Merge lp:~sil2100/compiz-core/cherry_3243 into lp:compiz-core

[Łukasz Zemczak]

Cherry-picked from compiz trunk (rev 3243):
Avoid needless STL operations leading to expensive heap operations.
(LP: #1006335)

Original description:

Fixes needless list copying in event queues

[Daniel van Vugt (vanvugt)]

review: Approve

=== modified file 'src/main.cpp'
--- src/main.cpp	2012-03-08 12:37:21 +0000
+++ src/main.cpp	2012-06-21 15:42:25 +0000
@@ -172,14 +172,6 @@
     screen->priv->setDirtyPluginList ();
     screen->priv->updatePlugins ();
 
-    if (debugOutput)
-    {
-	StackDebugger::SetDefault (new StackDebugger (screen->dpy (),
-						      screen->root (),
-						      boost::bind (&PrivateScreen::queueEvents,
-								   screen->priv.get())));
-    }
-
      if (!disableSm)
      {
 	if (clientId == NULL)
 
=== modified file 'src/privatescreen.h'
--- src/privatescreen.h	2012-04-04 03:11:55 +0000
+++ src/privatescreen.h	2012-06-21 15:42:25 +0000
@@ -788,6 +788,23 @@
 
 }} // namespace compiz::private_screen
 
+class FetchXEventInterface
+{
+    public:
+
+	virtual ~FetchXEventInterface () {}
+
+	virtual bool getNextXEvent (XEvent &) = 0;
+};
+
+class FetchEventInterface
+{
+    public:
+
+	virtual ~FetchEventInterface () {}
+	virtual bool getNextEvent (XEvent &) = 0;
+};
+
 class PrivateScreen :
     public compiz::private_screen::EventManager,
     public compiz::private_screen::WindowManager,
@@ -795,7 +812,9 @@
     public compiz::private_screen::History,
     public compiz::private_screen::StartupSequence,
     public compiz::private_screen::OrphanData,
-    public compiz::private_screen::PseudoNamespace
+    public compiz::private_screen::PseudoNamespace,
+    public FetchXEventInterface,
+    public FetchEventInterface
 {
 
     public:
@@ -804,7 +823,8 @@
 
 	bool setOption (const CompString &name, CompOption::Value &value);
 
-	std::list <XEvent> queueEvents ();
+	bool getNextEvent (XEvent &);
+	bool getNextXEvent (XEvent &);
 	void processEvents ();
 
 	bool triggerButtonPressBindings (CompOption::Vector &options,
 
=== modified file 'src/privatestackdebugger.h'
--- src/privatestackdebugger.h	2011-09-29 03:29:41 +0000
+++ src/privatestackdebugger.h	2012-06-21 15:42:25 +0000
@@ -27,20 +27,23 @@
  * so that this can be come a truly standalone
  * object */
 #include <core/core.h>
+#include <list>
 
 #ifndef _COMPIZ_PRIVATESTACKDEBUGGER_H
 #define _COMPIZ_PRIVATESTACKDEBUGGER_H
 
+class FetchXEventInterface;
+
 class StackDebugger
 {
     public:
 
-	typedef std::list<XEvent> eventList;
+	typedef std::vector<XEvent> eventList;
 
-	StackDebugger (Display *, Window, boost::function<eventList ()> evProc);
+	StackDebugger (Display *, Window, FetchXEventInterface *fetchXEvent);
 	~StackDebugger ();
 
-	eventList loadStack (CompWindowList &serverWindows, bool wait = false);
+	void loadStack (CompWindowList &serverWindows, bool wait = false);
 	void windowsChanged (bool change) { mWindowsChanged = change; };
 	void serverWindowsChanged (bool change) { mServerWindowsChanged = change; };
 	bool windowsChanged () { return mWindowsChanged; }
@@ -54,6 +57,7 @@
 		       CompWindowList &serverWindows,
 		       bool verbose = false);
 	bool timedOut ();
+	bool getNextEvent (XEvent &);
 
 	bool checkSanity (CompWindowList &serverWindows, bool verbose = false);
 
@@ -70,9 +74,10 @@
 	bool         mServerWindowsChanged;
 	Window       mRoot;
 	Display      *mDpy;
-	boost::function<eventList ()> getEventsProc;
+	FetchXEventInterface *mFetchXEvent;
 	bool         mTimeoutRequired;
 	CompWindowList mLastServerWindows;
+	std::list <XEvent> mEvents;
 };
 
 #endif
 
=== modified file 'src/screen.cpp'
--- src/screen.cpp	2012-03-30 06:26:33 +0000
+++ src/screen.cpp	2012-06-21 15:42:25 +0000
@@ -742,41 +742,48 @@
     return rv;
 }
 
-std::list <XEvent>
-PrivateScreen::queueEvents ()
+bool
+PrivateScreen::getNextXEvent (XEvent &ev)
 {
-    std::list <XEvent> events;
+    if (!XEventsQueued (dpy, QueuedAlready))
+	return false;
+    XNextEvent (dpy, &ev);
 
