initial import

1 files changed, 127 insertions, 0 deletions

diff --git a/hurd/alloc-fd.c b/hurd/alloc-fd.c
new file mode 100644
index 0000000000..02a1bdfd52
--- /dev/null
+++ b/hurd/alloc-fd.c
@@ -0,0 +1,127 @@
+/* Copyright (C) 1994 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 Library General Public License as
+published by the Free Software Foundation; either version 2 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <hurd.h>
+#include <hurd/fd.h>
+#include <hurd/resource.h>
+#include <stdlib.h>
+#include "hurdmalloc.h"		/* XXX */
+
+/* Allocate a new file descriptor and return it, locked.  The new
+   descriptor number will be no less than FIRST_FD.  If the table is full,
+   set errno to EMFILE and return NULL.  If FIRST_FD is negative or bigger
+   than the size of the table, set errno to EINVAL and return NULL.  */
+
+struct hurd_fd *
+_hurd_alloc_fd (int *fd, int first_fd)
+{
+  int i;
+  void *crit;
+  long int rlimit;
+
+  if (first_fd < 0)
+    {
+      errno = EINVAL;
+      return NULL;
+    }
+
+  crit = _hurd_critical_section_lock ();
+
+  __mutex_lock (&_hurd_dtable_lock);
+
+ search:
+  for (i = first_fd; i < _hurd_dtablesize; ++i)
+    {
+      struct hurd_fd *d = _hurd_dtable[i];
+      if (d == NULL)
+	{
+	  /* Allocate a new descriptor structure for this slot,
+	     initializing its port cells to nil.  The test below will catch
+	     and return this descriptor cell after locking it.  */
+	  d = _hurd_new_fd (MACH_PORT_NULL, MACH_PORT_NULL);
+	  if (d == NULL)
+	    {
+	      __mutex_unlock (&_hurd_dtable_lock);
+	      _hurd_critical_section_unlock (crit);
+	      return NULL;
+	    }
+	  _hurd_dtable[i] = d;
+	}
+
+      __spin_lock (&d->port.lock);
+      if (d->port.port == MACH_PORT_NULL)
+	{
+	  __mutex_unlock (&_hurd_dtable_lock);
+	  _hurd_critical_section_unlock (crit);
+	  if (fd != NULL)
+	    *fd = i;
+	  return d;
+	}
+      else
+	__spin_unlock (&d->port.lock);
+    }
+
+  __mutex_lock (&_hurd_rlimit_lock);
+  rlimit = _hurd_rlimits[RLIMIT_OFILE].rlim_cur;
+  __mutex_unlock (&_hurd_rlimit_lock);
+
+  if (first_fd < rlimit)
+    {
+      /* The descriptor table is full.  Check if we have reached the
+	 resource limit, or only the allocated size.  */
+      if (_hurd_dtablesize < rlimit)
+	{
+	  /* Enlarge the table.  */
+	  int save = errno;
+	  struct hurd_fd **new;
+	  /* Try to double the table size (but don't exceed the limit).
+	     If there isn't any at all, give it three slots (because
+	     stdio will take that many anyway).  */
+	  int size = _hurd_dtablesize ? _hurd_dtablesize * 2 : 3;
+	  if (size > rlimit)
+	    size = rlimit;
+	  /* If we fail to allocate that, decrement the desired size
+	     until we succeed in allocating it.  */
+	  do
+	    new = realloc (_hurd_dtable, size * sizeof (*_hurd_dtable));
+	  while (new == NULL && size-- > _hurd_dtablesize);
+	  if (new != NULL)
+	    {
+	      /* We managed to allocate a new table.  Now install it.  */
+	      errno = save;
+	      first_fd = _hurd_dtablesize;
+	      /* Initialize the new slots.  */
+	      for (i = first_fd; i < size; ++i)
+		new[i] = NULL;
+	      _hurd_dtablesize = size;
+	      _hurd_dtable = new;
+	      /* Go back to the loop to initialize the first new slot.  */
+	      goto search;
+	    }
+	}
+      else
+	errno = EMFILE;
+    }
+  else
+    errno = EINVAL;		/* Bogus FIRST_FD value.  */
+
+  __mutex_unlock (&_hurd_dtable_lock);
+  _hurd_critical_section_unlock (crit);
+
+  return NULL;
+}