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--- a/src/common/rclinit.h
+++ b/src/common/rclinit.h
@@ -54,4 +54,7 @@
 // The main thread handles all signals.
 extern void recoll_threadinit();
 
+// Check if main thread
+extern bool recoll_ismainthread();
+
 #endif /* _RCLINIT_H_INCLUDED_ */