Descriptor.cpp

Go to the documentation of this file.

// DUNE DAQ modification notice:
// This file has been modified from the original ATLAS system source for the DUNE DAQ project.
// Fork baseline commit: system-00-00-20 (2020-09-25).
// Renamed since fork: yes (from src/Descriptor.cxx to src/Descriptor.cpp).
 
/*
 *  Descriptor.cxx
 *  OksSystem
 *
 *  Created by Matthias Wiesmann on 08.02.05.
 *  Copyright 2005 CERN. All rights reserved.
 *
 */
 
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
 
#include "okssystem/Descriptor.hpp"
#include "okssystem/File.hpp"
#include "okssystem/exceptions.hpp"
 
#include "ers/ers.hpp"
 
int
OksSystem::Descriptor::flags(bool read_mode, bool write_mode)
{
  if (read_mode && write_mode) {
    return O_RDWR | O_CREAT;
  }
  if (read_mode) {
    return O_RDONLY;
  }
  if (write_mode) {
    return O_WRONLY | O_CREAT;
  }
  return 0;
} // flags
 
OksSystem::Descriptor::Descriptor(const File* file, int i_flags, mode_t perm)
{
  ERS_ASSERT(file)
  open(file, i_flags, perm);
} // Descriptor
 
OksSystem::Descriptor::~Descriptor()
{
  if (m_fd >= 0) {
    close_safe();
  }
} //  ~Descriptor
 
OksSystem::Descriptor::operator int() const throw()
{
  return m_fd;
} // operator int()

 
void
OksSystem::Descriptor::open(const File* file, int i_flags, mode_t perm)
{
  ERS_ASSERT(file)
  bool alreadyExists = file->exists();
  m_fd = ::open(*file, i_flags, perm);
  m_name = file->full_name();
  if (m_fd < 0)
    throw OksSystem::OpenFileIssue(ERS_HERE, errno, m_name.c_str());
  if ((alreadyExists == false) && ((i_flags & O_CREAT) != 0)) {
    ::fchmod(m_fd, perm);
  }
} // open

 
void
OksSystem::Descriptor::close()
{
  const int status = ::close(m_fd);
  if (status < 0) {
    throw OksSystem::CloseFileIssue(ERS_HERE, errno, m_name.c_str());
  } //
  m_fd = -1;
} // close

 
void
OksSystem::Descriptor::close_safe() throw()
{
  const int status = ::close(m_fd);
  if (status < 0) {
    ers::warning(OksSystem::CloseFileIssue(ERS_HERE, errno, m_name.c_str()));
  } // if
} // close_safe
 
int
OksSystem::Descriptor::read(void* buffer, size_t number) const
{
  ssize_t status = ::read(m_fd, buffer, number);
  if (status < 0)
    throw OksSystem::ReadIssue(ERS_HERE, errno, m_name.c_str());
  return status;
} // read
 
int
OksSystem::Descriptor::write(const void* buffer, size_t number) const
{
  ssize_t status = ::write(m_fd, buffer, number);
  if (status < 0)
    throw OksSystem::WriteIssue(ERS_HERE, errno, m_name.c_str());
  return status;
} // write
 
int
OksSystem::Descriptor::fd() const throw()
{
  return m_fd;
}

 
void
OksSystem::Descriptor::closeOnExec()
{
 
  bool success = false;
  int storeErrno = 0;
 
  int oldFlags = ::fcntl(m_fd, F_GETFD);
  if (oldFlags != -1) {
    int newFlags = ::fcntl(m_fd, F_SETFD, oldFlags | FD_CLOEXEC);
    if (newFlags == -1) {
      storeErrno = errno;
    } else {
      success = true;
    }
  } else {
    storeErrno = errno;
  }
 
  if (!success) {
    std::string eMsg = "File descriptor for file " + m_name +
                       " will not be closed after exec. Reason: " + std::string(::strerror(storeErrno));
    throw OksSystem::OksSystemCallIssue(ERS_HERE, storeErrno, "fcntl", eMsg.c_str());
  }
}