llvm/tools/llvm-exegesis/lib/SubprocessMemory.h

   1 //===-- SubprocessMemory.h --------------------------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 ///
   9 /// \file
  10 /// Defines a class that automatically handles auxiliary memory and the
  11 /// underlying shared memory backings for memory definitions
  12 ///
  13 //===----------------------------------------------------------------------===//
  14
  15 #ifndef LLVM_TOOLS_LLVM_EXEGESIS_SUBPROCESSMEMORY_H
  16 #define LLVM_TOOLS_LLVM_EXEGESIS_SUBPROCESSMEMORY_H
  17
  18 #include "BenchmarkResult.h"
  19 #include <string>
  20 #include <unordered_map>
  21 #include <vector>
  22
  23 #ifdef _MSC_VER
  24 typedef int pid_t;
  25 #else
  26 #include <sys/types.h>
  27 #endif // _MSC_VER
  28
  29
  30 namespace llvm {
  31 namespace exegesis {
  32
  33 class SubprocessMemory {
  34 public:
  35   static constexpr const size_t AuxiliaryMemoryOffset = 1;
  36   static constexpr const size_t AuxiliaryMemorySize = 4096;
  37
  38   Error initializeSubprocessMemory(pid_t ProcessID);
  39
  40   // The following function sets up memory definitions. It creates shared
  41   // memory objects for the definitions and fills them with the specified
  42   // values. Arguments: MemoryDefinitions - A map from memory value names to
  43   // MemoryValues, ProcessID - The ID of the current process.
  44   Error addMemoryDefinition(
  45       std::unordered_map<std::string, MemoryValue> MemoryDefinitions,
  46       pid_t ProcessID);
  47
  48   // The following function sets up the auxiliary memory by opening shared
  49   // memory objects backing memory definitions and putting file descriptors
  50   // into appropriate places. Arguments: MemoryDefinitions - A map from memory
  51   // values names to Memoryvalues, ParentPID - The ID of the process that
  52   // setup the memory definitions, CounterFileDescriptor - The file descriptor
  53   // for the performance counter that will be placed in the auxiliary memory
  54   // section.
  55   static Expected<int> setupAuxiliaryMemoryInSubprocess(
  56       std::unordered_map<std::string, MemoryValue> MemoryDefinitions,
  57       pid_t ParentPID, int CounterFileDescriptor);
  58
  59   ~SubprocessMemory();
  60
  61 private:
  62   std::vector<std::string> SharedMemoryNames;
  63 };
  64
  65 } // namespace exegesis
  66 } // namespace llvm
  67
  68 #endif