Commit Diff
- Commit:
8806b6e2379372900e3d9e0bf6604bc7f727350b- From:
- Chris Down <chris@chrisdown.name>
- Via:
- Hiltjo Posthuma <hiltjo@codemadness.org>
- Date:
- Message:
- manage: propertynotify: Reduce cost of unused size hints This patch defers all size hint calculations until they are actually needed, drastically reducing the number of calls to updatesizehints(), which can be expensive when called repeatedly (as it currently is during resizes). In my unscientific testing this reduces calls to updatesizehints() by over 90% during a typical work session. There are no functional changes for users other than an increase in responsiveness after resizes and a reduction in CPU time. In slower environments or X servers, this patch also offers an improvement in responsiveness that is often tangible after resizing a client that changes hints during resizes. There are two main motivations to defer this work to the time of hint application: 1. Some clients, especially terminals using incremental size hints, resend XA_WM_NORMAL_HINTS events on resize to avoid fighting with the WM or mouse resizing. For example, some terminals like urxvt clear PBaseSize and PResizeInc during XResizeWindow and restore them afterwards. For this reason, after the resize is concluded, we typically receive a backlogged XA_WM_NORMAL_HINTS message for each update period with movement, which is useless. In some cases one may get hundreds or thousands of XA_WM_NORMAL_HINTS messages on large resizes, and currently all of these result in a separate updatesizehints() call, of which all but the final one are immediately outdated. (We can't just blindly discard these messages during resizes like we do for EnterNotify, because some of them might actually be for other windows, and may not be XA_WM_NORMAL_HINTS events.) 2. For users which use resizehints=0 most of these updates are unused anyway -- in the normal case where the client is not floating these values won't be used, so there's no need to calculate them up front. A synthetic test using the mouse to resize a floating terminal window from roughly 256x256 to 1024x1024 and back again shows that the number of calls to updatesizehints() goes from over 500 before this patch (one for each update interval with movement) to 2 after this patch (one for each hint application), with no change in user visible behaviour. This also reduces the delay before dwm is ready to process new events again after a large resize on such a client, as it avoids the thundering herd of updatesizehints() calls when hundreds of backlogged XA_WM_NORMAL_HINTS messages appear at once after a resize is finished.
- Actions:
- Patch | Tree
--- dwm.c +++ dwm.c @@ -89,7 +89,7 @@ struct Client { float mina, maxa; int x, y, w, h; int oldx, oldy, oldw, oldh; - int basew, baseh, incw, inch, maxw, maxh, minw, minh; + int basew, baseh, incw, inch, maxw, maxh, minw, minh, hintsvalid; int bw, oldbw; unsigned int tags; int isfixed, isfloating, isurgent, neverfocus, oldstate, isfullscreen; @@ -345,6 +345,8 @@ applysizehints(Client *c, int *x, int *y, int *w, int if (*w < bh) *w = bh; if (resizehints || c->isfloating || !c->mon->lt[c->mon->sellt]->arrange) { + if (!c->hintsvalid) + updatesizehints(c); /* see last two sentences in ICCCM 4.1.2.3 */ baseismin = c->basew == c->minw && c->baseh == c->minh; if (!baseismin) { /* temporarily remove base dimensions */ @@ -1059,7 +1061,6 @@ manage(Window w, XWindowAttributes *wa) XSetWindowBorder(dpy, w, scheme[SchemeNorm][ColBorder].pixel); configure(c); /* propagates border_width, if size doesn't change */ updatewindowtype(c); - updatesizehints(c); updatewmhints(c); XSelectInput(dpy, w, EnterWindowMask|FocusChangeMask|PropertyChangeMask|StructureNotifyMask); grabbuttons(c, 0); @@ -1233,7 +1234,7 @@ propertynotify(XEvent *e) arrange(c->mon); break; case XA_WM_NORMAL_HINTS: - updatesizehints(c); + c->hintsvalid = 0; break; case XA_WM_HINTS: updatewmhints(c); @@ -1989,6 +1990,7 @@ updatesizehints(Client *c) } else c->maxa = c->mina = 0.0; c->isfixed = (c->maxw && c->maxh && c->maxw == c->minw && c->maxh == c->minh); + c->hintsvalid = 1; } void