Utils.h

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//===-- Utils.h -- Utilities header --===//
//
// Part of the Proteus Project, under the Apache License v2.0 with LLVM
// Exceptions. See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
//===----------------------------------------------------------------------===//
 
#ifndef PROTEUS_UTILS_H
#define PROTEUS_UTILS_H
 
#include "proteus/Error.h"
#include "proteus/impl/Logger.h"
#include "proteus/impl/TimeTracing.h"
 
#include <llvm/ADT/Twine.h>
#include <llvm/Support/SourceMgr.h>
 
#include <atomic>
#include <filesystem>
#include <string>
 
template <typename T>
inline void saveToFile(llvm::StringRef Filepath, T &&Data) {
  std::error_code EC;
  llvm::raw_fd_ostream Out(Filepath, EC);
  if (EC)
    proteus::reportFatalError("Cannot open file" + Filepath);
  Out << Data;
  Out.close();
}
 
// Write to temp file first, then rename so readers never see a partial file.
// Note: rename() atomicity is not guaranteed on NFS; concurrent readers may
// occasionally see missing files, causing redundant compilation.
template <typename T>
void saveToFileAtomic(llvm::StringRef Filepath, T &&Data) {
  static std::atomic<uint64_t> TempCounter{0};
  std::string TempPath =
      Filepath.str() + ".tmp." +
      std::to_string(TempCounter.fetch_add(1, std::memory_order_relaxed));
 
  std::error_code EC;
  llvm::raw_fd_ostream Out(TempPath, EC);
  if (EC)
    proteus::reportFatalError("Cannot open file " + TempPath);
  Out << Data;
  Out.close();
 
  std::filesystem::rename(TempPath, Filepath.str());
}
 
inline std::string getDistributedRank() {
  // Try commonly used environment variables to get the rank in distributed
  // runs.
  const char *Id = nullptr;
 
  // MPICH, Intel MPI, MVAPICH.
  if (!Id)
    Id = std::getenv("PMI_RANK");
  if (!Id)
    Id = std::getenv("MPI_RANK");
 
  // Open MPI.
  if (!Id)
    Id = std::getenv("OMPI_COMM_WORLD_RANK");
 
  // SLURM (if using srun).
  if (!Id)
    Id = std::getenv("SLURM_PROCID");
 
  // PBS/Torque.
  if (!Id)
    Id = std::getenv("PBS_TASKNUM");
 
  if (Id) {
    return std::string(Id);
  }
 
  // Fallback for non-distributed execution.
  return "0";
}
 
#if PROTEUS_ENABLE_HIP
#include "proteus/impl/UtilsHIP.h"
#endif
 
#if PROTEUS_ENABLE_CUDA
#include "proteus/impl/UtilsCUDA.h"
#endif
 
#endif