add some explanatory comments

dlang · Dec 12, 2014 · f4b55e9 · f4b55e9
1 parent e75225d
commit f4b55e9
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/src/core/thread.d b/src/core/thread.d
@@ -455,10 +455,13 @@ else version( Posix )
 
         }
 
-        // HACK to avoid deadlocks on FreeBSD, see Issue 13416
+        // HACK libthr internal (thr_private.h) macro, used to
+        // avoid deadlocks in signal handler, see Issue 13416
         version (FreeBSD) bool THR_IN_CRITICAL(pthread_t p) nothrow @nogc
         {
             import core.sys.posix.sys.types : c_long, lwpid_t;
+            // If the begin of pthread would be changed in libthr (unlikely)
+            // we'll run into undefined behavior, compare with thr_private.h.
             static struct pthread
             {
                 c_long tid;