Decouple allocation and creation of deopt tables

src/deoptimizer.cc

Index: src/deoptimizer.cc
diff --git a/src/deoptimizer.cc b/src/deoptimizer.cc
index e7576562ba09c894f78809c0c4fdf09bf4a34ca0..aeec43665c54484159ead01261d30db1fcc81b9f 100644
--- a/src/deoptimizer.cc
+++ b/src/deoptimizer.cc
@@ -41,8 +41,11 @@ namespace v8 {
 namespace internal {
 
 DeoptimizerData::DeoptimizerData() {
-  eager_deoptimization_entry_code_ = NULL;
-  lazy_deoptimization_entry_code_ = NULL;
+  eager_deoptimization_entry_code_entries_ = -1;
+  lazy_deoptimization_entry_code_entries_ = -1;
+  size_t deopt_table_size = Deoptimizer::GetMaxDeoptTableSize();
+  eager_deoptimization_entry_code_ = new VirtualMemory(deopt_table_size);
+  lazy_deoptimization_entry_code_ = new VirtualMemory(deopt_table_size);
   current_ = NULL;
   deoptimizing_code_list_ = NULL;
 #ifdef ENABLE_DEBUGGER_SUPPORT
@@ -53,13 +56,11 @@ DeoptimizerData::DeoptimizerData() {
 
 DeoptimizerData::~DeoptimizerData() {
   if (eager_deoptimization_entry_code_ != NULL) {

[Jakob Kummerow, 2012/11/06 11:40:50]

nit: you can simplify this a bit by removing the condition. |delete| is safe to
call on NULL pointers.

Again below.

[danno, 2012/11/06 11:59:03]

Done.

-    Isolate::Current()->memory_allocator()->Free(
-        eager_deoptimization_entry_code_);
+    delete eager_deoptimization_entry_code_;
     eager_deoptimization_entry_code_ = NULL;
   }
   if (lazy_deoptimization_entry_code_ != NULL) {
-    Isolate::Current()->memory_allocator()->Free(
-        lazy_deoptimization_entry_code_);
+    delete lazy_deoptimization_entry_code_;
     lazy_deoptimization_entry_code_ = NULL;
   }
   DeoptimizingCodeListNode* current = deoptimizing_code_list_;
@@ -103,6 +104,19 @@ Deoptimizer* Deoptimizer::New(JSFunction* function,
 }
 
 
+// No larger than 2K on all platforms
+static const int kDeoptTableMaxEpilogueCodeSize = 2 * 1024;

[Jakob Kummerow, 2012/11/06 11:40:50]

nit: 2 * KB

+
+
+size_t Deoptimizer::GetMaxDeoptTableSize() {
+  size_t entries_size =
+      Deoptimizer::kMaxNumberOfEntries * Deoptimizer::table_entry_size_;
+  int page_count = ((kDeoptTableMaxEpilogueCodeSize + entries_size - 1) /
+                    OS::CommitPageSize()) + 1;
+  return OS::CommitPageSize() * page_count;
+}
+
+
 Deoptimizer* Deoptimizer::Grab(Isolate* isolate) {
   ASSERT(isolate == Isolate::Current());
   Deoptimizer* result = isolate->deoptimizer_data()->current_;
@@ -461,44 +475,44 @@ void Deoptimizer::DeleteFrameDescriptions() {
 }
 
 
-Address Deoptimizer::GetDeoptimizationEntry(int id, BailoutType type) {
+Address Deoptimizer::GetDeoptimizationEntry(int id, BailoutType type,

[Jakob Kummerow, 2012/11/06 11:40:50]

nit: one line per argument

[danno, 2012/11/06 11:59:03]

Done.

+                                            GetEntryMode mode) {
   ASSERT(id >= 0);
-  if (id >= kNumberOfEntries) return NULL;
-  MemoryChunk* base = NULL;
+  if (id >= kMaxNumberOfEntries) return NULL;
+  VirtualMemory* base = NULL;
+  if (mode == ENSURE_ENTRY_CODE) {
+    EnsureCodeForDeoptimizationEntry(type, id);
+  } else {
+    ASSERT(mode == CALCULATE_ENTRY_ADDRESS);
+  }
   DeoptimizerData* data = Isolate::Current()->deoptimizer_data();
   if (type == EAGER) {
-    if (data->eager_deoptimization_entry_code_ == NULL) {
-      data->eager_deoptimization_entry_code_ = CreateCode(type);
-    }
     base = data->eager_deoptimization_entry_code_;
   } else {
-    if (data->lazy_deoptimization_entry_code_ == NULL) {
-      data->lazy_deoptimization_entry_code_ = CreateCode(type);
-    }
     base = data->lazy_deoptimization_entry_code_;
   }
   return
-      static_cast<Address>(base->area_start()) + (id * table_entry_size_);
+      static_cast<Address>(base->address()) + (id * table_entry_size_);
 }
 
