handle OS X's lack of unnamed semaphores, phase 1

git-svn-id: svn://localhost/ardour2/branches/3.0@8049 d708f5d6-7413-0410-9779-e7cbd77b26cf

1 files changed, 46 insertions, 0 deletions

diff --git a/libs/pbd/pbd/semutils.h b/libs/pbd/pbd/semutils.h
new file mode 100644
index 0000000000..1d4a7eb838
--- /dev/null
+++ b/libs/pbd/pbd/semutils.h
@@ -0,0 +1,46 @@
+/*
+    Copyright (C) 2010 Paul Davis
+
+    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., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#ifndef __pbd_semutils_h__
+#define __pbd_semutils_h__
+
+#include <semaphore.h>
+
+namespace PBD {
+
+class ProcessSemaphore {
+  private:
+#ifdef __APPLE__
+	sem_t* _sem;
+	sem_t* ptr_to_sem() const { return _sem; }
+#else
+	sem_t _sem;
+	sem_t* ptr_to_sem() const { return &_sem; }
+#endif
+
+  public:
+	ProcessSemaphore (const char* name, int val);
+	~ProcessSemaphore ();
+
+	int signal () { return sem_post (ptr_to_sem()); }
+	int wait () { return sem_wait (ptr_to_sem()); }
+};
+
+}
+
+#endif /* __pbd_semutils_h__ */