From d79726e9ebf65d1722f73d56cbc2ac68c7489a45 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?M=C3=A5rten=20Nordheim?= Date: Mon, 7 Oct 2019 15:48:30 +0200 Subject: Win: QUdpSocket: Use QVarLengthArray for retrieving size Increased size of the peek buffer to 2048 from 1500 and now uses QVarLengthArray with space for 10 stack-allocated WSABUF instances, but still growing at the pace of 5. In benchmarking (created for and included in this patch) this shows better performance when retrieving the datagram size for larger datagrams, and the same performance as before for smaller datagrams (at the cost of 2048 - 1500 + 16 * 10 = 708 bytes extra stack space). Benchmarks: With changes: ********* Start testing of tst_QUdpSocket ********* Config: Using QtTest library 5.13.1, Qt 5.13.1 (x86_64-little_endian-llp64 shared (dynamic) release build; by MSVC 2019) PASS : tst_QUdpSocket::initTestCase() PASS : tst_QUdpSocket::pendingDatagramSize(52) RESULT : tst_QUdpSocket::pendingDatagramSize():"52": 0.0038 msecs per iteration (total: 63, iterations: 16384) PASS : tst_QUdpSocket::pendingDatagramSize(1024) RESULT : tst_QUdpSocket::pendingDatagramSize():"1024": 0.0039 msecs per iteration (total: 64, iterations: 16384) PASS : tst_QUdpSocket::pendingDatagramSize(2049) RESULT : tst_QUdpSocket::pendingDatagramSize():"2049": 0.0038 msecs per iteration (total: 63, iterations: 16384) PASS : tst_QUdpSocket::pendingDatagramSize(4500) RESULT : tst_QUdpSocket::pendingDatagramSize():"4500": 0.0039 msecs per iteration (total: 64, iterations: 16384) PASS : tst_QUdpSocket::pendingDatagramSize(4098) RESULT : tst_QUdpSocket::pendingDatagramSize():"4098": 0.0040 msecs per iteration (total: 66, iterations: 16384) PASS : tst_QUdpSocket::pendingDatagramSize(8192) RESULT : tst_QUdpSocket::pendingDatagramSize():"8192": 0.0040 msecs per iteration (total: 67, iterations: 16384) PASS : tst_QUdpSocket::pendingDatagramSize(12000) RESULT : tst_QUdpSocket::pendingDatagramSize():"12000": 0.010 msecs per iteration (total: 90, iterations: 8192) PASS : tst_QUdpSocket::pendingDatagramSize(25000) RESULT : tst_QUdpSocket::pendingDatagramSize():"25000": 0.021 msecs per iteration (total: 88, iterations: 4096) PASS : tst_QUdpSocket::pendingDatagramSize(32768) RESULT : tst_QUdpSocket::pendingDatagramSize():"32768": 0.033 msecs per iteration (total: 69, iterations: 2048) PASS : tst_QUdpSocket::pendingDatagramSize(64512) RESULT : tst_QUdpSocket::pendingDatagramSize():"64512": 0.088 msecs per iteration (total: 91, iterations: 1024) PASS : tst_QUdpSocket::cleanupTestCase() Totals: 12 passed, 0 failed, 0 skipped, 0 blacklisted, 3090ms ********* Finished testing of tst_QUdpSocket ********* Without changes: ********* Start testing of tst_QUdpSocket ********* Config: Using QtTest library 5.13.1, Qt 5.13.1 (x86_64-little_endian-llp64 shared (dynamic) release build; by MSVC 2019) PASS : tst_QUdpSocket::initTestCase() PASS : tst_QUdpSocket::pendingDatagramSize(52) RESULT : tst_QUdpSocket::pendingDatagramSize():"52": 0.0039 msecs per iteration (total: 65, iterations: 16384) PASS : tst_QUdpSocket::pendingDatagramSize(1024) RESULT : tst_QUdpSocket::pendingDatagramSize():"1024": 0.0039 msecs per iteration (total: 65, iterations: 16384) PASS : tst_QUdpSocket::pendingDatagramSize(2049) RESULT : tst_QUdpSocket::pendingDatagramSize():"2049": 0.0040 msecs per iteration (total: 66, iterations: 16384) PASS : tst_QUdpSocket::pendingDatagramSize(4500) RESULT : tst_QUdpSocket::pendingDatagramSize():"4500": 0.0040 msecs per iteration (total: 67, iterations: 16384) PASS : tst_QUdpSocket::pendingDatagramSize(4098) RESULT : tst_QUdpSocket::pendingDatagramSize():"4098": 0.0040 msecs per iteration (total: 67, iterations: 16384) PASS : tst_QUdpSocket::pendingDatagramSize(8192) RESULT : tst_QUdpSocket::pendingDatagramSize():"8192": 0.010 msecs per iteration (total: 90, iterations: 8192) PASS : tst_QUdpSocket::pendingDatagramSize(12000) RESULT : tst_QUdpSocket::pendingDatagramSize():"12000": 0.010 msecs per iteration (total: 90, iterations: 8192) PASS : tst_QUdpSocket::pendingDatagramSize(25000) RESULT : tst_QUdpSocket::pendingDatagramSize():"25000": 0.033 msecs per iteration (total: 69, iterations: 2048) PASS : tst_QUdpSocket::pendingDatagramSize(32768) RESULT : tst_QUdpSocket::pendingDatagramSize():"32768": 0.0502 msecs per iteration (total: 103, iterations: 2048) PASS : tst_QUdpSocket::pendingDatagramSize(64512) RESULT : tst_QUdpSocket::pendingDatagramSize():"64512": 0.13 msecs per iteration (total: 70, iterations: 512) PASS : tst_QUdpSocket::cleanupTestCase() Totals: 12 passed, 0 failed, 0 skipped, 0 blacklisted, 3192ms ********* Finished testing of tst_QUdpSocket ********* Fixes: QTBUG-78275 Change-Id: If86a226620244aa4e470600c6c1db4a7863b5617 Reviewed-by: Timur Pocheptsov Reviewed-by: Thiago Macieira --- src/network/socket/qnativesocketengine_win.cpp | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) (limited to 'src/network/socket') diff --git a/src/network/socket/qnativesocketengine_win.cpp b/src/network/socket/qnativesocketengine_win.cpp index 9edabd7822..dd115c33dc 100644 --- a/src/network/socket/qnativesocketengine_win.cpp +++ b/src/network/socket/qnativesocketengine_win.cpp @@ -53,6 +53,8 @@ #include #include +#include + //#define QNATIVESOCKETENGINE_DEBUG #if defined(QNATIVESOCKETENGINE_DEBUG) # include @@ -1141,13 +1143,14 @@ qint64 QNativeSocketEnginePrivate::nativePendingDatagramSize() const qint64 ret = -1; int recvResult = 0; DWORD flags; - // We start at 1500 bytes (the MTU for Ethernet V2), which should catch - // almost all uses (effective MTU for UDP under IPv4 is 1468), except - // for localhost datagrams and those reassembled by the IP layer. - char udpMessagePeekBuffer[1500]; - std::vector buf; + // We increase the amount we peek by 2048 * 5 on each iteration + // Grabs most cases fast and early. + char udpMessagePeekBuffer[2048]; + const int increments = 5; + QVarLengthArray buf; for (;;) { - buf.resize(buf.size() + 5, {sizeof(udpMessagePeekBuffer), udpMessagePeekBuffer}); + buf.reserve(buf.size() + increments); + std::fill_n(std::back_inserter(buf), increments, WSABUF{sizeof(udpMessagePeekBuffer), udpMessagePeekBuffer}); flags = MSG_PEEK; DWORD bytesRead = 0; -- cgit v1.2.3