+# define lock_define(name) __libc_lock_define (, name)
+# define lock_init(lock) (__libc_lock_init (lock), 0)
+# define lock_fini(lock) 0
+# define lock_lock(lock) __libc_lock_lock (lock)
+# define lock_unlock(lock) __libc_lock_unlock (lock)
+#elif defined GNULIB_LOCK
+# include "glthread/lock.h"
+ /* Use gl_lock_define if empty macro arguments are known to work.
+ Otherwise, fall back on less-portable substitutes. */
+# if ((defined __GNUC__ && !defined __STRICT_ANSI__) \
+ || (defined __STDC_VERSION__ && 199901L <= __STDC_VERSION__))
+# define lock_define(name) gl_lock_define (, name)
+# elif USE_POSIX_THREADS
+# define lock_define(name) pthread_mutex_t name;
+# elif USE_PTH_THREADS
+# define lock_define(name) pth_mutex_t name;
+# elif USE_SOLARIS_THREADS
+# define lock_define(name) mutex_t name;
+# elif USE_WINDOWS_THREADS
+# define lock_define(name) gl_lock_t name;
+# else
+# define lock_define(name)
+# endif
+# define lock_init(lock) glthread_lock_init (&(lock))
+# define lock_fini(lock) glthread_lock_destroy (&(lock))
+# define lock_lock(lock) glthread_lock_lock (&(lock))
+# define lock_unlock(lock) glthread_lock_unlock (&(lock))
+#elif defined GNULIB_PTHREAD
+# include <pthread.h>
+# define lock_define(name) pthread_mutex_t name;
+# define lock_init(lock) pthread_mutex_init (&(lock), 0)
+# define lock_fini(lock) pthread_mutex_destroy (&(lock))
+# define lock_lock(lock) pthread_mutex_lock (&(lock))
+# define lock_unlock(lock) pthread_mutex_unlock (&(lock))