Reland "Add mechanism to postpone interrupts selectively."

src/isolate.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_ISOLATE_H_
 #define V8_ISOLATE_H_
 
 #include "include/v8-debug.h"
 #include "src/allocation.h"
 #include "src/assert-scope.h"
@@ skipping 1402 matching lines @@
   Isolate* isolate_;
 };
 
 
 // Support for temporarily postponing interrupts. When the outermost
 // postpone scope is left the interrupts will be re-enabled and any
 // interrupts that occurred while in the scope will be taken into
 // account.
 class PostponeInterruptsScope BASE_EMBEDDED {
  public:
-  explicit PostponeInterruptsScope(Isolate* isolate)
-      : stack_guard_(isolate->stack_guard()), isolate_(isolate) {
-    ExecutionAccess access(isolate_);
-    stack_guard_->thread_local_.postpone_interrupts_nesting_++;
-    stack_guard_->DisableInterrupts();
+  PostponeInterruptsScope(Isolate* isolate,
+                          int intercept_mask = StackGuard::ALL_INTERRUPTS)
+      : stack_guard_(isolate->stack_guard()),
+        intercept_mask_(intercept_mask),
+        intercepted_flags_(0) {
+    stack_guard_->PushPostponeInterruptsScope(this);
   }
 
   ~PostponeInterruptsScope() {
-    ExecutionAccess access(isolate_);
-    if (--stack_guard_->thread_local_.postpone_interrupts_nesting_ == 0) {
-      stack_guard_->EnableInterrupts();
-    }
+    stack_guard_->PopPostponeInterruptsScope();
   }
+
+  // Find the bottom-most scope that intercepts this interrupt.
+  // Return whether the interrupt has been intercepted.
+  bool Intercept(StackGuard::InterruptFlag flag);
+
  private:
   StackGuard* stack_guard_;
-  Isolate* isolate_;
+  int intercept_mask_;
+  int intercepted_flags_;
+  PostponeInterruptsScope* prev_;
+
+  friend class StackGuard;
 };
 
 
 class CodeTracer V8_FINAL : public Malloced {
  public:
   explicit CodeTracer(int isolate_id)
       : file_(NULL),
         scope_depth_(0) {
     if (!ShouldRedirect()) {
       file_ = stdout;
@@ skipping 54 matching lines @@
   }
 
   EmbeddedVector<char, 128> filename_;
   FILE* file_;
   int scope_depth_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_ISOLATE_H_