README change

1 files changed, 103 insertions, 0 deletions

diff --git a/gruel/src/lib/msg/msg_queue.cc b/gruel/src/lib/msg/msg_queue.cc
new file mode 100644
index 000000000..a0b120e40
--- /dev/null
+++ b/gruel/src/lib/msg/msg_queue.cc
@@ -0,0 +1,103 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2009 Free Software Foundation, Inc.
+ *
+ * This file is part of GNU Radio
+ *
+ * GNU Radio 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 3, or (at your option)
+ * any later version.
+ *
+ * GNU Radio 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 GNU Radio; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gruel/msg_queue.h>
+#include <stdexcept>
+
+using namespace pmt;
+
+namespace gruel {
+
+  msg_queue_sptr
+  make_msg_queue(unsigned int limit)
+  {
+    return msg_queue_sptr(new msg_queue(limit));
+  }
+
+  msg_queue::msg_queue(unsigned int limit)
+    : d_limit(limit)
+  {
+  }
+
+  msg_queue::~msg_queue()
+  {
+    flush();
+  }
+
+  void
+  msg_queue::insert_tail(pmt_t msg)
+  {
+    gruel::scoped_lock guard(d_mutex);
+
+    while (full_p())
+      d_not_full.wait(guard);
+
+    d_msgs.push_back(msg);
+    d_not_empty.notify_one();
+  }
+
+  pmt_t
+  msg_queue::delete_head()
+  {
+    gruel::scoped_lock guard(d_mutex);
+
+    while (empty_p())
+      d_not_empty.wait(guard);
+
+    pmt_t m(d_msgs.front());
+    d_msgs.pop_front();
+
+    if (d_limit > 0)		// Unlimited length queues never block on write
+      d_not_full.notify_one();
+
+    return m;
+  }
+
+  pmt_t
+  msg_queue::delete_head_nowait()
+  {
+    gruel::scoped_lock guard(d_mutex);
+
+    if (empty_p())
+      return pmt_t();
+
+    pmt_t m(d_msgs.front());
+    d_msgs.pop_front();
+
+    if (d_limit > 0)		// Unlimited length queues never block on write
+      d_not_full.notify_one();
+
+    return m;
+  }
+
+  void
+  msg_queue::flush()
+  {
+    while (delete_head_nowait() != pmt_t())
+      ;
+  }
+
+} /* namespace gruel */