X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fpipe2.c;h=cd1fe56413c7048a2ce9d0f6a83a948295e9f8ef;hb=efbbfb91034a125333b7b147bc6a32170b25c890;hp=726813f9af5fc4e54c217ff9b87af84d5e21e41a;hpb=d7834f34cb055a90437b1076b2c94bad34e317b8;p=gnulib.git

diff --git a/lib/pipe2.c b/lib/pipe2.c
index 726813f9a..cd1fe5641 100644
--- 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 +23,106 @@
 #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)
 {
+  /* Mingw _pipe() corrupts fd on failure; also, if we succeed at
+     creating the pipe but later fail at changing fcntl, we want
+     to leave fd unchanged: http://austingroupbugs.net/view.php?id=467  */
+  int tmp[2];
+  tmp[0] = fd[0];
+  tmp[1] = fd[1];
+
+#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.  */
-
-# ifndef O_CLOEXEC
-#  define O_CLOEXEC 0
-# endif
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+/* Native Woe32 API.  */
 
-int
-pipe2 (int fd[2], int flags)
-{
-  /* Check the supported flags.  */
-  if ((flags & ~(O_CLOEXEC | O_NONBLOCK | O_TEXT | O_BINARY)) != 0)
+  if (_pipe (fd, 4096, flags & ~O_NONBLOCK) < 0)
     {
-      errno = EINVAL;
+      fd[0] = tmp[0];
+      fd[1] = tmp[1];
       return -1;
     }
 
+  /* 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)
+    {
+      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) == -1
-	  || (fcntl_flags = fcntl (fd[0], F_GETFL, 0)) < 0
-	  || fcntl (fd[0], F_SETFL, fcntl_flags | O_NONBLOCK) == -1)
-	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)
@@ -81,13 +130,13 @@ 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) == -1
-	  || (fcntl_flags = fcntl (fd[0], F_GETFD, 0)) < 0
-	  || fcntl (fd[0], F_SETFD, fcntl_flags | FD_CLOEXEC) == -1)
-	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 O_BINARY
   if (flags & O_BINARY)
     {
       setmode (fd[1], O_BINARY);
@@ -98,18 +147,23 @@ pipe2 (int fd[2], int flags)
       setmode (fd[1], O_TEXT);
       setmode (fd[0], O_TEXT);
     }
-#endif
+# endif
 
   return 0;
 
+#endif
+
+#if GNULIB_defined_O_NONBLOCK || \
+  !((defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__)
  fail:
   {
     int saved_errno = errno;
     close (fd[0]);
     close (fd[1]);
+    fd[0] = tmp[0];
+    fd[1] = tmp[1];
     errno = saved_errno;
     return -1;
   }
-}
-
 #endif
+}