Closed
Description
- Version: v12.5.0
- Platform: Darwin beast 18.7.0 Darwin Kernel Version 18.7.0: Tue Aug 20 16:57:14 PDT 2019; root:xnu-4903.271.2~2/RELEASE_X86_64 x86_64
- Subsystem:
I'm trying to make use of 0-copy when passing buffers from native to JS. For this I'm using N-API for C++. Here is a simple example of such a little function which just returns a buffer with 3 bytes in it.
1. The sample native addon source, exporting a single function
struct sample_finalized_buffer_t {
std::vector<uint8_t> _buffer;
static Napi::Value New(Napi::Env&& env) {
sample_finalized_buffer_t *pResult = new sample_finalized_buffer_t();
pResult->_buffer.push_back(1);
pResult->_buffer.push_back(2);
pResult->_buffer.push_back(3);
return Napi::Buffer<uint8_t>::New(env,
pResult->_buffer.data(),
pResult->_buffer.size(),
Delete,
pResult
);
}
static void Delete(Napi::Env env, uint8_t *pRawBytes, sample_finalized_buffer_t *pThis) {
if (pThis != NULL)
delete pThis;
}
};
Napi::Value getSampleBuffer(const Napi::CallbackInfo& args){
return sample_finalized_buffer_t::New(args.Env());
}
Napi::Object RegisterModule(Napi::Env env, Napi::Object exports) {
exports.Set(Napi::String::New(env, "getSampleBuffer"), Napi::Function::New(env, getSampleBuffer));
return exports;
}
NODE_API_MODULE(addon, RegisterModule);
2. The sample JS source which calls that native function
const addon = require('path/to/addon');
console.log(addon.getSampleBuffer());
setInterval(() => {
console.log("working...");
}, 1000);
3. The output of running that sample JS script
<Buffer 01 02 03>
working...
working...
working...
working...
working...
working...
working...
working...
FATAL ERROR: v8::HandleScope::CreateHandle() Cannot create a handle without a HandleScope
1: 0x10006d2dc node::DumpBacktrace(__sFILE*) [/Users/shiretu/work/node/out/Debug/node]
2: 0x100167bdb node::Abort() [/Users/shiretu/work/node/out/Debug/node]
3: 0x100168762 node::OnFatalError(char const*, char const*) [/Users/shiretu/work/node/out/Debug/node]
4: 0x1003ef951 v8::Utils::ReportApiFailure(char const*, char const*) [/Users/shiretu/work/node/out/Debug/node]
5: 0x1007212f2 v8::internal::HandleScope::Extend(v8::internal::Isolate*) [/Users/shiretu/work/node/out/Debug/node]
6: 0x1003e0a67 v8::internal::HandleScope::CreateHandle(v8::internal::Isolate*, unsigned long) [/Users/shiretu/work/node/out/Debug/node]
7: 0x1003f4f8c v8::EmbedderDataFor(v8::Context*, int, bool, char const*) [/Users/shiretu/work/node/out/Debug/node]
8: 0x1003f541d v8::Context::SlowGetAlignedPointerFromEmbedderData(int) [/Users/shiretu/work/node/out/Debug/node]
9: 0x10001410b v8::Context::GetAlignedPointerFromEmbedderData(int) [/Users/shiretu/work/node/out/Debug/node]
10: 0x100014051 node::Environment::GetCurrent(v8::Local<v8::Context>) [/Users/shiretu/work/node/out/Debug/node]
11: 0x10010c872 node_napi_env__::node_env() const [/Users/shiretu/work/node/out/Debug/node]
12: 0x10010d1f3 v8impl::(anonymous namespace)::BufferFinalizer::FinalizeBufferCallback(char*, void*) [/Users/shiretu/work/node/out/Debug/node]
13: 0x10012194d node::Buffer::(anonymous namespace)::CallbackInfo::WeakCallback(v8::Isolate*) [/Users/shiretu/work/node/out/Debug/node]
14: 0x100121809 node::Buffer::(anonymous namespace)::CallbackInfo::WeakCallback(v8::WeakCallbackInfo<node::Buffer::(anonymous namespace)::CallbackInfo> const&) [/Users/shiretu/work/node/out/Debug/node]
15: 0x10071b83d unsigned long v8::internal::GlobalHandles::InvokeFirstPassWeakCallbacks<v8::internal::GlobalHandles::Node>(std::__1::vector<std::__1::pair<v8::internal::GlobalHandles::Node*, v8::internal::GlobalHandles::PendingPhantomCallback>, std::__1::allocator<std::__1::pair<v8::internal::GlobalHandles::Node*, v8::internal::GlobalHandles::PendingPhantomCallback> > >*) [/Users/shiretu/work/node/out/Debug/node]
16: 0x10071b703 v8::internal::GlobalHandles::InvokeFirstPassWeakCallbacks() [/Users/shiretu/work/node/out/Debug/node]
17: 0x100777d11 v8::internal::Heap::PerformGarbageCollection(v8::internal::GarbageCollector, v8::GCCallbackFlags) [/Users/shiretu/work/node/out/Debug/node]
18: 0x100775800 v8::internal::Heap::CollectGarbage(v8::internal::AllocationSpace, v8::internal::GarbageCollectionReason, v8::GCCallbackFlags) [/Users/shiretu/work/node/out/Debug/node]
19: 0x100781516 v8::internal::Heap::FinalizeIncrementalMarkingIfComplete(v8::internal::GarbageCollectionReason) [/Users/shiretu/work/node/out/Debug/node]
20: 0x10079ad2f v8::internal::IncrementalMarkingJob::Task::RunInternal() [/Users/shiretu/work/node/out/Debug/node]
21: 0x100261e0e node::PerIsolatePlatformData::RunForegroundTask(std::__1::unique_ptr<v8::Task, std::__1::default_delete<v8::Task> >) [/Users/shiretu/work/node/out/Debug/node]
22: 0x100260966 node::PerIsolatePlatformData::FlushForegroundTasksInternal() [/Users/shiretu/work/node/out/Debug/node]
23: 0x100260730 node::PerIsolatePlatformData::FlushTasks(uv_async_s*) [/Users/shiretu/work/node/out/Debug/node]
24: 0x100f59fc2 uv__async_io [/Users/shiretu/work/node/out/Debug/node]
25: 0x100f78c00 uv__io_poll [/Users/shiretu/work/node/out/Debug/node]
26: 0x100f5a66f uv_run [/Users/shiretu/work/node/out/Debug/node]
27: 0x1001e7d3e node::NodeMainInstance::Run() [/Users/shiretu/work/node/out/Debug/node]
28: 0x100105c3c node::Start(int, char**) [/Users/shiretu/work/node/out/Debug/node]
29: 0x1017368ce main [/Users/shiretu/work/node/out/Debug/node]
30: 0x7fff61d123d5 start [/usr/lib/system/libdyld.dylib]
4. The fix:
Inserting v8::HandleScope hs(isolate); as the first line of code in void CallbackInfo::WeakCallback(Isolate* isolate) function which is located here solves the issue