--- /dev/null
+/*
+ *
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_SURFACE_CHANNEL_INIT_H
+#define GRPC_CORE_LIB_SURFACE_CHANNEL_INIT_H
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/lib/channel/channel_stack_builder.h"
+#include "src/core/lib/surface/channel_stack_type.h"
+#include "src/core/lib/transport/transport.h"
+
+#define GRPC_CHANNEL_INIT_BUILTIN_PRIORITY 10000
+
+/// This module provides a way for plugins (and the grpc core library itself)
+/// to register mutators for channel stacks.
+/// It also provides a universal entry path to run those mutators to build
+/// a channel stack for various subsystems.
+
+/// One stage of mutation: call functions against \a builder to influence the
+/// finally constructed channel stack
+typedef bool (*grpc_channel_init_stage)(grpc_channel_stack_builder* builder,
+ void* arg);
+
+/// Global initialization of the system
+void grpc_channel_init_init(void);
+
+/// Register one stage of mutators.
+/// Stages are run in priority order (lowest to highest), and then in
+/// registration order (in the case of a tie).
+/// Stages are registered against one of the pre-determined channel stack
+/// types.
+/// If the channel stack type is GRPC_CLIENT_SUBCHANNEL, the caller should
+/// ensure that subchannels with different filter lists will always have
+/// different channel args. This requires setting a channel arg in case the
+/// registration function relies on some condition other than channel args to
+/// decide whether to add a filter or not.
+void grpc_channel_init_register_stage(grpc_channel_stack_type type,
+ int priority,
+ grpc_channel_init_stage stage_fn,
+ void* stage_arg);
+
+/// Finalize registration. No more calls to grpc_channel_init_register_stage are
+/// allowed.
+void grpc_channel_init_finalize(void);
+/// Shutdown the channel init system
+void grpc_channel_init_shutdown(void);
+
+/// Construct a channel stack of some sort: see channel_stack.h for details
+/// \a type is the type of channel stack to create
+/// \a prefix_bytes is the number of bytes before the channel stack to allocate
+/// \a args are configuration arguments for the channel stack
+/// \a initial_refs is the initial refcount to give the channel stack
+/// \a destroy and \a destroy_arg specify how to destroy the channel stack
+/// if destroy_arg is NULL, the returned value from this function will be
+/// substituted
+/// \a optional_transport is either NULL or a constructed transport object
+/// Returns a pointer to the base of the memory allocated (the actual channel
+/// stack object will be prefix_bytes past that pointer)
+bool grpc_channel_init_create_stack(grpc_channel_stack_builder* builder,
+ grpc_channel_stack_type type);
+
+#endif /* GRPC_CORE_LIB_SURFACE_CHANNEL_INIT_H */