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src/share/vm/ci/ciMethodData.cpp

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rev 9358 : 8057038: Speculative traps not robust when compilation and class unloading are concurrent
Summary: speculative traps can be removed from MDO while being copied by compiler
Reviewed-by: kvn, iveresov


  64   Copy::zero_to_words((HeapWord*) &_orig, sizeof(_orig) / sizeof(HeapWord));
  65   _data = NULL;
  66   _data_size = 0;
  67   _extra_data_size = 0;
  68   _current_mileage = 0;
  69   _invocation_counter = 0;
  70   _backedge_counter = 0;
  71   _state = empty_state;
  72   _saw_free_extra_data = false;
  73   // Set an initial hint. Don't use set_hint_di() because
  74   // first_di() may be out of bounds if data_size is 0.
  75   _hint_di = first_di();
  76   // Initialize the escape information (to "don't know.");
  77   _eflags = _arg_local = _arg_stack = _arg_returned = 0;
  78   _parameters = NULL;
  79 }
  80 
  81 void ciMethodData::load_extra_data() {
  82   MethodData* mdo = get_MethodData();
  83 


  84   // speculative trap entries also hold a pointer to a Method so need to be translated
  85   DataLayout* dp_src  = mdo->extra_data_base();
  86   DataLayout* end_src = mdo->extra_data_limit();
  87   DataLayout* dp_dst  = extra_data_base();
  88   for (;; dp_src = MethodData::next_extra(dp_src), dp_dst = MethodData::next_extra(dp_dst)) {
  89     assert(dp_src < end_src, "moved past end of extra data");
  90     // New traps in the MDO can be added as we translate the copy so
  91     // look at the entries in the copy.
  92     switch(dp_dst->tag()) {









  93     case DataLayout::speculative_trap_data_tag: {
  94       ciSpeculativeTrapData* data_dst = new ciSpeculativeTrapData(dp_dst);
  95       SpeculativeTrapData* data_src = new SpeculativeTrapData(dp_src);

  96       data_dst->translate_from(data_src);






  97       break;
  98     }
  99     case DataLayout::bit_data_tag:
 100       break;
 101     case DataLayout::no_tag:
 102     case DataLayout::arg_info_data_tag:
 103       // An empty slot or ArgInfoData entry marks the end of the trap data
 104       return;
 105     default:
 106       fatal(err_msg("bad tag = %d", dp_dst->tag()));
 107     }
 108   }
 109 }
 110 
 111 void ciMethodData::load_data() {
 112   MethodData* mdo = get_MethodData();
 113   if (mdo == NULL) {
 114     return;
 115   }
 116 


 227   case DataLayout::arg_info_data_tag:
 228     return new ciArgInfoData(data_layout);
 229   case DataLayout::call_type_data_tag:
 230     return new ciCallTypeData(data_layout);
 231   case DataLayout::virtual_call_type_data_tag:
 232     return new ciVirtualCallTypeData(data_layout);
 233   case DataLayout::parameters_type_data_tag:
 234     return new ciParametersTypeData(data_layout);
 235   };
 236 }
 237 
 238 // Iteration over data.
 239 ciProfileData* ciMethodData::next_data(ciProfileData* current) {
 240   int current_index = dp_to_di(current->dp());
 241   int next_index = current_index + current->size_in_bytes();
 242   ciProfileData* next = data_at(next_index);
 243   return next;
 244 }
 245 
 246 ciProfileData* ciMethodData::bci_to_extra_data(int bci, ciMethod* m, bool& two_free_slots) {
 247   // bci_to_extra_data(bci) ...
 248   DataLayout* dp  = data_layout_at(data_size());
 249   DataLayout* end = data_layout_at(data_size() + extra_data_size());
 250   two_free_slots = false;
 251   for (;dp < end; dp = MethodData::next_extra(dp)) {
 252     switch(dp->tag()) {
 253     case DataLayout::no_tag:
 254       _saw_free_extra_data = true;  // observed an empty slot (common case)
 255       two_free_slots = (MethodData::next_extra(dp)->tag() == DataLayout::no_tag);
 256       return NULL;
 257     case DataLayout::arg_info_data_tag:
 258       return NULL; // ArgInfoData is at the end of extra data section.
 259     case DataLayout::bit_data_tag:
 260       if (m == NULL && dp->bci() == bci) {
 261         return new ciBitData(dp);
 262       }
 263       break;
 264     case DataLayout::speculative_trap_data_tag: {
 265       ciSpeculativeTrapData* data = new ciSpeculativeTrapData(dp);
 266       // data->method() might be null if the MDO is snapshotted
 267       // concurrently with a trap
 268       if (m != NULL && data->method() == m && dp->bci() == bci) {
 269         return data;


