add thread local storage macro and make gActiveTPM local to the thread

configure.ac

@@ -64,6 +64,10 @@ AC_CHECK_SIZEOF([long], 4)
 AC_CHECK_FUNCS([gethostbyname getaddrinfo gettimeofday inet_ntoa memset socket])
 AC_CHECK_LIB([network],[socket])
 
+# Thread local storage
+AX_TLS([thread_ls_on=yes],[thread_ls_on=no])
+AS_IF([test "x$thread_ls_on" = "xyes"],[AM_CFLAGS="$AM_CFLAGS -DHAVE_THREAD_LS"])
+
 # DEBUG
 DEBUG_CFLAGS="-g -O0 -DDEBUG_WOLFTPM"
 

src/tpm2.c

@@ -32,7 +32,7 @@
 /* --- Local Variables -- */
 /******************************************************************************/
 
-static TPM2_CTX* gActiveTPM;
+static THREAD_LS_T TPM2_CTX* gActiveTPM;
 #ifndef WOLFTPM2_NO_WOLFCRYPT
 static volatile int gWolfCryptRefCount = 0;
 #endif

wolftpm/tpm2_types.h

@@ -189,6 +189,21 @@ typedef int64_t  INT64;
     #define XFEOF      feof
 #endif
 
+    /* set up thread local storage if available */
+    #ifdef HAVE_THREAD_LS
+        #if defined(_MSC_VER)
+            #define THREAD_LS_T __declspec(thread)
+        /* Thread local storage only in FreeRTOS v8.2.1 and higher */
+        #elif defined(FREERTOS) || defined(FREERTOS_TCP) || \
+                                                         defined(WOLFSSL_ZEPHYR)
+            #define THREAD_LS_T
+        #else
+            #define THREAD_LS_T __thread
+        #endif
+    #else
+        #define THREAD_LS_T
+    #endif
+
 #endif /* !WOLFTPM2_NO_WOLFCRYPT */
 
 #ifndef WOLFTPM_CUSTOM_TYPES