Initial import of sane-backends version 1.0.24-1.2

1 files changed, 97 insertions, 0 deletions

diff --git a/include/sane/sanei_access.h b/include/sane/sanei_access.h
new file mode 100644
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+++ b/include/sane/sanei_access.h
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+/* sane - Scanner Access Now Easy.
+
+   Copyright (C) 2005 Gerhard Jaeger <gerhard@gjaeger.de>
+
+   This file is part of the SANE package.
+
+   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 of the
+   License, 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., 59 Temple Place - Suite 330, Boston,
+   MA 02111-1307, USA.
+
+   As a special exception, the authors of SANE give permission for
+   additional uses of the libraries contained in this release of SANE.
+
+   The exception is that, if you link a SANE library with other files
+   to produce an executable, this does not by itself cause the
+   resulting executable to be covered by the GNU General Public
+   License.  Your use of that executable is in no way restricted on
+   account of linking the SANE library code into it.
+
+   This exception does not, however, invalidate any other reasons why
+   the executable file might be covered by the GNU General Public
+   License.
+
+   If you submit changes to SANE to the maintainers to be included in
+   a subsequent release, you agree by submitting the changes that
+   those changes may be distributed with this exception intact.
+
+   If you write modifications of your own for SANE, it is your choice
+   whether to permit this exception to apply to your modifications.
+   If you do not wish that, delete this exception notice.
+
+*/
+
+/** @file sanei_access.h
+ *  Interface file for the sanei_access functions.
+ *
+ *  The idea is to provide some simple locking/unlocking mecanism, which
+ *  can be used to protect device access from more than one frontend 
+ *  simultaneously.
+ */
+
+#ifndef sanei_access_h
+#define sanei_access_h
+
+#include "../include/sane/config.h"
+#include "../include/sane/sane.h"
+
+/** Initialize sanei_access.
+ *
+ * This function must be called before any other sanei_access function.
+ *
+ * @param backend - backend name, who uses this lib
+ */
+extern void sanei_access_init( const char * backend );
+
+/** Set a lock.
+ *
+ * The function tries to open/create exclusively a lock file in 
+ * $PATH_SANE_LOCK_DIR.
+ * If the file could be created successfully, the function fills in the
+ * process ID.
+ * The complete filename of the lockfile is created as follows:
+ * $PATH_SANE_LOCK_DIR/LCK..&lt;devicename&gt;
+ * If the lock could not be set, the function tries it until the timeout
+ * period has been elapsed.
+ *
+ * @param devicename - unique part of the lockfile name
+ * @param timeout    - time in seconds to try to set a lock
+ * @return  
+ * - SANE_STATUS_GOOD          - if the lock has been successfully set
+ * - SANE_STATUS_ACCESS_DENIED - the lock could not set
+ */
+extern SANE_Status sanei_access_lock( const char * devicename, SANE_Word timeout );
+
+/** Unlock a previously set lock.
+ *
+ * The function tries to unlock a previously created lock. The lockfile will be
+ * closed and removed.
+ *
+ * @param devicename - part of the lockfile name, use for sanei_acess_lock()
+ * @return
+ * - SANE_STATUS_GOOD - currently the one and only return value
+ */
+extern SANE_Status sanei_access_unlock( const char * devicename );
+
+#endif /* sanei_access_h */