Fix compilation with gdbjit=on.

src/gdb-jit.cc

 // Copyright 2010 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 1427 matching lines @@
                                     desc->CodeStart());
     desc->SetStackStateStartAddress(CodeDescription::POST_RBP_SET,
                                     desc->CodeStart());
     desc->SetStackStateStartAddress(CodeDescription::POST_RBP_POP,
                                     desc->CodeEnd());
   }
 #endif  // V8_TARGET_ARCH_X64
 }
 
 
+Mutex* GDBJITInterface::mutex_ = OS::CreateMutex();
+
+
 void GDBJITInterface::AddCode(const char* name,
                               Code* code,
                               GDBJITInterface::CodeTag tag,
                               Script* script) {
   if (!FLAG_gdbjit) return;
+
+  ScopedLock lock(mutex_);
   AssertNoAllocation no_gc;
 
   HashMap::Entry* e = GetEntries()->Lookup(code, HashForCodeObject(code), true);
   if (e->value != NULL && !IsLineInfoTagged(e->value)) return;
 
   GDBJITLineInfo* lineinfo = UntagLineInfo(e->value);
   CodeDescription code_desc(name,
                             code,
                             script != NULL ? Handle<Script>(script)
                                            : Handle<Script>(),
@@ skipping 48 matching lines @@
 void GDBJITInterface::AddCode(GDBJITInterface::CodeTag tag, Code* code) {
   if (!FLAG_gdbjit) return;
 
   AddCode(tag, "", code);
 }
 
 
 void GDBJITInterface::RemoveCode(Code* code) {
   if (!FLAG_gdbjit) return;
 
+  ScopedLock lock(mutex_);
   HashMap::Entry* e = GetEntries()->Lookup(code,
                                            HashForCodeObject(code),
                                            false);
   if (e == NULL) return;
 
   if (IsLineInfoTagged(e->value)) {
     delete UntagLineInfo(e->value);
   } else {
     JITCodeEntry* entry = static_cast<JITCodeEntry*>(e->value);
     UnregisterCodeEntry(entry);
     DestroyCodeEntry(entry);
   }
   e->value = NULL;
   GetEntries()->Remove(code, HashForCodeObject(code));
 }
 
 
 void GDBJITInterface::RegisterDetailedLineInfo(Code* code,
                                                GDBJITLineInfo* line_info) {
+  ScopedLock lock(mutex_);
   ASSERT(!IsLineInfoTagged(line_info));
   HashMap::Entry* e = GetEntries()->Lookup(code, HashForCodeObject(code), true);
   ASSERT(e->value == NULL);
   e->value = TagLineInfo(line_info);
 }
 
 
 } }  // namespace v8::internal
 #endif