1 files changed, 83 insertions, 0 deletions
diff --git a/src/mercury/mercury_atomic_queue.c b/src/mercury/mercury_atomic_queue.c
new file mode 100644
index 0000000..4c6a8e2
--- /dev/null
+++ b/src/mercury/mercury_atomic_queue.c
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2013-2019 Argonne National Laboratory, Department of Energy,
+ *                    UChicago Argonne, LLC and The HDF Group.
+ * All rights reserved.
+ *
+ * The full copyright notice, including terms governing use, modification,
+ * and redistribution, is contained in the COPYING file that can be
+ * found at the root of the source code distribution tree.
+ */
+
+/* Implementation derived from:
+ * https://github.com/freebsd/freebsd/blob/master/sys/sys/buf_ring.h
+ *
+ * -
+ * Copyright (c) 2007-2009 Kip Macy <kmacy@freebsd.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ */
+
+#include "mercury_atomic_queue.h"
+#include "mercury_util_error.h"
+
+#include <stdlib.h>
+
+/****************/
+/* Local Macros */
+/****************/
+
+/* From <sys/param.h> */
+#define powerof2(x) ((((x) -1) & (x)) == 0)
+
+/*---------------------------------------------------------------------------*/
+struct hg_atomic_queue *
+hg_atomic_queue_alloc(unsigned int count)
+{
+    struct hg_atomic_queue *hg_atomic_queue = NULL;
+
+    HG_UTIL_CHECK_ERROR_NORET(
+        !powerof2(count), done, "atomic queue size must be power of 2");
+
+    hg_atomic_queue = malloc(
+        sizeof(struct hg_atomic_queue) + count * sizeof(hg_atomic_int64_t));
+    HG_UTIL_CHECK_ERROR_NORET(
+        hg_atomic_queue == NULL, done, "Could not allocate atomic queue");
+
+    hg_atomic_queue->prod_size = hg_atomic_queue->cons_size = count;
+    hg_atomic_queue->prod_mask = hg_atomic_queue->cons_mask = count - 1;
+    hg_atomic_init32(&hg_atomic_queue->prod_head, 0);
+    hg_atomic_init32(&hg_atomic_queue->cons_head, 0);
+    hg_atomic_init32(&hg_atomic_queue->prod_tail, 0);
+    hg_atomic_init32(&hg_atomic_queue->cons_tail, 0);
+
+done:
+    return hg_atomic_queue;
+}
+
+/*---------------------------------------------------------------------------*/
+void
+hg_atomic_queue_free(struct hg_atomic_queue *hg_atomic_queue)
+{
+    free(hg_atomic_queue);
+}