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 * modification, are permitted provided that the following conditions are
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 *
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 * notice, this list of conditions and the following disclaimer.
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 * in the documentation and/or other materials provided with the
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 * this software without specific prior written permission.
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#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_H
#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_H

#include "src/core/channel/channel_stack.h"
#include "src/core/client_config/connector.h"
#include "src/core/transport/connectivity_state.h"

/** A (sub-)channel that knows how to connect to exactly one target
    address. Provides a target for load balancing. */
typedef struct grpc_subchannel grpc_subchannel;
typedef struct grpc_subchannel_call grpc_subchannel_call;
typedef struct grpc_subchannel_args grpc_subchannel_args;

#ifdef GRPC_SUBCHANNEL_REFCOUNT_DEBUG
#define GRPC_SUBCHANNEL_REF(p, r) \
  grpc_subchannel_ref((p), __FILE__, __LINE__, (r))
#define GRPC_SUBCHANNEL_UNREF(p, r, cl) \
  grpc_subchannel_unref((p), (cl), __FILE__, __LINE__, (r))
#define GRPC_SUBCHANNEL_CALL_REF(p, r) \
  grpc_subchannel_call_ref((p), __FILE__, __LINE__, (r))
#define GRPC_SUBCHANNEL_CALL_UNREF(p, r, cl) \
  grpc_subchannel_call_unref((p), (cl), __FILE__, __LINE__, (r))
#define GRPC_SUBCHANNEL_REF_EXTRA_ARGS \
  , const char *file, int line, const char *reason
#else
#define GRPC_SUBCHANNEL_REF(p, r) grpc_subchannel_ref((p))
#define GRPC_SUBCHANNEL_UNREF(p, r, cl) grpc_subchannel_unref((p), (cl))
#define GRPC_SUBCHANNEL_CALL_REF(p, r) grpc_subchannel_call_ref((p))
#define GRPC_SUBCHANNEL_CALL_UNREF(p, r, cl) \
  grpc_subchannel_call_unref((p), (cl))
#define GRPC_SUBCHANNEL_REF_EXTRA_ARGS
#endif

void grpc_subchannel_ref (grpc_subchannel * channel GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
void grpc_subchannel_unref (grpc_subchannel * channel, grpc_closure_list * closure_list GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
void grpc_subchannel_call_ref (grpc_subchannel_call * call GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
void grpc_subchannel_call_unref (grpc_subchannel_call * call, grpc_closure_list * closure_list GRPC_SUBCHANNEL_REF_EXTRA_ARGS);

/** construct a call (possibly asynchronously) */
void grpc_subchannel_create_call (grpc_exec_ctx * exec_ctx, grpc_subchannel * subchannel, grpc_pollset * pollset, grpc_subchannel_call ** target, grpc_closure * notify);

/** process a transport level op */
void grpc_subchannel_process_transport_op (grpc_exec_ctx * exec_ctx, grpc_subchannel * subchannel, grpc_transport_op * op);

/** poll the current connectivity state of a channel */
grpc_connectivity_state grpc_subchannel_check_connectivity (grpc_subchannel * channel);

/** call notify when the connectivity state of a channel changes from *state.
    Updates *state with the new state of the channel */
void grpc_subchannel_notify_on_state_change (grpc_exec_ctx * exec_ctx, grpc_subchannel * channel, grpc_connectivity_state * state, grpc_closure * notify);

/** express interest in \a channel's activities through \a pollset. */
void grpc_subchannel_add_interested_party (grpc_exec_ctx * exec_ctx, grpc_subchannel * channel, grpc_pollset * pollset);
/** stop following \a channel's activity through \a pollset. */
void grpc_subchannel_del_interested_party (grpc_exec_ctx * exec_ctx, grpc_subchannel * channel, grpc_pollset * pollset);

/** continue processing a transport op */
void grpc_subchannel_call_process_op (grpc_exec_ctx * exec_ctx, grpc_subchannel_call * subchannel_call, grpc_transport_stream_op * op);

/** continue querying for peer */
char *grpc_subchannel_call_get_peer (grpc_exec_ctx * exec_ctx, grpc_subchannel_call * subchannel_call);

struct grpc_subchannel_args
{
  /** Channel filters for this channel - wrapped factories will likely
      want to mutate this */
  const grpc_channel_filter **filters;
  /** The number of filters in the above array */
  size_t filter_count;
  /** Channel arguments to be supplied to the newly created channel */
  const grpc_channel_args *args;
  /** Address to connect to */
  struct sockaddr *addr;
  size_t addr_len;
  /** metadata context to use */
  grpc_mdctx *mdctx;
  /** master channel */
  grpc_channel *master;
};

/** create a subchannel given a connector */
grpc_subchannel *grpc_subchannel_create (grpc_connector * connector, grpc_subchannel_args * args);

#endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_H */