 480     return 0;
 481   assert(arg >= 0 && arg < aid->number_of_args(), "valid argument number");
 482   return aid->arg_modified(arg);
 483 }
 484 
 485 ByteSize ciMethodData::offset_of_slot(ciProfileData* data, ByteSize slot_offset_in_data) {
 486   // Get offset within MethodData* of the data array
 487   ByteSize data_offset = MethodData::data_offset();
 488 
 489   // Get cell offset of the ProfileData within data array
 490   int cell_offset = dp_to_di(data->dp());
 491 
 492   // Add in counter_offset, the # of bytes into the ProfileData of counter or flag
 493   int offset = in_bytes(data_offset) + cell_offset + in_bytes(slot_offset_in_data);
 494 
 495   return in_ByteSize(offset);
 496 }
 497 
 498 ciArgInfoData *ciMethodData::arg_info() const {
 499   // Should be last, have to skip all traps.
 500   DataLayout* dp  = data_layout_at(data_size());
 501   DataLayout* end = data_layout_at(data_size() + extra_data_size());
 502   for (; dp < end; dp = MethodData::next_extra(dp)) {
 503     if (dp->tag() == DataLayout::arg_info_data_tag)
 504       return new ciArgInfoData(dp);
 505   }
 506   return NULL;
 507 }
 508 
 509 
 510 // Implementation of the print method.
 511 void ciMethodData::print_impl(outputStream* st) {
 512   ciMetadata::print_impl(st);
 513 }
 514 
 515 void ciMethodData::dump_replay_data(outputStream* out) {
 516   ResourceMark rm;
 517   MethodData* mdo = get_MethodData();
 518   Method* method = mdo->method();
 519   Klass* holder = method->method_holder();
 520   out->print("ciMethodData %s %s %s %d %d",
 521              holder->name()->as_quoted_ascii(),


 582       }
 583     }
 584   }
 585   out->cr();
 586 }
 587 
 588 #ifndef PRODUCT
 589 void ciMethodData::print() {
 590   print_data_on(tty);
 591 }
 592 
 593 void ciMethodData::print_data_on(outputStream* st) {
 594   ResourceMark rm;
 595   ciProfileData* data;
 596   for (data = first_data(); is_valid(data); data = next_data(data)) {
 597     st->print("%d", dp_to_di(data->dp()));
 598     st->fill_to(6);
 599     data->print_data_on(st);
 600   }
 601   st->print_cr("--- Extra data:");
 602   DataLayout* dp  = data_layout_at(data_size());
 603   DataLayout* end = data_layout_at(data_size() + extra_data_size());
 604   for (;; dp = MethodData::next_extra(dp)) {
 605     assert(dp < end, "moved past end of extra data");
 606     switch (dp->tag()) {
 607     case DataLayout::no_tag:
 608       continue;
 609     case DataLayout::bit_data_tag:
 610       data = new BitData(dp);
 611       break;
 612     case DataLayout::arg_info_data_tag:
 613       data = new ciArgInfoData(dp);
 614       dp = end; // ArgInfoData is at the end of extra data section.
 615       break;
 616     default:
 617       fatal(err_msg("unexpected tag %d", dp->tag()));
 618     }
 619     st->print("%d", dp_to_di(data->dp()));
 620     st->fill_to(6);
 621     data->print_data_on(st);
 622     if (dp >= end) return;
 623   }




