Use TLS variables to store RNG state, make RNG lockless

CHANGES

+5020.	[func]		RNG uses thread-local storage instead of locks, if
+			supported by platform. [GL #496]
+
 5019.	[cleanup]	A message is now logged when ixfr-from-differences is
 			set at zone level for an inline-signed zone. [GL #470]

lib/dns/tests/dnstest.c

@@ -161,18 +161,19 @@ dns_test_begin(FILE *logfile, bool start_managers) {
 
 void
 dns_test_end(void) {
+	cleanup_managers();
+
 	if (dst_active) {
 		dst_lib_destroy();
 		dst_active = false;
 	}
 
-	cleanup_managers();
-
 	if (lctx != NULL)
 		isc_log_destroy(&lctx);
 
 	if (mctx != NULL)
 		isc_mem_destroy(&mctx);
+
 }
 
 /*

lib/isc/random.c

@@ -62,14 +62,26 @@
  */
 #include "xoshiro128starstar.c"
 
+#if defined(HAVE_TLS)
+#if defined(HAVE_THREAD_LOCAL)
+static thread_local isc_once_t isc_random_once = ISC_ONCE_INIT;
+#elif defined(HAVE___THREAD)
+static __thread isc_once_t isc_random_once = ISC_ONCE_INIT;
+#else
+#error "Unknown method for defining a TLS variable!"
+#endif
+#else
 static isc_once_t isc_random_once = ISC_ONCE_INIT;
+#endif
 
 static void
 isc_random_initialize(void) {
 #if FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
 	memset(seed, 0, sizeof(seed));
 #else
-	isc_entropy_get(seed, sizeof(seed));
+	int useed[4] = {0,0,0,0};
+	isc_entropy_get(useed, sizeof(useed));
+	memcpy(seed, useed, sizeof(seed));
 #endif
 }
 

lib/isc/xoshiro128starstar.c

@@ -34,6 +34,19 @@
  *
  * The state must be seeded so that it is not everywhere zero.
  */
+#if defined(HAVE_TLS)
+#define _LOCK() {};
+#define _UNLOCK() {};
+
+#if defined(HAVE_THREAD_LOCAL)
+static thread_local uint32_t seed[4];
+#elif defined(HAVE___THREAD)
+static __thread uint32_t seed[4];
+#else
+#error "Unknown method for defining a TLS variable!"
+#endif
+
+#else
 #if defined(_WIN32) || defined(_WIN64)
 #include <windows.h>
 static volatile HANDLE _mutex = NULL;
@@ -65,12 +78,14 @@ static pthread_mutex_t _mutex = PTHREAD_MUTEX_INITIALIZER;
 #define _UNLOCK() pthread_mutex_unlock(&_mutex)
 #endif /* defined(_WIN32) || defined(_WIN64) */
 
+static uint32_t seed[4];
+
+#endif /* defined(HAVE_TLS) */
+
 static inline uint32_t rotl(const uint32_t x, int k) {
 	return (x << k) | (x >> (32 - k));
 }
 
-static uint32_t seed[4];
-
 static inline uint32_t
 next(void) {
 	uint32_t result_starstar, t;

lib/ns/tests/nstest.c

@@ -277,13 +277,13 @@ ns_test_begin(FILE *logfile, bool start_managers) {
 
 void
 ns_test_end(void) {
+	cleanup_managers();
+
 	if (dst_active) {
 		dst_lib_destroy();
 		dst_active = false;
 	}
 
-	cleanup_managers();
-
 	if (lctx != NULL)
 		isc_log_destroy(&lctx);