Change atfork lock from mutex to rwlock, also make mutexes used by malloc()

module private type, when private type mutex is locked/unlocked, thread
critical region is entered or leaved. These changes makes fork()
async-signal safe which required by POSIX. Note that user's atfork handler
still needs to be async-signal safe, but it is not problem of libthr, it
is user's responsiblity.

1 files changed, 7 insertions, 0 deletions

diff --git a/lib/libthr/thread/thr_umtx.c b/lib/libthr/thread/thr_umtx.c
index b712b7a..dabfa35 100644
--- a/lib/libthr/thread/thr_umtx.c
+++ b/lib/libthr/thread/thr_umtx.c
@@ -47,6 +47,13 @@ _thr_umutex_init(struct umutex *mtx)
 	*mtx = default_mtx;
 }
 
+void
+_thr_urwlock_init(struct urwlock *rwl)
+{
+	static struct urwlock default_rwl = DEFAULT_URWLOCK;
+	*rwl = default_rwl;
+}
+
 int
 __thr_umutex_lock(struct umutex *mtx, uint32_t id)
 {