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chore: cherry-pick 7abc7e45b2 from node
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indutny authored and indutny-signal committed May 5, 2021
1 parent 8f69f4f commit 74a6476
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1 change: 1 addition & 0 deletions patches/node/.patches
Expand Up @@ -32,3 +32,4 @@ remove_makeexternal_case_for_uncached_internal_strings.patch
fix_remove_outdated_--experimental-wasm-bigint_flag.patch
fix_parallel_test-crypto-ecdh-convert-key_to_use_compatible_group.patch
src_inline_asynccleanuphookhandle_in_headers.patch
node-api_faster_threadsafe_function.patch
262 changes: 262 additions & 0 deletions patches/node/node-api_faster_threadsafe_function.patch
@@ -0,0 +1,262 @@
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Fedor Indutny <fedor@indutny.com>
Date: Sat, 1 May 2021 11:26:46 -0700
Subject: node-api: faster threadsafe_function

Invoke threadsafe_function during the same tick and avoid marshalling
costs between threads and/or churning event loop if either:

1. There's a queued call already
2. `Push()` is called while the main thread was running
threadsafe_function

PR-URL: https://github.com/nodejs/node/pull/38506
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

diff --git a/src/node_api.cc b/src/node_api.cc
index f1a5265b6a7234dc754aedc86ecd3132f3d90b09..d1076b29aeb5133a0325d3e7ebd097d207e4f4a6 100644
--- a/src/node_api.cc
+++ b/src/node_api.cc
@@ -12,6 +12,7 @@
#include "tracing/traced_value.h"
#include "util-inl.h"

+#include <atomic>
#include <memory>

struct node_napi_env__ : public napi_env__ {
@@ -131,6 +132,7 @@ class ThreadSafeFunction : public node::AsyncResource {
*v8::String::Utf8Value(env_->isolate, name)),
thread_count(thread_count_),
is_closing(false),
+ dispatch_state(kDispatchIdle),
context(context_),
max_queue_size(max_queue_size_),
env(env_),
@@ -170,10 +172,8 @@ class ThreadSafeFunction : public node::AsyncResource {
return napi_closing;
}
} else {
- if (uv_async_send(&async) != 0) {
- return napi_generic_failure;
- }
queue.push(data);
+ Send();
return napi_ok;
}
}
@@ -205,9 +205,7 @@ class ThreadSafeFunction : public node::AsyncResource {
if (is_closing && max_queue_size > 0) {
cond->Signal(lock);
}
- if (uv_async_send(&async) != 0) {
- return napi_generic_failure;
- }
+ Send();
}
}

@@ -232,7 +230,6 @@ class ThreadSafeFunction : public node::AsyncResource {
cond = std::make_unique<node::ConditionVariable>();
}
if (max_queue_size == 0 || cond) {
- CHECK_EQ(0, uv_idle_init(loop, &idle));
return napi_ok;
}

@@ -257,21 +254,46 @@ class ThreadSafeFunction : public node::AsyncResource {

napi_status Unref() {
uv_unref(reinterpret_cast<uv_handle_t*>(&async));
- uv_unref(reinterpret_cast<uv_handle_t*>(&idle));

return napi_ok;
}

napi_status Ref() {
uv_ref(reinterpret_cast<uv_handle_t*>(&async));
- uv_ref(reinterpret_cast<uv_handle_t*>(&idle));

return napi_ok;
}

- void DispatchOne() {
+ inline void* Context() {
+ return context;
+ }
+
+ protected:
+ void Dispatch() {
+ bool has_more = true;
+
+ // Limit maximum synchronous iteration count to prevent event loop
+ // starvation. See `src/node_messaging.cc` for an inspiration.
+ unsigned int iterations_left = kMaxIterationCount;
+ while (has_more && --iterations_left != 0) {
+ dispatch_state = kDispatchRunning;
+ has_more = DispatchOne();
+
+ // Send() was called while we were executing the JS function
+ if (dispatch_state.exchange(kDispatchIdle) != kDispatchRunning) {
+ has_more = true;
+ }
+ }
+
+ if (has_more) {
+ Send();
+ }
+ }
+
+ bool DispatchOne() {
void* data = nullptr;
bool popped_value = false;
+ bool has_more = false;

{
node::Mutex::ScopedLock lock(this->mutex);
@@ -296,9 +318,9 @@ class ThreadSafeFunction : public node::AsyncResource {
cond->Signal(lock);
}
CloseHandlesAndMaybeDelete();
- } else {
- CHECK_EQ(0, uv_idle_stop(&idle));
}
+ } else {
+ has_more = true;
}
}
}
@@ -316,6 +338,8 @@ class ThreadSafeFunction : public node::AsyncResource {
call_js_cb(env, js_callback, context, data);
});
}
+
+ return has_more;
}

void Finalize() {
@@ -329,10 +353,6 @@ class ThreadSafeFunction : public node::AsyncResource {
EmptyQueueAndDelete();
}

