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/*
*
* 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 <grpc/support/port_platform.h>
#include "src/core/ext/filters/client_channel/lb_policy.h"
#include "src/core/ext/filters/client_channel/lb_policy_registry.h"
#include "src/core/lib/iomgr/combiner.h"
namespace grpc_core {
DebugOnlyTraceFlag grpc_trace_lb_policy_refcount(false, "lb_policy_refcount");
//
// LoadBalancingPolicy
//
LoadBalancingPolicy::LoadBalancingPolicy(Args args, intptr_t initial_refcount)
: InternallyRefCounted(
GRPC_TRACE_FLAG_ENABLED(grpc_trace_lb_policy_refcount)
? "LoadBalancingPolicy"
: nullptr,
initial_refcount),
work_serializer_(std::move(args.work_serializer)),
interested_parties_(grpc_pollset_set_create()),
channel_control_helper_(std::move(args.channel_control_helper)) {}
LoadBalancingPolicy::~LoadBalancingPolicy() {
grpc_pollset_set_destroy(interested_parties_);
}
void LoadBalancingPolicy::Orphan() {
ShutdownLocked();
Unref(DEBUG_LOCATION, "Orphan");
}
//
// LoadBalancingPolicy::UpdateArgs
//
LoadBalancingPolicy::UpdateArgs::UpdateArgs(const UpdateArgs& other) {
addresses = other.addresses;
config = other.config;
args = grpc_channel_args_copy(other.args);
}
LoadBalancingPolicy::UpdateArgs::UpdateArgs(UpdateArgs&& other) noexcept {
addresses = std::move(other.addresses);
config = std::move(other.config);
// TODO(roth): Use std::move() once channel args is converted to C++.
args = other.args;
other.args = nullptr;
}
LoadBalancingPolicy::UpdateArgs& LoadBalancingPolicy::UpdateArgs::operator=(
const UpdateArgs& other) {
if (&other == this) {
return *this;
}
addresses = other.addresses;
config = other.config;
grpc_channel_args_destroy(args);
args = grpc_channel_args_copy(other.args);
return *this;
}
LoadBalancingPolicy::UpdateArgs& LoadBalancingPolicy::UpdateArgs::operator=(
UpdateArgs&& other) noexcept {
addresses = std::move(other.addresses);
config = std::move(other.config);
// TODO(roth): Use std::move() once channel args is converted to C++.
grpc_channel_args_destroy(args);
args = other.args;
other.args = nullptr;
return *this;
}
//
// LoadBalancingPolicy::QueuePicker
//
LoadBalancingPolicy::PickResult LoadBalancingPolicy::QueuePicker::Pick(
PickArgs /*args*/) {
// We invoke the parent's ExitIdleLocked() via a closure instead
// of doing it directly here, for two reasons:
// 1. ExitIdleLocked() may cause the policy's state to change and
// a new picker to be delivered to the channel. If that new
// picker is delivered before ExitIdleLocked() returns, then by
// the time this function returns, the pick will already have
// been processed, and we'll be trying to re-process the same
// pick again, leading to a crash.
// 2. We are currently running in the data plane mutex, but we
// need to bounce into the control plane work_serializer to call
// ExitIdleLocked().
if (!exit_idle_called_ && parent_ != nullptr) {
exit_idle_called_ = true;
auto* parent = parent_->Ref().release(); // ref held by lambda.
ExecCtx::Run(DEBUG_LOCATION,
GRPC_CLOSURE_CREATE(
[](void* arg, grpc_error_handle /*error*/) {
auto* parent = static_cast<LoadBalancingPolicy*>(arg);
parent->work_serializer()->Run(
[parent]() {
parent->ExitIdleLocked();
parent->Unref();
},
DEBUG_LOCATION);
},
parent, nullptr),
GRPC_ERROR_NONE);
}
PickResult result;
result.type = PickResult::PICK_QUEUE;
return result;
}
//
// LoadBalancingPolicy::TransientFailurePicker
//
LoadBalancingPolicy::PickResult
LoadBalancingPolicy::TransientFailurePicker::Pick(PickArgs /*args*/) {
PickResult result;
result.type = PickResult::PICK_FAILED;
result.error = GRPC_ERROR_REF(error_);
return result;
}
} // namespace grpc_core
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