Check for GC interrupt in JSON parser.

BUG=v8:3974
LOG=NO

Review URL: https://codereview.chromium.org/1021523002

Cr-Commit-Position: refs/heads/master@{#27334}

src/execution.cc

@@ -651,6 +651,13 @@ Handle<String> Execution::GetStackTraceLine(Handle<Object> recv,
 }
 
 
+void StackGuard::CheckAndHandleGCInterrupt() {
+  if (CheckAndClearInterrupt(GC_REQUEST)) {
+    isolate_->heap()->HandleGCRequest();
+  }
+}
+
+
 Object* StackGuard::HandleInterrupts() {
   if (CheckAndClearInterrupt(GC_REQUEST)) {
     isolate_->heap()->HandleGCRequest();

src/execution.h

@@ -197,6 +197,10 @@ class StackGuard FINAL {
   // stack overflow, then handle the interruption accordingly.
   Object* HandleInterrupts();
 
+  bool InterruptRequested() { return GetCurrentStackPosition() < climit(); }
+
+  void CheckAndHandleGCInterrupt();
+
  private:
   StackGuard();
 

src/json-parser.h

@@ -261,6 +261,11 @@ Handle<Object> JsonParser<seq_one_byte>::ParseJsonValue() {
     return Handle<Object>::null();
   }
 
+  if (isolate_->stack_guard()->InterruptRequested()) {
+    // Avoid blocking GC in long running parser (v8:3974).
+    isolate_->stack_guard()->CheckAndHandleGCInterrupt();
+  }
+
   if (c0_ == '"') return ParseJsonString();
   if ((c0_ >= '0' && c0_ <= '9') || c0_ == '-') return ParseJsonNumber();
   if (c0_ == '{') return ParseJsonObject();