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Paddle/paddle/fluid/operators/reader/create_threaded_reader_op.cc

95 lines
3.2 KiB

// Copyright (c) 2018 PaddlePaddle Authors. All Rights Reserved.
//
// 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 "paddle/fluid/operators/detail/safe_ref.h"
#include "paddle/fluid/operators/reader/reader_op_registry.h"
namespace paddle {
namespace operators {
namespace reader {
class ThreadedReader : public framework::DecoratedReader {
public:
ThreadedReader(ReaderBase* reader, bool safe_mode)
: DecoratedReader(reader), safe_mode_(safe_mode) {}
void ReadNext(std::vector<framework::LoDTensor>* out) override {
std::lock_guard<std::mutex> lock(mutex_);
reader_->ReadNext(out);
}
void ReInit() override {
if (safe_mode_) {
PADDLE_THROW(
"ThreadedReader::ReInit() is disabled when 'safe_mode' is true.");
}
VLOG(5) << "ThreadedReader::ReInit() is invoked! It might be buggy in "
"multi-thread environment.";
reader_->ReInit();
}
private:
bool safe_mode_;
std::mutex mutex_;
};
class CreateThreadedReaderOp : public framework::OperatorBase {
public:
using framework::OperatorBase::OperatorBase;
private:
void RunImpl(const framework::Scope& scope,
const platform::Place& dev_place) const override {
auto* out = detail::Ref(scope.FindVar(Output("Out")))
.GetMutable<framework::ReaderHolder>();
if (out->Get() != nullptr) {
return;
}
const auto& underlying_reader = scope.FindVar(Input("UnderlyingReader"))
->Get<framework::ReaderHolder>();
bool safe_mode = Attr<bool>("safe_mode");
out->Reset(new ThreadedReader(underlying_reader.Get(), safe_mode));
}
};
class CreateThreadedReaderOpMaker : public DecoratedReaderMakerBase {
public:
CreateThreadedReaderOpMaker(OpProto* op_proto, OpAttrChecker* op_checker)
: DecoratedReaderMakerBase(op_proto, op_checker) {
AddAttr<bool>("safe_mode",
"When 'safe_mode' is true, 'ReInit()' is disabled to avoid "
"unexpected bugs in multi-thread environment.")
.SetDefault(true);
AddComment(R"DOC(
CreateThreadedReader Operator
This operator creates a threaded reader. A threaded reader's
'ReadNext()' can be invoked by several threads at the same
time.
When the attribute 'safe_mode' is true, the threaded reader's
'ReInit()' is disabled to avoid unexpected bugs in multi-thread
environment.
)DOC");
}
};
} // namespace reader
} // namespace operators
} // namespace paddle
namespace reader = paddle::operators::reader;
REGISTER_DECORATED_READER_OPERATOR(create_threaded_reader,
reader::CreateThreadedReaderOp,
reader::CreateThreadedReaderOpMaker);