From 901103af3f95b0dfacc1fca77c773955b5e64f74 Mon Sep 17 00:00:00 2001
From: "Pierre-Loup A. Griffais" <git@plagman.net>
Date: Mon, 13 Jan 2020 22:09:55 -0800
Subject: [PATCH] wlserver: anti-fd exhaustion measures.

If we only take the first commit, we leave a bunch in the queue, which
makes us that much more likely to run out of FDs when importing the
myriad of buffer referenced coming from a non-vsynced client. Fixes
crashes with vblank_mode=0 glxgears after the recent changes.

We were always subject to such crashes, just getting lucky/fast before.
---
 src/steamcompmgr.c | 22 ++++++++++++----------
 src/wlserver.c     |  9 +++++++--
 2 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/src/steamcompmgr.c b/src/steamcompmgr.c
index 4b66a18..056ad76 100644
--- a/src/steamcompmgr.c
+++ b/src/steamcompmgr.c
@@ -349,6 +349,13 @@ ensure_win_resources (Display *dpy, win *w)
 			// We'll also need a copy for Vulkan to consume below.
 			
 			int fdCopy = dup( w->dmabuf_attribs.fd[0] );
+			
+			if ( fdCopy == -1 )
+			{
+				w->dmabuf_attribs_valid = False;
+				close( w->dmabuf_attribs.fd[0] );
+				return;
+			}
 
 			w->fb_id = drm_fbid_from_dmabuf( &g_DRM, &w->dmabuf_attribs );
 			assert( w->fb_id != 0 );
@@ -779,18 +786,10 @@ paint_all (Display *dpy)
 	if (drawDebugInfo)
 		paint_debug_info(dpy);
 	
-	for ( int i = 0; i < k_nMaxLayers; i++ )
+	if ( BIsNested() == false )
 	{
-		bool bHasSeenZero = false;
-		
-		if ( pipeline.layerBindings[ i ].tex == 0 )
+		if ( pipeline.layerBindings[ 0 ].fbid == 0 )
 		{
-			bHasSeenZero = true;
-		}
-		else if ( bHasSeenZero == true )
-		{
-			// We have a hole in this binding that will cause GPU crashes.
-			// TODO write compacting code here
 			return;
 		}
 	}
@@ -1635,6 +1634,9 @@ void check_new_wayland_res(void)
 					// Existing data here hasn't been consumed - need to consume the dma-buf fd
 					close(w->dmabuf_attribs.fd[0]);
 				}
+				
+				assert( newEntry.attribs.fd[0] != -1 );
+				
 				w->dmabuf_attribs = newEntry.attribs;
 				w->dmabuf_attribs_valid = True;
 				
diff --git a/src/wlserver.c b/src/wlserver.c
index b4da4c7..b085d26 100644
--- a/src/wlserver.c
+++ b/src/wlserver.c
@@ -67,9 +67,14 @@ static void xwayland_surface_role_commit(struct wlr_surface *wlr_surface) {
 	bool result = False;
 	result = wlr_texture_to_dmabuf( tex, &dmabuf_attribs );
 	
-	if (result == False)
+	assert( result == true );
+	if ( result == false || dmabuf_attribs.fd[0] == -1 )
 	{
-		//
+		struct timespec now;
+		clock_gettime(CLOCK_MONOTONIC, &now);
+		
+		wlr_surface_send_frame_done( wlr_surface, &now );
+		return;
 	}
 	
 	gpuvis_trace_printf( "xwayland_surface_role_commit wlr_surface %p\n", wlr_surface );