* fhandler.h (enum del_lock_called_from): New enumeration.

	(fhandler_base::del_my_locks): Declare taking a del_lock_called_from
	as argument.
	* fhandler.cc (fhandler_base::close): Call del_my_locks with "on_close".
	(fhandler_base::fixup_after_fork): Call del_my_locks with "after_fork".
	(fhandler_base::fixup_after_exec): Call del_my_locks with "after_exec".
	* flock.cc (fhandler_base::del_my_locks): Take del_lock_called_from
	as argument.  Call node->del_my_locks with NULL handle in after_exec
	case.  Explain why.

4 files changed, 35 insertions, 7 deletions

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index e12bd85c9..e82125c1f 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,15 @@
+2009-07-21  Corinna Vinschen  <corinna@vinschen.de>
+
+	* fhandler.h (enum del_lock_called_from): New enumeration.
+	(fhandler_base::del_my_locks): Declare taking a del_lock_called_from
+	as argument.
+	* fhandler.cc (fhandler_base::close): Call del_my_locks with "on_close".
+	(fhandler_base::fixup_after_fork): Call del_my_locks with "after_fork".
+	(fhandler_base::fixup_after_exec): Call del_my_locks with "after_exec".
+	* flock.cc (fhandler_base::del_my_locks): Take del_lock_called_from
+	as argument.  Call node->del_my_locks with NULL handle in after_exec
+	case.  Explain why.
+
 2009-07-21  Eric Blake  <ebb9@byu.net>
 
 	* dtable.cc (dup2): Correct return value for no-op.
diff --git a/winsup/cygwin/fhandler.cc b/winsup/cygwin/fhandler.cc
index ffbd02ffa..9ba286ec0 100644
--- a/winsup/cygwin/fhandler.cc
+++ b/winsup/cygwin/fhandler.cc
@@ -1,7 +1,7 @@
 /* fhandler.cc.  See console.cc for fhandler_console functions.
 
    Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
-   2005, 2006, 2007, 2008 Red Hat, Inc.
+   2005, 2006, 2007, 2008, 2009 Red Hat, Inc.
 
 This file is part of Cygwin.
 
@@ -1034,7 +1034,7 @@ fhandler_base::close ()
   /* Delete all POSIX locks on the file.  Delete all flock locks on the
      file if this is the last reference to this file. */
   if (unique_id)
-    del_my_locks (false);
+    del_my_locks (on_close);
   if (nohandle () || CloseHandle (get_handle ()))
     res = 0;
   else
@@ -1359,7 +1359,7 @@ fhandler_base::fixup_after_fork (HANDLE parent)
     setup_overlapped ();
   /* POSIX locks are not inherited across fork. */
   if (unique_id)
-    del_my_locks (true);
+    del_my_locks (after_fork);
 }
 
 void
@@ -1369,7 +1369,7 @@ fhandler_base::fixup_after_exec ()
   if (get_overlapped ())
     setup_overlapped ();
   if (unique_id && close_on_exec ())
-    del_my_locks (false);
+    del_my_locks (after_exec);
 }
 
 bool
diff --git a/winsup/cygwin/fhandler.h b/winsup/cygwin/fhandler.h
index 465924190..4995d15b2 100644
--- a/winsup/cygwin/fhandler.h
+++ b/winsup/cygwin/fhandler.h
@@ -93,6 +93,12 @@ enum query_state {
   query_write_attributes = 4
 };
 
+enum del_lock_called_from {
+  on_close,
+  after_fork,
+  after_exec
+};
+
 class fhandler_base
 {
   friend class dtable;
@@ -141,7 +147,7 @@ class fhandler_base
 
   /* Used for advisory file locking.  See flock.cc.  */
   long long unique_id;
-  void del_my_locks (bool);
+  void del_my_locks (del_lock_called_from);
 
   HANDLE read_state;
   int wait_overlapped (bool, bool, DWORD *, DWORD = 0) __attribute__ ((regparm (3)));
diff --git a/winsup/cygwin/flock.cc b/winsup/cygwin/flock.cc
index 72b9ef447..92b03d51e 100644
--- a/winsup/cygwin/flock.cc
+++ b/winsup/cygwin/flock.cc
@@ -344,14 +344,24 @@ inode_t::del_my_locks (long long id, HANDLE fhdl)
    case the close_on_exec flag is set.  The whole inode is deleted as
    soon as no lock exists on it anymore. */
 void
-fhandler_base::del_my_locks (bool after_fork)
+fhandler_base::del_my_locks (del_lock_called_from from)
 {
   INODE_LIST_LOCK ();
   inode_t *node = inode_t::get (get_dev (), get_ino (), false);
   if (node)
     {
+      /* When we're called from fixup_after_exec, the fhandler is a
+	 close-on-exec fhandler.  In this case our io handle is already
+	 invalid.  We can't use it to test for the object reference count.
+	 However, that shouldn't be necessary for the following reason.
+	 After exec, there are no threads in the current process waiting for
+	 the lock.  So, either we're the only process accessing the file table
+	 entry and there are no threads which require signalling, or we have
+	 a parent process still accessing the file object and signalling the
+	 lock event would be premature. */
       bool no_locks_left =
-	node->del_my_locks (after_fork ? 0 : get_unique_id (), get_handle ());
+	node->del_my_locks (from == after_fork ? 0 : get_unique_id (),
+			    from == after_exec ? NULL : get_handle ());
       if (no_locks_left)
 	{
 	  LIST_REMOVE (node, i_next);