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+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * 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.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
+ * OWNER 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.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_SUPPORT_MPSCQ_H
+#define GRPC_CORE_LIB_SUPPORT_MPSCQ_H
+
+#include <grpc/support/atm.h>
+#include <stddef.h>
+
+// Multiple-producer single-consumer lock free queue, based upon the
+// implementation from Dmitry Vyukov here:
+// http://www.1024cores.net/home/lock-free-algorithms/queues/intrusive-mpsc-node-based-queue
+
+// List node (include this in a data structure at the top, and add application
+// fields after it - to simulate inheritance)
+typedef struct gpr_mpscq_node { gpr_atm next; } gpr_mpscq_node;
+
+// Actual queue type
+typedef struct gpr_mpscq {
+  gpr_atm head;
+  // make sure head & tail don't share a cacheline
+  char padding[GPR_CACHELINE_SIZE];
+  gpr_mpscq_node *tail;
+  gpr_mpscq_node stub;
+} gpr_mpscq;
+
+void gpr_mpscq_init(gpr_mpscq *q);
+void gpr_mpscq_destroy(gpr_mpscq *q);
+// Push a node
+void gpr_mpscq_push(gpr_mpscq *q, gpr_mpscq_node *n);
+// Pop a node (returns NULL if no node is ready - which doesn't indicate that
+// the queue is empty!!)
+gpr_mpscq_node *gpr_mpscq_pop(gpr_mpscq *q);
+
+#endif /* GRPC_CORE_LIB_SUPPORT_MPSCQ_H */