  64   Copy::zero_to_words((HeapWord*) &_orig, sizeof(_orig) / sizeof(HeapWord));
  65   _data = NULL;
  66   _data_size = 0;
  67   _extra_data_size = 0;
  68   _current_mileage = 0;
  69   _invocation_counter = 0;
  70   _backedge_counter = 0;
  71   _state = empty_state;
  72   _saw_free_extra_data = false;
  73   // Set an initial hint. Don't use set_hint_di() because
  74   // first_di() may be out of bounds if data_size is 0.
  75   _hint_di = first_di();
  76   // Initialize the escape information (to "don't know.");
  77   _eflags = _arg_local = _arg_stack = _arg_returned = 0;
  78   _parameters = NULL;
  79 }
  80 
  81 void ciMethodData::load_extra_data() {
  82   MethodData* mdo = get_MethodData();
  83 
  84   MutexLocker(mdo->extra_data_lock());
  85 
  86   // speculative trap entries also hold a pointer to a Method so need to be translated
  87   DataLayout* dp_src  = mdo->extra_data_base();
  88   DataLayout* end_src = mdo->args_data_limit();
  89   DataLayout* dp_dst  = extra_data_base();
  90   for (;; dp_src = MethodData::next_extra(dp_src), dp_dst = MethodData::next_extra(dp_dst)) {
  91     assert(dp_src < end_src, "moved past end of extra data");
  92     assert(((intptr_t)dp_dst) - ((intptr_t)extra_data_base()) == ((intptr_t)dp_src) - ((intptr_t)mdo->extra_data_base()), "source and destination don't match");
  93     // New traps in the MDO may have been added since we copied the
  94     // data (concurrent deoptimizations before we acquired
  95     // extra_data_lock above) or can be removed (a safepoint may occur
  96     // in the translate_from call below) as we translate the copy:
  97     // update the copy as we go.
  98     int tag = dp_src->tag();
  99     if (tag != DataLayout::arg_info_data_tag) {
 100       memcpy(dp_dst, dp_src, ((intptr_t)MethodData::next_extra(dp_src)) - ((intptr_t)dp_src));
 101     }
 102 
 103     switch(tag) {
 104     case DataLayout::speculative_trap_data_tag: {
 105       ciSpeculativeTrapData* data_dst = new ciSpeculativeTrapData(dp_dst);
 106       SpeculativeTrapData* data_src = new SpeculativeTrapData(dp_src);
 107 
 108       data_dst->translate_from(data_src);
 109 
 110 #ifdef ASSERT
 111       SpeculativeTrapData* data_src2 = new SpeculativeTrapData(dp_src);
 112       assert(data_src2->method() == data_src->method() && data_src2->bci() == data_src->bci(), "entries changed while translating");
 113 #endif
 114 
 115       break;
 116     }
 117     case DataLayout::bit_data_tag:
 118       break;
 119     case DataLayout::no_tag:
 120     case DataLayout::arg_info_data_tag:
 121       // An empty slot or ArgInfoData entry marks the end of the trap data
 122       return;
 123     default:
 124       fatal(err_msg("bad tag = %d", dp_dst->tag()));
 125     }
 126   }
 127 }
 128 
 129 void ciMethodData::load_data() {
 130   MethodData* mdo = get_MethodData();
 131   if (mdo == NULL) {
 132     return;
 133   }
 134 


 245   case DataLayout::arg_info_data_tag:
 246     return new ciArgInfoData(data_layout);
 247   case DataLayout::call_type_data_tag:
 248     return new ciCallTypeData(data_layout);
 249   case DataLayout::virtual_call_type_data_tag:
 250     return new ciVirtualCallTypeData(data_layout);
 251   case DataLayout::parameters_type_data_tag:
 252     return new ciParametersTypeData(data_layout);
 253   };
 254 }
 255 
 256 // Iteration over data.
 257 ciProfileData* ciMethodData::next_data(ciProfileData* current) {
 258   int current_index = dp_to_di(current->dp());
 259   int next_index = current_index + current->size_in_bytes();
 260   ciProfileData* next = data_at(next_index);
 261   return next;
 262 }
 263 
 264 ciProfileData* ciMethodData::bci_to_extra_data(int bci, ciMethod* m, bool& two_free_slots) {
 265   DataLayout* dp  = extra_data_base();
 266   DataLayout* end = args_data_limit();

