Imported Upstream version 3.2.2

[debian/gnuradio] / gcell / lib / runtime / gc_jd_queue.c

diff --git a/gcell/lib/runtime/gc_jd_queue.c b/gcell/lib/runtime/gc_jd_queue.c
new file mode 100644 (file)
index 0000000..aeabd30
--- /dev/null
+++ b/gcell/lib/runtime/gc_jd_queue.c
@@ -0,0 +1,78 @@
+/* -*- c -*- */
+/*
+ * Copyright 2007 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 this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <gcell/gc_jd_queue.h>
+#include <gcell/memory_barrier.h>
+#include <mutex_init.h>
+#include <mutex_lock.h>
+#include <mutex_unlock.h>
+
+void 
+gc_jd_queue_init(gc_jd_queue_t *q)
+{
+  _mutex_init(ptr_to_ea(&q->mutex));
+  q->head = 0;
+  q->tail = 0;
+  smp_wmb();
+}
+  
+void
+gc_jd_queue_enqueue(gc_jd_queue_t *q, gc_job_desc_t *item)
+{
+  item->sys.next = 0;
+  _mutex_lock(ptr_to_ea(&q->mutex));
+  smp_rmb();           // import barrier
+
+  if (q->tail == 0){    // currently empty
+    q->tail = q->head = jdp_to_ea(item);
+  }
+  else {               // not empty, append
+    ea_to_jdp(q->tail)->sys.next = jdp_to_ea(item);
+    q->tail = jdp_to_ea(item);
+  }
+
+  smp_wmb();           // orders stores above before clearing of mutex
+  _mutex_unlock(ptr_to_ea(&q->mutex));
+}
+
+gc_job_desc_t *
+gc_jd_queue_dequeue(gc_jd_queue_t *q)
+{
+  _mutex_lock(ptr_to_ea(&q->mutex));
+  smp_rmb();           // import barrier
+  
+  gc_eaddr_t item_ea = q->head;
+  if (item_ea == 0){   // empty
+    _mutex_unlock(ptr_to_ea(&q->mutex));
+    return 0;
+  }
+
+  q->head = ea_to_jdp(item_ea)->sys.next;
+  if (q->head == 0)    // now emtpy
+    q->tail = 0;
+
+  gc_job_desc_t *item = ea_to_jdp(item_ea);
+  item->sys.next = 0;
+
+  smp_wmb();           // orders stores above before clearing of mutex
+  _mutex_unlock(ptr_to_ea(&q->mutex));
+  return item;
+}