/* * * Copyright 2015 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. * */ #include "src/core/ext/filters/client_channel/lb_policy.h" #include "src/core/lib/iomgr/combiner.h" #define WEAK_REF_BITS 16 #ifndef NDEBUG grpc_tracer_flag grpc_trace_lb_policy_refcount = GRPC_TRACER_INITIALIZER(false); #endif void grpc_lb_policy_init(grpc_lb_policy *policy, const grpc_lb_policy_vtable *vtable, grpc_combiner *combiner) { policy->vtable = vtable; gpr_atm_no_barrier_store(&policy->ref_pair, 1 << WEAK_REF_BITS); policy->interested_parties = grpc_pollset_set_create(); policy->combiner = GRPC_COMBINER_REF(combiner, "lb_policy"); } #ifndef NDEBUG #define REF_FUNC_EXTRA_ARGS , const char *file, int line, const char *reason #define REF_MUTATE_EXTRA_ARGS REF_FUNC_EXTRA_ARGS, const char *purpose #define REF_FUNC_PASS_ARGS(new_reason) , file, line, new_reason #define REF_MUTATE_PASS_ARGS(purpose) , file, line, reason, purpose #else #define REF_FUNC_EXTRA_ARGS #define REF_MUTATE_EXTRA_ARGS #define REF_FUNC_PASS_ARGS(new_reason) #define REF_MUTATE_PASS_ARGS(x) #endif static gpr_atm ref_mutate(grpc_lb_policy *c, gpr_atm delta, int barrier REF_MUTATE_EXTRA_ARGS) { gpr_atm old_val = barrier ? gpr_atm_full_fetch_add(&c->ref_pair, delta) : gpr_atm_no_barrier_fetch_add(&c->ref_pair, delta); #ifndef NDEBUG if (GRPC_TRACER_ON(grpc_trace_lb_policy_refcount)) { gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "LB_POLICY: 0x%p %12s 0x%" PRIxPTR " -> 0x%" PRIxPTR " [%s]", c, purpose, old_val, old_val + delta, reason); } #endif return old_val; } void grpc_lb_policy_ref(grpc_lb_policy *policy REF_FUNC_EXTRA_ARGS) { ref_mutate(policy, 1 << WEAK_REF_BITS, 0 REF_MUTATE_PASS_ARGS("STRONG_REF")); } static void shutdown_locked(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) { grpc_lb_policy *policy = arg; policy->vtable->shutdown_locked(exec_ctx, policy); GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, policy, "strong-unref"); } void grpc_lb_policy_unref(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy REF_FUNC_EXTRA_ARGS) { gpr_atm old_val = ref_mutate(policy, (gpr_atm)1 - (gpr_atm)(1 << WEAK_REF_BITS), 1 REF_MUTATE_PASS_ARGS("STRONG_UNREF")); gpr_atm mask = ~(gpr_atm)((1 << WEAK_REF_BITS) - 1); gpr_atm check = 1 << WEAK_REF_BITS; if ((old_val & mask) == check) { GRPC_CLOSURE_SCHED(exec_ctx, GRPC_CLOSURE_CREATE( shutdown_locked, policy, grpc_combiner_scheduler(policy->combiner)), GRPC_ERROR_NONE); } else { grpc_lb_policy_weak_unref(exec_ctx, policy REF_FUNC_PASS_ARGS("strong-unref")); } } void grpc_lb_policy_weak_ref(grpc_lb_policy *policy REF_FUNC_EXTRA_ARGS) { ref_mutate(policy, 1, 0 REF_MUTATE_PASS_ARGS("WEAK_REF")); } void grpc_lb_policy_weak_unref(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy REF_FUNC_EXTRA_ARGS) { gpr_atm old_val = ref_mutate(policy, -(gpr_atm)1, 1 REF_MUTATE_PASS_ARGS("WEAK_UNREF")); if (old_val == 1) { grpc_pollset_set_destroy(exec_ctx, policy->interested_parties); grpc_combiner *combiner = policy->combiner; policy->vtable->destroy(exec_ctx, policy); GRPC_COMBINER_UNREF(exec_ctx, combiner, "lb_policy"); } } int grpc_lb_policy_pick_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, const grpc_lb_policy_pick_args *pick_args, grpc_connected_subchannel **target, grpc_call_context_element *context, void **user_data, grpc_closure *on_complete) { return policy->vtable->pick_locked(exec_ctx, policy, pick_args, target, context, user_data, on_complete); } void grpc_lb_policy_cancel_pick_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, grpc_connected_subchannel **target, grpc_error *error) { policy->vtable->cancel_pick_locked(exec_ctx, policy, target, error); } void grpc_lb_policy_cancel_picks_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, uint32_t initial_metadata_flags_mask, uint32_t initial_metadata_flags_eq, grpc_error *error) { policy->vtable->cancel_picks_locked(exec_ctx, policy, initial_metadata_flags_mask, initial_metadata_flags_eq, error); } void grpc_lb_policy_exit_idle_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy) { policy->vtable->exit_idle_locked(exec_ctx, policy); } void grpc_lb_policy_ping_one_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, grpc_closure *closure) { policy->vtable->ping_one_locked(exec_ctx, policy, closure); } void grpc_lb_policy_notify_on_state_change_locked( grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, grpc_connectivity_state *state, grpc_closure *closure) { policy->vtable->notify_on_state_change_locked(exec_ctx, policy, state, closure); } grpc_connectivity_state grpc_lb_policy_check_connectivity_locked( grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, grpc_error **connectivity_error) { return policy->vtable->check_connectivity_locked(exec_ctx, policy, connectivity_error); } void grpc_lb_policy_update_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, const grpc_lb_policy_args *lb_policy_args) { policy->vtable->update_locked(exec_ctx, policy, lb_policy_args); }