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, 49 insertions, 0 deletions

diff --git a/libs/pbd/semutils.cc b/libs/pbd/semutils.cc
new file mode 100644
index 0000000000..b07b791fd0
--- /dev/null
+++ b/libs/pbd/semutils.cc
@@ -0,0 +1,49 @@
+/*
+    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.
+*/
+
+#include "pbd/semutils.h"
+#include "pbd/failed_constructor.h"
+
+using namespace PBD;
+
+ProcessSemaphore::ProcessSemaphore (const char* name, int val)
+{
+#ifdef __APPLE__
+	if ((_sem = sem_open (name, O_CREAT, 0600, val)) == (sem_t*) SEM_FAILED) {
+		throw failed_constructor ();
+	}
+
+	/* this semaphore does not exist for IPC */
+	
+	if (sem_unlink (name)) {
+		throw failed_constructor ();
+	}
+
+#else
+	if (sem_init (&sem, 0, val)) {
+		throw failed_constructor ();
+	}
+#endif
+}
+
+ProcessSemaphore::~ProcessSemaphore ()
+{
+#ifdef __APPLE__
+	sem_close (ptr_to_sem());
+#endif
+}