From cf418455633fda7264e069f6493f064d6f328757 Mon Sep 17 00:00:00 2001 From: Anna Henningsen Date: Wed, 2 Oct 2019 23:26:51 +0200 Subject: [PATCH] dgram: use `uv_udp_try_send()` This improves dgram performance by avoiding unnecessary async operations. One issue with this commit is that it seems hard to actually create conditions under which the fallback path to the async case is actually taken, for all supported OS, so an internal CLI option is used for testing that path. Another caveat is that the lack of an async operation means that there are slight timing differences (essentially `nextTick()` rather than `setImmediate()` for the send callback). PR-URL: https://github.com/nodejs/node/pull/29832 Reviewed-By: David Carlier Reviewed-By: James M Snell Reviewed-By: Ben Noordhuis --- benchmark/dgram/array-vs-concat.js | 20 ++++++--- benchmark/dgram/multi-buffer.js | 10 +++-- benchmark/dgram/offset-length.js | 10 +++-- benchmark/dgram/single-buffer.js | 10 +++-- lib/dgram.js | 8 ++++ src/node_options.cc | 2 + src/node_options.h | 1 + src/udp_wrap.cc | 44 ++++++++++++++----- test/async-hooks/test-udpsendwrap.js | 1 + .../test-dgram-send-callback-recursive.js | 2 +- test/sequential/test-async-wrap-getasyncid.js | 2 +- 11 files changed, 82 insertions(+), 28 deletions(-) diff --git a/benchmark/dgram/array-vs-concat.js b/benchmark/dgram/array-vs-concat.js index 669cf47df4..d260a48063 100644 --- a/benchmark/dgram/array-vs-concat.js +++ b/benchmark/dgram/array-vs-concat.js @@ -29,17 +29,25 @@ function main({ dur, len, num, type, chunks }) { function onsendConcat() { if (sent++ % num === 0) { - for (var i = 0; i < num; i++) { - socket.send(Buffer.concat(chunk), PORT, '127.0.0.1', onsend); - } + // The setImmediate() is necessary to have event loop progress on OSes + // that only perform synchronous I/O on nonblocking UDP sockets. + setImmediate(() => { + for (var i = 0; i < num; i++) { + socket.send(Buffer.concat(chunk), PORT, '127.0.0.1', onsend); + } + }); } } function onsendMulti() { if (sent++ % num === 0) { - for (var i = 0; i < num; i++) { - socket.send(chunk, PORT, '127.0.0.1', onsend); - } + // The setImmediate() is necessary to have event loop progress on OSes + // that only perform synchronous I/O on nonblocking UDP sockets. + setImmediate(() => { + for (var i = 0; i < num; i++) { + socket.send(chunk, PORT, '127.0.0.1', onsend); + } + }); } } diff --git a/benchmark/dgram/multi-buffer.js b/benchmark/dgram/multi-buffer.js index a1c50551b8..7b69a82255 100644 --- a/benchmark/dgram/multi-buffer.js +++ b/benchmark/dgram/multi-buffer.js @@ -27,9 +27,13 @@ function main({ dur, len, num, type, chunks }) { function onsend() { if (sent++ % num === 0) { - for (var i = 0; i < num; i++) { - socket.send(chunk, PORT, '127.0.0.1', onsend); - } + // The setImmediate() is necessary to have event loop progress on OSes + // that only perform synchronous I/O on nonblocking UDP sockets. + setImmediate(() => { + for (var i = 0; i < num; i++) { + socket.send(chunk, PORT, '127.0.0.1', onsend); + } + }); } } diff --git a/benchmark/dgram/offset-length.js b/benchmark/dgram/offset-length.js index 7c672acae2..696fa6a7a0 100644 --- a/benchmark/dgram/offset-length.js +++ b/benchmark/dgram/offset-length.js @@ -23,9 +23,13 @@ function main({ dur, len, num, type }) { function onsend() { if (sent++ % num === 0) { - for (var i = 0; i < num; i++) { - socket.send(chunk, 0, chunk.length, PORT, '127.0.0.1', onsend); - } + // The setImmediate() is necessary to have event loop progress on OSes + // that only perform synchronous I/O on nonblocking UDP sockets. + setImmediate(() => { + for (var i = 0; i < num; i++) { + socket.send(chunk, 0, chunk.length, PORT, '127.0.0.1', onsend); + } + }); } } diff --git a/benchmark/dgram/single-buffer.js b/benchmark/dgram/single-buffer.js index d183b9cd1d..5c95b17887 100644 --- a/benchmark/dgram/single-buffer.js +++ b/benchmark/dgram/single-buffer.js @@ -23,9 +23,13 @@ function main({ dur, len, num, type }) { function onsend() { if (sent++ % num === 0) { - for (var i = 0; i < num; i++) { - socket.send(chunk, PORT, '127.0.0.1', onsend); - } + // The setImmediate() is necessary to have event loop progress on OSes + // that only perform synchronous I/O on nonblocking UDP sockets. + setImmediate(() => { + for (var i = 0; i < num; i++) { + socket.send(chunk, PORT, '127.0.0.1', onsend); + } + }); } } diff --git a/lib/dgram.js b/lib/dgram.js index 923463cc2e..cc61d4d274 100644 --- a/lib/dgram.js +++ b/lib/dgram.js @@ -666,6 +666,14 @@ function doSend(ex, self, ip, list, address, port, callback) { else err = state.handle.send(req, list, list.length, !!callback); + if (err >= 1) { + // Synchronous finish. The return code is msg_length + 1 so that we can + // distinguish between synchronous success and asynchronous success. + if (callback) + process.nextTick(callback, null, err - 1); + return; + } + if (err && callback) { // Don't emit as error, dgram_legacy.js compatibility const ex = exceptionWithHostPort(err, 'send', address, port); diff --git a/src/node_options.cc b/src/node_options.cc index 34efe6336a..4320493e08 100644 --- a/src/node_options.cc +++ b/src/node_options.cc @@ -449,6 +449,8 @@ EnvironmentOptionsParser::EnvironmentOptionsParser() { "write warnings to file instead of stderr", &EnvironmentOptions::redirect_warnings, kAllowedInEnvironment); + AddOption("--test-udp-no-try-send", "", // For testing only. + &EnvironmentOptions::test_udp_no_try_send); AddOption("--throw-deprecation", "throw an exception on deprecations", &EnvironmentOptions::throw_deprecation, diff --git a/src/node_options.h b/src/node_options.h index 780e669eb6..236f1aab92 100644 --- a/src/node_options.h +++ b/src/node_options.h @@ -134,6 +134,7 @@ class EnvironmentOptions : public Options { bool heap_prof = false; #endif // HAVE_INSPECTOR std::string redirect_warnings; + bool test_udp_no_try_send = false; bool throw_deprecation = false; bool trace_deprecation = false; bool trace_sync_io = false; diff --git a/src/udp_wrap.cc b/src/udp_wrap.cc index 3c66db2155..64c4c8b304 100644 --- a/src/udp_wrap.cc +++ b/src/udp_wrap.cc @@ -429,11 +429,6 @@ void UDPWrap::DoSend(const FunctionCallbackInfo& args, int family) { size_t count = args[2].As()->Value(); const bool have_callback = sendto ? args[5]->IsTrue() : args[3]->IsTrue(); - SendWrap* req_wrap; - { - AsyncHooks::DefaultTriggerAsyncIdScope trigger_scope(wrap); - req_wrap = new SendWrap(env, req_wrap_obj, have_callback); - } size_t msg_size = 0; MaybeStackBuffer bufs(count); @@ -448,8 +443,6 @@ void UDPWrap::DoSend(const FunctionCallbackInfo& args, int family) { msg_size += length; } - req_wrap->msg_size = msg_size; - int err = 0; struct sockaddr_storage addr_storage; sockaddr* addr = nullptr; @@ -462,18 +455,47 @@ void UDPWrap::DoSend(const FunctionCallbackInfo& args, int family) { } } + uv_buf_t* bufs_ptr = *bufs; + if (err == 0 && !UNLIKELY(env->options()->test_udp_no_try_send)) { + err = uv_udp_try_send(&wrap->handle_, bufs_ptr, count, addr); + if (err == UV_ENOSYS || err == UV_EAGAIN) { + err = 0; + } else if (err >= 0) { + size_t sent = err; + while (count > 0 && bufs_ptr->len <= sent) { + sent -= bufs_ptr->len; + bufs_ptr++; + count--; + } + if (count > 0) { + CHECK_LT(sent, bufs_ptr->len); + bufs_ptr->base += sent; + bufs_ptr->len -= sent; + } else { + CHECK_EQ(static_cast(err), msg_size); + // + 1 so that the JS side can distinguish 0-length async sends from + // 0-length sync sends. + args.GetReturnValue().Set(static_cast(msg_size) + 1); + return; + } + } + } + if (err == 0) { + AsyncHooks::DefaultTriggerAsyncIdScope trigger_scope(wrap); + SendWrap* req_wrap = new SendWrap(env, req_wrap_obj, have_callback); + req_wrap->msg_size = msg_size; + err = req_wrap->Dispatch(uv_udp_send, &wrap->handle_, - *bufs, + bufs_ptr, count, addr, OnSend); + if (err) + delete req_wrap; } - if (err) - delete req_wrap; - args.GetReturnValue().Set(err); } diff --git a/test/async-hooks/test-udpsendwrap.js b/test/async-hooks/test-udpsendwrap.js index 25b7eb6103..f1403e3226 100644 --- a/test/async-hooks/test-udpsendwrap.js +++ b/test/async-hooks/test-udpsendwrap.js @@ -1,3 +1,4 @@ +// Flags: --test-udp-no-try-send 'use strict'; const common = require('../common'); diff --git a/test/parallel/test-dgram-send-callback-recursive.js b/test/parallel/test-dgram-send-callback-recursive.js index 835fa332df..1a4c7c84fc 100644 --- a/test/parallel/test-dgram-send-callback-recursive.js +++ b/test/parallel/test-dgram-send-callback-recursive.js @@ -22,7 +22,7 @@ function onsend() { client.on('listening', function() { port = this.address().port; - setImmediate(function() { + process.nextTick(() => { async = true; }); diff --git a/test/sequential/test-async-wrap-getasyncid.js b/test/sequential/test-async-wrap-getasyncid.js index 39fd8f6183..2abe7f61d7 100644 --- a/test/sequential/test-async-wrap-getasyncid.js +++ b/test/sequential/test-async-wrap-getasyncid.js @@ -1,5 +1,5 @@ 'use strict'; -// Flags: --expose-gc --expose-internals --no-warnings +// Flags: --expose-gc --expose-internals --no-warnings --test-udp-no-try-send const common = require('../common'); const { internalBinding } = require('internal/test/binding');