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Diffstat (limited to 'src/core/channel/subchannel_call_holder.h')
| -rw-r--r-- | src/core/channel/subchannel_call_holder.h | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/src/core/channel/subchannel_call_holder.h b/src/core/channel/subchannel_call_holder.h new file mode 100644 index 0000000000..bda051c566 --- /dev/null +++ b/src/core/channel/subchannel_call_holder.h @@ -0,0 +1,98 @@ +/* + * + * Copyright 2015, 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_INTERNAL_CORE_CHANNEL_SUBCHANNEL_CALL_HOLDER_H +#define GRPC_INTERNAL_CORE_CHANNEL_SUBCHANNEL_CALL_HOLDER_H + +#include "src/core/client_config/subchannel.h" + +/** Pick a subchannel for grpc_subchannel_call_holder; + Return 1 if subchannel is available immediately (in which case on_ready + should not be called), or 0 otherwise (in which case on_ready should be + called when the subchannel is available) */ +typedef int (*grpc_subchannel_call_holder_pick_subchannel)( + grpc_exec_ctx *exec_ctx, void *arg, grpc_metadata_batch *initial_metadata, + grpc_subchannel **subchannel, grpc_closure *on_ready); + +typedef enum { + GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING, + GRPC_SUBCHANNEL_CALL_HOLDER_PICKING_SUBCHANNEL, + GRPC_SUBCHANNEL_CALL_HOLDER_CREATING_CALL +} grpc_subchannel_call_holder_creation_phase; + +/** Wrapper for holding a pointer to grpc_subchannel_call, and the + associated machinery to create such a pointer. + Handles queueing of stream ops until a call object is ready, waiting + for initial metadata before trying to create a call object, + and handling cancellation gracefully. + + Both the channel and uchannel filter use this as their call_data. */ +typedef struct grpc_subchannel_call_holder { + /** either 0 for no call, 1 for cancelled, or a pointer to a + grpc_subchannel_call */ + gpr_atm subchannel_call; + /** Helper function to choose the subchannel on which to create + the call object. Channel filter delegates to the load + balancing policy (once it's ready); uchannel returns + immediately */ + grpc_subchannel_call_holder_pick_subchannel pick_subchannel; + void *pick_subchannel_arg; + + gpr_mu mu; + + grpc_subchannel_call_holder_creation_phase creation_phase; + grpc_subchannel *subchannel; + grpc_pollset *pollset; + + grpc_transport_stream_op *waiting_ops; + size_t waiting_ops_count; + size_t waiting_ops_capacity; + + grpc_closure next_step; +} grpc_subchannel_call_holder; + +void grpc_subchannel_call_holder_init( + grpc_subchannel_call_holder *holder, + grpc_subchannel_call_holder_pick_subchannel pick_subchannel, + void *pick_subchannel_arg); +void grpc_subchannel_call_holder_destroy(grpc_exec_ctx *exec_ctx, + grpc_subchannel_call_holder *holder); + +void grpc_subchannel_call_holder_perform_op(grpc_exec_ctx *exec_ctx, + grpc_subchannel_call_holder *holder, + grpc_transport_stream_op *op); +char *grpc_subchannel_call_holder_get_peer(grpc_exec_ctx *exec_ctx, + grpc_subchannel_call_holder *holder, + grpc_channel *master); + +#endif |