From 13cb6ad835a049370978d775da26bb63754e1a64 Mon Sep 17 00:00:00 2001
From: gb <741021719@qq.com>
Date: Wed, 18 Oct 2023 14:49:29 +0800
Subject: [PATCH] blocking during stop() call until all worker-threads exit

---
 hgdriver/hgdev/scanner_manager.cpp | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/hgdriver/hgdev/scanner_manager.cpp b/hgdriver/hgdev/scanner_manager.cpp
index bacb681..445177e 100644
--- a/hgdriver/hgdev/scanner_manager.cpp
+++ b/hgdriver/hgdev/scanner_manager.cpp
@@ -1056,7 +1056,13 @@ scanner_err hg_scanner_mgr::hg_scanner_start(scanner_handle h, void* async_event
 }
 scanner_err hg_scanner_mgr::hg_scanner_stop(scanner_handle h)
 {
-	return (scanner_err)SCAN_PTR(h)->stop();
+    scanner_err err = (scanner_err)SCAN_PTR(h)->stop();
+
+    // call from APP, block when all working-threads stopped - added on 2023-10-18 when handled double-feeding in SANE
+    while (SCAN_PTR(h)->is_running() != hg_scanner::THREAD_RUNNING_IDLE)
+        std::this_thread::sleep_for(std::chrono::milliseconds(3));
+
+    return err;
 }
 scanner_err hg_scanner_mgr::hg_scanner_get_img_info(scanner_handle h, SANE_Parameters* bmi, long len)
 {