improve perf. of VCL event dispatch
Anectodal evidence: for removal of 32 slides from 64 slide presentation,
time spent in Window::CallEventListeners has been cut down from 70% to
19% of the total time.
Change-Id: Ic8fbb44fa935f068e1b18235592dec0d7e71aec7
diff --git a/vcl/inc/window.h b/vcl/inc/window.h
index e06a6b1..302e9d0 100644
--- a/vcl/inc/window.h
+++ b/vcl/inc/window.h
@@ -201,6 +201,8 @@ public:
VclPtr<vcl::Window> mpLastFocusWindow;
VclPtr<vcl::Window> mpDlgCtrlDownWindow;
std::vector<Link<VclWindowEvent&,void>> maEventListeners;
int mnEventListenersIteratingCount;
std::set<Link<VclWindowEvent&,void>> maEventListenersDeleted;
std::vector<Link<VclWindowEvent&,void>> maChildEventListeners;
int mnChildEventListenersIteratingCount;
std::set<Link<VclWindowEvent&,void>> maChildEventListenersDeleted;
diff --git a/vcl/source/window/event.cxx b/vcl/source/window/event.cxx
index cb39104..68e822b 100644
--- a/vcl/source/window/event.cxx
+++ b/vcl/source/window/event.cxx
@@ -216,11 +216,22 @@ void Window::CallEventListeners( sal_uLong nEvent, void* pData )
{
// Copy the list, because this can be destroyed when calling a Link...
std::vector<Link<VclWindowEvent&,void>> aCopy( mpWindowImpl->maEventListeners );
// we use an iterating counter/flag and a set of deleted Link's to avoid O(n^2) behaviour
mpWindowImpl->mnEventListenersIteratingCount++;
auto& rWindowImpl = *mpWindowImpl;
comphelper::ScopeGuard aGuard(
[&rWindowImpl]()
{
rWindowImpl.mnEventListenersIteratingCount--;
if (rWindowImpl.mnEventListenersIteratingCount == 0)
rWindowImpl.maEventListenersDeleted.clear();
}
);
for ( Link<VclWindowEvent&,void>& rLink : aCopy )
{
if (xWindow->IsDisposed()) break;
// check this hasn't been removed in some re-enterancy scenario fdo#47368
if( std::find(mpWindowImpl->maEventListeners.begin(), mpWindowImpl->maEventListeners.end(), rLink) != mpWindowImpl->maEventListeners.end() )
if( rWindowImpl.maEventListenersDeleted.find(rLink) == rWindowImpl.maEventListenersDeleted.end() )
rLink.Call( aEvent );
}
}
diff --git a/vcl/source/window/window.cxx b/vcl/source/window/window.cxx
index f245c47..d1c1ffe 100644
--- a/vcl/source/window/window.cxx
+++ b/vcl/source/window/window.cxx
@@ -615,6 +615,7 @@ WindowImpl::WindowImpl( WindowType nType )
mpNextOverlap = nullptr; // next overlap window of frame
mpLastFocusWindow = nullptr; // window for focus restore
mpDlgCtrlDownWindow = nullptr; // window for dialog control
mnEventListenersIteratingCount = 0;
mnChildEventListenersIteratingCount = 0;
mpUserData = nullptr; // user data
mpCursor = nullptr; // cursor
