Add a new libevent_global_shutdown() to free all globals before exiting.

Mark Ellzey added a function libevent_shutdown() which calls a set of
private functions:

       * event_free_globals()
       * event_free_debug_globals()
       * event_free_debug_globals_locks()
       * event_free_evsig_globals()
       * evsig_free_globals()
       * evsig_free_globals_locks()
       * evutil_free_globals()
       * evutil_free_secure_rng_globals()
       * evutil_free_secure_rng_globals_lock()

Nick tweaked this libevent global shutdown code:

  - rename the function to emphasize that it's for global resources
  - write more in the doxygen
  - make function brace style consistent
  - add a missing void in a function definition.

1 files changed, 18 insertions, 0 deletions

diff --git a/evutil_rand.c b/evutil_rand.c
index 58d8bd9e..fbb0ed43 100644
--- a/evutil_rand.c
+++ b/evutil_rand.c
@@ -50,11 +50,13 @@ evutil_secure_rng_init(void)
 	(void) arc4random();
 	return 0;
 }
+#ifndef EVENT__DISABLE_THREAD_SUPPORT
 int
 evutil_secure_rng_global_setup_locks_(const int enable_locks)
 {
 	return 0;
 }
+#endif
 
 static void
 ev_arc4random_buf(void *buf, size_t n)
@@ -112,6 +114,22 @@ evutil_secure_rng_global_setup_locks_(const int enable_locks)
 }
 #endif
 
+static void
+evutil_free_secure_rng_globals_locks(void)
+{
+#ifndef EVENT__DISABLE_THREAD_SUPPORT
+	if (arc4rand_lock != NULL) {
+		EVTHREAD_FREE_LOCK(arc4rand_lock, 0);
+	}
+#endif
+	return;
+}
+void
+evutil_free_secure_rng_globals_(void) {
+{
+    evutil_free_secure_rng_globals_locks();
+}
+
 int
 evutil_secure_rng_init(void)
 {