Introduce concurrent on-stack replacement.

src/deoptimizer.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2573 matching lines @@
       return false;
     }
   }
 
   *input_offset -= kPointerSize;
   return true;
 }
 
 
 void Deoptimizer::PatchInterruptCode(Isolate* isolate,
-                                     Code* unoptimized_code) {
+                                     Code* unoptimized) {
   DisallowHeapAllocation no_gc;
   Code* replacement_code =
       isolate->builtins()->builtin(Builtins::kOnStackReplacement);
 
   // Iterate over the back edge table and patch every interrupt
   // call to an unconditional call to the replacement code.
-  int loop_nesting_level = unoptimized_code->allow_osr_at_loop_nesting_level();
+  int loop_nesting_level = unoptimized->allow_osr_at_loop_nesting_level();
 
-  for (FullCodeGenerator::BackEdgeTableIterator back_edges(unoptimized_code);
+  for (FullCodeGenerator::BackEdgeTableIterator back_edges(unoptimized, &no_gc);
        !back_edges.Done();
        back_edges.Next()) {
     if (static_cast<int>(back_edges.loop_depth()) == loop_nesting_level) {
       ASSERT_EQ(NOT_PATCHED, GetInterruptPatchState(isolate,
-                                                    unoptimized_code,
+                                                    unoptimized,
                                                     back_edges.pc()));
-      PatchInterruptCodeAt(unoptimized_code,
+      PatchInterruptCodeAt(unoptimized,
                            back_edges.pc(),
                            replacement_code);
     }
   }
 
-  unoptimized_code->set_back_edges_patched_for_osr(true);
-#ifdef DEBUG
-  Deoptimizer::VerifyInterruptCode(
-      isolate, unoptimized_code, loop_nesting_level);
-#endif  // DEBUG
+  unoptimized->set_back_edges_patched_for_osr(true);
+  ASSERT(Deoptimizer::VerifyInterruptCode(
+             isolate, unoptimized, loop_nesting_level));
 }
 
 
 void Deoptimizer::RevertInterruptCode(Isolate* isolate,
-                                      Code* unoptimized_code) {
+                                      Code* unoptimized) {
   DisallowHeapAllocation no_gc;
   Code* interrupt_code =
       isolate->builtins()->builtin(Builtins::kInterruptCheck);
 
   // Iterate over the back edge table and revert the patched interrupt calls.
-  ASSERT(unoptimized_code->back_edges_patched_for_osr());
-  int loop_nesting_level = unoptimized_code->allow_osr_at_loop_nesting_level();
+  ASSERT(unoptimized->back_edges_patched_for_osr());
+  int loop_nesting_level = unoptimized->allow_osr_at_loop_nesting_level();
 
-  for (FullCodeGenerator::BackEdgeTableIterator back_edges(unoptimized_code);
+  for (FullCodeGenerator::BackEdgeTableIterator back_edges(unoptimized, &no_gc);
        !back_edges.Done();
        back_edges.Next()) {
     if (static_cast<int>(back_edges.loop_depth()) <= loop_nesting_level) {
       ASSERT_EQ(PATCHED_FOR_OSR, GetInterruptPatchState(isolate,
-                                                        unoptimized_code,
+                                                        unoptimized,
                                                         back_edges.pc()));
-      RevertInterruptCodeAt(unoptimized_code, back_edges.pc(), interrupt_code);
+      RevertInterruptCodeAt(unoptimized, back_edges.pc(), interrupt_code);
     }
   }
 
-  unoptimized_code->set_back_edges_patched_for_osr(false);
-  unoptimized_code->set_allow_osr_at_loop_nesting_level(0);
-#ifdef DEBUG
+  unoptimized->set_back_edges_patched_for_osr(false);
+  unoptimized->set_allow_osr_at_loop_nesting_level(0);
   // Assert that none of the back edges are patched anymore.
-  Deoptimizer::VerifyInterruptCode(isolate, unoptimized_code, -1);
-#endif  // DEBUG
+  ASSERT(Deoptimizer::VerifyInterruptCode(isolate, unoptimized, -1));
 }
 
 
 #ifdef DEBUG
-void Deoptimizer::VerifyInterruptCode(Isolate* isolate,
-                                      Code* unoptimized_code,
+bool Deoptimizer::VerifyInterruptCode(Isolate* isolate,
+                                      Code* unoptimized,
                                       int loop_nesting_level) {
-  for (FullCodeGenerator::BackEdgeTableIterator back_edges(unoptimized_code);
+  DisallowHeapAllocation no_gc;
+  for (FullCodeGenerator::BackEdgeTableIterator back_edges(unoptimized, &no_gc);
        !back_edges.Done();
        back_edges.Next()) {
     uint32_t loop_depth = back_edges.loop_depth();
     CHECK_LE(static_cast<int>(loop_depth), Code::kMaxLoopNestingMarker);
     // Assert that all back edges for shallower loops (and only those)
     // have already been patched.
     CHECK_EQ((static_cast<int>(loop_depth) <= loop_nesting_level),
              GetInterruptPatchState(isolate,
-                                    unoptimized_code,
+                                    unoptimized,
                                     back_edges.pc()) != NOT_PATCHED);
   }
+  return true;
 }
 #endif  // DEBUG
 
 
 unsigned Deoptimizer::ComputeInputFrameSize() const {
   unsigned fixed_size = ComputeFixedSize(function_);
   // The fp-to-sp delta already takes the context and the function
   // into account so we have to avoid double counting them (-2).
   unsigned result = fixed_size + fp_to_sp_delta_ - (2 * kPointerSize);
 #ifdef DEBUG
@@ skipping 647 matching lines @@
 
 void DeoptimizedFrameInfo::Iterate(ObjectVisitor* v) {
   v->VisitPointer(BitCast<Object**>(&function_));
   v->VisitPointers(parameters_, parameters_ + parameters_count_);
   v->VisitPointers(expression_stack_, expression_stack_ + expression_count_);
 }
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 } }  // namespace v8::internal