 
 int Deoptimizer::GetDeoptimizationId(Address addr, BailoutType type) {
-  MemoryChunk* base = NULL;
+  VirtualMemory* base = NULL;
   DeoptimizerData* data = Isolate::Current()->deoptimizer_data();
   if (type == EAGER) {
     base = data->eager_deoptimization_entry_code_;
   } else {
     base = data->lazy_deoptimization_entry_code_;
   }
+  Address base_casted = reinterpret_cast<Address>(base->address());
   if (base == NULL ||
-      addr < base->area_start() ||
-      addr >= base->area_start() +
-          (kNumberOfEntries * table_entry_size_)) {
+      addr < base->address() ||
+      addr >= base_casted + (kMaxNumberOfEntries * table_entry_size_)) {
     return kNotDeoptimizationEntry;
   }
   ASSERT_EQ(0,
-      static_cast<int>(addr - base->area_start()) % table_entry_size_);
-  return static_cast<int>(addr - base->area_start()) / table_entry_size_;
+            static_cast<int>(addr - base_casted) % table_entry_size_);
+  return static_cast<int>(addr - base_casted) / table_entry_size_;
 }
 
 
@@ -1384,31 +1398,44 @@ void Deoptimizer::AddDoubleValue(intptr_t slot_address, double value) {
 }
 
 
-MemoryChunk* Deoptimizer::CreateCode(BailoutType type) {
+void Deoptimizer::EnsureCodeForDeoptimizationEntry(BailoutType type,
+                                                   int max_entry_id) {
   // We cannot run this if the serializer is enabled because this will
   // cause us to emit relocation information for the external
   // references. This is fine because the deoptimizer's code section
   // isn't meant to be serialized at all.
   ASSERT(!Serializer::enabled());
 
+  ASSERT(type == EAGER || type == LAZY);
+  DeoptimizerData* data = Isolate::Current()->deoptimizer_data();
+  int entry_count = (type == EAGER)
+      ? data->eager_deoptimization_entry_code_entries_
+      : data->lazy_deoptimization_entry_code_entries_;
+  if (max_entry_id < entry_count) return;
+  entry_count = Min(Max(entry_count * 2, Deoptimizer::kMinNumberOfEntries),
+                    Deoptimizer::kMaxNumberOfEntries);
+
   MacroAssembler masm(Isolate::Current(), NULL, 16 * KB);
   masm.set_emit_debug_code(false);
-  GenerateDeoptimizationEntries(&masm, kNumberOfEntries, type);
+  GenerateDeoptimizationEntries(&masm, entry_count, type);
   CodeDesc desc;
   masm.GetCode(&desc);
   ASSERT(desc.reloc_size == 0);
 
-  MemoryChunk* chunk =
-      Isolate::Current()->memory_allocator()->AllocateChunk(desc.instr_size,
-                                                            EXECUTABLE,
-                                                            NULL);
-  ASSERT(chunk->area_size() >= desc.instr_size);
-  if (chunk == NULL) {
-    V8::FatalProcessOutOfMemory("Not enough memory for deoptimization table");
+  VirtualMemory* memory = type == EAGER
+      ? data->eager_deoptimization_entry_code_
+      : data->lazy_deoptimization_entry_code_;
+  size_t table_size = Deoptimizer::GetMaxDeoptTableSize();
+  ASSERT(static_cast<int>(table_size) >= desc.instr_size);
+  memory->Commit(memory->address(), table_size, true);
+  memcpy(memory->address(), desc.buffer, desc.instr_size);
+  CPU::FlushICache(memory->address(), desc.instr_size);
+
+  if (type == EAGER) {
+    data->eager_deoptimization_entry_code_entries_ = entry_count;
+  } else {
+    data->lazy_deoptimization_entry_code_entries_ = entry_count;
   }
-  memcpy(chunk->area_start(), desc.buffer, desc.instr_size);
-  CPU::FlushICache(chunk->area_start(), desc.instr_size);
-  return chunk;
 }