imanage: propertynotify: Reduce cost of unused size hints - dwm - dynamic window manager	Err	parazyd.org	70
hgit clone https://git.parazyd.org/dwm	URL:https://git.parazyd.org/dwm	parazyd.org	70
1Log	/git/dwm/log.gph	parazyd.org	70
1Files	/git/dwm/files.gph	parazyd.org	70
1Refs	/git/dwm/refs.gph	parazyd.org	70
1README	/git/dwm/file/README.gph	parazyd.org	70
1LICENSE	/git/dwm/file/LICENSE.gph	parazyd.org	70
i---	Err	parazyd.org	70
1commit 8806b6e2379372900e3d9e0bf6604bc7f727350b	/git/dwm/commit/8806b6e2379372900e3d9e0bf6604bc7f727350b.gph	parazyd.org	70
1parent bece862a0fc4fc18ef9065b18cd28e2032d0d975	/git/dwm/commit/bece862a0fc4fc18ef9065b18cd28e2032d0d975.gph	parazyd.org	70
hAuthor: Chris Down <chris@chrisdown.name>	URL:mailto:chris@chrisdown.name	parazyd.org	70
iDate:   Thu, 17 Mar 2022 15:56:13 +0000	Err	parazyd.org	70
i	Err	parazyd.org	70
imanage: propertynotify: Reduce cost of unused size hints	Err	parazyd.org	70
i	Err	parazyd.org	70
iThis patch defers all size hint calculations until they are actually	Err	parazyd.org	70
ineeded, drastically reducing the number of calls to updatesizehints(),	Err	parazyd.org	70
iwhich can be expensive when called repeatedly (as it currently is during	Err	parazyd.org	70
iresizes).	Err	parazyd.org	70
i	Err	parazyd.org	70
iIn my unscientific testing this reduces calls to updatesizehints() by	Err	parazyd.org	70
iover 90% during a typical work session. There are no functional changes	Err	parazyd.org	70
ifor users other than an increase in responsiveness after resizes and	Err	parazyd.org	70
ia reduction in CPU time.	Err	parazyd.org	70
i	Err	parazyd.org	70
iIn slower environments or X servers, this patch also offers an	Err	parazyd.org	70
iimprovement in responsiveness that is often tangible after resizing a	Err	parazyd.org	70
iclient that changes hints during resizes.	Err	parazyd.org	70
i	Err	parazyd.org	70
iThere are two main motivations to defer this work to the time of hint	Err	parazyd.org	70
iapplication:	Err	parazyd.org	70
i	Err	parazyd.org	70
i1. Some clients, especially terminals using incremental size hints,	Err	parazyd.org	70
i   resend XA_WM_NORMAL_HINTS events on resize to avoid fighting with the	Err	parazyd.org	70
i   WM or mouse resizing. For example, some terminals like urxvt clear	Err	parazyd.org	70
i   PBaseSize and PResizeInc during XResizeWindow and restore them	Err	parazyd.org	70
i   afterwards.	Err	parazyd.org	70
i	Err	parazyd.org	70
i   For this reason, after the resize is concluded, we typically receive	Err	parazyd.org	70
i   a backlogged XA_WM_NORMAL_HINTS message for each update period with	Err	parazyd.org	70
i   movement, which is useless. In some cases one may get hundreds or	Err	parazyd.org	70
i   thousands of XA_WM_NORMAL_HINTS messages on large resizes, and	Err	parazyd.org	70
i   currently all of these result in a separate updatesizehints() call,	Err	parazyd.org	70
i   of which all but the final one are immediately outdated.	Err	parazyd.org	70
i	Err	parazyd.org	70
i   (We can't just blindly discard these messages during resizes like we	Err	parazyd.org	70
i   do for EnterNotify, because some of them might actually be for other	Err	parazyd.org	70
i   windows, and may not be XA_WM_NORMAL_HINTS events.)	Err	parazyd.org	70
i	Err	parazyd.org	70
i2. For users which use resizehints=0 most of these updates are unused	Err	parazyd.org	70
i   anyway -- in the normal case where the client is not floating these	Err	parazyd.org	70
i   values won't be used, so there's no need to calculate them up front.	Err	parazyd.org	70
i	Err	parazyd.org	70
iA synthetic test using the mouse to resize a floating terminal window	Err	parazyd.org	70
ifrom roughly 256x256 to 1024x1024 and back again shows that the number	Err	parazyd.org	70
