From 4e8e4b78ec3b49079fd2c838a850ce27f036790a Mon Sep 17 00:00:00 2001
From: tomascz <nestorovic@seznam.cz>
Date: Sat, 25 Dec 2021 15:22:50 +0100
Subject: [PATCH] [#40] Track Map: General improvements and bugfixes (Part 24:
 Fixed concurrent access to the disk)

---
 Main/src/ViewTrackMap.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Main/src/ViewTrackMap.cpp b/Main/src/ViewTrackMap.cpp
index 57d13d77..9cb3d993 100644
--- a/Main/src/ViewTrackMap.cpp
+++ b/Main/src/ViewTrackMap.cpp
@@ -229,12 +229,19 @@
 				break;
 			const div_t d=div(trackNumber,nHeads);
 			// . scanning the Track to draw its Sector Statuses
+		{	EXCLUSIVELY_LOCK_IMAGE(*image);
+			if (!::IsWindow(pvtm->m_hWnd)) // TrackMap may not exist if, for instance, switched to another view while still scanning some Track(s)
+				continue;
 			ti.cylinder=d.quot, ti.head=d.rem;
 			//if (pvtm->displayType==TDisplayType::STATUS) // commented out because this scanning always needed
 			ti.nSectors=image->ScanTrack( ti.cylinder, ti.head, nullptr, ti.bufferId, ti.bufferLength, ti.bufferStartNanoseconds );
+		}
 			// . scanning the Track to draw its Sector data
 			if (pvtm->displayType>=TDisplayType::DATA_OK_ONLY){
 				TFdcStatus statuses[(TSector)-1];
+				EXCLUSIVELY_LOCK_IMAGE(*image);
+				if (!::IsWindow(pvtm->m_hWnd)) // TrackMap may not exist if, for instance, switched to another view while still scanning some Track(s)
+					continue;
 				image->GetTrackData( ti.cylinder, ti.head, Revolution::CURRENT, ti.bufferId, sectorIdAndPositionIdentity, ti.nSectors, ti.bufferSectorData, ti.bufferLength, statuses );
 				for( TSector n=0; n<ti.nSectors; n++ )
 					if (pvtm->displayType!=TDisplayType::DATA_ALL && !statuses[n].IsWithoutError())
@@ -638,6 +645,7 @@
 		// - disposing the RainbowPens (assuming that the FillerByte color is a stock object)
 		for( int t=TRACK_MAP_COLORS_COUNT; t--; ::DeleteObject(rainbowBrushes[t]) );
 		// - base
+		EXCLUSIVELY_LOCK_IMAGE(*IMAGE);
 		__super::OnDestroy();
 	}