From 08ad96404b4c915eece1a547bf12e91664e7cdff Mon Sep 17 00:00:00 2001 From: Marc Mutz Date: Wed, 21 Aug 2019 22:14:16 +0200 Subject: QCoreApplication: work towards replacing a QRecursiveMutex with a QMutex At first glance, libraryPathMutex is only recursive because setLibraryPaths(), addLibraryPath() and removeLibraryPath(), all of which lock libraryPathMutex, may call libraryPaths(), which does, too. This is easily fixed by splitting libraryPaths() into public libraryPaths() and private libraryPathsLocked(), the latter expecting to be called with the libraryPathMutex already held. And this is what this patch does. However, on second glance, the building of the initial app_libpaths calls a monstrous amount of code, incl. QLibraryInfo, and some of that code probably re-enters one of the library-path functions. So while this patch is a step towards making libraryPathMutex non-recursive, it's probably not the end. Change-Id: I3ed83272ace6966980cf8e1db877f24c89789da3 Reviewed-by: Ulf Hermann Reviewed-by: Edward Welbourne Reviewed-by: Olivier Goffart (Woboq GmbH) --- src/corelib/kernel/qcoreapplication.cpp | 13 ++++++++++--- src/corelib/kernel/qcoreapplication.h | 3 +++ 2 files changed, 13 insertions(+), 3 deletions(-) (limited to 'src/corelib/kernel') diff --git a/src/corelib/kernel/qcoreapplication.cpp b/src/corelib/kernel/qcoreapplication.cpp index 6647ea99f5..c537e8f51b 100644 --- a/src/corelib/kernel/qcoreapplication.cpp +++ b/src/corelib/kernel/qcoreapplication.cpp @@ -2693,7 +2693,14 @@ Q_GLOBAL_STATIC(QRecursiveMutex, libraryPathMutex) QStringList QCoreApplication::libraryPaths() { QMutexLocker locker(libraryPathMutex()); + return libraryPathsLocked(); +} +/*! + \internal +*/ +QStringList QCoreApplication::libraryPathsLocked() +{ if (coreappdata()->manual_libpaths) return *(coreappdata()->manual_libpaths); @@ -2769,7 +2776,7 @@ void QCoreApplication::setLibraryPaths(const QStringList &paths) // When the application is constructed it should still amend the paths. So we keep the originals // around, and even create them if they don't exist, yet. if (!coreappdata()->app_libpaths) - libraryPaths(); + libraryPathsLocked(); if (coreappdata()->manual_libpaths) *(coreappdata()->manual_libpaths) = paths; @@ -2812,7 +2819,7 @@ void QCoreApplication::addLibraryPath(const QString &path) return; } else { // make sure that library paths are initialized - libraryPaths(); + libraryPathsLocked(); QStringList *app_libpaths = coreappdata()->app_libpaths.data(); if (app_libpaths->contains(canonicalPath)) return; @@ -2851,7 +2858,7 @@ void QCoreApplication::removeLibraryPath(const QString &path) return; } else { // make sure that library paths is initialized - libraryPaths(); + libraryPathsLocked(); QStringList *app_libpaths = coreappdata()->app_libpaths.data(); if (!app_libpaths->contains(canonicalPath)) return; diff --git a/src/corelib/kernel/qcoreapplication.h b/src/corelib/kernel/qcoreapplication.h index b7df004736..71ea124fbe 100644 --- a/src/corelib/kernel/qcoreapplication.h +++ b/src/corelib/kernel/qcoreapplication.h @@ -208,6 +208,9 @@ private: static bool notifyInternal2(QObject *receiver, QEvent *); static bool forwardEvent(QObject *receiver, QEvent *event, QEvent *originatingEvent = nullptr); #endif +#if QT_CONFIG(library) + static QStringList libraryPathsLocked(); +#endif static QCoreApplication *self; -- cgit v1.2.3