From f10491a9afe7d6e11456b2c4b2c5f6eaf1594737 Mon Sep 17 00:00:00 2001
From: Alex Trotsenko <alex1973tr@gmail.com>
Date: Mon, 26 Apr 2021 19:50:14 +0300
Subject: [PATCH] QLocalSocket/Win: simplify flush()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Replacing a call to waitForWrite(0) with checkForWrite() changes
nothing in logic, but saves one system call. As a result, unused
functions in the QWindowsPipeWriter class have been removed.

Change-Id: I34ec6310d9659f59a720056b9be54e31f2193116
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
---
 src/corelib/io/qwindowspipewriter.cpp   | 43 -------------------------
 src/corelib/io/qwindowspipewriter_p.h   |  4 ---
 src/network/socket/qlocalsocket_win.cpp |  6 ++--
 3 files changed, 2 insertions(+), 51 deletions(-)

diff --git a/src/corelib/io/qwindowspipewriter.cpp b/src/corelib/io/qwindowspipewriter.cpp
index 6a5e43db0d..2db3cb4060 100644
--- a/src/corelib/io/qwindowspipewriter.cpp
+++ b/src/corelib/io/qwindowspipewriter.cpp
@@ -114,16 +114,6 @@ void QWindowsPipeWriter::stop()
     WaitForThreadpoolWaitCallbacks(waitObject, TRUE);
 }
 
-/*!
-    Returns \c true if async operation is in progress or a bytesWritten
-    signal is pending.
- */
-bool QWindowsPipeWriter::isWriteOperationActive() const
-{
-    QMutexLocker locker(&mutex);
-    return writeSequenceStarted || bytesWrittenPending;
-}
-
 /*!
     Returns the number of bytes that are waiting to be written.
  */
@@ -322,37 +312,4 @@ bool QWindowsPipeWriter::consumePendingAndEmit(bool allowWinActPosting)
     return true;
 }
 
-bool QWindowsPipeWriter::waitForNotification(const QDeadlineTimer &deadline)
-{
-    do {
-        DWORD waitRet = WaitForSingleObjectEx(syncHandle, deadline.remainingTime(), TRUE);
-        if (waitRet == WAIT_OBJECT_0)
-            return true;
-
-        if (waitRet != WAIT_IO_COMPLETION)
-            return false;
-
-        // Some I/O completion routine was called. Wait some more.
-    } while (!deadline.hasExpired());
-
-    return false;
-}
-
-/*!
-    Waits for the completion of the asynchronous write operation.
-    Returns \c true, if we've emitted the bytesWritten signal.
- */
-bool QWindowsPipeWriter::waitForWrite(int msecs)
-{
-    QDeadlineTimer timer(msecs);
-
-    // Make sure that 'syncHandle' was triggered by the thread pool callback.
-    while (isWriteOperationActive() && waitForNotification(timer)) {
-        if (consumePendingAndEmit(false))
-            return true;
-    }
-
-    return false;
-}
-
 QT_END_NAMESPACE
diff --git a/src/corelib/io/qwindowspipewriter_p.h b/src/corelib/io/qwindowspipewriter_p.h
index e20f1ec90a..8a3b3068e5 100644
--- a/src/corelib/io/qwindowspipewriter_p.h
+++ b/src/corelib/io/qwindowspipewriter_p.h
@@ -53,7 +53,6 @@
 //
 
 #include <qobject.h>
-#include <qdeadlinetimer.h>
 #include <qmutex.h>
 #include <private/qringbuffer_p.h>
 
@@ -72,9 +71,7 @@ public:
     bool write(const QByteArray &ba);
     bool write(const char *data, qint64 size);
     void stop();
-    bool waitForWrite(int msecs);
     bool checkForWrite() { return consumePendingAndEmit(false); }
-    bool isWriteOperationActive() const;
     qint64 bytesToWrite() const;
     HANDLE syncEvent() const { return syncHandle; }
 
@@ -92,7 +89,6 @@ private:
     static void CALLBACK waitCallback(PTP_CALLBACK_INSTANCE instance, PVOID context,
                                       PTP_WAIT wait, TP_WAIT_RESULT waitResult);
     bool writeCompleted(DWORD errorCode, DWORD numberOfBytesWritten);
-    bool waitForNotification(const QDeadlineTimer &deadline);
     bool consumePendingAndEmit(bool allowWinActPosting);
 
     HANDLE handle;
diff --git a/src/network/socket/qlocalsocket_win.cpp b/src/network/socket/qlocalsocket_win.cpp
index 912ebf412c..aa5c12b5b8 100644
--- a/src/network/socket/qlocalsocket_win.cpp
+++ b/src/network/socket/qlocalsocket_win.cpp
@@ -377,10 +377,8 @@ void QLocalSocket::close()
 bool QLocalSocket::flush()
 {
     Q_D(QLocalSocket);
-    bool written = false;
-    while (d->pipeWriter && d->pipeWriter->waitForWrite(0))
-        written = true;
-    return written;
+
+    return d->pipeWriter && d->pipeWriter->checkForWrite();
 }
 
 void QLocalSocket::disconnectFromServer()