Replace event_init() with new API if detect newer version

If we detect libevent version >= 2.0.2-alpha, change to use
event_base_new_with_config() instead of obsolete event_init() for creating new
event base. Set config flag to EVENT_BASE_FLAG_NOLOCK to avoid lock/unlock
around every libevent operation.

For newer version of libevent, the event_init() API is deprecated and is
totally unsafe for multithreaded use. By using the new API, we can explicitly
disable/enable locking on the event_base.

1 files changed, 11 insertions, 0 deletions

diff --git a/thread.c b/thread.c
index df05d5f..d17a387 100644
--- a/thread.c
+++ b/thread.c
@@ -309,7 +309,16 @@ void accept_new_conns(const bool do_accept) {
  * Set up a thread's information.
  */
 static void setup_thread(LIBEVENT_THREAD *me) {
+#if defined(LIBEVENT_VERSION_NUMBER) && LIBEVENT_VERSION_NUMBER >= 0x02000101
+    struct event_config *ev_config;
+    ev_config = event_config_new();
+    event_config_set_flag(ev_config, EVENT_BASE_FLAG_NOLOCK);
+    me->base = event_base_new_with_config(ev_config);
+    event_config_free(ev_config);
+#else
     me->base = event_init();
+#endif
+
     if (! me->base) {
         fprintf(stderr, "Can't allocate event base\n");
         exit(1);
@@ -374,6 +383,8 @@ static void *worker_libevent(void *arg) {
     register_thread_initialized();
 
     event_base_loop(me->base, 0);
+
+    event_base_free(me->base);
     return NULL;
 }