Make adding a pending deopt atomic.

runtime/vm/code_generator.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/code_generator.h"
 
 #include "vm/assembler.h"
 #include "vm/ast.h"
 #include "vm/code_patcher.h"
 #include "vm/compiler.h"
@@ skipping 2030 matching lines @@
 #else  // !DBC
   if (frame->IsMarkedForLazyDeopt()) {
     // Deopt already scheduled.
     if (FLAG_trace_deoptimization) {
       THR_Print("Lazy deopt already scheduled for fp=%" Pp "\n", frame->fp());
     }
   } else {
     uword deopt_pc = frame->pc();
     ASSERT(optimized_code.ContainsInstructionAt(deopt_pc));
 
-    // N.B.: Update the pending deopt table before updating the frame. The
-    // profiler may attempt a stack walk in between.
-    MallocGrowableArray<PendingLazyDeopt>* pending_deopts =
-        thread->isolate()->pending_deopts();
-    for (intptr_t i = 0; i < pending_deopts->length(); i++) {
-      ASSERT((*pending_deopts)[i].fp() != frame->fp());
-    }
-    PendingLazyDeopt pair(frame->fp(), deopt_pc);
-    pending_deopts->Add(pair);
-
 #if defined(DEBUG)
     ValidateFrames();
 #endif
 
+    // N.B.: Update the pending deopt table before updating the frame. The
+    // profiler may attempt a stack walk in between.
+    thread->isolate()->AddPendingDeopt(frame->fp(), deopt_pc);
     frame->MarkForLazyDeopt();
 
     if (FLAG_trace_deoptimization) {
       THR_Print("Lazy deopt scheduled for fp=%" Pp ", pc=%" Pp "\n",
                 frame->fp(), deopt_pc);
     }
   }
 #endif  // !DBC
 
   // Mark code as dead (do not GC its embedded objects).
@@ skipping 86 matching lines @@
   if (FLAG_trace_deoptimization) {
     const Function& function = Function::Handle(optimized_code.function());
     THR_Print("== Deoptimizing code for '%s', %s, %s\n",
        function.ToFullyQualifiedCString(),
        deoptimizing_code ? "code & frame" : "frame",
        is_lazy_deopt ? "lazy-deopt" : "");
   }
 
 #if !defined(TARGET_ARCH_DBC)
   if (is_lazy_deopt) {
-    uword deopt_pc = 0;
-    MallocGrowableArray<PendingLazyDeopt>* pending_deopts =
-        isolate->pending_deopts();
-    for (intptr_t i = 0; i < pending_deopts->length(); i++) {
-      if ((*pending_deopts)[i].fp() == caller_frame->fp()) {
-        deopt_pc = (*pending_deopts)[i].pc();
-        break;
-      }
-    }
-#if defined(DEBUG)
-    // Check for conflicting entries.
-    for (intptr_t i = 0; i < pending_deopts->length(); i++) {
-      if ((*pending_deopts)[i].fp() == caller_frame->fp()) {
-        ASSERT((*pending_deopts)[i].pc() == deopt_pc);
-      }
-    }
-#endif
+    uword deopt_pc = isolate->FindPendingDeopt(caller_frame->fp());
     if (FLAG_trace_deoptimization) {
       THR_Print("Lazy deopt fp=%" Pp " pc=%" Pp "\n",
                 caller_frame->fp(), deopt_pc);
     }
-    ASSERT(deopt_pc != 0);
 
     // N.B.: Update frame before updating pending deopt table. The profiler
     // may attempt a stack walk in between.
     caller_frame->set_pc(deopt_pc);
     ASSERT(caller_frame->pc() == deopt_pc);
     ASSERT(optimized_code.ContainsInstructionAt(caller_frame->pc()));
-
-    for (intptr_t i = pending_deopts->length() - 1; i >= 0; i--) {
-      if ((*pending_deopts)[i].fp() <= caller_frame->fp()) {
-        pending_deopts->RemoveAt(i);
-      }
-    }
+    isolate->ClearPendingDeoptsAtOrBelow(caller_frame->fp());
   } else {
     if (FLAG_trace_deoptimization) {
       THR_Print("Eager deopt fp=%" Pp " pc=%" Pp "\n",
                 caller_frame->fp(), caller_frame->pc());
     }
   }
 #endif  // !DBC
 
   // Copy the saved registers from the stack.
   fpu_register_t* fpu_registers;
@@ skipping 158 matching lines @@
   const intptr_t elm_size = old_data.ElementSizeInBytes();
   const TypedData& new_data =
       TypedData::Handle(TypedData::New(cid, new_size, Heap::kOld));
   TypedData::Copy(new_data, 0, old_data, 0, old_size * elm_size);
   typed_data_cell.SetAt(0, new_data);
   arguments.SetReturn(new_data);
 }
 
 
 }  // namespace dart