remove the "wonderful Windows notifier" from QProcess

Remove the 100 ms timer that was used to nudge QProcess to write data
to the child's stdin. Instead, react on the canWrite() signal of
QWindowsPipeWriter.
QProcess::writeData needs to call _q_canWrite via the event loop to
start the write operation. The socket notifier code was never in use on
Windows.

Task-number: QTBUG-45457
Change-Id: I99c956ba5f2169f80068eee206543ceb9788b2e0
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>

1 files changed, 27 insertions, 7 deletions

diff --git a/src/corelib/io/qprocess.cpp b/src/corelib/io/qprocess.cpp
index 7d7cdef203..ead04791e5 100644
--- a/src/corelib/io/qprocess.cpp
+++ b/src/corelib/io/qprocess.cpp
@@ -36,6 +36,9 @@
 
 #include <qdebug.h>
 #include <qdir.h>
+#if defined(Q_OS_WIN)
+#include <qtimer.h>
+#endif
 #if defined QPROCESS_DEBUG
 #include <qstring.h>
 #include <ctype.h>
@@ -819,7 +822,7 @@ QProcessPrivate::QProcessPrivate()
     emittedReadyRead = false;
     emittedBytesWritten = false;
 #ifdef Q_OS_WIN
-    notifier = 0;
+    stdinWriteTrigger = 0;
     processFinishedNotifier = 0;
 #endif // Q_OS_WIN
 }
@@ -848,6 +851,10 @@ void QProcessPrivate::cleanup()
         delete pid;
         pid = 0;
     }
+    if (stdinWriteTrigger) {
+        delete stdinWriteTrigger;
+        stdinWriteTrigger = 0;
+    }
     if (processFinishedNotifier) {
         delete processFinishedNotifier;
         processFinishedNotifier = 0;
@@ -878,12 +885,6 @@ void QProcessPrivate::cleanup()
         delete deathNotifier;
         deathNotifier = 0;
     }
-#ifdef Q_OS_WIN
-    if (notifier) {
-        delete notifier;
-        notifier = 0;
-    }
-#endif
     closeChannel(&stdoutChannel);
     closeChannel(&stderrChannel);
     closeChannel(&stdinChannel);
@@ -1953,10 +1954,24 @@ qint64 QProcess::writeData(const char *data, qint64 len)
         return 0;
     }
 
+#if defined(Q_OS_WIN)
+    if (!d->stdinWriteTrigger) {
+        d->stdinWriteTrigger = new QTimer;
+        d->stdinWriteTrigger->setSingleShot(true);
+        QObjectPrivate::connect(d->stdinWriteTrigger, &QTimer::timeout,
+                                d, &QProcessPrivate::_q_canWrite);
+    }
+#endif
+
     if (len == 1) {
         d->stdinChannel.buffer.putChar(*data);
+#ifdef Q_OS_WIN
+        if (!d->stdinWriteTrigger->isActive())
+            d->stdinWriteTrigger->start();
+#else
         if (d->stdinChannel.notifier)
             d->stdinChannel.notifier->setEnabled(true);
+#endif
 #if defined QPROCESS_DEBUG
     qDebug("QProcess::writeData(%p \"%s\", %lld) == 1 (written to buffer)",
            data, qt_prettyDebug(data, len, 16).constData(), len);
@@ -1966,8 +1981,13 @@ qint64 QProcess::writeData(const char *data, qint64 len)
 
     char *dest = d->stdinChannel.buffer.reserve(len);
     memcpy(dest, data, len);
+#ifdef Q_OS_WIN
+    if (!d->stdinWriteTrigger->isActive())
+        d->stdinWriteTrigger->start();
+#else
     if (d->stdinChannel.notifier)
         d->stdinChannel.notifier->setEnabled(true);
+#endif
 #if defined QPROCESS_DEBUG
     qDebug("QProcess::writeData(%p \"%s\", %lld) == %lld (written to buffer)",
            data, qt_prettyDebug(data, len, 16).constData(), len, len);