/* * * 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_CORE_LIB_CLIENT_CONFIG_LB_POLICY_H #define GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICY_H #include "src/core/lib/client_config/subchannel.h" #include "src/core/lib/transport/connectivity_state.h" /** A load balancing policy: specified by a vtable and a struct (which is expected to be extended to contain some parameters) */ typedef struct grpc_lb_policy grpc_lb_policy; typedef struct grpc_lb_policy_vtable grpc_lb_policy_vtable; typedef void (*grpc_lb_completion)(void *cb_arg, grpc_subchannel *subchannel, grpc_status_code status, const char *errmsg); struct grpc_lb_policy { const grpc_lb_policy_vtable *vtable; gpr_atm ref_pair; /* owned pointer to interested parties in load balancing decisions */ grpc_pollset_set *interested_parties; }; struct grpc_lb_policy_vtable { void (*destroy)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy); void (*shutdown)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy); /** implement grpc_lb_policy_pick */ int (*pick)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, grpc_pollset *pollset, grpc_metadata_batch *initial_metadata, grpc_connected_subchannel **target, grpc_closure *on_complete); void (*cancel_pick)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, grpc_connected_subchannel **target); void (*ping_one)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, grpc_closure *closure); /** try to enter a READY connectivity state */ void (*exit_idle)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy); /** check the current connectivity of the lb_policy */ grpc_connectivity_state (*check_connectivity)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy); /** call notify when the connectivity state of a channel changes from *state. Updates *state with the new state of the policy */ void (*notify_on_state_change)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, grpc_connectivity_state *state, grpc_closure *closure); }; /*#define GRPC_LB_POLICY_REFCOUNT_DEBUG*/ #ifdef GRPC_LB_POLICY_REFCOUNT_DEBUG #define GRPC_LB_POLICY_REF(p, r) \ grpc_lb_policy_ref((p), __FILE__, __LINE__, (r)) #define GRPC_LB_POLICY_UNREF(exec_ctx, p, r) \ grpc_lb_policy_unref((exec_ctx), (p), __FILE__, __LINE__, (r)) #define GRPC_LB_POLICY_WEAK_REF(p, r) \ grpc_lb_policy_weak_ref((p), __FILE__, __LINE__, (r)) #define GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, p, r) \ grpc_lb_policy_weak_unref((exec_ctx), (p), __FILE__, __LINE__, (r)) void grpc_lb_policy_ref(grpc_lb_policy *policy, const char *file, int line, const char *reason); void grpc_lb_policy_unref(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, const char *file, int line, const char *reason); void grpc_lb_policy_weak_ref(grpc_lb_policy *policy, const char *file, int line, const char *reason); void grpc_lb_policy_weak_unref(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, const char *file, int line, const char *reason); #else #define GRPC_LB_POLICY_REF(p, r) grpc_lb_policy_ref((p)) #define GRPC_LB_POLICY_UNREF(cl, p, r) grpc_lb_policy_unref((cl), (p)) #define GRPC_LB_POLICY_WEAK_REF(p, r) grpc_lb_policy_weak_ref((p)) #define GRPC_LB_POLICY_WEAK_UNREF(cl, p, r) grpc_lb_policy_weak_unref((cl), (p)) void grpc_lb_policy_ref(grpc_lb_policy *policy); void grpc_lb_policy_unref(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy); void grpc_lb_policy_weak_ref(grpc_lb_policy *policy); void grpc_lb_policy_weak_unref(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy); #endif /** called by concrete implementations to initialize the base struct */ void grpc_lb_policy_init(grpc_lb_policy *policy, const grpc_lb_policy_vtable *vtable); /** Given initial metadata in \a initial_metadata, find an appropriate target for this rpc, and 'return' it by calling \a on_complete after setting \a target. Picking can be asynchronous. Any IO should be done under \a pollset. */ int grpc_lb_policy_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, grpc_pollset *pollset, grpc_metadata_batch *initial_metadata, grpc_connected_subchannel **target, grpc_closure *on_complete); void grpc_lb_policy_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, grpc_closure *closure); void grpc_lb_policy_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, grpc_connected_subchannel **target); void grpc_lb_policy_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy); void grpc_lb_policy_notify_on_state_change(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, grpc_connectivity_state *state, grpc_closure *closure); grpc_connectivity_state grpc_lb_policy_check_connectivity( grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy); #endif /* GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICY_H */