iof calls to updatesizehints() goes from over 500 before this patch (one	Err	parazyd.org	70
ifor each update interval with movement) to 2 after this patch (one for	Err	parazyd.org	70
ieach hint application), with no change in user visible behaviour.	Err	parazyd.org	70
i	Err	parazyd.org	70
iThis also reduces the delay before dwm is ready to process new events	Err	parazyd.org	70
iagain after a large resize on such a client, as it avoids the thundering	Err	parazyd.org	70
iherd of updatesizehints() calls when hundreds of backlogged	Err	parazyd.org	70
iXA_WM_NORMAL_HINTS messages appear at once after a resize is finished.	Err	parazyd.org	70
i	Err	parazyd.org	70
iDiffstat:	Err	parazyd.org	70
i  M dwm.c                               |       8 +++++---	Err	parazyd.org	70
i	Err	parazyd.org	70
i1 file changed, 5 insertions(+), 3 deletions(-)	Err	parazyd.org	70
i---	Err	parazyd.org	70
1diff --git a/dwm.c b/dwm.c	/git/dwm/file/dwm.c.gph	parazyd.org	70
i@@ -89,7 +89,7 @@ struct Client {	Err	parazyd.org	70
i         float mina, maxa;	Err	parazyd.org	70
i         int x, y, w, h;	Err	parazyd.org	70
i         int oldx, oldy, oldw, oldh;	Err	parazyd.org	70
i-        int basew, baseh, incw, inch, maxw, maxh, minw, minh;	Err	parazyd.org	70
i+        int basew, baseh, incw, inch, maxw, maxh, minw, minh, hintsvalid;	Err	parazyd.org	70
i         int bw, oldbw;	Err	parazyd.org	70
i         unsigned int tags;	Err	parazyd.org	70
i         int isfixed, isfloating, isurgent, neverfocus, oldstate, isfullscreen;	Err	parazyd.org	70
i@@ -345,6 +345,8 @@ applysizehints(Client *c, int *x, int *y, int *w, int *h, int interact)	Err	parazyd.org	70
i         if (*w < bh)	Err	parazyd.org	70
i                 *w = bh;	Err	parazyd.org	70
i         if (resizehints || c->isfloating || !c->mon->lt[c->mon->sellt]->arrange) {	Err	parazyd.org	70
i+                if (!c->hintsvalid)	Err	parazyd.org	70
i+                        updatesizehints(c);	Err	parazyd.org	70
i                 /* see last two sentences in ICCCM 4.1.2.3 */	Err	parazyd.org	70
i                 baseismin = c->basew == c->minw && c->baseh == c->minh;	Err	parazyd.org	70
i                 if (!baseismin) { /* temporarily remove base dimensions */	Err	parazyd.org	70
i@@ -1059,7 +1061,6 @@ manage(Window w, XWindowAttributes *wa)	Err	parazyd.org	70
i         XSetWindowBorder(dpy, w, scheme[SchemeNorm][ColBorder].pixel);	Err	parazyd.org	70
i         configure(c); /* propagates border_width, if size doesn't change */	Err	parazyd.org	70
i         updatewindowtype(c);	Err	parazyd.org	70
i-        updatesizehints(c);	Err	parazyd.org	70
i         updatewmhints(c);	Err	parazyd.org	70
i         XSelectInput(dpy, w, EnterWindowMask|FocusChangeMask|PropertyChangeMask|StructureNotifyMask);	Err	parazyd.org	70
i         grabbuttons(c, 0);	Err	parazyd.org	70
i@@ -1233,7 +1234,7 @@ propertynotify(XEvent *e)	Err	parazyd.org	70
i                                 arrange(c->mon);	Err	parazyd.org	70
i                         break;	Err	parazyd.org	70
i                 case XA_WM_NORMAL_HINTS:	Err	parazyd.org	70
i-                        updatesizehints(c);	Err	parazyd.org	70
i+                        c->hintsvalid = 0;	Err	parazyd.org	70
i                         break;	Err	parazyd.org	70
i                 case XA_WM_HINTS:	Err	parazyd.org	70
i                         updatewmhints(c);	Err	parazyd.org	70
i@@ -1989,6 +1990,7 @@ updatesizehints(Client *c)	Err	parazyd.org	70
i         } else	Err	parazyd.org	70
i                 c->maxa = c->mina = 0.0;	Err	parazyd.org	70
i         c->isfixed = (c->maxw && c->maxh && c->maxw == c->minw && c->maxh == c->minh);	Err	parazyd.org	70
i+        c->hintsvalid = 1;	Err	parazyd.org	70
i }	Err	parazyd.org	70
i 	Err	parazyd.org	70
i void	Err	parazyd.org	70
.