locks: use once execution for on-demand initialization of globals

This makes sure that the global variables are initialized only once.
Most of those variables are initialized at ELF constructor, though a
couple of occasions they are initialized on-demand: the global keylog
file pointer and TPM2 TCTI context.  To properly protect the
initialization this patch uses gl_once provided by Gnulib.

Signed-off-by: Daiki Ueno <ueno@gnu.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/lib/locks.c b/lib/locks.c
index 3c05e4d988..146a806132 100644
--- a/lib/locks.c
+++ b/lib/locks.c
@@ -117,3 +117,12 @@ gnutls_rwlock_unlock(gnutls_rwlock_t rwlock)
 	}
 	return 0;
 }
+
+int
+gnutls_once(gnutls_once_t once, void (*init_func) (void))
+{
+	if (unlikely(glthread_once(once, init_func))) {
+		return gnutls_assert_val(GNUTLS_E_LOCKING_ERROR);
+	}
+	return 0;
+}