threading_backend.h

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

#ifndef TVM_RUNTIME_THREADING_BACKEND_H_
#define TVM_RUNTIME_THREADING_BACKEND_H_

#include <functional>
#include <memory>
#include <vector>

#if defined(__linux__) || defined(__ANDROID__)
#if defined(__ANDROID__)
#ifndef CPU_SET
#define CPU_SETSIZE 1024
#define __NCPUBITS (8 * sizeof(uint64_t))
typedef struct {
  uint64_t __bits[CPU_SETSIZE / __NCPUBITS];
} cpu_set_t;

#define CPU_SET(cpu, cpusetp) \
  ((cpusetp)->__bits[(cpu) / __NCPUBITS] |= (1UL << ((cpu) % __NCPUBITS)))
#define CPU_ZERO(cpusetp) memset((cpusetp), 0, sizeof(cpu_set_t))
#define CPU_ISSET(cpu, cpusetp)    \
  (1UL << ((cpu) % __NCPUBITS)) == \
      ((cpusetp)->__bits[(cpu) / __NCPUBITS] & (1UL << ((cpu) % __NCPUBITS)))
#define CPU_EQUAL(left, right) (memcmp(&left, &right, sizeof(cpu_set_t)) == 0)

#endif
#endif
#endif

namespace tvm {
namespace runtime {
namespace threading {

class ThreadGroup {
 public:
  class Impl;

  ThreadGroup(int num_workers, std::function<void(int)> worker_callback,
              bool exclude_worker0 = false);
  ~ThreadGroup();

  void Join();

  enum AffinityMode : int {
    kBig = 1,
    kLittle = -1,
    /*Different threads will get different affinities.*/
    kSpecifyOneCorePerThread = -2,
    /*All threads will get the same core group affinity.*/
    kSpecifyThreadShareAllCore = -3,
  };
  int Configure(AffinityMode mode, int nthreads, bool exclude_worker0,
                std::vector<unsigned int> cpus = {});

 private:
  Impl* impl_;
};

void Yield();
int MaxConcurrency();
void SetMaxConcurrency(int value);
void ResetThreadPool();

TVM_DLL void Configure(tvm::runtime::threading::ThreadGroup::AffinityMode mode, int nthreads,
                       std::vector<unsigned int> cpus);

int32_t NumThreads();

}  // namespace threading
}  // namespace runtime
}  // namespace tvm

#endif  // TVM_RUNTIME_THREADING_BACKEND_H_