Imported Upstream version 1.2.4

[nfs-utils.git] / support / nfs / atomicio.c

diff --git a/support/nfs/atomicio.c b/support/nfs/atomicio.c
new file mode 100644 (file)
index 0000000..5e760e6
--- /dev/null
+++ b/support/nfs/atomicio.c
@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2002 Marius Aamodt Eriksen <marius@monkey.org>
+ * Copyright (c) 1995,1999 Theo de Raadt.  All rights reserved.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/types.h>
+#include <unistd.h>
+#include <errno.h>
+
+/*
+ * ensure all of data on socket comes through. f==read || f==write
+ */
+ssize_t atomicio(ssize_t(*f) (int, void *, size_t), int fd, void *_s, size_t n)
+{
+       char *s = _s;
+       ssize_t res, pos = 0;
+
+       while ((ssize_t)n > pos) {
+               res = (f) (fd, s + pos, n - pos);
+               switch (res) {
+               case -1:
+                       if (errno == EINTR || errno == EAGAIN)
+                               continue;
+               case 0:
+                       if (pos != 0)
+                               return pos;
+                       return res;
+               default:
+                       pos += res;
+               }
+       }
+       return pos;
+}