From 69260dd9604f39f5e7270ac44502c7e60618500b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Fri, 16 Jul 2021 16:47:15 +0200
Subject: [PATCH] shm: we may exit with busy buffers remaining (seen on KDE)

---
 render.c |  2 +-
 shm.c    | 28 +++++++++++++++++++++-------
 2 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/render.c b/render.c
index c48c515a..90fdae7b 100644
--- a/render.c
+++ b/render.c
@@ -2311,7 +2311,7 @@ grid_render(struct terminal *term)
     }
 
     else if (buf->age > 0) {
-        LOG_DBG("buffer age: %u", buf->age);
+        LOG_DBG("buffer age: %u (%p)", buf->age, (void *)buf);
 
         xassert(term->render.last_buf != NULL);
         xassert(term->render.last_buf != buf);
diff --git a/shm.c b/shm.c
index cd26c62e..87900f01 100644
--- a/shm.c
+++ b/shm.c
@@ -151,13 +151,26 @@ buffer_destroy(struct buffer_private *buf)
 void
 shm_fini(void)
 {
-    xassert(tll_length(buffers) == 0);
+    size_t busy_count UNUSED = 0;
+    size_t non_busy_count UNUSED = 0;
 
     tll_foreach(buffers, it) {
+        if (it->item.busy)
+            busy_count++;
+        else
+            non_busy_count++;
+
         buffer_destroy(&it->item);
         tll_remove(buffers, it);
     }
 
+    LOG_DBG("buffers left: busy=%zu, non-busy=%zu", busy_count, non_busy_count);
+
+    if (non_busy_count > 0) {
+        BUG("%zu non-busy buffers remaining (%zu buffers in total)",
+            non_busy_count, busy_count + non_busy_count);
+    }
+
 #if defined(MEASURE_SHM_ALLOCS) && MEASURE_SHM_ALLOCS
     LOG_INFO("max total allocations was: %zu MB", max_alloced / 1024 / 1024);
 #endif
@@ -272,8 +285,9 @@ destroy_all_purgeables(void)
         if (it->item.busy)
             continue;
 
-        LOG_DBG("cookie=%lx: purging buffer %p (width=%d, height=%d): %zu KB",
-                cookie, (void *)&it->item, it->item.width, it->item.height,
+        LOG_DBG("purging buffer %p (width=%d, height=%d): %zu KB",
+                (void *)&it->item,
+                it->item.public.width, it->item.public.height,
                 it->item.size / 1024);
 
         buffer_destroy(&it->item);
@@ -630,7 +644,7 @@ shm_scroll_forward(struct wl_shm *shm, struct buffer_private *buf, int rows,
     xassert(pool->ref_count == 1);
     xassert(pool->fd >= 0);
 
-    LOG_DBG("scrolling %d rows (%d bytes)", rows, rows * buf->stride);
+    LOG_DBG("scrolling %d rows (%d bytes)", rows, rows * buf->public.stride);
 
     const off_t diff = rows * buf->public.stride;
     xassert(rows > 0);
@@ -865,9 +879,9 @@ shm_purge(struct wl_shm *shm, unsigned long cookie)
         if (it->item.cookie != cookie)
             continue;
 
-         if (it->item.busy) {
-            LOG_WARN("deferring purge of 'busy' buffer (width=%d, height=%d)",
-                     it->item.public.width, it->item.public.height);
+        if (it->item.busy) {
+            LOG_DBG("deferring purge of 'busy' buffer (width=%d, height=%d)",
+                    it->item.public.width, it->item.public.height);
             it->item.purge = true;
         } else {
             buffer_destroy(&it->item);