MIPS: Fix for 3303 MultithreadedParallelIsolates has a race condition.

Port r21165 (50673b25)

Original commit message:
The fix is to make the code aging sequence hang off the isolate.

BUG=
R=plind44@gmail.com

Review URL: https://codereview.chromium.org/264823004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21180 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/assembler-mips-inl.h

@@ -255,7 +255,7 @@ void RelocInfo::set_target_cell(Cell* cell, WriteBarrierMode mode) {
 }
 
 
-static const int kNoCodeAgeSequenceLength = 7;
+static const int kNoCodeAgeSequenceLength = 7 * Assembler::kInstrSize;
 
 
 Handle<Object> RelocInfo::code_age_stub_handle(Assembler* origin) {

src/mips/builtins-mips.cc

@@ -865,7 +865,7 @@ static void GenerateMakeCodeYoungAgainCommon(MacroAssembler* masm) {
 
   // Set a0 to point to the head of the PlatformCodeAge sequence.
   __ Subu(a0, a0,
-      Operand((kNoCodeAgeSequenceLength - 1) * Assembler::kInstrSize));
+      Operand(kNoCodeAgeSequenceLength - Assembler::kInstrSize));
 
   // The following registers must be saved and restored when calling through to
   // the runtime:
@@ -904,7 +904,7 @@ void Builtins::Generate_MarkCodeAsExecutedOnce(MacroAssembler* masm) {
 
   // Set a0 to point to the head of the PlatformCodeAge sequence.
   __ Subu(a0, a0,
-      Operand((kNoCodeAgeSequenceLength - 1) * Assembler::kInstrSize));
+      Operand(kNoCodeAgeSequenceLength - Assembler::kInstrSize));
 
   // The following registers must be saved and restored when calling through to
   // the runtime:
@@ -926,7 +926,7 @@ void Builtins::Generate_MarkCodeAsExecutedOnce(MacroAssembler* masm) {
   __ Addu(fp, sp, Operand(StandardFrameConstants::kFixedFrameSizeFromFp));
 
   // Jump to point after the code-age stub.
-  __ Addu(a0, a0, Operand((kNoCodeAgeSequenceLength) * Assembler::kInstrSize));
+  __ Addu(a0, a0, Operand(kNoCodeAgeSequenceLength));
   __ Jump(a0);
 }
 

src/mips/codegen-mips.cc

@@ -1122,42 +1122,42 @@ void MathExpGenerator::EmitMathExp(MacroAssembler* masm,
 static const uint32_t kCodeAgePatchFirstInstruction = 0x00010180;
 #endif
 
-static byte* GetNoCodeAgeSequence(uint32_t* length) {
-  // The sequence of instructions that is patched out for aging code is the
-  // following boilerplate stack-building prologue that is found in FUNCTIONS
-  static bool initialized = false;
-  static uint32_t sequence[kNoCodeAgeSequenceLength];
-  byte* byte_sequence = reinterpret_cast<byte*>(sequence);
-  *length = kNoCodeAgeSequenceLength * Assembler::kInstrSize;
-  if (!initialized) {
-    // Since patcher is a large object, allocate it dynamically when needed,
-    // to avoid overloading the stack in stress conditions.
-    SmartPointer<CodePatcher>
-        patcher(new CodePatcher(byte_sequence, kNoCodeAgeSequenceLength));
-    PredictableCodeSizeScope scope(patcher->masm(), *length);
-    patcher->masm()->Push(ra, fp, cp, a1);
-    patcher->masm()->nop(Assembler::CODE_AGE_SEQUENCE_NOP);
-    patcher->masm()->Addu(
-        fp, sp, Operand(StandardFrameConstants::kFixedFrameSizeFromFp));
-    initialized = true;
-  }
-  return byte_sequence;
+
+CodeAgingHelper::CodeAgingHelper() {
+  ASSERT(young_sequence_.length() == kNoCodeAgeSequenceLength);
+  // Since patcher is a large object, allocate it dynamically when needed,
+  // to avoid overloading the stack in stress conditions.
+  // DONT_FLUSH is used because the CodeAgingHelper is initialized early in
+  // the process, before MIPS simulator ICache is setup.
+  SmartPointer<CodePatcher> patcher(
+      new CodePatcher(young_sequence_.start(),
+                      young_sequence_.length() / Assembler::kInstrSize,
+                      CodePatcher::DONT_FLUSH));
+  PredictableCodeSizeScope scope(patcher->masm(), young_sequence_.length());
+  patcher->masm()->Push(ra, fp, cp, a1);
+  patcher->masm()->nop(Assembler::CODE_AGE_SEQUENCE_NOP);
+  patcher->masm()->Addu(
+      fp, sp, Operand(StandardFrameConstants::kFixedFrameSizeFromFp));
 }
 
