QFilesystemWatcher: speed up the unittests

The only backend that requires longer wait times is
QPollingFileSystemWatcherEngine; lower the interval of the polling
engine for the unittests (using the same objectName() trick that is used
to force using a specific watcher engine).

Remove the comment about FAT32 filesystems, there is no where on the CI
where this test fails so far.

Before:
Totals: 23 passed, 0 failed, 0 skipped, 0 blacklisted, 127027ms

After:
Totals: 23 passed, 0 failed, 0 skipped, 0 blacklisted, 666ms

Change-Id: I96378f810463fa5c4ebdc13946ea23810e80f144
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/src/corelib/io/qfilesystemwatcher_polling.cpp b/src/corelib/io/qfilesystemwatcher_polling.cpp
index a74205b713..d34c8c49e8 100644
--- a/src/corelib/io/qfilesystemwatcher_polling.cpp
+++ b/src/corelib/io/qfilesystemwatcher_polling.cpp
@@ -3,6 +3,7 @@
 
 #include "qfilesystemwatcher_polling_p.h"
 
+#include <QtCore/qlatin1stringview.h>
 #include <QtCore/qscopeguard.h>
 #include <QtCore/qtimer.h>
 
@@ -12,6 +13,8 @@ using namespace std::chrono_literals;
 
 QT_BEGIN_NAMESPACE
 
+using namespace Qt::StringLiterals;
+
 static constexpr auto PollingInterval = 1s;
 
 QPollingFileSystemWatcherEngine::QPollingFileSystemWatcherEngine(QObject *parent)
@@ -45,10 +48,17 @@ QStringList QPollingFileSystemWatcherEngine::addPaths(const QStringList &paths,
         sg.dismiss();
     }
 
+    std::chrono::milliseconds interval = PollingInterval;
+#ifdef QT_BUILD_INTERNAL
+    if (Q_UNLIKELY(parent()->objectName().startsWith("_qt_autotest_force_engine_"_L1))) {
+        interval = 10ms; // Special case to speed up the unittests
+    }
+#endif
+
     if ((!this->files.isEmpty() ||
          !this->directories.isEmpty()) &&
         !timer.isActive()) {
-        timer.start(PollingInterval, this);
+            timer.start(interval, this);
     }
 
     return unhandled;