From 457603e96194b4858ad715f9faacb3ad7fec7f35 Mon Sep 17 00:00:00 2001
From: Joyee Cheung <joyeec9h3@gmail.com>
Date: Wed, 19 Dec 2018 18:44:14 +0800
Subject: src: move process.nextTick and promise setup into node_task_queue.cc

This patch:

- Moves the process.nextTick and promise setup C++ code into
  node_task_queue.cc which is exposed as
  `internalBinding('task_queue')`
- Makes `lib/internal/process/promises.js` and
  `lib/internal/process/next_tick.js` as side-effect-free
  as possible
- Removes the bootstrapper object being passed into
  `bootstrap/node.js`, let `next_tick.js` and `promises.js`
  load whatever they need from `internalBinding('task_queue')`
  instead.
- Rename `process._tickCallback` to `runNextTicks` internally
  for clarity but still expose it as `process._tickCallback`.

PR-URL: https://github.com/nodejs/node/pull/25163
Refs: https://github.com/nodejs/node/issues/24961
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
---
 src/node_task_queue.cc | 136 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 136 insertions(+)
 create mode 100644 src/node_task_queue.cc

(limited to 'src/node_task_queue.cc')

diff --git a/src/node_task_queue.cc b/src/node_task_queue.cc
new file mode 100644
index 0000000000..f65f420081
--- /dev/null
+++ b/src/node_task_queue.cc
@@ -0,0 +1,136 @@
+#include "env-inl.h"
+#include "node.h"
+#include "node_internals.h"
+#include "v8.h"
+
+#include <atomic>
+
+namespace node {
+
+using v8::Array;
+using v8::Context;
+using v8::Function;
+using v8::FunctionCallbackInfo;
+using v8::Isolate;
+using v8::kPromiseHandlerAddedAfterReject;
+using v8::kPromiseRejectAfterResolved;
+using v8::kPromiseRejectWithNoHandler;
+using v8::kPromiseResolveAfterResolved;
+using v8::Local;
+using v8::MaybeLocal;
+using v8::Number;
+using v8::Object;
+using v8::Promise;
+using v8::PromiseRejectEvent;
+using v8::PromiseRejectMessage;
+using v8::Value;
+
+namespace task_queue {
+
+static void RunMicrotasks(const FunctionCallbackInfo<Value>& args) {
+  args.GetIsolate()->RunMicrotasks();
+}
+
+static void SetTickCallback(const FunctionCallbackInfo<Value>& args) {
+  Environment* env = Environment::GetCurrent(args);
+  CHECK(args[0]->IsFunction());
+  env->set_tick_callback_function(args[0].As<Function>());
+}
+
+static void PromiseRejectCallback(PromiseRejectMessage message) {
+  static std::atomic<uint64_t> unhandledRejections{0};
+  static std::atomic<uint64_t> rejectionsHandledAfter{0};
+
+  Local<Promise> promise = message.GetPromise();
+  Isolate* isolate = promise->GetIsolate();
+  PromiseRejectEvent event = message.GetEvent();
+
+  Environment* env = Environment::GetCurrent(isolate);
+
+  if (env == nullptr) return;
+
+  Local<Function> callback = env->promise_reject_callback();
+  Local<Value> value;
+  Local<Value> type = Number::New(env->isolate(), event);
+
+  if (event == kPromiseRejectWithNoHandler) {
+    value = message.GetValue();
+    unhandledRejections++;
+    TRACE_COUNTER2(TRACING_CATEGORY_NODE2(promises, rejections),
+                  "rejections",
+                  "unhandled", unhandledRejections,
+                  "handledAfter", rejectionsHandledAfter);
+  } else if (event == kPromiseHandlerAddedAfterReject) {
+    value = Undefined(isolate);
+    rejectionsHandledAfter++;
+    TRACE_COUNTER2(TRACING_CATEGORY_NODE2(promises, rejections),
+                  "rejections",
+                  "unhandled", unhandledRejections,
+                  "handledAfter", rejectionsHandledAfter);
+  } else if (event == kPromiseResolveAfterResolved) {
+    value = message.GetValue();
+  } else if (event == kPromiseRejectAfterResolved) {
+    value = message.GetValue();
+  } else {
+    return;
+  }
+
+  if (value.IsEmpty()) {
+    value = Undefined(isolate);
+  }
+
+  Local<Value> args[] = { type, promise, value };
+  MaybeLocal<Value> ret = callback->Call(env->context(),
+                                         Undefined(isolate),
+                                         arraysize(args),
+                                         args);
+
+  if (!ret.IsEmpty() && ret.ToLocalChecked()->IsTrue())
+    env->tick_info()->promise_rejections_toggle_on();
+}
+
+static void InitializePromiseRejectCallback(
+    const FunctionCallbackInfo<Value>& args) {
+  Environment* env = Environment::GetCurrent(args);
+  Isolate* isolate = env->isolate();
+
+  CHECK(args[0]->IsFunction());
+
+  // TODO(joyeecheung): this may be moved to somewhere earlier in the bootstrap
+  // to make sure it's only called once
+  isolate->SetPromiseRejectCallback(PromiseRejectCallback);
+
+  env->set_promise_reject_callback(args[0].As<Function>());
+}
+
+static void Initialize(Local<Object> target,
+                       Local<Value> unused,
+                       Local<Context> context,
+                       void* priv) {
+  Environment* env = Environment::GetCurrent(context);
+  Isolate* isolate = env->isolate();
+
+  env->SetMethod(target, "setTickCallback", SetTickCallback);
+  env->SetMethod(target, "runMicrotasks", RunMicrotasks);
+  target->Set(env->context(),
+              FIXED_ONE_BYTE_STRING(isolate, "tickInfo"),
+              env->tick_info()->fields().GetJSArray()).FromJust();
+
+  Local<Object> events = Object::New(isolate);
+  NODE_DEFINE_CONSTANT(events, kPromiseRejectWithNoHandler);
+  NODE_DEFINE_CONSTANT(events, kPromiseHandlerAddedAfterReject);
+  NODE_DEFINE_CONSTANT(events, kPromiseResolveAfterResolved);
+  NODE_DEFINE_CONSTANT(events, kPromiseRejectAfterResolved);
+
+  target->Set(env->context(),
+              FIXED_ONE_BYTE_STRING(isolate, "promiseRejectEvents"),
+              events).FromJust();
+  env->SetMethod(target,
+                 "initializePromiseRejectCallback",
+                 InitializePromiseRejectCallback);
+}
+
+}  // namespace task_queue
+}  // namespace node
+
+NODE_MODULE_CONTEXT_AWARE_INTERNAL(task_queue, node::task_queue::Initialize)
-- 
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