Package: emacs;
Reported by: Stefan Kangas <stefankangas <at> gmail.com>
Date: Mon, 30 Sep 2024 08:03:02 UTC
Severity: normal
View this message in rfc822 format
From: Eli Zaretskii <eliz <at> gnu.org> To: Jordan Ellis Coppard <jc+o.emacs <at> wz.ht>, Alan Third <alan <at> idiocy.org>, Gerd Möllmann <gerd.moellmann <at> gmail.com> Cc: ben <at> bensimms.moe, 73563 <at> debbugs.gnu.org Subject: bug#73563: [Ben Simms] Performance bottleneck in ns_draw_fringe_bitmap Date: Sat, 17 May 2025 12:26:26 +0300
> Cc: Ben Simms <ben <at> bensimms.moe>
> Date: Tue, 13 May 2025 20:37:55 +0900
> From: Jordan Ellis Coppard via "Bug reports for GNU Emacs,
> the Swiss army knife of text editors" <bug-gnu-emacs <at> gnu.org>
>
> Howdy,
>
>
> I've been using the following patch (bottom of this email) until my most
> recent rebuild of Emacs from master. Since the recent commit fixing
> stipple drawing the patch can be reduced to just:
> https://github.com/emacs-mirror/emacs/commit/7f2efe6503fdce2a4e552c14802644a05b581bc7
> (link to a diff authored by Ben Simms).
>
> I've now noticed again extreme slowdown when fringe bitmaps are used. It
> appears to be proportional to the number of bits set in the bitmap. An
> 'empty' bitmap (all zeroes) doesn't yield any noticeable slowdown, a
> bitmap with 1 bit set yields a little, with 2 its noticeable and with
> all 8 bits set Emacs takes up to 1 second to respond to any input at all.
>
> This has been the case since at least August of last year. I can get a
> minimal reproduction but it has happened on completely different
> configurations with the only common denominator being the NS build (on
> ARM-based macOS), and the use of fringe bitmaps.
>
> Below is trace with update_frame as the root context. Captured with
> Instruments.app (which uses dtrace and more under the hood IIRC).
>
> ns_draw_fringe_bitmap takes up 94% of the time for the short
> reproduction this trace records. The deepest the trace goes is to
> CG::Path::recalculate_bounding_box() which eats 80% of time. So instead
> of a cached value the bounding box is being recalculated every time
> which appears very expensive, but beyond that I have close to zero
> experience with macOS' graphics stack.
>
> I've just recompiled Emacs against the same commit of my recent master
> build (648453c04d9b91d96452b930c0c948b0b39b5dc0) except now with the
> patch applied (since the stipple changes are merged it's just the
> smallest subset:
> https://github.com/emacs-mirror/emacs/commit/7f2efe6503fdce2a4e552c14802644a05b581bc7)
> and once again fringe performance is back to being buttery smooth.
Alan and Gerd, any comments or suggestions?
> (trace also here in-case formatting gets borked:
> trace:
>
> 3.07 s 100.0% 0 s update_frame
> 3.06 s 100.0% 0 s update_window_tree
> 3.06 s 100.0% 1.00 ms update_window
> 2.89 s 94.2% 0 s gui_update_window_end
> 2.88 s 94.1% 0 s draw_window_fringes
> 2.88 s 93.9% 0 s draw_fringe_bitmap
> 2.88 s 93.9% 0 s draw_fringe_bitmap_1
> 2.88 s 93.9% 0 s ns_draw_fringe_bitmap
> 2.72 s 88.7% 0 s -[NSBezierPath copyWithZone:]
