From d7382f1df160f5d1835a776ab779cc59715d2ad7 Mon Sep 17 00:00:00 2001
From: "Michael I. Bushnell" <mib@gnu.org>
Date: Thu, 13 Jan 1994 20:30:58 +0000
Subject: Initial revision

---
 libpager/data-unlock.c | 98 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 98 insertions(+)
 create mode 100644 libpager/data-unlock.c

(limited to 'libpager/data-unlock.c')

diff --git a/libpager/data-unlock.c b/libpager/data-unlock.c
new file mode 100644
index 00000000..038a3339
--- /dev/null
+++ b/libpager/data-unlock.c
@@ -0,0 +1,98 @@
+/* Implementation of memory_object_data_unlock for pager library
+   Copyright (C) 1994 Free Software Foundation
+
+   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 the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   This program 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
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+/* Called by the kernel to request a lock on memory. */
+/* We provide all data read-write except for "holes".  Therefore,
+   lock requests should only happen for holes, and this routine does the
+   allocation.  */
+kern_return_t
+seqnos_memory_object_data_unlock (mach_port_t object, 
+			   mach_port_seqno_t seqno,
+			   mach_port_t control,
+			   vm_offset_t offset,
+			   vm_size_t length,
+			   vm_prot_t access)
+{
+  struct pager *p;
+  volatile int err;
+  struct inode *volatile ip;
+  daddr_t newblk;
+  daddr_t vblkno;
+  daddr_t *slot;
+  daddr_t *table;
+  
+  if (!(p = check_port_type (object, PT_PAGER)))
+    return EOPNOTSUPP;
+
+  mutex_lock (&p->interlock);
+  wait_for_seqno (p, seqno);
+  release_seqno (p);
+  mutex_unlock (&p->interlock);
+
+  if (p->pager_state != NORMAL)
+    {
+      printf ("pager in wrong state for unlock\n");
+      goto out;
+    }
+
+  if (control != p->memobjcntl)
+    {
+      printf ("incg data unlock: wrong control port");
+      goto out;
+    }
+  /* The only thing we ever block is writes */
+  if ((access & VM_PROT_WRITE) == 0)
+    {
+      printf ("incg data unlock: not unlock writes");
+      goto out;
+    }
+  if (offset % __vm_page_size)
+    {
+      printf ("incg data unlock: misaligned request");
+      goto out;
+    }
+  if (length != __vm_page_size)
+    {
+      printf ("incg data request: bad length size");
+      goto out;
+    }
+
+  if (shutting_down)
+    {
+      /* Let the kernel stew. */
+      return EIEIO;
+    }
+
+  err = pager_unlock_page (p->upi, offset);
+  
+  if (!err)
+    /* We can go ahead and release the lock.  */
+    lock_object (p, offset, length, MEMORY_OBJECT_RETURN_NONE, 0,
+		 VM_PROT_NONE, 0);
+  else
+    {
+      /* Flush the page, and set a bit so that m_o_data_request knows
+	 to issue an error.  */
+      lock_object (p, offset, length, MEMORY_OBJECT_RETURN_NONE, 1,
+		   VM_PROT_WRITE, 1);
+      mark_next_request_error (p, offset, length, err);
+    }
+ out:
+  done_with_port (p);
+  return 0;
+}
+
-- 
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