 
-bool Code::IsYoungSequence(byte* sequence) {
-  uint32_t young_length;
-  byte* young_sequence = GetNoCodeAgeSequence(&young_length);
-  bool result = !memcmp(sequence, young_sequence, young_length);
-  ASSERT(result ||
-         Memory::uint32_at(sequence) == kCodeAgePatchFirstInstruction);
+#ifdef DEBUG
+bool CodeAgingHelper::IsOld(byte* candidate) const {
+  return Memory::uint32_at(candidate) == kCodeAgePatchFirstInstruction;
+}
+#endif
+
+
+bool Code::IsYoungSequence(Isolate* isolate, byte* sequence) {
+  bool result = isolate->code_aging_helper()->IsYoung(sequence);
+  ASSERT(result || isolate->code_aging_helper()->IsOld(sequence));
   return result;
 }
 
 
-void Code::GetCodeAgeAndParity(byte* sequence, Age* age,
+void Code::GetCodeAgeAndParity(Isolate* isolate, byte* sequence, Age* age,
                                MarkingParity* parity) {
-  if (IsYoungSequence(sequence)) {
+  if (IsYoungSequence(isolate, sequence)) {
     *age = kNoAgeCodeAge;
     *parity = NO_MARKING_PARITY;
   } else {
@@ -1173,10 +1173,9 @@ void Code::PatchPlatformCodeAge(Isolate* isolate,
                                 byte* sequence,
                                 Code::Age age,
                                 MarkingParity parity) {
-  uint32_t young_length;
-  byte* young_sequence = GetNoCodeAgeSequence(&young_length);
+  uint32_t young_length = isolate->code_aging_helper()->young_sequence_length();
   if (age == kNoAgeCodeAge) {
-    CopyBytes(sequence, young_sequence, young_length);
+    isolate->code_aging_helper()->CopyYoungSequenceTo(sequence);
     CPU::FlushICache(sequence, young_length);
   } else {
     Code* stub = GetCodeAgeStub(isolate, age, parity);

src/mips/deoptimizer-mips.cc

@@ -30,7 +30,7 @@ void Deoptimizer::PatchCodeForDeoptimization(Isolate* isolate, Code* code) {
     // Fail hard and early if we enter this code object again.
     byte* pointer = code->FindCodeAgeSequence();
     if (pointer != NULL) {
-      pointer += kNoCodeAgeSequenceLength * Assembler::kInstrSize;
+      pointer += kNoCodeAgeSequenceLength;
     } else {
       pointer = code->instruction_start();
     }

src/mips/macro-assembler-mips.cc

@@ -4460,7 +4460,7 @@ void MacroAssembler::Prologue(PrologueFrameMode frame_mode) {
     Addu(fp, sp, Operand(StandardFrameConstants::kFixedFrameSizeFromFp));
   } else {
     PredictableCodeSizeScope predictible_code_size_scope(
-      this, kNoCodeAgeSequenceLength * Assembler::kInstrSize);
+      this, kNoCodeAgeSequenceLength);
     // The following three instructions must remain together and unmodified
     // for code aging to work properly.
     if (isolate()->IsCodePreAgingActive()) {
@@ -5664,10 +5664,13 @@ bool AreAliased(Register r1, Register r2, Register r3, Register r4) {
 }
 
 
-CodePatcher::CodePatcher(byte* address, int instructions)
+CodePatcher::CodePatcher(byte* address,
+                         int instructions,
+                         FlushICache flush_cache)
     : address_(address),
       size_(instructions * Assembler::kInstrSize),
-      masm_(NULL, address, size_ + Assembler::kGap) {
+      masm_(NULL, address, size_ + Assembler::kGap),
+      flush_cache_(flush_cache) {
   // Create a new macro assembler pointing to the address of the code to patch.
   // The size is adjusted with kGap on order for the assembler to generate size
   // bytes of instructions without failing with buffer size constraints.
@@ -5677,7 +5680,9 @@ CodePatcher::CodePatcher(byte* address, int instructions)
 
 CodePatcher::~CodePatcher() {
   // Indicate that code has changed.
-  CPU::FlushICache(address_, size_);
+  if (flush_cache_ == FLUSH) {
+    CPU::FlushICache(address_, size_);
+  }
 
   // Check that the code was patched as expected.
   ASSERT(masm_.pc_ == address_ + size_);

src/mips/macro-assembler-mips.h

@@ -1614,7 +1614,14 @@ const Operand& rt = Operand(zero_reg), BranchDelaySlot bd = PROTECT
 // 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.
@@ -1634,6 +1641,7 @@ class CodePatcher {
   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.
 };