> 2.72 s 88.7% 0 s -[NSBezierPath _appendToPath:]
> 2.72 s 88.7% 0 s -[NSBezierPath
> _enumeratePathElementsUsingBlock:]
> 2.72 s 88.7% 0 s CGPathApplyWithBlock2
> 2.72 s 88.7% 5.00 ms CG::Path::apply(void
> (CGPathElementType, CGPoint const*, bool*) block_pointer) const
> 2.71 s 88.5% 30.00 ms
> __CGPathApplyWithBlock2_block_invoke
> 2.68 s 87.4% 11.00 ms __49-[NSBezierPath
> _enumeratePathElementsUsingBlock:]_block_invoke
> 2.48 s 80.8% 1.00 ms
> -[NSBezierPath(NSBezierPathDevicePrimitives) _deviceMoveToPoint:]
> 2.47 s 80.6% 2.00 ms CGPathMoveToPoint
> 2.46 s 80.3% 2.46 s
> CG::Path::recalculate_bounding_box()
> 5.00 ms 0.2% 4.00 ms
> CG::Path::move_to_point(CGPoint const&, CGAffineTransform const*)
> 1.00 ms 0.0% 1.00 ms
> CG::Path::convert_to_huge()
> 2.00 ms 0.1% 2.00 ms (anonymous
> namespace)::transform_is_valid(CGAffineTransform const*)
> 1.00 ms 0.0% 1.00 ms
> CG::Path::convert_to_huge()
> 1.00 ms 0.0% 1.00 ms
> CGFloatValidateWithLog
> 1.00 ms 0.0% 1.00 ms
> DYLD-STUB$$CGPathMoveToPoint
> 1.00 ms 0.0% 1.00 ms -[NSBezierPath
> _cgPath]
> 1.00 ms 0.0% 1.00 ms objc_msgSend
> 1.00 ms 0.0% 1.00 ms (anonymous
> namespace)::transform_is_valid(CGAffineTransform const*)
> 67.00 ms 2.2% 7.00 ms
> -[NSBezierPath(NSBezierPathDevicePrimitives) _deviceLineToPoint:]
> 40.00 ms 1.3% 5.00 ms
> -[NSBezierPath(NSBezierPathDevicePrimitives) _deviceClosePath]
> 39.00 ms 1.3% 2.00 ms -[NSBezierPath
> lineToPoint:]
> 14.00 ms 0.5% 14.00 ms objc_msgSend
> 6.00 ms 0.2% 6.00 ms -[NSBezierPath _cgPath]
> 5.00 ms 0.2% 5.00 ms CGPathAddLineToPoint
> 4.00 ms 0.1% 4.00 ms __30-[NSBezierPath
> _appendToPath:]_block_invoke
> 4.00 ms 0.1% 4.00 ms
> objc_msgSend$lineToPoint:
> 2.00 ms 0.1% 2.00 ms CGPathIsEmpty
> 2.00 ms 0.1% 2.00 ms
> objc_msgSend$moveToPoint:
> 2.00 ms 0.1% 2.00 ms
> CG::Path::close_subpath()
> 1.00 ms 0.0% 1.00 ms
> objc_msgSend$_deviceLineToPoint:
> 1.00 ms 0.0% 1.00 ms CGPathGetCurrentPoint
> 1.00 ms 0.0% 1.00 ms -[NSBezierPath
> moveToPoint:]
> 1.00 ms 0.0% 1.00 ms
> objc_msgSend$_deviceClosePath
> 1.00 ms 0.0% 1.00 ms objc_msgSend$closePath
> 1.00 ms 0.0% 1.00 ms
> objc_msgSend$_deviceMoveToPoint:
> 3.00 ms 0.1% 3.00 ms -[NSBezierPath
> lineToPoint:]
> 1.00 ms 0.0% 1.00 ms
> -[NSBezierPath(NSBezierPathDevicePrimitives) _deviceLineToPoint:]
> 2.00 ms 0.1% 2.00 ms __49-[NSBezierPath
> _enumeratePathElementsUsingBlock:]_block_invoke
> 1.00 ms 0.0% 1.00 ms objc_msgSend$setFlatness:
> 104.00 ms 3.4% 0 s -[NSBezierPath fill]
> 42.00 ms 1.4% 0 s -[NSBezierPath
> transformUsingAffineTransform:]
> 7.00 ms 0.2% 0 s NSRectFill
> 2.00 ms 0.1% 0 s NSColorSetWithFillAndStroke
> 1.00 ms 0.0% 1.00 ms CGContextClipToRect
> 1.00 ms 0.0% 0 s -[NSBezierPath dealloc]
> 1.00 ms 0.0% 1.00 ms CGGStateSetCompositeOperation
> 1.00 ms 0.0% 1.00 ms lookup_named_face
> 5.00 ms 0.2% 4.00 ms set_buffer_internal_2
> 1.00 ms 0.0% 0 s unblock_input
> 1.00 ms 0.0% 0 s ns_draw_window_cursor
> 121.00 ms 3.9% 0 s ns_scroll_run
> 51.00 ms 1.7% 1.00 ms update_window_line
> 4.00 ms 0.1% 4.00 ms row_equal_p
> 1.00 ms 0.0% 1.00 ms xwidget_end_redisplay
> 1.00 ms 0.0% 0 s ns_update_end
>
>
>
> Patch:
