pipe2: Remove dependency on 'nonblocking' module.

[gnulib.git] / lib / pipe2.c

diff --git a/lib/pipe2.c b/lib/pipe2.c
index 68677de..f50dae6 100644 (file)
--- a/lib/pipe2.c
+++ b/lib/pipe2.c
@@ -1,5 +1,5 @@
 /* Create a pipe, with specific opening flags.
-   Copyright (C) 2009 Free Software Foundation, Inc.
+   Copyright (C) 2009-2011 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -23,57 +23,93 @@
 #include <errno.h>
 #include <fcntl.h>
 
+#include "binary-io.h"
+#include "verify.h"
+
+#if GNULIB_defined_O_NONBLOCK
+# include "nonblocking.h"
+#endif
+
 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
 /* Native Woe32 API.  */
 
 # include <io.h>
 
+#endif
+
 int
 pipe2 (int fd[2], int flags)
 {
+#if HAVE_PIPE2
+# undef pipe2
+  /* Try the system call first, if it exists.  (We may be running with a glibc
+     that has the function but with an older kernel that lacks it.)  */
+  {
+    /* Cache the information whether the system call really exists.  */
+    static int have_pipe2_really; /* 0 = unknown, 1 = yes, -1 = no */
+    if (have_pipe2_really >= 0)
+      {
+        int result = pipe2 (fd, flags);
+        if (!(result < 0 && errno == ENOSYS))
+          {
+            have_pipe2_really = 1;
+            return result;
+          }
+        have_pipe2_really = -1;
+      }
+  }
+#endif
+
   /* Check the supported flags.  */
-  if ((flags & ~(O_CLOEXEC | O_BINARY | O_TEXT)) != 0)
+  if ((flags & ~(O_CLOEXEC | O_NONBLOCK | O_BINARY | O_TEXT)) != 0)
     {
       errno = EINVAL;
       return -1;
     }
 
-  return _pipe (fd, 4096, flags);
-}
-
-#else
-/* Unix API.  */
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+/* Native Woe32 API.  */
 
-# ifndef O_CLOEXEC
-#  define O_CLOEXEC 0
-# endif
+  if (_pipe (fd, 4096, flags & ~O_NONBLOCK) < 0)
+    return -1;
 
-int
-pipe2 (int fd[2], int flags)
-{
-  /* Check the supported flags.  */
-  if ((flags & ~(O_CLOEXEC | O_NONBLOCK)) != 0)
+  /* O_NONBLOCK handling.
+     On native Windows platforms, O_NONBLOCK is defined by gnulib.  Use the
+     functions defined by the gnulib module 'nonblocking'.  */
+# if GNULIB_defined_O_NONBLOCK
+  if (flags & O_NONBLOCK)
     {
-      errno = EINVAL;
-      return -1;
+      if (set_nonblocking_flag (fd[0], true) != 0
+          || set_nonblocking_flag (fd[1], true) != 0)
+        goto fail;
     }
+# else
+  verify (O_NONBLOCK == 0);
+# endif
+
+  return 0;
+
+#else
+/* Unix API.  */
 
   if (pipe (fd) < 0)
     return -1;
 
   /* POSIX <http://www.opengroup.org/onlinepubs/9699919799/functions/pipe.html>
      says that initially, the O_NONBLOCK and FD_CLOEXEC flags are cleared on
-     both fd[0] amd fd[1].  */
+     both fd[0] and fd[1].  */
 
+  /* O_NONBLOCK handling.
+     On Unix platforms, O_NONBLOCK is defined by the system.  Use fcntl().  */
   if (flags & O_NONBLOCK)
     {
       int fcntl_flags;
 
       if ((fcntl_flags = fcntl (fd[1], F_GETFL, 0)) < 0
-         || fcntl (fd[1], F_SETFL, fcntl_flags | O_NONBLOCK) < 0
-         || (fcntl_flags = fcntl (fd[0], F_GETFL, 0)) < 0
-         || fcntl (fd[0], F_SETFL, fcntl_flags | O_NONBLOCK) < 0)
-       goto fail;
+          || fcntl (fd[1], F_SETFL, fcntl_flags | O_NONBLOCK) == -1
+          || (fcntl_flags = fcntl (fd[0], F_GETFL, 0)) < 0
+          || fcntl (fd[0], F_SETFL, fcntl_flags | O_NONBLOCK) == -1)
+        goto fail;
     }
 
   if (flags & O_CLOEXEC)
@@ -81,14 +117,29 @@ pipe2 (int fd[2], int flags)
       int fcntl_flags;
 
       if ((fcntl_flags = fcntl (fd[1], F_GETFD, 0)) < 0
-         || fcntl (fd[1], F_SETFD, fcntl_flags | FD_CLOEXEC) < 0
-         || (fcntl_flags = fcntl (fd[0], F_GETFD, 0)) < 0
-         || fcntl (fd[0], F_SETFD, fcntl_flags | FD_CLOEXEC) < 0)
-       goto fail;
+          || fcntl (fd[1], F_SETFD, fcntl_flags | FD_CLOEXEC) == -1
+          || (fcntl_flags = fcntl (fd[0], F_GETFD, 0)) < 0
+          || fcntl (fd[0], F_SETFD, fcntl_flags | FD_CLOEXEC) == -1)
+        goto fail;
     }
 
+# if O_BINARY
+  if (flags & O_BINARY)
+    {
+      setmode (fd[1], O_BINARY);
+      setmode (fd[0], O_BINARY);
+    }
+  else if (flags & O_TEXT)
+    {
+      setmode (fd[1], O_TEXT);
+      setmode (fd[0], O_TEXT);
+    }
+# endif
+
   return 0;
 
+#endif
+
  fail:
   {
     int saved_errno = errno;
@@ -98,5 +149,3 @@ pipe2 (int fd[2], int flags)
     return -1;
   }
 }
-
-#endif