3 files changed, 14 insertions, 1 deletions
diff --git a/newlib/libc/include/sys/_types.h b/newlib/libc/include/sys/_types.h
index 9f3b05b39..c47a6adac 100644
--- a/newlib/libc/include/sys/_types.h
+++ b/newlib/libc/include/sys/_types.h
@@ -43,4 +43,6 @@ typedef _mbstate_t mbstate_t;
 # define WEOF (0xffffffffu)
 #endif /* __CYGWIN__ */
 
+typedef int _flock_t;
+
 #endif	/* _SYS__TYPES_H */
diff --git a/newlib/libc/include/sys/lock.h b/newlib/libc/include/sys/lock.h
index efdd7316f..984bc5f80 100644
--- a/newlib/libc/include/sys/lock.h
+++ b/newlib/libc/include/sys/lock.h
@@ -14,6 +14,8 @@ typedef int _LOCK_RECURSIVE_T;
 #define __lock_close_recursive(lock) {}
 #define __lock_acquire(lock) {}
 #define __lock_acquire_recursive(lock) {}
+#define __lock_try_acquire(lock) {}
+#define __lock_try_acquire_recursive(lock) {}
 #define __lock_release(lock) {}
 #define __lock_release_recursive(lock) {}
 
diff --git a/newlib/libc/include/sys/reent.h b/newlib/libc/include/sys/reent.h
index ebdf32a8e..09160a9fc 100644
--- a/newlib/libc/include/sys/reent.h
+++ b/newlib/libc/include/sys/reent.h
@@ -192,7 +192,11 @@ struct __sFILE {
   int	_offset;	/* current lseek offset */
 
 #ifndef _REENT_SMALL
-  struct _reent *_data;		/* Here for binary compatibility? Remove? */
+  struct _reent *_data;	/* Here for binary compatibility? Remove? */
+#endif
+
+#ifndef __SINGLE_THREAD__
+  _flock_t _lock;	/* for thread-safety locking */
 #endif
 };
 
@@ -232,8 +236,13 @@ struct __sFILE64 {
   /* Unix stdio files get aligned to block boundaries on fseek() */
   int	_blksize;	/* stat.st_blksize (may be != _bf._size) */
   int   _flags2;        /* for future use */
+
   _off64_t _offset;     /* current lseek offset */
   _fpos64_t _EXFUN((*_seek64),(_PTR _cookie, _fpos64_t _offset, int _whence));
+
+#ifndef __SINGLE_THREAD__
+  _flock_t _lock;	/* for thread-safety locking */
+#endif
 };
 typedef struct __sFILE64 __FILE;
 #else