MIPS: Fix for 3303 MultithreadedParallelIsolates has a race condition.

src/mips/macro-assembler-mips.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_MIPS_MACRO_ASSEMBLER_MIPS_H_
 #define V8_MIPS_MACRO_ASSEMBLER_MIPS_H_
 
 #include "assembler.h"
 #include "mips/assembler-mips.h"
 #include "v8globals.h"
@@ skipping 1596 matching lines @@
 };
 
 
 // The code patcher is used to patch (typically) small parts of code e.g. for
 // debugging and other types of instrumentation. When using the code patcher
 // the exact number of bytes specified must be emitted. It is not legal to emit
 // relocation information. If any of these constraints are violated it causes
 // an assertion to fail.
 class CodePatcher {
  public:
-  CodePatcher(byte* address, int instructions);
+  enum FlushICache {
+    FLUSH,
+    DONT_FLUSH
+  };
+
+  CodePatcher(byte* address,
+              int instructions,
+              FlushICache flush_cache = FLUSH);
   virtual ~CodePatcher();
 
   // Macro assembler to emit code.
   MacroAssembler* masm() { return &masm_; }
 
   // Emit an instruction directly.
   void Emit(Instr instr);
 
   // Emit an address directly.
   void Emit(Address addr);
 
   // Change the condition part of an instruction leaving the rest of the current
   // instruction unchanged.
   void ChangeBranchCondition(Condition cond);
 
  private:
   byte* address_;  // The address of the code being patched.
   int size_;  // Number of bytes of the expected patch size.
   MacroAssembler masm_;  // Macro assembler used to generate the code.
+  FlushICache flush_cache_;  // Whether to flush the I cache after patching.
 };
 
 
 
 #ifdef GENERATED_CODE_COVERAGE
 #define CODE_COVERAGE_STRINGIFY(x) #x
 #define CODE_COVERAGE_TOSTRING(x) CODE_COVERAGE_STRINGIFY(x)
 #define __FILE_LINE__ __FILE__ ":" CODE_COVERAGE_TOSTRING(__LINE__)
 #define ACCESS_MASM(masm) masm->stop(__FILE_LINE__); masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 } }  // namespace v8::internal
 
 #endif  // V8_MIPS_MACRO_ASSEMBLER_MIPS_H_