diff options
Diffstat (limited to 'src/corelib/io/qwindowspipereader.cpp')
| -rw-r--r-- | src/corelib/io/qwindowspipereader.cpp | 158 |
1 files changed, 97 insertions, 61 deletions
diff --git a/src/corelib/io/qwindowspipereader.cpp b/src/corelib/io/qwindowspipereader.cpp index d8e9834ea0..31d0dc1417 100644 --- a/src/corelib/io/qwindowspipereader.cpp +++ b/src/corelib/io/qwindowspipereader.cpp @@ -1,49 +1,16 @@ -/**************************************************************************** -** -** Copyright (C) 2016 The Qt Company Ltd. -** Copyright (C) 2021 Alex Trotsenko <alex1973tr@gmail.com> -** Contact: https://www.qt.io/licensing/ -** -** This file is part of the QtCore module of the Qt Toolkit. -** -** $QT_BEGIN_LICENSE:LGPL$ -** Commercial License Usage -** Licensees holding valid commercial Qt licenses may use this file in -** accordance with the commercial license agreement provided with the -** Software or, alternatively, in accordance with the terms contained in -** a written agreement between you and The Qt Company. For licensing terms -** and conditions see https://www.qt.io/terms-conditions. For further -** information use the contact form at https://www.qt.io/contact-us. -** -** GNU Lesser General Public License Usage -** Alternatively, this file may be used under the terms of the GNU Lesser -** General Public License version 3 as published by the Free Software -** Foundation and appearing in the file LICENSE.LGPL3 included in the -** packaging of this file. Please review the following information to -** ensure the GNU Lesser General Public License version 3 requirements -** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. -** -** GNU General Public License Usage -** Alternatively, this file may be used under the terms of the GNU -** General Public License version 2.0 or (at your option) the GNU General -** Public license version 3 or any later version approved by the KDE Free -** Qt Foundation. The licenses are as published by the Free Software -** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 -** included in the packaging of this file. Please review the following -** information to ensure the GNU General Public License requirements will -** be met: https://www.gnu.org/licenses/gpl-2.0.html and -** https://www.gnu.org/licenses/gpl-3.0.html. -** -** $QT_END_LICENSE$ -** -****************************************************************************/ +// Copyright (C) 2016 The Qt Company Ltd. +// Copyright (C) 2021 Alex Trotsenko <alex1973tr@gmail.com> +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only #include "qwindowspipereader_p.h" #include <qcoreapplication.h> #include <QMutexLocker> +#include <QPointer> QT_BEGIN_NAMESPACE +using namespace Qt::StringLiterals; + static const DWORD minReadBufferSize = 4096; QWindowsPipeReader::QWindowsPipeReader(QObject *parent) @@ -58,7 +25,7 @@ QWindowsPipeReader::QWindowsPipeReader(QObject *parent) lastError(ERROR_SUCCESS), state(Stopped), readSequenceStarted(false), - pipeBroken(false), + pipeBroken(true), readyReadPending(false), winEventActPosted(false) { @@ -103,6 +70,7 @@ void QWindowsPipeReader::setHandle(HANDLE hPipeReadEnd) void QWindowsPipeReader::stop() { cancelAsyncRead(Stopped); + pipeBroken = true; } /*! @@ -112,10 +80,22 @@ void QWindowsPipeReader::stop() void QWindowsPipeReader::drainAndStop() { cancelAsyncRead(Draining); + pipeBroken = true; +} - // Note that signals are not emitted in the call below, as the caller - // is expected to do that synchronously. - consumePending(); +/*! + Stops the asynchronous read sequence. + Clears the internal buffer and discards any pending data. + */ +void QWindowsPipeReader::stopAndClear() +{ + cancelAsyncRead(Stopped); + readBuffer.clear(); + actualReadBufferSize = 0; + // QLocalSocket is supposed to write data in the 'Closing' + // state, so we don't set 'pipeBroken' flag here. Also, avoid + // setting this flag in checkForReadyRead(). + lastError = ERROR_SUCCESS; } /*! @@ -126,7 +106,7 @@ void QWindowsPipeReader::cancelAsyncRead(State newState) if (state != Running) return; - QMutexLocker