Check for GC interrupt in JSON parser.

src/json-parser.h

 // Copyright 2011 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_JSON_PARSER_H_
 #define V8_JSON_PARSER_H_
 
 #include "src/v8.h"
 
 #include "src/char-predicates-inl.h"
@@ skipping 243 matching lines @@
 
 // Parse any JSON value.
 template <bool seq_one_byte>
 Handle<Object> JsonParser<seq_one_byte>::ParseJsonValue() {
   StackLimitCheck stack_check(isolate_);
   if (stack_check.HasOverflowed()) {
     isolate_->StackOverflow();
     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();
   if (c0_ == '[') return ParseJsonArray();
   if (c0_ == 'f') {
     if (AdvanceGetChar() == 'a' && AdvanceGetChar() == 'l' &&
         AdvanceGetChar() == 's' && AdvanceGetChar() == 'e') {
       AdvanceSkipWhitespace();
       return factory()->false_value();
     }
@@ skipping 513 matching lines @@
 
   DCHECK_EQ('"', c0_);
   // Advance past the last '"'.
   AdvanceSkipWhitespace();
   return result;
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_JSON_PARSER_H_