--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/data-provider.c	Wed Jan 22 14:45:24 2014 +0100
@@ -0,0 +1,34 @@
+#include <ansi_c.h>
+#include <userint.h>
+
+/* message buffer */
+#define DATA_PROVIDER_MSGLEN 256
+#define DATA_PROVIDER_MSGNUM 16
+static char messages[DATA_PROVIDER_MSGLEN][DATA_PROVIDER_MSGNUM];
+static unsigned int messageid = 0;
+
+/* logging function defined in main program */
+extern void logmsg(const char *frmt, ...);
+
+/* message callback */
+void CVICALLBACK MessageCB (void *msg)
+{
+	if (msg != NULL)
+		logmsg(msg);
+}
+
+void SendMessage(int threadId, const char *frmt, ...)
+{
+	/* message buffer */
+	char *message = messages[messageid++ % DATA_PROVIDER_MSGNUM];
+	
+	/* format message */
+	va_list args;
+	va_start(args, frmt);
+	vsnprintf(message, DATA_PROVIDER_MSGLEN - 1, frmt, args);
+	va_end(args);
+	
+	/* signal main thread */
+	PostDeferredCallToThread(MessageCB, message, threadId);
+}
+