>
> --- src/nsimage.m.orig
> +++ src/nsimage.m
> @@ -28,6 +28,7 @@ Updated by Christian Limpach (chris <at> nice.ch)
> /* This should be the first include, as it may set up #defines affecting
> interpretation of even the system includes. */
> #include <config.h>
> +#include <CoreGraphics/CoreGraphics.h>
>
> #include "lisp.h"
> #include "dispextern.h"
> @@ -510,10 +511,20 @@ - (void) setAlphaAtX: (int) x Y: (int) y to:
> (unsigned char) a
> }
>
> /* Returns a pattern color, which is cached here. */
> -- (NSColor *)stippleMask
> +- (CGImageRef)stippleMask
> {
> - if (stippleMask == nil)
> - stippleMask = [[NSColor colorWithPatternImage: self] retain];
> + if (stippleMask == nil) {
> + CGDataProviderRef provider = CGDataProviderCreateWithData (NULL,
> [bmRep bitmapData],
> + [self
> sizeInBytes], NULL);
> + id mask = (id)CGImageMaskCreate(
> + [self size].width,
> + [self size].height,
> + 8, 8, [self size].width,
> + provider, NULL, 0);
> +
> + CGDataProviderRelease(provider);
> + stippleMask = (CGImageRef)[mask retain];
> + }
> return stippleMask;
> }
>
> --- src/nsterm.h.orig
> +++ src/nsterm.h
> @@ -670,7 +670,7 @@ enum ns_return_frame_mode
> {
> NSBitmapImageRep *bmRep; /* used for accessing pixel data */
> unsigned char *pixmapData[5]; /* shortcut to access pixel data */
> - NSColor *stippleMask;
> + CGImageRef stippleMask;
> @public
> NSAffineTransform *transform;
> BOOL smoothing;
> @@ -687,8 +687,8 @@ enum ns_return_frame_mode
> green: (unsigned char)g blue: (unsigned char)b
> alpha:(unsigned char)a;
> - (void)setAlphaAtX: (int)x Y: (int)y to: (unsigned char)a;
> -- (NSColor *)stippleMask;
> +- (CGImageRef)stippleMask;
> - (Lisp_Object)getMetadata;
> - (BOOL)setFrame: (unsigned int) index;
> - (void)setTransform: (double[3][3]) m;
>
> --- src/nsterm.m.orig
> +++ src/nsterm.m
> @@ -2903,22 +2903,24 @@ Hide the window (X11 semantics)
> static void
> ns_define_fringe_bitmap (int which, unsigned short *bits, int h, int w)
> {
> - NSBezierPath *p = [NSBezierPath bezierPath];
> -
> if (!fringe_bmp)
> fringe_bmp = [[NSMutableDictionary alloc] initWithCapacity:25];
>
> - [p moveToPoint:NSMakePoint (0, 0)];
>
> - for (int y = 0 ; y < h ; y++)
> - for (int x = 0 ; x < w ; x++)
> - {
> - bool bit = bits[y] & (1 << (w - x - 1));
> - if (bit)
> - [p appendBezierPathWithRect:NSMakeRect (x, y, 1, 1)];
> - }
> + for (int i = 0; i < h; i++)
> + bits[i] = ~bits[i];
> +
> + CGDataProviderRef provider = CGDataProviderCreateWithData (NULL, bits,
> + sizeof (unsigned short) * h, NULL);
> + if (provider) {
> + id p = (id)CGImageMaskCreate (w, h, 1, 1,
> + sizeof (unsigned short),
> + provider, NULL, 0);
> + CGDataProviderRelease (provider);
> +
> + [fringe_bmp setObject:p forKey:[NSNumber numberWithInt:which]];
> + }
>
> - [fringe_bmp setObject:p forKey:[NSNumber numberWithInt:which]];
> }
>
>
> @@ -2981,26 +2983,29 @@ Hide the window (X11 semantics)
> NSRectFill (clearRect);
> }
>
> - NSBezierPath *bmp = [fringe_bmp objectForKey:[NSNumber
> numberWithInt:p->which]];
> + CGImageRef bmp = (CGImageRef)[fringe_bmp objectForKey:[NSNumber
> numberWithInt:p->which]];
