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authorZack Weinberg <zackw@panix.com>2017-06-08 15:39:03 -0400
committerZack Weinberg <zackw@panix.com>2017-06-08 15:39:03 -0400
commit5046dbb4a7eba5eccfd258f92f4735c9ffc8d069 (patch)
tree4470480d904b65cf14ca524f96f79eca818c3eaf /REORG.TODO/hurd/alloc-fd.c
parent199fc19d3aaaf57944ef036e15904febe877fc93 (diff)
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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).
Diffstat (limited to 'REORG.TODO/hurd/alloc-fd.c')
-rw-r--r--REORG.TODO/hurd/alloc-fd.c140
1 files changed, 140 insertions, 0 deletions
diff --git a/REORG.TODO/hurd/alloc-fd.c b/REORG.TODO/hurd/alloc-fd.c
new file mode 100644
index 0000000000..18e542ce5f
--- /dev/null
+++ b/REORG.TODO/hurd/alloc-fd.c
@@ -0,0 +1,140 @@
+/* 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/>.  */
+
+#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,
+	     and make sure it exceeds FIRST_FD.  */
+	  int size = _hurd_dtablesize * 2;
+	  if (size > rlimit)
+	    size = rlimit;
+	  else if (size <= first_fd)
+	    size = first_fd + 1;
+
+	  if (size * sizeof (*_hurd_dtable) < size)
+	    {
+	      /* Integer overflow! */
+	      errno = ENOMEM;
+	      goto out;
+	    }
+
+	  /* 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-- > first_fd);
+
+	  if (new != NULL)
+	    {
+	      /* We managed to allocate a new table.  Now install it.  */
+	      errno = save;
+	      if (first_fd < _hurd_dtablesize)
+		first_fd = _hurd_dtablesize;
+	      /* Initialize the new slots.  */
+	      for (i = _hurd_dtablesize; 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 = ENOMEM;
+	}
+      else
+	errno = EMFILE;
+    }
+  else
+    errno = EINVAL;		/* Bogus FIRST_FD value.  */
+
+ out:
+  __mutex_unlock (&_hurd_dtable_lock);
+  _hurd_critical_section_unlock (crit);
+
+  return NULL;
+}