Serializer enable/disable flags need thread safety.

src/arm/assembler-arm.cc

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // 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.
 //
@@ skipping 1061 matching lines @@
   return false;
 }
 
 
 // We have to use the temporary register for things that can be relocated even
 // if they can be encoded in the ARM's 12 bits of immediate-offset instruction
 // space.  There is no guarantee that the relocated location can be similarly
 // encoded.
 bool Operand::must_output_reloc_info(const Assembler* assembler) const {
   if (rmode_ == RelocInfo::EXTERNAL_REFERENCE) {
 #ifdef DEBUG

[Sven Panne, 2014/04/16 09:18:46]

Why do we wrap this into #ifdef DEBUG here plus some other places, but not in
ohters? I propose to move any #ifdef logic (if really necessary) into
TrySetPermanentlyDisabled, avoiding the need to repeat this horror at all call
sites (something which we should do in general).

[mvstanton, 2014/04/16 13:43:30]

Thx Sven you got me wondering why we have this call at all. We actually decide
the Enabled/Disabled state at process startup, and we don't toggle it. So this
is superfluous code, removed.

-    if (!Serializer::enabled()) {
-      Serializer::TooLateToEnableNow();
-    }
+    Serializer::TrySetPermanentlyDisabled();
 #endif  // def DEBUG
     if (assembler != NULL && assembler->predictable_code_size()) return true;
     return Serializer::enabled();
   } else if (RelocInfo::IsNone(rmode_)) {
     return false;
   }
   return true;
 }
 
 
@@ skipping 2165 matching lines @@
   RelocInfo rinfo(pc_, rmode, data, NULL);
   RecordRelocInfo(rinfo);
 }
 
 
 void Assembler::RecordRelocInfo(const RelocInfo& rinfo) {
   if (!RelocInfo::IsNone(rinfo.rmode())) {
     // Don't record external references unless the heap will be serialized.
     if (rinfo.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 (rinfo.rmode() == RelocInfo::CODE_TARGET_WITH_ID) {
       RelocInfo reloc_info_with_ast_id(rinfo.pc(),
                                        rinfo.rmode(),
                                        RecordedAstId().ToInt(),
@@ skipping 449 matching lines @@
   ASSERT((index_64bit == count_of_64bit_) &&
          (index_code_ptr == (index_64bit + count_of_code_ptr_)) &&
          (index_heap_ptr == (index_code_ptr + count_of_heap_ptr_)) &&
          (index_32bit == (index_heap_ptr + count_of_32bit_)));
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM