diff --git a/examples/server/server.c b/examples/server/server.c
index bc4591b64..896d4760a 100644
--- a/examples/server/server.c
+++ b/examples/server/server.c
@@ -484,9 +484,7 @@ THREAD_RETURN CYASSL_THREAD server_test(void* args)
     int    resume = 0;
     int    resumeCount = 0;
     int    loops = 1;
-#ifdef WOLFSSL_FUNC_TIME
     int    cnt = 0;
-#endif
     int    echoData = 0;
     int    block = TEST_BUFFER_SIZE;
     int    throughput = 0;
@@ -1641,15 +1639,14 @@ THREAD_RETURN CYASSL_THREAD server_test(void* args)
         }
         resumeCount = 0;
 
-#ifdef WOLFSSL_FUNC_TIME
         cnt++;
-#endif
         if (loops > 0 && --loops == 0) {
             break;  /* out of while loop, done with normal and resume option */
         }
     } /* while(1) */
 
     WOLFSSL_TIME(cnt);
+    (void)cnt;
 
 #if defined(HAVE_CERTIFICATE_STATUS_REQUEST) \
  || defined(HAVE_CERTIFICATE_STATUS_REQUEST_V2)
diff --git a/wolfcrypt/src/logging.c b/wolfcrypt/src/logging.c
index d417a126c..0fdab2654 100644
--- a/wolfcrypt/src/logging.c
+++ b/wolfcrypt/src/logging.c
@@ -57,6 +57,10 @@ static struct wc_error_queue* wc_last_node;
 #endif
 
 #ifdef WOLFSSL_FUNC_TIME
+/* WARNING: This code is only to be used for debugging performance.
+ *          The code is not thread-safe.
+ *          Do not use WOLFSSL_FUNC_TIME in production code.
+ */
 static double wc_func_start[WC_FUNC_COUNT];
 static double wc_func_time[WC_FUNC_COUNT] = { 0, };
 static const char* wc_func_name[WC_FUNC_COUNT] = {
@@ -94,52 +98,18 @@ static const char* wc_func_name[WC_FUNC_COUNT] = {
     "DoEarlyData",
 };
 
-#if defined(WOLFSSL_USER_CURRTIME)
-    extern   double current_time(int reset);
+#include <sys/time.h>
 
-#elif defined(USE_WINDOWS_API)
+/* WARNING: This function is not portable. */
+static INLINE double current_time(int reset)
+{
+    struct timeval tv;
+    gettimeofday(&tv, 0);
+    (void)reset;
 
-    #define WIN32_LEAN_AND_MEAN
-    #include <windows.h>
-
-    static INLINE double current_time(int reset)
-    {
-        static int init = 0;
-        static LARGE_INTEGER freq;
-
-        LARGE_INTEGER count;
-
-        if (!init) {
-            QueryPerformanceFrequency(&freq);
-            init = 1;
-        }
-
-        QueryPerformanceCounter(&count);
-
-        (void)reset;
-        return (double)count.QuadPart / freq.QuadPart;
-    }
-
-#elif defined(WOLFSSL_TIRTOS)
-    extern double current_time();
-#else
-
-#if !defined(WOLFSSL_MDK_ARM) && !defined(WOLFSSL_KEIL_TCP_NET) && !defined(WOLFSSL_CHIBIOS)
-    #include <sys/time.h>
-
-    static INLINE double current_time(int reset)
-    {
-        struct timeval tv;
-        gettimeofday(&tv, 0);
-        (void)reset;
-
-        return (double)tv.tv_sec + (double)tv.tv_usec / 1000000;
-    }
-#else
-    extern double current_time(int reset);
-#endif
-#endif /* USE_WINDOWS_API */
-#endif
+    return (double)tv.tv_sec + (double)tv.tv_usec / 1000000;
+}
+#endif /* WOLFSSL_FUNC_TIME */
 
 #ifdef DEBUG_WOLFSSL
 
@@ -182,6 +152,10 @@ void wolfSSL_Debugging_OFF(void)
 }
 
 #ifdef WOLFSSL_FUNC_TIME
+/* WARNING: This code is only to be used for debugging performance.
+ *          The code is not thread-safe.
+ *          Do not use WOLFSSL_FUNC_TIME in production code.
+ */
 void WOLFSSL_START(int funcNum)
 {
     double now = current_time(0) * 1000.0;
diff --git a/wolfssl/wolfcrypt/logging.h b/wolfssl/wolfcrypt/logging.h
index dc8e31902..cbff0fa64 100644
--- a/wolfssl/wolfcrypt/logging.h
+++ b/wolfssl/wolfcrypt/logging.h
@@ -46,6 +46,10 @@ enum wc_LogLevels {
 };
 
 #ifdef WOLFSSL_FUNC_TIME
+/* WARNING: This code is only to be used for debugging performance.
+ *          The code is not thread-safe.
+ *          Do not use WOLFSSL_FUNC_TIME in production code.
+ */
 enum wc_FuncNum {
     WC_FUNC_CLIENT_HELLO_SEND = 0,
     WC_FUNC_CLIENT_HELLO_DO,
@@ -113,6 +117,10 @@ WOLFSSL_API void wolfSSL_Debugging_OFF(void);
 #endif /* OPENSSL_EXTRA || DEBUG_WOLFSSL_VERBOSE */
 
 #ifdef WOLFSSL_FUNC_TIME
+    /* WARNING: This code is only to be used for debugging performance.
+     *          The code is not thread-safe.
+     *          Do not use WOLFSSL_FUNC_TIME in production code.
+     */
     WOLFSSL_API void WOLFSSL_START(int funcNum);
     WOLFSSL_API void WOLFSSL_END(int funcNum);
     WOLFSSL_API void WOLFSSL_TIME(int count);