freebsd: fix infinite recursion during startup

pthread_mutex_lock needs malloc under FreeBSD :<

1 files changed, 12 insertions, 2 deletions

diff --git a/mymalloc.h b/mymalloc.h
index 72cb013..4f504b7 100644
--- a/mymalloc.h
+++ b/mymalloc.h
@@ -147,9 +147,18 @@ ATTR_COLD static void atfork_child(void)
         call_rcu_after_fork_child();
 }
 
+#if defined(__GLIBC__)
+#        define FIRST_TIME 0
+#else /* pthread_mutex_lock calls malloc on FreeBSD */
+        static int once;
+#        define FIRST_TIME (uatomic_cmpxchg(&once, 0, 1))
+#endif
+
 static __attribute__((noinline)) mstate mstate_acquire_harder(void)
 {
-        CHECK(int, 0, pthread_mutex_lock(&global_mtx));
+        bool do_lock = FIRST_TIME ? false : true;
+        if (do_lock)
+                CHECK(int, 0, pthread_mutex_lock(&global_mtx));
         if (cds_list_empty(&arenas_unused)) {
                 ms_tsd = create_mspace(0, 0);
                 ms_tsd->seg.sflags = EXTERN_BIT | USE_MMAP_BIT;
@@ -163,7 +172,8 @@ static __attribute__((noinline)) mstate mstate_acquire_harder(void)
         if (!tlskey)
                 CHECK(int, 0, pthread_key_create(&tlskey, mstate_tsd_dtor));
 
-        CHECK(int, 0, pthread_mutex_unlock(&global_mtx));
+        if (do_lock)
+                CHECK(int, 0, pthread_mutex_unlock(&global_mtx));
         CHECK(int, 0, pthread_setspecific(tlskey, ms_tsd));
         return ms_tsd;
 }