC* c_ic = new CompiledIC(nm, nativeCall_before(return_addr));
 253   c_ic->verify();
 254   return c_ic;
 255 }
 256 
 257 inline CompiledIC* CompiledIC_at(nmethod* nm, address call_site) {
 258   CompiledIC* c_ic = new CompiledIC(nm, nativeCall_at(call_site));
 259   c_ic->verify();
 260   return c_ic;
 261 }
 262 
 263 inline CompiledIC* CompiledIC_at(Relocation* call_site) {
 264   assert(call_site->type() == relocInfo::virtual_call_type ||
 265          call_site->type() == relocInfo::opt_virtual_call_type, "wrong reloc. info");
 266   CompiledIC* c_ic = new CompiledIC(call_site->code(), nativeCall_at(call_site->addr()));
 267   c_ic->verify();
 268   return c_ic;
 269 }
 270 
 271 inline CompiledIC* CompiledIC_at(RelocIterator* reloc_iter) {
 272   assert(reloc_iter->type() == relocInfo::virtual_call_type ||
 273       reloc_iter->type() == relocInfo::opt_virtual_call_type, "wrong reloc. info");
 274   CompiledIC* c_ic = new CompiledIC(reloc_iter);
 275   c_ic->verify();
 276   return c_ic;
 277 }
 278 
 279 //-----------------------------------------------------------------------------
 280 // The CompiledStaticCall represents a call to a static method in the compiled
 281 //
 282 // Transition diagram of a static call site is somewhat simpler than for an inlined cache:
 283 //
 284 //
 285 //           -----<----- Clean ----->-----
 286 //          /                             \
 287 //         /                               \
 288 //    compilled code <------------> interpreted code
 289 //
 290 //  Clean:            Calls directly to runtime method for fixup
 291 //  Compiled code:    Calls directly to compiled code
 292 //  Interpreted code: Calls to stub that set Method* reference
 293 //
 294 //
 295 class CompiledStaticCall;
 296 
 297 class StaticCallInfo {
 298  private:
 299   address      _entry;          // Entrypoint
 300   methodHandle _callee;         // Callee (used when calling interpreter)
 301   bool         _to_interpreter; // call to interpreted method (otherwise compiled)
 302 
 303   friend class CompiledStaticCall;
 304  public:
 305   address      entry() const    { return _entry;  }
 306   methodHandle callee() const   { return _callee; }
 307 };
 308 
 309 
 310 class CompiledStaticCall: public NativeCall {
 311   friend class CompiledIC;
 312 
 313   // Also used by CompiledIC
 314   void set_to_interpreted(methodHandle callee, address entry);
 315   bool is_optimized_virtual();
 316 
 317  public:
 318   friend CompiledStaticCall* compiledStaticCall_before(address return_addr);
 319   friend CompiledStaticCall* compiledStaticCall_at(address native_call);
 320   friend CompiledStaticCall* compiledStaticCall_at(Relocation* call_site);
 321 
 322   // Code
 323   static address emit_to_interp_stub(CodeBuffer &cbuf);
 324   static int to_interp_stub_size();
 325   static int reloc_to_interp_stub();
 326 
 327   // State
 328   bool is_clean() const;
 329   bool is_call_to_compiled() const;
 330   bool is_call_to_interpreted() const;
 331 
 332   // Clean static call (will force resolving on next use)
 333   void set_to_clean();
 334 
 335   // Set state. The entry must be the same, as computed by compute_entry.
 336   // Computation and setting is split up, since the actions are separate during
 337   // a OptoRuntime::resolve_xxx.
 338   void set(const StaticCallInfo& info);
 339 
 340   // Compute entry point given a method
 341   static void compute_entry(methodHandle m, StaticCallInfo& info);
 342 
 343   // Stub support
 344   address find_stub();
 345   static void set_stub_to_clean(static_stub_Relocation* static_stub);
 346 
 347   // Misc.
 348   void print()  PRODUCT_RETURN;
 349   void verify() PRODUCT_RETURN;
 350 };
 351 
 352 
 353 inline CompiledStaticCall* compiledStaticCall_before(address return_addr) {
 354   CompiledStaticCall* st = (CompiledStaticCall*)nativeCall_before(return_addr);
 355   st->verify();
 356   return st;
 357 }
 358 
 359 inline CompiledStaticCall* compiledStaticCall_at(address native_call) {
 360   CompiledStaticCall* st = (CompiledStaticCall*)native_call;
 361   st->verify();
 362   return st;
 363 }
 364 
 365 inline CompiledStaticCall* compiledStaticCall_at(Relocation* call_site) {
 366   return compiledStaticCall_at(call_site->addr());
 367 }
 368 
 369 #endif // SHARE_VM_CODE_COMPILEDIC_HPP