Hey Gautham B A,
I am currently experiencing a similar issue. I have found that using
NewInstance() causes a slow memory growth/leak in our application. We
aggressively call LowMemoryNotification()
on our scripts, as they are meant to run for a very long time and accept
the performance tradeoff. This should theoretically clean up stray
objects, but it seems that objects created via
NewInstance() are never properly marked for GC (maybe, I don't really know
what's being held). What's odd is that I can create a weak persistent
beneath one of these objects, and they
get cleaned up regularly in the memory notification calls.
Are you still having issues? I might make a test program and throw it on a
gist and report back here. I'd be curious as this doesn't seem like
acceptable behavior for the engine.
I don't see an actual memory leak in the code you posted but creating
> a new ObjectTemplate for every query isn't very efficient.
>
Just wanted to reply to this to say, that is an irrelevant point to this
discussion. Even if you are using it sparingly, if you have a long-running
script that calls NewInstance(), then
this would be a problem.
On Tuesday, April 18, 2017 at 5:27:59 AM UTC-4, Gautham B A wrote:
>
> Yes, the memory leak in this code isn't visible as it appears.
> I observed the memory leak when I ran the "top" command. But when I
> commented out the call to "NewInstance()", there wasn't any growth in
> memory (which is obvious because there's nothing being created and passed
> onto the JS world).
>
> On Tuesday, 18 April 2017 14:49:11 UTC+5:30, Ben Noordhuis wrote:
>>
>> On Tue, Apr 18, 2017 at 9:31 AM, Gautham B A
>> <gautham....@gmail.com> wrote:
>> > Thank you Ben.
>> > Yes, there's a try_catch.HasCaught() before running the script in order
>> to
>> > prevent the process from exiting.
>> > Here's the code that will cause the script to run -
>> > int SendUpdate(std::string value, std::string meta,
>> > std::string doc_type) {
>> > v8::Locker locker(GetIsolate());
>> > v8::Isolate::Scope isolate_scope(GetIsolate());
>> > v8::HandleScope handle_scope(GetIsolate());
>> >
>> > v8::Local<v8::Context> context =
>> > v8::Local<v8::Context>::New(GetIsolate(), context_);
>> > v8::Context::Scope context_scope(context);
>> >
>> > v8::TryCatch try_catch(GetIsolate());
>> >
>> > v8::Handle<v8::Value> args[2];
>> > if (doc_type.compare("json") == 0) {
>> > args[0] =
>> > v8::JSON::Parse(v8::String::NewFromUtf8(GetIsolate(),
>> > value.c_str()));
>> > } else {
>> > args[0] = v8::String::NewFromUtf8(GetIsolate(), value.c_str());
>> > }
>> >
>> > args[1] =
>> > v8::JSON::Parse(v8::String::NewFromUtf8(GetIsolate(),
>> meta.c_str()));
>> >
>> > if (try_catch.HasCaught()) {
>> > last_exception = ExceptionString(GetIsolate(), &try_catch);
>> > LOG(logError) << "Last exception: " << last_exception << '\n';
>> > }
>> >
>> > v8::Local<v8::Function> on_doc_update =
>> > v8::Local<v8::Function>::New(GetIsolate(), on_update_);
>> > on_doc_update->Call(context->Global(), 2, args);
>> >
>> > if (try_catch.HasCaught()) {
>> > LOG(logDebug) << "Exception message: "
>> > << ExceptionString(GetIsolate(), &try_catch) << '\n';
>> >
>> > return ON_UPDATE_CALL_FAIL;
>> > }
>> >
>> > return SUCCESS;
>> > }
>> >
>> > Is it possible to reclaim the memory without shutting the VM down?
>>
>> Depends on what you mean by 'reclaim' and 'memory leak' - memory isn't
>> reclaimed until the garbage collector deems it necessary. People
>> often mistake that for a memory leak when it is in fact the garbage
>> collector doing its work (or rather, doing as little work as it can
>> get away with.)
>>
>> I don't see an actual memory leak in the code you posted but creating
>> a new ObjectTemplate for every query isn't very efficient. If you
>> don't use ObjectTemplate features, replace it with Object::New().
>>
>
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