| /* |
| * |
| * 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, "lb_policy_refcount"); |
| #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: %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 = (grpc_lb_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); |
| } |