Let SetEntropySource() fail if called after V8::Initialize().

src/api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 5157 matching lines @@
 bool v8::V8::Initialize() {
   i::Isolate* isolate = i::Isolate::UncheckedCurrent();
   if (isolate != NULL && isolate->IsInitialized()) {
     return true;
   }
   return InitializeHelper(isolate);
 }
 
 
 void v8::V8::SetEntropySource(EntropySource entropy_source) {
+  // The entropy source must be set before the library is initialized,
+  // as otherwise not all random number generators will pick up the
+  // entropy source and will fall back to weak entropy instead.
+  i::Isolate* isolate = i::Isolate::UncheckedCurrent();

[Michael Starzinger, 2013/09/23 14:51:31]

We try to get rid of Isolate::Current, please try not to add new call-site to
this function.

[Benedikt Meurer, 2013/09/23 20:25:51]

I know, but there's currently no other way to perform this check. We're planning
to add one, but that'll take some more cleanup time.

+  ApiCheck(isolate != NULL && isolate->IsInitialized(),
+           "v8::V8::SetEntropySource",
+           "Cannot set entropy source once V8 is initialized.");
   i::RandomNumberGenerator::SetEntropySource(entropy_source);
 }
 
 
 void v8::V8::SetReturnAddressLocationResolver(
       ReturnAddressLocationResolver return_address_resolver) {
   i::V8::SetReturnAddressLocationResolver(return_address_resolver);
 }
 
 
@@ skipping 2680 matching lines @@
   Isolate* isolate = reinterpret_cast<Isolate*>(info.GetIsolate());
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 } }  // namespace v8::internal