[heap] Remove obsolete DisallowAllocationFailure scope.

This removes the DisallowAllocationFailure assertion scope which mostly
coincided with the AlwaysAllocateScope anyways. Access to the bitfield
in the Isolate was not synchronized and hence the AlwaysAllocateScope
was not thread-safe in debug mode, now it is.

R=mlippautz@chromium.org

Review URL: https://codereview.chromium.org/1319153006

Cr-Commit-Position: refs/heads/master@{#30637}

src/assert-scope.cc

@@ -145,8 +145,6 @@ template class PerIsolateAssertScope<JAVASCRIPT_EXECUTION_ASSERT, false>;
 template class PerIsolateAssertScope<JAVASCRIPT_EXECUTION_ASSERT, true>;
 template class PerIsolateAssertScope<JAVASCRIPT_EXECUTION_THROWS, false>;
 template class PerIsolateAssertScope<JAVASCRIPT_EXECUTION_THROWS, true>;
-template class PerIsolateAssertScope<ALLOCATION_FAILURE_ASSERT, false>;
-template class PerIsolateAssertScope<ALLOCATION_FAILURE_ASSERT, true>;
 template class PerIsolateAssertScope<DEOPTIMIZATION_ASSERT, false>;
 template class PerIsolateAssertScope<DEOPTIMIZATION_ASSERT, true>;
 template class PerIsolateAssertScope<COMPILATION_ASSERT, false>;

src/assert-scope.h

@@ -29,7 +29,6 @@ enum PerThreadAssertType {
 enum PerIsolateAssertType {
   JAVASCRIPT_EXECUTION_ASSERT,
   JAVASCRIPT_EXECUTION_THROWS,
-  ALLOCATION_FAILURE_ASSERT,
   DEOPTIMIZATION_ASSERT,
   COMPILATION_ASSERT
 };
@@ -156,14 +155,6 @@ typedef PerIsolateAssertScope<JAVASCRIPT_EXECUTION_THROWS, false>
 typedef PerIsolateAssertScope<JAVASCRIPT_EXECUTION_THROWS, true>
     NoThrowOnJavascriptExecution;
 
-// Scope to document where we do not expect an allocation failure.
-typedef PerIsolateAssertScopeDebugOnly<ALLOCATION_FAILURE_ASSERT, false>
-    DisallowAllocationFailure;
-
-// Scope to introduce an exception to DisallowAllocationFailure.
-typedef PerIsolateAssertScopeDebugOnly<ALLOCATION_FAILURE_ASSERT, true>
-    AllowAllocationFailure;
-
 // Scope to document where we do not expect deoptimization.
 typedef PerIsolateAssertScopeDebugOnly<DEOPTIMIZATION_ASSERT, false>
     DisallowDeoptimization;

src/heap/heap-inl.h

@@ -198,7 +198,7 @@ AllocationResult Heap::AllocateRaw(int size_in_bytes, AllocationSpace space,
   DCHECK(AllowHeapAllocation::IsAllowed());
   DCHECK(gc_state_ == NOT_IN_GC);
 #ifdef DEBUG
-  if (FLAG_gc_interval >= 0 && AllowAllocationFailure::IsAllowed(isolate_) &&
+  if (FLAG_gc_interval >= 0 && !always_allocate() &&
       Heap::allocation_timeout_-- <= 0) {
     return AllocationResult::Retry(space);
   }
@@ -748,7 +748,7 @@ void Heap::SetSetterStubDeoptPCOffset(int pc_offset) {
 
 
 AlwaysAllocateScope::AlwaysAllocateScope(Isolate* isolate)
-    : heap_(isolate->heap()), daf_(isolate) {
+    : heap_(isolate->heap()) {
   heap_->always_allocate_scope_count_.Increment(1);
 }
 

src/heap/heap.h

@@ -2398,9 +2398,7 @@ class AlwaysAllocateScope {
   inline ~AlwaysAllocateScope();
 
  private:
-  // Implicitly disable artificial allocation failures.
   Heap* heap_;
-  DisallowAllocationFailure daf_;
 };
 
 

src/isolate.cc

@@ -2074,7 +2074,7 @@ bool Isolate::Init(Deserializer* des) {
   }
 
   // The initialization process does not handle memory exhaustion.
-  DisallowAllocationFailure disallow_allocation_failure(this);
+  AlwaysAllocateScope always_allocate(this);
 
   memory_allocator_ = new MemoryAllocator(this);
   code_range_ = new CodeRange(this);