Implement thread_ctrl::is_main()

Utilities/Thread.cpp

@@ -2987,3 +2987,8 @@ u64 thread_ctrl::get_tid()
 	return reinterpret_cast<u64>(pthread_self());
 #endif
 }
+
+bool thread_ctrl::is_main()
+{
+	return get_tid() == utils::main_tid;
+}

Utilities/Thread.h

@@ -342,6 +342,9 @@ public:
 	// Get thread ID (works for all threads)
 	static u64 get_tid();
 
+	// Check whether current thread is main thread (usually Qt GUI)
+	static bool is_main();
+
 private:
 	// Miscellaneous
 	static const u64 process_affinity_mask;

rpcs3/main.cpp

@@ -377,6 +377,8 @@ int main(int argc, char** argv)
 	}
 #endif
 
+	ensure(thread_ctrl::is_main());
+
 	// Initialize TSC freq (in case it isn't)
 	static_cast<void>(utils::get_tsc_freq());