locker(&mutex); + mutex.lock(); state = newState; if (readSequenceStarted) { // This can legitimately fail due to the GetOverlappedResult() @@ -142,11 +122,17 @@ void QWindowsPipeReader::cancelAsyncRead(State newState) // Wait for callback to complete. do { - locker.unlock(); + mutex.unlock(); waitForNotification(); - locker.relock(); + mutex.lock(); } while (readSequenceStarted); } + mutex.unlock(); + + // Finish reading to keep the class state consistent. Note that + // signals are not emitted in the call below, as the caller is + // expected to do that synchronously. + consumePending(); } /*! @@ -182,11 +168,9 @@ qint64 QWindowsPipeReader::bytesAvailable() const */ qint64 QWindowsPipeReader::read(char *data, qint64 maxlen) { - if (pipeBroken && actualReadBufferSize == 0) - return 0; // signal EOF - - mutex.lock(); + QMutexLocker locker(&mutex); qint64 readSoFar; + // If startAsyncRead() has read data, copy it to its destination. if (maxlen == 1 && actualReadBufferSize > 0) { *data = readBuffer.getChar(); @@ -196,11 +180,9 @@ qint64 QWindowsPipeReader::read(char *data, qint64 maxlen) readSoFar = readBuffer.read(data, qMin(actualReadBufferSize, maxlen)); actualReadBufferSize -= readSoFar; } - mutex.unlock(); if (!pipeBroken) { - if (state == Running) - startAsyncRead(); + startAsyncReadHelper(&locker); if (readSoFar == 0) return -2; // signal EWOULDBLOCK } @@ -209,6 +191,49 @@ qint64 QWindowsPipeReader::read(char *data, qint64 maxlen) } /*! + Reads a line from the internal buffer, but no more than \c{maxlen} + characters. A terminating '\0' byte is always appended to \c{data}, + so \c{maxlen} must be larger than 1. + */ +qint64 QWindowsPipeReader::readLine(char *data, qint64 maxlen) +{ + QMutexLocker locker(&mutex); + qint64 readSoFar = 0; + + if (actualReadBufferSize > 0) { + readSoFar = readBuffer.readLine(data, qMin(actualReadBufferSize + 1, maxlen)); + actualReadBufferSize -= readSoFar; + } + + if (!pipeBroken) { + startAsyncReadHelper(&locker); + if (readSoFar == 0) + return -2; // signal EWOULDBLOCK + } + + return readSoFar; +} + +/*! + Skips up to \c{maxlen} bytes from the internal read buffer. + */ +qint64 QWindowsPipeReader::skip(qint64 maxlen) +{ + QMutexLocker locker(&mutex); + + const qint64 skippedSoFar = readBuffer.skip(qMin(actualReadBufferSize, maxlen)); + actualReadBufferSize -= skippedSoFar; + + if (!pipeBroken) { + startAsyncReadHelper(&locker); + if (skippedSoFar == 0) + return -2; // signal EWOULDBLOCK + } + + return skippedSoFar; +} + +/*! Returns \c true if a complete line of data can be read from the buffer. */ bool QWindowsPipeReader::canReadLine() const @@ -223,7 +248,11 @@ bool QWindowsPipeReader::canReadLine() const void QWindowsPipeReader::startAsyncRead() { QMutexLocker locker(&mutex); + startAsyncReadHelper(&locker); +} +void QWindowsPipeReader::startAsyncReadHelper(QMutexLocker<QMutex> *locker) +{ if (readSequenceStarted || lastError != ERROR_SUCCESS) return; @@ -236,10 +265,10 @@ void QWindowsPipeReader::startAsyncRead() if (!winEventActPosted) { winEventActPosted = true; - locker.unlock(); + locker->unlock(); QCoreApplication::postEvent(this, new QEvent(QEvent::WinEventAct)); } else { - locker.unlock(); + locker->unlock(); } SetEvent(syncHandle); @@ -422,12 +451,17 @@ bool QWindowsPipeReader::consumePendingAndEmit(bool allowWinActPosting) if (state != Running) return false; - if (emitReadyRead) - emit readyRead(); - if (emitPipeClosed) { - if (dwError != ERROR_BROKEN_PIPE && dwError != ERROR_PIPE_NOT_CONNECTED) - emit winError(dwError, QLatin1String("QWindowsPipeReader::consumePendingAndEmit")); - emit pipeClosed(); + if (!emitPipeClosed) { + if (emitReadyRead) + emit readyRead(); + } else { + QPointer<QWindowsPipeReader> alive(this); + if (emitReadyRead) + emit readyRead(); + if (alive && dwError != ERROR_BROKEN_PIPE && dwError != ERROR_PIPE_NOT_CONNECTED) + emit winError(dwError, "QWindowsPipeReader::consumePendingAndEmit"_L1); + if (alive) + emit pipeClosed(); } return emitReadyRead; @@ -477,3 +511,5 @@ bool QWindowsPipeReader::waitForNotification() } QT_END_NAMESPACE + +#include "moc_qwindowspipereader_p.cpp" |