[d8 Workers] Add max worker count, throw an exception if too many.

src/d8.cc

 // 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.
 
 
 // Defined when linking against shared lib on Windows.
 #if defined(USING_V8_SHARED) && !defined(V8_SHARED)
 #define V8_SHARED
 #endif
 
@@ skipping 57 matching lines @@
 
 #ifndef CHECK
 #define CHECK(condition) assert(condition)
 #endif
 
 namespace v8 {
 
 namespace {
 
 const int MB = 1024 * 1024;
+const int kMaxWorkers = 50;
 
 
 class ShellArrayBufferAllocator : public v8::ArrayBuffer::Allocator {
  public:
   virtual void* Allocate(size_t length) {
     void* data = AllocateUninitialized(length);
     return data == NULL ? data : memset(data, 0, length);
   }
   virtual void* AllocateUninitialized(size_t length) { return malloc(length); }
   virtual void Free(void* data, size_t) { free(data); }
@@ skipping 611 matching lines @@
     return;
   }
 
   if (!args.IsConstructCall()) {
     Throw(args.GetIsolate(), "Worker must be constructed with new");
     return;
   }
 
   {
     base::LockGuard<base::Mutex> lock_guard(workers_mutex_.Pointer());
+    if (workers_.length() >= kMaxWorkers) {
+      Throw(args.GetIsolate(), "Too many workers, I won't let you create more");
+      return;
+    }
+
     // Initialize the internal field to NULL; if we return early without
     // creating a new Worker (because the main thread is terminating) we can
     // early-out from the instance calls.
     args.Holder()->SetAlignedPointerInInternalField(0, NULL);
 
     if (!allow_new_workers_) return;
 
     Worker* worker = new Worker;
     args.Holder()->SetAlignedPointerInInternalField(0, worker);
     workers_.Add(worker);
@@ skipping 1751 matching lines @@
 }
 
 }  // namespace v8
 
 
 #ifndef GOOGLE3
 int main(int argc, char* argv[]) {
   return v8::Shell::Main(argc, argv);
 }
 #endif