Changeset: 9f79c6af29bb for MonetDB
URL: https://dev.monetdb.org/hg/MonetDB/rev/9f79c6af29bb
Modified Files:
gdk/gdk_storage.c
Branch: Jul2021
Log Message:
To avoid deadlock, and also unnecessary work, try the lock, don't wait.
diffs (25 lines):
diff --git a/gdk/gdk_storage.c b/gdk/gdk_storage.c
--- a/gdk/gdk_storage.c
+++ b/gdk/gdk_storage.c
@@ -860,10 +860,17 @@ BATsave_locked(BAT *bd)
bd->tvheap->wasempty = vhs.wasempty;
bd->batCopiedtodisk = true;
DESCclean(bd);
- MT_rwlock_rdlock(&bd->thashlock);
- if (bd->thash && bd->thash != (Hash *) 1)
- BAThashsave(bd, dosync);
- MT_rwlock_rdunlock(&bd->thashlock);
+ if (MT_rwlock_rdtry(&bd->thashlock)) {
+ /* if we can't get the lock, don't bother saving
+ * the hash (normally, the hash lock should not
+ * be acquired when the heap lock has already
+ * been acquired, and here we have the heap
+ * lock, so we must be careful with the hash
+ * lock) */
+ if (bd->thash && bd->thash != (Hash *) 1)
+ BAThashsave(bd, dosync);
+ MT_rwlock_rdunlock(&bd->thashlock);
+ }
}
return err;
}
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