Add a "fork" of musl as //fusl.
This is musl verbatim at d5f8394f6ea9549607567bd92de12a2446c15614.
See http://www.musl-libc.org/.
R=kulakowski@chromium.org
Review URL: https://codereview.chromium.org/1573973002 .
diff --git a/fusl/src/stdio/ftrylockfile.c b/fusl/src/stdio/ftrylockfile.c
new file mode 100644
index 0000000..eb13c83
--- /dev/null
+++ b/fusl/src/stdio/ftrylockfile.c
@@ -0,0 +1,40 @@
+#include "stdio_impl.h"
+#include "pthread_impl.h"
+#include <limits.h>
+
+void __do_orphaned_stdio_locks()
+{
+ FILE *f;
+ for (f=__pthread_self()->stdio_locks; f; f=f->next_locked)
+ a_store(&f->lock, 0x40000000);
+}
+
+void __unlist_locked_file(FILE *f)
+{
+ if (f->lockcount) {
+ if (f->next_locked) f->next_locked->prev_locked = f->prev_locked;
+ if (f->prev_locked) f->prev_locked->next_locked = f->next_locked;
+ else __pthread_self()->stdio_locks = f->next_locked;
+ }
+}
+
+int ftrylockfile(FILE *f)
+{
+ pthread_t self = __pthread_self();
+ int tid = self->tid;
+ if (f->lock == 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))
+ 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;
+ return 0;
+}
