Serializer enable/disable flags need thread safety.

src/arm64/assembler-arm64.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
@@ skipping 256 matching lines @@
     STATIC_ASSERT(sizeof(intptr_t) == sizeof(int64_t));
     immediate_ = reinterpret_cast<intptr_t>(obj);
     rmode_ = RelocInfo::NONE64;
   }
 }
 
 
 bool Operand::NeedsRelocation() const {
   if (rmode_ == RelocInfo::EXTERNAL_REFERENCE) {
 #ifdef DEBUG
-    if (!Serializer::enabled()) {
-      Serializer::TooLateToEnableNow();
-    }
+    Serializer::TrySetPermanentlyDisabled();
 #endif
     return Serializer::enabled();
   }
 
   return !RelocInfo::IsNone(rmode_);
 }
 
 
 // Assembler
 
@@ skipping 1674 matching lines @@
   Emit(BRK | ImmException(code));
 }
 
 
 void Assembler::debug(const char* message, uint32_t code, Instr params) {
 #ifdef USE_SIMULATOR
   // Don't generate simulator specific code if we are building a snapshot, which
   // might be run on real hardware.
   if (!Serializer::enabled()) {
 #ifdef DEBUG
-    Serializer::TooLateToEnableNow();
+    Serializer::TrySetPermanentlyDisabled();
 #endif
     // The arguments to the debug marker need to be contiguous in memory, so
     // make sure we don't try to emit pools.
     BlockPoolsScope scope(this);
 
     Label start;
     bind(&start);
 
     // Refer to instructions-arm64.h for a description of the marker and its
     // arguments.
@@ skipping 534 matching lines @@
     pending_reloc_info_[num_pending_reloc_info_++] = rinfo;
     // Make sure the constant pool is not emitted in place of the next
     // instruction for which we just recorded relocation info.
     BlockConstPoolFor(1);
   }
 
   if (!RelocInfo::IsNone(rmode)) {
     // Don't record external references unless the heap will be serialized.
     if (rmode == RelocInfo::EXTERNAL_REFERENCE) {
 #ifdef DEBUG
-      if (!Serializer::enabled()) {
-        Serializer::TooLateToEnableNow();
-      }
+      Serializer::TrySetPermanentlyDisabled();
 #endif
       if (!Serializer::enabled() && !emit_debug_code()) {
         return;
       }
     }
     ASSERT(buffer_space() >= kMaxRelocSize);  // too late to grow buffer here
     if (rmode == RelocInfo::CODE_TARGET_WITH_ID) {
       RelocInfo reloc_info_with_ast_id(
           reinterpret_cast<byte*>(pc_), rmode, RecordedAstId().ToInt(), NULL);
       ClearRecordedAstId();
@@ skipping 368 matching lines @@
     adr(rd, 0);
     MovInt64(scratch, target_offset);
     add(rd, rd, scratch);
   }
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM64