don't wait for thread pools unless on valgrind

r/R/arrow-package.R

@@ -82,7 +82,11 @@
 }
 
 .onUnload <- function(...) {
-  WaitForIdleThreadPool()
+  # When running valgrind we need to wait for the thread pools to finish
+  # running background tasks or else we may get spurious memory leaks reported.
+  if (on_linux_dev()) {
+    WaitForIdleThreadPool()
+  }
 }
 
 configure_tzdb <- function() {