art::LinuxProcMgr Class Reference

#include <LinuxProcMgr.h>

Public Member Functions
	LinuxProcMgr () noexcept(false)
	~LinuxProcMgr () noexcept
LinuxProcData::proc_tuple	getCurrentData () const noexcept(false)
double	getVmPeak () const noexcept(false)
double	getVmHWM () const noexcept(false)
	LinuxProcMgr (LinuxProcMgr const &)=delete
	LinuxProcMgr (LinuxProcMgr &&)=delete
LinuxProcMgr &	operator= (LinuxProcMgr const &)=delete
LinuxProcMgr &	operator= (LinuxProcMgr &&)=delete

Private Member Functions
double	getStatusData_ (std::string const &field) const noexcept(false)

Private Attributes
pid_t const	pid_
long const	pgSize_
FILE *const	file_

Detailed Description

Definition at line 22 of file LinuxProcMgr.h.

Constructor & Destructor Documentation

art::LinuxProcMgr::LinuxProcMgr ( )

noexcept

Definition at line 59 of file LinuxProcMgr.cc.

    : pid_{getpid()}
    , pgSize_{sysconf(_SC_PAGESIZE)}
    , file_{new_proc_file_descriptor(pid_)}
  {}

art::LinuxProcMgr::~LinuxProcMgr ( )

noexcept

Definition at line 65 of file LinuxProcMgr.cc.

{ fclose(file_); }

art::LinuxProcMgr::LinuxProcMgr ( LinuxProcMgr const &  )

delete

art::LinuxProcMgr::LinuxProcMgr ( LinuxProcMgr &&  )

delete

Member Function Documentation

LinuxProcData::proc_tuple art::LinuxProcMgr::getCurrentData ( ) const

noexcept

Definition at line 69 of file LinuxProcMgr.cc.

  {
    HEP_CONCURRENCY_ASSERT_ONLY_ONE_THREAD();

    int const seek_result{fseek(file_, 0, SEEK_SET)};
    if (seek_result != 0) {
      throw Exception{errors::FileReadError,
                      "Error while retrieving Linux proc data."}
        << "\nCould not reset position indicator while retrieving proc "
           "stat information.\n";
    }

    char buf[400];
    size_t const cnt{fread(buf, 1, sizeof(buf), file_)};

    if (cnt == 0) {
      throw Exception{errors::FileReadError,
                      "Error while retrieving Linux proc data."}
        << "\nCould not read proc stat information.\n";
    }

    buf[cnt] = '\0';

    LinuxProcData::vsize_t::value_type vsize;
    LinuxProcData::rss_t::value_type rss;

    std::istringstream iss{buf};
    iss >> token_ignore(22) >> vsize >> rss;

    return LinuxProcData::make_proc_tuple(vsize, rss * pgSize_);
  }

double art::LinuxProcMgr::getStatusData_ ( std::string const &  field ) const

privatenoexcept

Definition at line 103 of file LinuxProcMgr.cc.

  {
    HEP_CONCURRENCY_ASSERT_ONLY_ONE_THREAD();

    std::ostringstream ost;
    ost << "/proc/" << pid_ << "/status";

    auto file = fopen(ost.str().c_str(), "r");
    if (file == nullptr) {
      throw Exception{errors::Configuration} << " Failed to open: " << ost.str()
                                             << std::endl;
    }

    double value{};
    std::regex const pattern{"^" + field + R"(:\s*(\d+)\s*kB)"};
    while (!feof(file)) {
      char buffer[128];
      if (fgets(buffer, sizeof(buffer), file) != nullptr) {
        std::cmatch cm;
        if (std::regex_search(buffer, cm, pattern)) {
          // Reported value from proc (although labeled 'kB') is
          // actually in KiB.  Will convert to base-10 MB.
          value = std::stod(cm.str(1)) * LinuxProcData::KiB / LinuxProcData::MB;
          break;
        }
      }
    }
    fclose(file);
    return value;
  }

double art::LinuxProcMgr::getVmHWM ( ) const

inlinenoexcept

Definition at line 34 of file LinuxProcMgr.h.

    {
      return getStatusData_("VmHWM");
    }

double art::LinuxProcMgr::getVmPeak ( ) const

inlinenoexcept

Definition at line 29 of file LinuxProcMgr.h.

    {
      return getStatusData_("VmPeak");
    }

LinuxProcMgr& art::LinuxProcMgr::operator= ( LinuxProcMgr const &  )

delete

LinuxProcMgr& art::LinuxProcMgr::operator= ( LinuxProcMgr &&  )

delete

Member Data Documentation

FILE* const art::LinuxProcMgr::file_

private

Definition at line 49 of file LinuxProcMgr.h.

long const art::LinuxProcMgr::pgSize_

private

Definition at line 48 of file LinuxProcMgr.h.

pid_t const art::LinuxProcMgr::pid_

private

Definition at line 47 of file LinuxProcMgr.h.

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The documentation for this class was generated from the following files:

• art/art/Utilities/LinuxProcMgr.h
• art/art/Utilities/LinuxProcMgr.cc