Prepare for radical source tree reorganization. zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 85 insertions, 0 deletions

diff --git a/REORG.TODO/io/lockf.c b/REORG.TODO/io/lockf.c
new file mode 100644
index 0000000000..4ab7e9357f
--- /dev/null
+++ b/REORG.TODO/io/lockf.c
@@ -0,0 +1,85 @@
+/* Copyright (C) 1994-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* We need to avoid the header declaration of lockf64, because
+   the types don't match lockf and then the compiler will
+   complain about the mismatch when we do the alias below.  */
+#define lockf64	__renamed_lockf64
+
+#include <fcntl.h>
+
+#undef	lockf64
+
+#include <sys/types.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+
+/* lockf is a simplified interface to fcntl's locking facilities.  */
+
+int
+lockf (int fd, int cmd, off_t len)
+{
+  struct flock fl;
+
+  memset ((char *) &fl, '\0', sizeof (fl));
+
+  /* lockf is always relative to the current file position.  */
+  fl.l_whence = SEEK_CUR;
+  fl.l_start = 0;
+  fl.l_len = len;
+
+  switch (cmd)
+    {
+    case F_TEST:
+      /* Test the lock: return 0 if FD is unlocked or locked by this process;
+	 return -1, set errno to EACCES, if another process holds the lock.  */
+      fl.l_type = F_RDLCK;
+      if (__fcntl (fd, F_GETLK, &fl) < 0)
+	return -1;
+      if (fl.l_type == F_UNLCK || fl.l_pid == __getpid ())
+	return 0;
+      __set_errno (EACCES);
+      return -1;
+
+    case F_ULOCK:
+      fl.l_type = F_UNLCK;
+      cmd = F_SETLK;
+      break;
+    case F_LOCK:
+      fl.l_type = F_WRLCK;
+      cmd = F_SETLKW;
+      break;
+    case F_TLOCK:
+      fl.l_type = F_WRLCK;
+      cmd = F_SETLK;
+      break;
+
+    default:
+      __set_errno (EINVAL);
+      return -1;
+    }
+
+  /* lockf() is a cancellation point but so is fcntl() if F_SETLKW is
+     used.  Therefore we don't have to care about cancellation here,
+     the fcntl() function will take care of it.  */
+  return __fcntl (fd, cmd, &fl);
+}
+
+#ifdef __OFF_T_MATCHES_OFF64_T
+weak_alias (lockf, lockf64)
+#endif