>
> if (bmp == nil
> && p->which < max_used_fringe_bitmap)
> {
> gui_define_fringe_bitmap (f, p->which);
> - bmp = [fringe_bmp objectForKey: [NSNumber numberWithInt: p->which]];
> + bmp = (CGImageRef)[fringe_bmp objectForKey: [NSNumber
> numberWithInt: p->which]];
> }
>
> if (bmp)
> {
> - NSAffineTransform *transform = [NSAffineTransform transform];
> - NSColor *bm_color;
> + CGRect bounds = CGRectMake (p->x, p->y - p->dh,
> + CGImageGetWidth (bmp), CGImageGetHeight (bmp));
> +
> + NSGraphicsContext *ctx = [NSGraphicsContext currentContext];
> + [ctx saveGraphicsState];
> + CGContextRef context = [ctx CGContext];
>
> - /* Because the image is defined at (0, 0) we need to take a copy
> - and then transform that copy to the new origin. */
> - bmp = [bmp copy];
> - [transform translateXBy:p->x yBy:p->y - p->dh];
> - [bmp transformUsingAffineTransform:transform];
> + CGContextTranslateCTM (context,
> + CGRectGetMinX (bounds), CGRectGetMaxY (bounds));
> + CGContextScaleCTM (context, 1, -1);
>
> + NSColor *bm_color;
> if (!p->cursor_p)
> bm_color = [NSColor colorWithUnsignedLong:face->foreground];
> else if (p->overlay_p)
> @@ -3009,9 +3014,10 @@ Hide the window (X11 semantics)
> bm_color = f->output_data.ns->cursor_color;
>
> [bm_color set];
> - [bmp fill];
> + bounds.origin = CGPointZero;
> + CGContextDrawImage (context, bounds, bmp);
>
> - [bmp release];
> + [[NSGraphicsContext currentContext] restoreGraphicsState];
> }
> ns_unfocus (f);
> }
> @@ -3273,11 +3279,10 @@ Note that CURSOR_WIDTH is meaningful only for
> (h)bar cursors.
> ns_draw_underwave (struct glyph_string *s, EmacsCGFloat width,
> EmacsCGFloat x)
> {
> int wave_height = 3, wave_length = 2;
> - int y, dx, dy, odd, xmax;
> - NSPoint a, b;
> + int y, dx, dy, xmax;
> NSRect waveClip;
>
> - dx = wave_length;
> + dx = wave_length * 2;
> dy = wave_height - 1;
> y = s->ybase - wave_height + 3;
> xmax = x + width;
> @@ -3287,25 +3292,24 @@ Note that CURSOR_WIDTH is meaningful only for
> (h)bar cursors.
> [[NSGraphicsContext currentContext] saveGraphicsState];
> NSRectClip (waveClip);
>
> - /* Draw the waves */
> - a.x = x - ((int)(x) % dx) + (EmacsCGFloat) 0.5;
> - b.x = a.x + dx;
> - odd = (int)(a.x/dx) % 2;
> - a.y = b.y = y + 0.5;
> + float ax = x - ((int)(x) % dx);
> + float ay = y + wave_height / 2.0;
>
> - if (odd)
> - a.y += dy;
> - else
> - b.y += dy;
> + NSBezierPath *path = [[NSBezierPath alloc] init];
> + [path moveToPoint: (NSPoint){ ax, ay }];
> +
> + NSPoint stepOne = { dx, 0 };
> + NSPoint controlOne = { 0.5 * dx, dy };
> + NSPoint controlTwo = { 0.5 * dx, -dy };
>
> - while (a.x <= xmax)
> + while (ax <= xmax)
> {
> - [NSBezierPath strokeLineFromPoint:a toPoint:b];
> - a.x = b.x, a.y = b.y;
> - b.x += dx, b.y = y + 0.5 + odd*dy;
> - odd = !odd;
> + [path relativeCurveToPoint:stepOne controlPoint1:controlOne
> controlPoint2:controlTwo];
> + ax += dx;
> }
>
> + [path stroke];
> +
> /* Restore previous clipping rectangle(s) */
> [[NSGraphicsContext currentContext] restoreGraphicsState];
> }
> @@ -3825,10 +3829,35 @@ Function modeled after x_draw_glyph_string_box ().
