spinlock.cc

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// Copyright 2015 Cloudera Inc.
//
// 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 "util/spinlock.h"

namespace impala {

void SpinLock::SlowAcquire() {
  while (true) {
    if (try_lock()) return;
    for (int i = 0; i < NUM_SPIN_CYCLES; ++i) {
      AtomicUtil::CpuWait();
    }
    if (try_lock()) return;
    sched_yield();
  }
}

}