add TLSDESC support for 32-bit arm

[musl] / src / stdio / ftrylockfile.c

diff --git a/src/stdio/ftrylockfile.c b/src/stdio/ftrylockfile.c
index eb13c83..3b97807 100644 (file)
--- a/src/stdio/ftrylockfile.c
+++ b/src/stdio/ftrylockfile.c
@@ -2,6 +2,8 @@
 #include "pthread_impl.h"
 #include <limits.h>
 
+#define MAYBE_WAITERS 0x40000000
+
 void __do_orphaned_stdio_locks()
 {
        FILE *f;
@@ -18,23 +20,29 @@ void __unlist_locked_file(FILE *f)
        }
 }
 
+void __register_locked_file(FILE *f, pthread_t self)
+{
+       f->lockcount = 1;
+       f->prev_locked = 0;
+       f->next_locked = self->stdio_locks;
+       if (f->next_locked) f->next_locked->prev_locked = f;
+       self->stdio_locks = f;
+}
+
 int ftrylockfile(FILE *f)
 {
        pthread_t self = __pthread_self();
        int tid = self->tid;
-       if (f->lock == tid) {
+       int owner = f->lock;
+       if ((owner & ~MAYBE_WAITERS) == tid) {
                if (f->lockcount == LONG_MAX)
                        return -1;
                f->lockcount++;
                return 0;
        }
-       if (f->lock < 0) f->lock = 0;
-       if (f->lock || a_cas(&f->lock, 0, tid))
+       if (owner < 0) f->lock = owner = 0;
+       if (owner || a_cas(&f->lock, 0, tid))
                return -1;
-       f->lockcount = 1;
-       f->prev_locked = 0;
-       f->next_locked = self->stdio_locks;
-       if (f->next_locked) f->next_locked->prev_locked = f;
-       self->stdio_locks = f;
+       __register_locked_file(f, self);
        return 0;
 }