-    while (XPending (dpy))
+    /* Skip to the last MotionNotify
+     * event in this sequence */
+    if (ev.type == MotionNotify)
     {
-	XEvent event, peekEvent;
-	XNextEvent (dpy, &event);
-
-	/* Skip to the last MotionNotify
-	 * event in this sequence */
-	if (event.type == MotionNotify)
+	XEvent peekEvent;
+	while (XPending (dpy))
 	{
-	    while (XPending (dpy))
-	    {
-		XPeekEvent (dpy, &peekEvent);
-
-		if (peekEvent.type != MotionNotify)
-		    break;
-
-		XNextEvent (dpy, &event);
-	    }
+	    XPeekEvent (dpy, &peekEvent);
+
+	    if (peekEvent.type != MotionNotify)
+		break;
+
+	    XNextEvent (dpy, &peekEvent);
 	}
-
-	events.push_back (event);
-    }
-
-    return events;
+    }
+
+    return true;
+}
+
+bool
+PrivateScreen::getNextEvent (XEvent &ev)
+{
+    StackDebugger *dbg = StackDebugger::Default ();
+
+    if (StackDebugger::Default ())
+    {
+	return dbg->getNextEvent (ev);
+    }
+    else
+	return getNextXEvent (ev);
 }
 
 void
 PrivateScreen::processEvents ()
 {
-    std::list <XEvent> events;
     StackDebugger *dbg = StackDebugger::Default ();
 
     if (isDirtyPluginList ())
@@ -801,14 +808,14 @@
     {
 	dbg->windowsChanged (false);
 	dbg->serverWindowsChanged (false);
-	events = dbg->loadStack (serverWindows);
+	dbg->loadStack (serverWindows);
     }
-    else
-	events = queueEvents ();
 
     stackIsFresh = false;
 
-    foreach (XEvent &event, events)
+    XEvent event;
+
+    while (getNextEvent (event))
     {
 	switch (event.type) {
 	case ButtonPress:
 
=== modified file 'src/stackdebugger.cpp'
--- src/stackdebugger.cpp	2011-10-07 11:45:38 +0000
+++ src/stackdebugger.cpp	2012-06-21 15:42:25 +0000
@@ -24,6 +24,7 @@
  */
 
 #include "privatestackdebugger.h"
+#include "privatescreen.h"
 #include "privatewindow.h"
 #include <poll.h>
 
@@ -47,14 +48,14 @@
     gStackDebugger = dbg;
 }
 
-StackDebugger::StackDebugger (Display *dpy, Window root, boost::function <eventList ()> evProc) :
+StackDebugger::StackDebugger (Display *dpy, Window root, FetchXEventInterface *fetchXEvent) :
     mServerNChildren (0),
     mServerChildren (NULL),
     mWindowsChanged (false),
     mServerWindowsChanged (false),
     mRoot (root),
     mDpy (dpy),
-    getEventsProc (evProc)
+    mFetchXEvent (fetchXEvent)
 {
 }
 
@@ -118,11 +119,23 @@
 	mLastServerWindows.push_front (tl);
 }
 
-StackDebugger::eventList
+bool
+StackDebugger::getNextEvent (XEvent &ev)
+{
+    if (mEvents.empty ())
+	return false;
+
+    ev = mEvents.front ();
+
+    mEvents.pop_front ();
+
+    return true;
+}
+
+void
 StackDebugger::loadStack (CompWindowList &serverWindows, bool wait)
 {
     Window rootRet, parentRet;
-    eventList events;
 
     if (mServerChildren)
 	XFree (mServerChildren);
@@ -132,7 +145,16 @@
     XQueryTree (mDpy, mRoot, &rootRet, &parentRet,
 		&mServerChildren, &mServerNChildren);
 
-    events = getEventsProc ();
+    unsigned int n = XEventsQueued (mDpy, QueuedAfterFlush);
+    mEvents.clear ();
+    mEvents.resize (n);
+    std::list <XEvent>::iterator it = mEvents.begin ();
+
+    while (it != mEvents.end ())
+    {
+	mFetchXEvent->getNextXEvent ((*it));
+	it++;
+    }
 
     XSync (mDpy, FALSE);
 
@@ -145,7 +167,6 @@
 
     if (mServerNChildren != serverWindows.size () && wait)
     {
-	eventList moreEvents;
 	struct pollfd pfd;
 
 	pfd.events = POLLIN;
@@ -154,10 +175,10 @@
 
 	poll (&pfd, 1, 300);
 
-	moreEvents = getEventsProc ();
+	XEvent e;
 
-	foreach (XEvent e, moreEvents)
-	    events.push_back (e);
+	while (mFetchXEvent->getNextXEvent (e))
+	    mEvents.push_back (e);
 
 	mTimeoutRequired = true;
     }
@@ -166,8 +187,6 @@
 
     XUngrabServer (mDpy);
     XSync (mDpy, FALSE);
-
-    return events;
 }
 
 void