改进热插拔重连判断机制

hgdriver/hgdev/scanner_manager.cpp

@@ -168,37 +168,29 @@ void hg_scanner_mgr::on_hgscanner_pnp(usb_event ev, libusb_device* device, int v
         if (index != -1)
         {
             bool add = true;
-            for (size_t i = 0; i < online_devices_.size(); ++i)
+            size_t i = 0;
+            for (; i < online_devices_.size(); ++i)
             {
-                if (online_devices_[i].dev == device)
+                if (online_devices_[i].dev == device)   // 此处假定同一台设备重新连接后，设备对象“device”保持不变；如果假设不成立，会导致设备重连消息不能正常接收，绑定到该设备的scanner对象得不到释放
                 {
                     online_devices_[i].ind = index;
                     add = false;
                     break;
                 }
-                else if (online_devices_[i].scanner && !online_devices_[i].scanner->is_online()
-                    && online_devices_[i].scanner->get_pid() == pid && online_devices_[i].scanner->get_vid() == vid)
-                {
-                    usb_io* io = NULL;
-
-                    name = online_devices_[i].display_name;
-                    type = g_supporting_devices[index].type;
-                    online_devices_[i].dev = device;
-                    h = online_devices_[i].scanner;
-                    if (pid == 0x300 || pid == 0x400)
-                        std::this_thread::sleep_for(std::chrono::milliseconds(1000));
-                    len = usb_manager::instance()->open(device, &io);
-                    if (len == SCANNER_ERR_OK)
-                    {
-                        VLOG_MINI_3(LOG_LEVEL_WARNING, "[%04x:%04x]%s re-connected.\n", pid, vid, online_devices_[i].display_name.c_str());
-                        online_devices_[i].scanner->reset_io(io);
-                        de.openned = SANE_TRUE;
             }
-                    if (io)
+            if (add)    // 处理对象“device”改变的情景
-                        io->release();
+            {
+                i = 0;
+                for (auto& v : online_devices_)
+                {
+                    if (v.ind == index &&
+                        (v.scanner == NULL || !v.scanner->is_online()))
+                    {
                         add = false;
                         break;
                     }
+                    i++;
+                }
             }
 
             if (add)
@@ -216,10 +208,35 @@ void hg_scanner_mgr::on_hgscanner_pnp(usb_event ev, libusb_device* device, int v
                     sprintf(buf, " - %u", same_ind_++);
                     ols.display_name += buf;
                 }
+                libusb_ref_device(ols.dev);         // ref to the device of queue online_devices_
                 online_devices_.push_back(ols);
                 name = ols.display_name;
                 type = g_supporting_devices[ols.ind].type;
             }
+            else if (online_devices_[i].scanner && !online_devices_[i].scanner->is_online())
+            {
+                usb_io* io = NULL;
+
+                name = online_devices_[i].display_name;
+                type = g_supporting_devices[index].type;
+                if (online_devices_[i].dev)
+                    libusb_unref_device(online_devices_[i].dev);
+                online_devices_[i].dev = device;
+                libusb_ref_device(online_devices_[i].dev);
+                h = online_devices_[i].scanner;
+                if (pid == 0x300 || pid == 0x400)
+                    std::this_thread::sleep_for(std::chrono::milliseconds(1000));
+                len = usb_manager::instance()->open(device, &io);
+                if (len == SCANNER_ERR_OK)
+                {
+                    VLOG_MINI_3(LOG_LEVEL_WARNING, "[%04x:%04x]%s re-connected.\n", pid, vid, online_devices_[i].display_name.c_str());
+                    online_devices_[i].scanner->reset_io(io);
+                    de.openned = SANE_TRUE;
+                }
+                if (io)
+                    io->release();
+                add = false;
+            }
         }
     }
     else if (ev == USB_EVENT_DEVICE_LEFT)
@@ -235,9 +252,12 @@ void hg_scanner_mgr::on_hgscanner_pnp(usb_event ev, libusb_device* device, int v
             if (it->scanner)
                 it->scanner->io_disconnected();
             else
+            {
+                libusb_unref_device(it->dev);   // unref the device of queue online_devices_
                 online_devices_.erase(it);
             }
         }
+    }
 
     if (ev_ui)
     {

hgdriver/hgdev/usb_manager.cpp

@@ -72,7 +72,7 @@ int LIBUSB_CALL usb_manager::usb_pnp_callback(libusb_context* ctx, libusb_device
     usb_manager* obj = (usb_manager*)monitor;
 
 //    if (event == LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED)
-        libusb_ref_device(device);
+        libusb_ref_device(device);  // keep the object until handle it
     //else if(event == LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT)
     //    libusb_unref_device(device);
 
@@ -236,8 +236,7 @@ void usb_manager::notify_usb_event(PNPDEV& pd, bool* retry)
             retry = &re_try;
         usb_cb_(ev, pd.dev, ud.vid, ud.pid, HIBYTE(ud.ver), LOBYTE(ud.ver) / 0x10, retry, usb_cb_param_);
     }
-    if(LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT == pd.event)
+    libusb_unref_device(pd.dev);    // response for libusb_ref_device in usb_manager::usb_pnp_callback
-        libusb_unref_device(pd.dev);
 }
 void usb_manager::thread_trigger_usb_event()
 {

hgsane/sane_hg_mdw.cpp

@@ -59,7 +59,7 @@ namespace local_utility
 		RETURN_MATCH_ERROR(SCANNER_ERR_IO, SANE_STATUS_IO_ERROR);
 		RETURN_MATCH_ERROR(SCANNER_ERR_TIMEOUT, SANE_STATUS_IO_ERROR);
 
-		RETURN_MATCH_ERROR(SCANNER_ERR_DEVICE_NOT_FOUND, SANE_STATUS_NO_DOCS);
+	//	RETURN_MATCH_ERROR(SCANNER_ERR_DEVICE_NOT_FOUND, SANE_STATUS_NO_DOCS);
 		RETURN_MATCH_ERROR(SCANNER_ERR_DEVICE_NOT_SUPPORT, SANE_STATUS_UNSUPPORTED);
 		RETURN_MATCH_ERROR(SCANNER_ERR_DEVICE_BUSY, SANE_STATUS_DEVICE_BUSY);
 		RETURN_MATCH_ERROR(SCANNER_ERR_DEVICE_COVER_OPENNED, SANE_STATUS_COVER_OPEN);