added error reporting macro for invalid configuration

Author: bigbrett

examples/benchmark/tls_bench.c

@@ -78,6 +78,10 @@ Or
         #undef HAVE_PTHREAD
     #endif
 #endif
+/* Conversely, if both server and client are enabled, we must require pthreads */
+#if !defined(NO_WOLFSSL_CLIENT) && !defined(NO_WOLFSSL_SERVER) && !defined(HAVE_PTHREAD)
+    #error "pthreads must be enabled if building benchmark suite to run both client and server. Please define HAVE_PTHREAD if your platform supports it."
+#endif
 
 #ifdef HAVE_PTHREAD
     #include <pthread.h>