From 9d2b474b5f6aa07ee731d28f9774d10dfaa49b32 Mon Sep 17 00:00:00 2001 From: Allan Sandfeld Jensen Date: Tue, 2 Jun 2020 10:59:21 +0200 Subject: Do not multithread if already in a global threadpool thread This can lead to a deadlock if we block all the worker threads, waiting for the worker threads to finish. Fixes: QTBUG-84619 Change-Id: I92b7f96007897d86ece0c34223bab0df4ccbed9a Reviewed-by: Sona Kurazyan (cherry picked from commit 87d32424de2f471a520c1f3ba0c3035fbff7ee06) Reviewed-by: Qt Cherry-pick Bot --- src/corelib/thread/qthreadpool.cpp | 24 ++++++++++++++++++++++++ src/corelib/thread/qthreadpool.h | 2 ++ src/gui/image/qimage.cpp | 7 ++++--- src/gui/image/qimage_conversions.cpp | 15 +++++++++------ src/gui/painting/qimagescale.cpp | 5 +++-- src/gui/painting/qimagescale_neon.cpp | 5 +++-- src/gui/painting/qimagescale_sse4.cpp | 5 +++-- 7 files changed, 48 insertions(+), 15 deletions(-) diff --git a/src/corelib/thread/qthreadpool.cpp b/src/corelib/thread/qthreadpool.cpp index 1f99bad247..d2dcc32280 100644 --- a/src/corelib/thread/qthreadpool.cpp +++ b/src/corelib/thread/qthreadpool.cpp @@ -52,6 +52,7 @@ Q_GLOBAL_STATIC(QThreadPool, theInstance) */ class QThreadPoolThread : public QThread { + Q_OBJECT public: QThreadPoolThread(QThreadPoolPrivate *manager); void run() override; @@ -763,6 +764,28 @@ void QThreadPool::clear() d->clear(); } +#if QT_VERSION < QT_VERSION_CHECK(6,0,0) +/*! + \internal + + Returns \c true if \a thread is a thread managed by this thread pool. +*/ +#else +/*! + \since 6.0 + + Returns \c true if \a thread is a thread managed by this thread pool. +*/ +#endif +bool QThreadPool::contains(const QThread *thread) const +{ + Q_D(const QThreadPool); + const QThreadPoolThread *poolThread = qobject_cast(thread); + if (!poolThread) + return false; + return d->allThreads.contains(const_cast(poolThread)); +} + #if QT_DEPRECATED_SINCE(5, 9) /*! \since 5.5 @@ -784,3 +807,4 @@ void QThreadPool::cancel(QRunnable *runnable) QT_END_NAMESPACE #include "moc_qthreadpool.cpp" +#include "qthreadpool.moc" diff --git a/src/corelib/thread/qthreadpool.h b/src/corelib/thread/qthreadpool.h index e3691ab010..004f76a240 100644 --- a/src/corelib/thread/qthreadpool.h +++ b/src/corelib/thread/qthreadpool.h @@ -93,6 +93,8 @@ public: void clear(); + bool contains(const QThread *thread) const; + #if QT_DEPRECATED_SINCE(5, 9) QT_DEPRECATED_X("use tryTake(), but note the different deletion rules") void cancel(QRunnable *runnable); diff --git a/src/gui/image/qimage.cpp b/src/gui/image/qimage.cpp index 499c527cfc..c443836c0a 100644 --- a/src/gui/image/qimage.cpp +++ b/src/gui/image/qimage.cpp @@ -5042,15 +5042,16 @@ void QImage::applyColorTransform(const QColorTransform &transform) }; } -#if QT_CONFIG(thread) +#if QT_CONFIG(thread) && !defined(Q_OS_WASM) int segments = sizeInBytes() / (1<<16); segments = std::min(segments, height()); - if (segments > 1) { + QThreadPool *threadPool = QThreadPool::globalInstance(); + if (segments > 1 && !threadPool->contains(QThread::currentThread())) { QSemaphore semaphore; int y = 0; for (int i = 0; i < segments; ++i) { int yn = (height() - y) / (segments - i); - QThreadPool::globalInstance()->start([&, y, yn]() { + threadPool->start([&, y, yn]() { transformSegment(y, y + yn); semaphore.release(1); }); diff --git a/src/gui/image/qimage_conversions.cpp b/src/gui/image/qimage_conversions.cpp index a3868a64c7..e804b3b788 100644 --- a/src/gui/image/qimage_conversions.cpp +++ b/src/gui/image/qimage_conversions.cpp @@ -236,14 +236,15 @@ void convert_generic(QImageData *dest, const QImageData *src, Qt::ImageConversio int segments = src->nbytes / (1<<16); segments = std::min(segments, src->height); - if (segments <= 1) + QThreadPool *threadPool = QThreadPool::globalInstance(); + if (segments <= 1 || threadPool->contains(QThread::currentThread())) return convertSegment(0, src->height); QSemaphore semaphore; int y = 0; for (int i = 0; i < segments; ++i) { int yn = (src->height - y) / (segments - i); - QThreadPool::globalInstance()->start([&, y, yn]() { + threadPool->start([&, y, yn]() { convertSegment(y, y + yn); semaphore.release(1); }); @@ -290,14 +291,15 @@ void convert_generic_to_rgb64(QImageData *dest, const QImageData *src, Qt::Image int segments = src->nbytes / (1<<16); segments = std::min(segments, src->height); - if (segments <= 1) + QThreadPool *threadPool = QThreadPool::globalInstance(); + if (segments <= 1 || threadPool->contains(QThread::currentThread())) return convertSegment(0, src->height); QSemaphore semaphore; int y = 0; for (int i = 0; i < segments; ++i) { int yn = (src->height - y) / (segments - i); - QThreadPool::globalInstance()->start([&, y, yn]() { + threadPool->start([&, y, yn]() { convertSegment(y, y + yn); semaphore.release(1); }); @@ -396,12 +398,13 @@ bool convert_generic_inplace(QImageData *data, QImage::Format dst_format, Qt::Im #ifdef QT_USE_THREAD_PARALLEL_IMAGE_CONVERSIONS int segments = data->nbytes / (1<<16); segments = std::min(segments, data->height); - if (segments > 1) { + QThreadPool *threadPool = QThreadPool::globalInstance(); + if (segments > 1 && !threadPool->contains(QThread::currentThread())) { QSemaphore semaphore; int y = 0; for (int i = 0; i < segments; ++i) { int yn = (data->height - y) / (segments - i); - QThreadPool::globalInstance()->start([&, y, yn]() { + threadPool->start([&, y, yn]() { convertSegment(y, y + yn); semaphore.release(1); }); diff --git a/src/gui/painting/qimagescale.cpp b/src/gui/painting/qimagescale.cpp index 2395c891ce..aac1e20f7b 100644 --- a/src/gui/painting/qimagescale.cpp +++ b/src/gui/painting/qimagescale.cpp @@ -307,12 +307,13 @@ static inline void multithread_pixels_function(QImageScaleInfo *isi, int dh, con #if QT_CONFIG(thread) && !defined(Q_OS_WASM) int segments = (qsizetype(isi->sh) * isi->sw) / (1<<16); segments = std::min(segments, dh); - if (segments > 1) { + QThreadPool *threadPool = QThreadPool::globalInstance(); + if (segments > 1 && !threadPool->contains(QThread::currentThread())) { QSemaphore semaphore; int y = 0; for (int i = 0; i < segments; ++i) { int yn = (dh - y) / (segments - i); - QThreadPool::globalInstance()->start([&, y, yn]() { + threadPool->start([&, y, yn]() { scaleSection(y, y + yn); semaphore.release(1); }); diff --git a/src/gui/painting/qimagescale_neon.cpp b/src/gui/painting/qimagescale_neon.cpp index 65fe3fac3c..046e56b419 100644 --- a/src/gui/painting/qimagescale_neon.cpp +++ b/src/gui/painting/qimagescale_neon.cpp @@ -58,12 +58,13 @@ static inline void multithread_pixels_function(QImageScaleInfo *isi, int dh, con #if QT_CONFIG(thread) && !defined(Q_OS_WASM) int segments = (qsizetype(isi->sh) * isi->sw) / (1<<16); segments = std::min(segments, dh); - if (segments > 1) { + QThreadPool *threadPool = QThreadPool::globalInstance(); + if (segments > 1 && !threadPool->contains(QThread::currentThread())) { QSemaphore semaphore; int y = 0; for (int i = 0; i < segments; ++i) { int yn = (dh - y) / (segments - i); - QThreadPool::globalInstance()->start([&, y, yn]() { + threadPool->start([&, y, yn]() { scaleSection(y, y + yn); semaphore.release(1); }); diff --git a/src/gui/painting/qimagescale_sse4.cpp b/src/gui/painting/qimagescale_sse4.cpp index 1760e72f65..70cfa08d95 100644 --- a/src/gui/painting/qimagescale_sse4.cpp +++ b/src/gui/painting/qimagescale_sse4.cpp @@ -59,12 +59,13 @@ static inline void multithread_pixels_function(QImageScaleInfo *isi, int dh, con #if QT_CONFIG(thread) && !defined(Q_OS_WASM) int segments = (qsizetype(isi->sh) * isi->sw) / (1<<16); segments = std::min(segments, dh); - if (segments > 1) { + QThreadPool *threadPool = QThreadPool::globalInstance(); + if (segments > 1 && !threadPool->contains(QThread::currentThread())) { QSemaphore semaphore; int y = 0; for (int i = 0; i < segments; ++i) { int yn = (dh - y) / (segments - i); - QThreadPool::globalInstance()->start([&, y, yn]() { + threadPool->start([&, y, yn]() { scaleSection(y, y + yn); semaphore.release(1); }); -- cgit v1.2.3