- inline void* Context() {
- return context;
- }
-
void CloseHandlesAndMaybeDelete(bool set_closing = false) {
v8::HandleScope scope(env->isolate);
if (set_closing) {
@@ -352,18 +372,20 @@ class ThreadSafeFunction : public node::AsyncResource {
ThreadSafeFunction* ts_fn =
node::ContainerOf(&ThreadSafeFunction::async,
reinterpret_cast<uv_async_t*>(handle));
- v8::HandleScope scope(ts_fn->env->isolate);
- ts_fn->env->node_env()->CloseHandle(
- reinterpret_cast<uv_handle_t*>(&ts_fn->idle),
- [](uv_handle_t* handle) -> void {
- ThreadSafeFunction* ts_fn =
- node::ContainerOf(&ThreadSafeFunction::idle,
- reinterpret_cast<uv_idle_t*>(handle));
- ts_fn->Finalize();
- });
+ ts_fn->Finalize();
});
}

+ void Send() {
+ // Ask currently running Dispatch() to make one more iteration
+ unsigned char current_state = dispatch_state.fetch_or(kDispatchPending);
+ if ((current_state & kDispatchRunning) == kDispatchRunning) {
+ return;
+ }
+
+ CHECK_EQ(0, uv_async_send(&async));
+ }
+
// Default way of calling into JavaScript. Used when ThreadSafeFunction is
// without a call_js_cb_.
static void CallJs(napi_env env, napi_value cb, void* context, void* data) {
@@ -387,16 +409,10 @@ class ThreadSafeFunction : public node::AsyncResource {
}
}

- static void IdleCb(uv_idle_t* idle) {
- ThreadSafeFunction* ts_fn =
- node::ContainerOf(&ThreadSafeFunction::idle, idle);
- ts_fn->DispatchOne();
- }
-
static void AsyncCb(uv_async_t* async) {
ThreadSafeFunction* ts_fn =
node::ContainerOf(&ThreadSafeFunction::async, async);
- CHECK_EQ(0, uv_idle_start(&ts_fn->idle, IdleCb));
+ ts_fn->Dispatch();
}

static void Cleanup(void* data) {
@@ -405,14 +421,20 @@ class ThreadSafeFunction : public node::AsyncResource {
}

private:
+ static const unsigned char kDispatchIdle = 0;
+ static const unsigned char kDispatchRunning = 1 << 0;
+ static const unsigned char kDispatchPending = 1 << 1;
+
+ static const unsigned int kMaxIterationCount = 1000;
+
// These are variables protected by the mutex.
node::Mutex mutex;
std::unique_ptr<node::ConditionVariable> cond;
std::queue<void*> queue;
uv_async_t async;
- uv_idle_t idle;
size_t thread_count;
bool is_closing;
+ std::atomic_uchar dispatch_state;

// These are variables set once, upon creation, and then never again, which
// means we don't need the mutex to read them.
diff --git a/test/node-api/test_threadsafe_function/binding.c b/test/node-api/test_threadsafe_function/binding.c
index c9c526153804c60b5bd5844d2c2aacac7f0fb514..ae3ec67de43cfffdfb10772761dbd69f01c623bb 100644
--- a/test/node-api/test_threadsafe_function/binding.c
+++ b/test/node-api/test_threadsafe_function/binding.c
@@ -7,7 +7,7 @@
#include <node_api.h>
#include "../../js-native-api/common.h"

-#define ARRAY_LENGTH 10
+#define ARRAY_LENGTH 10000
#define MAX_QUEUE_SIZE 2

static uv_thread_t uv_threads[2];
@@ -72,7 +72,7 @@ static void data_source_thread(void* data) {
for (index = ARRAY_LENGTH - 1; index > -1 && !queue_was_closing; index--) {
status = napi_call_threadsafe_function(ts_fn, &ints[index],
ts_fn_info->block_on_full);
- if (ts_fn_info->max_queue_size == 0) {
+ if (ts_fn_info->max_queue_size == 0 && (index % 1000 == 0)) {
// Let's make this thread really busy for 200 ms to give the main thread a
// chance to abort.
uint64_t start = uv_hrtime();
diff --git a/test/node-api/test_threadsafe_function/test.js b/test/node-api/test_threadsafe_function/test.js
index 3603d79ee6b5d36590503989d8168368eaf12b03..ccd3f4228a793ae77eff760309e31191ba8de49a 100644
--- a/test/node-api/test_threadsafe_function/test.js
+++ b/test/node-api/test_threadsafe_function/test.js
@@ -210,6 +210,15 @@ new Promise(function testWithoutJSMarshaller(resolve) {
}))
.then((result) => assert.strictEqual(result.indexOf(0), -1))

+// Make sure that threadsafe function isn't stalled when we hit
+// `kMaxIterationCount` in `src/node_api.cc`
+.then(() => testWithJSMarshaller({
+ threadStarter: 'StartThreadNonblocking',
+ maxQueueSize: binding.ARRAY_LENGTH >>> 1,
+ quitAfter: binding.ARRAY_LENGTH
+}))
+.then((result) => assert.deepStrictEqual(result, expectedArray))
+
// Start a child process to test rapid teardown
.then(() => testUnref(binding.MAX_QUEUE_SIZE))

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