> int box_line_width = max (s->face->box_horizontal_line_width, 0);
>
> if (s->stippled_p)
> - {
> - struct ns_display_info *dpyinfo = FRAME_DISPLAY_INFO (s->f);
> - [[dpyinfo->bitmaps[face->stipple-1].img stippleMask] set];
> - goto fill;
> + {
> + [[NSColor colorWithUnsignedLong:face->background] set];
> + r = NSMakeRect (s->x, s->y + box_line_width,
> + s->background_width,
> + s->height - 2 * box_line_width);
> + NSRectFill (r);
> + s->background_filled_p = 1;
> +
> + struct ns_display_info *dpyinfo = FRAME_DISPLAY_INFO (s->f);
> + CGImageRef mask =
> + [dpyinfo->bitmaps[face->stipple - 1].img stippleMask];
> +
> + CGRect bounds = CGRectMake (s->x, s->y + box_line_width,
> + s->background_width,
> + s->height - 2 * box_line_width);
> + NSGraphicsContext *ctx = [NSGraphicsContext currentContext];
> + [ctx saveGraphicsState];
> + CGContextRef context = [ctx CGContext];
> +
> + CGContextClipToRect (context, bounds);
> +
> + CGContextScaleCTM (context, 1, -1);
> + [[NSColor colorWithUnsignedLong:face->foreground] set];
> +
> + CGRect imageSize = CGRectMake (0, 0, CGImageGetWidth (mask),
> + CGImageGetHeight (mask));
> +
> + CGContextDrawTiledImage (context, imageSize, mask);
> + [[NSGraphicsContext currentContext] restoreGraphicsState];
> }
> else if (FONT_HEIGHT (s->font) < s->height - 2 * box_line_width
> /* When xdisp.c ignores FONT_HEIGHT, we cannot trust font
> @@ -3851,7 +3880,6 @@ Function modeled after x_draw_glyph_string_box ().
> else
> [FRAME_CURSOR_COLOR (s->f) set];
>
> - fill:
> r = NSMakeRect (s->x, s->y + box_line_width,
> s->background_width,
> s->height - 2 * box_line_width);
> @@ -4175,12 +4203,42 @@ Function modeled after x_draw_glyph_string_box ().
> dpyinfo = FRAME_DISPLAY_INFO (s->f);
> if (s->hl == DRAW_CURSOR)
> [FRAME_CURSOR_COLOR (s->f) set];
> - else if (s->stippled_p)
> - [[dpyinfo->bitmaps[s->face->stipple - 1].img stippleMask] set];
> - else
> + else if (s->stippled_p) {
> + [[NSColor colorWithUnsignedLong:s->face->background]
> + set];
> + NSRectFill (
> + NSMakeRect (x, s->y, background_width, s->height));
> +
> + CGImageRef mask =
> + [dpyinfo->bitmaps[s->face->stipple - 1]
> + .img stippleMask];
> +
> + CGRect bounds
> + = CGRectMake (s->x, s->y, s->background_width,
> + s->height);
> +
> + NSGraphicsContext *ctx =
> + [NSGraphicsContext currentContext];
> + [ctx saveGraphicsState];
> + CGContextRef context = [ctx CGContext];
> + CGContextClipToRect(context, bounds);
> + CGContextScaleCTM (context, 1, -1);
> + [[NSColor colorWithUnsignedLong:s->face->foreground]
> + set];
> +
> + CGRect imageSize
> + = CGRectMake (0, 0, CGImageGetWidth (mask),
> + CGImageGetHeight (mask));
> +
> + CGContextDrawTiledImage (context, imageSize, mask);
> +
> + [[NSGraphicsContext currentContext]
> + restoreGraphicsState];
> + }
> + else {
> [[NSColor colorWithUnsignedLong: s->face->background] set];
> -
> - NSRectFill (NSMakeRect (x, s->y, background_width, s->height));
> + NSRectFill (NSMakeRect (x, s->y, background_width, s->height));
> + }
> }
> }
>
>
>
>
>
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