fix thread start callback prototype for Open Watcom toolchain

fix callback prototype for Windows and pthread, the Windows version does not return any value and the pthread version is a standard thread callback function (THREAD_CB) with a return value

fix callback function calling convention for Open Watcom toolchain
Open Watcom has an implementation of _beginthread for other operating systems as well, and uses a default calling convention that is not cdecl

examples/benchmark/tls_bench.c

@@ -1229,7 +1229,7 @@ static int bench_tls_client(info_t* info)
 }
 
 #if !defined(SINGLE_THREADED) && defined(WOLFSSL_THREAD_NO_JOIN)
-static THREAD_RETURN WOLFSSL_THREAD_NO_JOIN client_thread(void* args)
+static THREAD_RETURN_NOJOIN WOLFSSL_THREAD_NO_JOIN client_thread(void* args)
 {
     int ret;
     info_t* info = (info_t*)args;
@@ -1242,7 +1242,7 @@ static THREAD_RETURN WOLFSSL_THREAD_NO_JOIN client_thread(void* args)
     THREAD_CHECK_RET(wolfSSL_CondSignal(&info->to_server.cond));
     THREAD_CHECK_RET(wolfSSL_CondEnd(&info->to_server.cond));
 
-    WOLFSSL_RETURN_FROM_THREAD(0);
+    RETURN_FROM_THREAD_NOJOIN(0);
 }
 #endif /* !SINGLE_THREADED */
 #endif /* !NO_WOLFSSL_CLIENT */
@@ -1674,7 +1674,7 @@ static int bench_tls_server(info_t* info)
 }
 
 #if !defined(SINGLE_THREADED) && defined(WOLFSSL_THREAD_NO_JOIN)
-static THREAD_RETURN WOLFSSL_THREAD_NO_JOIN server_thread(void* args)
+static THREAD_RETURN_NOJOIN WOLFSSL_THREAD_NO_JOIN server_thread(void* args)
 {
     int ret = 0;
     info_t* info = (info_t*)args;
@@ -1702,7 +1702,7 @@ static THREAD_RETURN WOLFSSL_THREAD_NO_JOIN server_thread(void* args)
     THREAD_CHECK_RET(wolfSSL_CondSignal(&info->to_client.cond));
     THREAD_CHECK_RET(wolfSSL_CondEnd(&info->to_client.cond));
 
-    WOLFSSL_RETURN_FROM_THREAD(0);
+    RETURN_FROM_THREAD_NOJOIN(0);
 }
 #endif /* !SINGLE_THREADED */
 #endif /* !NO_WOLFSSL_SERVER */

wolfcrypt/src/random.c

@@ -913,7 +913,7 @@ static WC_INLINE word64 Entropy_TimeHiRes(void)
  * @param [in,out] args  Entropy data including: counter and stop flag.
  * @return  NULL always.
  */
-static THREAD_RETURN WOLFSSL_THREAD_NO_JOIN Entropy_IncCounter(void* args)
+static THREAD_RETURN_NOJOIN WOLFSSL_THREAD_NO_JOIN Entropy_IncCounter(void* args)
 {
     (void)args;
 
@@ -926,8 +926,8 @@ static THREAD_RETURN WOLFSSL_THREAD_NO_JOIN Entropy_IncCounter(void* args)
 #ifdef WOLFSSL_DEBUG_ENTROPY_MEMUSE
     fprintf(stderr, "EXITING ENTROPY COUNTER THREAD\n");
 #endif
-    /* Exit from thread. */
-    WOLFSSL_RETURN_FROM_THREAD(0);
+
+    RETURN_FROM_THREAD_NOJOIN(0);
 }
 
 /* Start a thread that increments counter if not one already.

wolfssl/wolfcrypt/types.h

@@ -1550,7 +1550,11 @@ typedef struct w64wrapper {
         #define INVALID_THREAD_VAL ((THREAD_TYPE)(INVALID_HANDLE_VALUE))
         #define WOLFSSL_THREAD __stdcall
         #if !defined(__MINGW32__)
-            #define WOLFSSL_THREAD_NO_JOIN __cdecl
+            #if defined(__WATCOMC__)
+                #define WOLFSSL_THREAD_NO_JOIN
+            #else
+                #define WOLFSSL_THREAD_NO_JOIN __cdecl
+            #endif
         #endif
     #else
         typedef unsigned int  THREAD_RETURN;
@@ -1580,17 +1584,23 @@ typedef struct w64wrapper {
          *                      to check if the value is an invalid thread
          * WOLFSSL_THREAD - attribute that should be used to declare thread
          *                  callbacks
-         * WOLFSSL_THREAD_NO_JOIN - attribute that should be used to declare
-         *                          thread callbacks that don't require cleanup
          * WOLFSSL_COND - defined if this system supports signaling
          * COND_TYPE - type that should be passed into the signaling API
          * WOLFSSL_THREAD_VOID_RETURN - defined if the thread callback has a
          *                              void return
          * WOLFSSL_RETURN_FROM_THREAD - define used to correctly return from a
          *                              thread callback
          * THREAD_CB - thread callback type for regular threading API
-         * THREAD_CB_NOJOIN - thread callback type for threading API that don't
+         *
+         * WOLFSSL_THREAD_NO_JOIN - attribute used to declare thread callbacks
+         *                          that do not require cleanup
+         * THREAD_CB_NOJOIN - thread callback type for thread APIs that do not
          *                    require cleanup
+         * THREAD_RETURN_NOJOIN - return type used to declare thread callbacks
+         *                        that do not require cleanup
+         * RETURN_FROM_THREAD_NOJOIN - define used to correctly return from
+         *                             a thread callback that do not require
+         *                             cleanup
          *
          * Other defines/types are specific for the threading implementation
          */
@@ -1613,8 +1623,16 @@ typedef struct w64wrapper {
             /* Create a thread that will be automatically cleaned up. We can't
              * return a handle/pointer to the new thread because there are no
              * guarantees for how long it will be valid. */
-            typedef THREAD_RETURN (WOLFSSL_THREAD_NO_JOIN *THREAD_CB_NOJOIN)
-                    (void* arg);
+            #if defined(WOLFSSL_PTHREADS)
+                #define THREAD_CB_NOJOIN        THREAD_CB
+                #define THREAD_RETURN_NOJOIN    THREAD_RETURN
+                #define RETURN_FROM_THREAD_NOJOIN(x) WOLFSSL_RETURN_FROM_THREAD(x)
+            #else
+                #define THREAD_RETURN_NOJOIN    void
+                typedef THREAD_RETURN_NOJOIN
+                    (WOLFSSL_THREAD_NO_JOIN *THREAD_CB_NOJOIN)(void* arg);
+                #define RETURN_FROM_THREAD_NOJOIN(x)
+            #endif
             WOLFSSL_API int wolfSSL_NewThreadNoJoin(THREAD_CB_NOJOIN cb,
                     void* arg);
         #endif