Revert "Do not wait in QWindowsPipe{Reader|Writer}::stop()"

This reverts commit c7ec07d40115bef849574c81d619b629af9434a9.

Reason for revert: This causes a memory leak on program termination.

The initial commit was an attempt to fix a deadlock where the user
destroys object from a thread that does not own the object. This is
an unsupported case and should be treated as an invalid report.

Pick-to: 5.15
Change-Id: I4957784b86a0361adb65b9d023542f96480f00ba
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>

1 files changed, 6 insertions, 14 deletions

diff --git a/src/corelib/io/qwindowspipewriter.cpp b/src/corelib/io/qwindowspipewriter.cpp
index 32536f495b..e374034a06 100644
--- a/src/corelib/io/qwindowspipewriter.cpp
+++ b/src/corelib/io/qwindowspipewriter.cpp
@@ -57,7 +57,7 @@ void QWindowsPipeWriter::Overlapped::clear()
 QWindowsPipeWriter::QWindowsPipeWriter(HANDLE pipeWriteEnd, QObject *parent)
     : QObject(parent),
       handle(pipeWriteEnd),
-      overlapped(nullptr),
+      overlapped(this),
       pendingBytesWrittenValue(0),
       stopped(true),
       writeSequenceStarted(false),
@@ -72,7 +72,6 @@ QWindowsPipeWriter::QWindowsPipeWriter(HANDLE pipeWriteEnd, QObject *parent)
 QWindowsPipeWriter::~QWindowsPipeWriter()
 {
     stop();
-    delete overlapped;
 }
 
 bool QWindowsPipeWriter::waitForWrite(int msecs)
@@ -122,10 +121,7 @@ void QWindowsPipeWriter::writeFileCompleted(DWORD errorCode, DWORD numberOfBytes
                                             OVERLAPPED *overlappedBase)
 {
     Overlapped *overlapped = static_cast<Overlapped *>(overlappedBase);
-    if (overlapped->pipeWriter)
-        overlapped->pipeWriter->notified(errorCode, numberOfBytesTransfered);
-    else
-        delete overlapped;
+    overlapped->pipeWriter->notified(errorCode, numberOfBytesTransfered);
 }
 
 /*!
@@ -187,14 +183,12 @@ bool QWindowsPipeWriter::write(const QByteArray &ba)
     if (writeSequenceStarted)
         return false;
 
-    if (!overlapped)
-        overlapped = new Overlapped(this);
-    overlapped->clear();
+    overlapped.clear();
     buffer = ba;
     stopped = false;
     writeSequenceStarted = true;
     if (!WriteFileEx(handle, buffer.constData(), buffer.size(),
-                     overlapped, &writeFileCompleted)) {
+                     &overlapped, &writeFileCompleted)) {
         writeSequenceStarted = false;
         buffer.clear();
 
@@ -218,16 +212,14 @@ void QWindowsPipeWriter::stop()
     bytesWrittenPending = false;
     pendingBytesWrittenValue = 0;
     if (writeSequenceStarted) {
-        overlapped->pipeWriter = nullptr;
-        if (!CancelIoEx(handle, overlapped)) {
+        if (!CancelIoEx(handle, &overlapped)) {
             const DWORD dwError = GetLastError();
             if (dwError != ERROR_NOT_FOUND) {
                 qErrnoWarning(dwError, "QWindowsPipeWriter: CancelIoEx on handle %p failed.",
                               handle);
             }
         }
-        overlapped = nullptr;       // The object will be deleted in the I/O callback.
-        writeSequenceStarted = false;
+        waitForNotification(-1);
     }
 }