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