 267   two_free_slots = false;
 268   for (;dp < end; dp = MethodData::next_extra(dp)) {
 269     switch(dp->tag()) {
 270     case DataLayout::no_tag:
 271       _saw_free_extra_data = true;  // observed an empty slot (common case)
 272       two_free_slots = (MethodData::next_extra(dp)->tag() == DataLayout::no_tag);
 273       return NULL;
 274     case DataLayout::arg_info_data_tag:
 275       return NULL; // ArgInfoData is at the end of extra data section.
 276     case DataLayout::bit_data_tag:
 277       if (m == NULL && dp->bci() == bci) {
 278         return new ciBitData(dp);
 279       }
 280       break;
 281     case DataLayout::speculative_trap_data_tag: {
 282       ciSpeculativeTrapData* data = new ciSpeculativeTrapData(dp);
 283       // data->method() might be null if the MDO is snapshotted
 284       // concurrently with a trap
 285       if (m != NULL && data->method() == m && dp->bci() == bci) {
 286         return data;


 497     return 0;
 498   assert(arg >= 0 && arg < aid->number_of_args(), "valid argument number");
 499   return aid->arg_modified(arg);
 500 }
 501 
 502 ByteSize ciMethodData::offset_of_slot(ciProfileData* data, ByteSize slot_offset_in_data) {
 503   // Get offset within MethodData* of the data array
 504   ByteSize data_offset = MethodData::data_offset();
 505 
 506   // Get cell offset of the ProfileData within data array
 507   int cell_offset = dp_to_di(data->dp());
 508 
 509   // Add in counter_offset, the # of bytes into the ProfileData of counter or flag
 510   int offset = in_bytes(data_offset) + cell_offset + in_bytes(slot_offset_in_data);
 511 
 512   return in_ByteSize(offset);
 513 }
 514 
 515 ciArgInfoData *ciMethodData::arg_info() const {
 516   // Should be last, have to skip all traps.
 517   DataLayout* dp  = extra_data_base();
 518   DataLayout* end = args_data_limit();
 519   for (; dp < end; dp = MethodData::next_extra(dp)) {
 520     if (dp->tag() == DataLayout::arg_info_data_tag)
 521       return new ciArgInfoData(dp);
 522   }
 523   return NULL;
 524 }
 525 
 526 
 527 // Implementation of the print method.
 528 void ciMethodData::print_impl(outputStream* st) {
 529   ciMetadata::print_impl(st);
 530 }
 531 
 532 void ciMethodData::dump_replay_data(outputStream* out) {
 533   ResourceMark rm;
 534   MethodData* mdo = get_MethodData();
 535   Method* method = mdo->method();
 536   Klass* holder = method->method_holder();
 537   out->print("ciMethodData %s %s %s %d %d",
 538              holder->name()->as_quoted_ascii(),


 599       }
 600     }
 601   }
 602   out->cr();
 603 }
 604 
 605 #ifndef PRODUCT
 606 void ciMethodData::print() {
 607   print_data_on(tty);
 608 }
 609 
 610 void ciMethodData::print_data_on(outputStream* st) {
 611   ResourceMark rm;
 612   ciProfileData* data;
 613   for (data = first_data(); is_valid(data); data = next_data(data)) {
 614     st->print("%d", dp_to_di(data->dp()));
 615     st->fill_to(6);
 616     data->print_data_on(st);
 617   }
 618   st->print_cr("--- Extra data:");
 619   DataLayout* dp  = extra_data_base();
 620   DataLayout* end = args_data_limit();
 621   for (;; dp = MethodData::next_extra(dp)) {
 622     assert(dp < end, "moved past end of extra data");
 623     switch (dp->tag()) {
 624     case DataLayout::no_tag:
 625       continue;
 626     case DataLayout::bit_data_tag:
 627       data = new BitData(dp);
 628       break;
 629     case DataLayout::arg_info_data_tag:
 630       data = new ciArgInfoData(dp);
 631       dp = end; // ArgInfoData is at the end of extra data section.
 632       break;
 633     default:
 634       fatal(err_msg("unexpected tag %d", dp->tag()));
 635     }
 636     st->print("%d", dp_to_di(data->dp()));
 637     st->fill_to(6);
 638     data->print_data_on(st);
 639     if (dp >= end) return;
 640   }


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