Chris@16: //////////////////////////////////////////////////////////////////////////////
Chris@16: //
Chris@16: // (C) Copyright Ion Gaztanaga 2009-2012. Distributed under the Boost
Chris@16: // Software License, Version 1.0. (See accompanying file
Chris@16: // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: //
Chris@16: // See http://www.boost.org/libs/interprocess for documentation.
Chris@16: //
Chris@16: //////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: #ifndef BOOST_INTERPROCESS_FILE_LOCKING_HELPERS_HPP
Chris@16: #define BOOST_INTERPROCESS_FILE_LOCKING_HELPERS_HPP
Chris@16: 
Chris@101: #ifndef BOOST_CONFIG_HPP
Chris@101: #  include <boost/config.hpp>
Chris@101: #endif
Chris@101: #
Chris@101: #if defined(BOOST_HAS_PRAGMA_ONCE)
Chris@16: #pragma once
Chris@16: #endif
Chris@16: 
Chris@16: #include <boost/interprocess/detail/config_begin.hpp>
Chris@16: #include <boost/interprocess/detail/workaround.hpp>
Chris@16: 
Chris@16: #include <sstream>
Chris@16: #include <string>
Chris@16: #include <sys/types.h>
Chris@16: #include <sys/stat.h>
Chris@16: #include <errno.h>
Chris@16: #include <cstddef>
Chris@16: #include <boost/interprocess/detail/os_file_functions.hpp>
Chris@16: 
Chris@101: #include <boost/interprocess/detail/shared_dir_helpers.hpp>
Chris@16: 
Chris@16: #if defined(BOOST_INTERPROCESS_WINDOWS)
Chris@16: 
Chris@16: #include <fcntl.h>
Chris@16: #include <io.h>
Chris@16: #include <sys/locking.h>
Chris@16: 
Chris@16: #else //defined(BOOST_INTERPROCESS_WINDOWS)
Chris@16: 
Chris@16: #include <fcntl.h>
Chris@16: #include <sys/stat.h>
Chris@16: #include <unistd.h>
Chris@16: 
Chris@16: #endif   //defined(BOOST_INTERPROCESS_WINDOWS)
Chris@16: 
Chris@16: namespace boost{
Chris@16: namespace interprocess{
Chris@16: namespace ipcdetail{
Chris@16: 
Chris@16: #if defined(BOOST_INTERPROCESS_WINDOWS)
Chris@16: 
Chris@16: struct locking_file_serial_id
Chris@16: {
Chris@16:    int fd;
Chris@16:    unsigned long dwVolumeSerialNumber;
Chris@16:    unsigned long nFileIndexHigh;
Chris@16:    unsigned long nFileIndexLow;
Chris@16:    //This reference count counts the number of modules attached
Chris@16:    //to the shared memory and lock file. This serves to unlink
Chris@16:    //the locking file and shared memory when all modules are
Chris@16:    //done with the global memory (shared memory)
Chris@16:    volatile boost::uint32_t modules_attached_to_gmem_count;
Chris@16: };
Chris@16: 
Chris@16: inline bool lock_locking_file(int fd)
Chris@16: {
Chris@16:    int ret = 0;
Chris@16:    while(ret != 0 && errno == EDEADLK){
Chris@16:       ret = _locking(fd, _LK_LOCK, 1/*lock_file_contents_length()*/);
Chris@16:    }
Chris@16:    return 0 == ret;
Chris@16: }
Chris@16: 
Chris@16: inline bool try_lock_locking_file(int fd)
Chris@16: {
Chris@16:    return 0 == _locking(fd, _LK_NBLCK , 1);
Chris@16: }
Chris@16: 
Chris@16: inline int open_or_create_and_lock_file(const char *name)
Chris@16: {
Chris@16:    permissions p;
Chris@16:    p.set_unrestricted();
Chris@16:    while(1){
Chris@16:       file_handle_t handle = create_or_open_file(name, read_write, p);
Chris@16:       int fd = _open_osfhandle((intptr_t)handle, _O_TEXT);
Chris@16:       if(fd < 0){
Chris@16:          close_file(handle);
Chris@16:          return fd;
Chris@16:       }
Chris@16:       if(!try_lock_locking_file(fd)){
Chris@16:          _close(fd);
Chris@16:          return -1;
Chris@16:       }
Chris@16:       struct _stat s;
Chris@16:       if(0 == _stat(name, &s)){
Chris@16:          return fd;
Chris@16:       }
Chris@16:       else{
Chris@16:          _close(fd);
Chris@16:       }
Chris@16:    }
Chris@16: }
Chris@16: 
Chris@16: inline int try_open_and_lock_file(const char *name)
Chris@16: {
Chris@16:    file_handle_t handle = open_existing_file(name, read_write);
Chris@16:    int fd = _open_osfhandle((intptr_t)handle, _O_TEXT);
Chris@16:    if(fd < 0){
Chris@16:       close_file(handle);
Chris@16:       return fd;
Chris@16:    }
Chris@16:    if(!try_lock_locking_file(fd)){
Chris@16:       _close(fd);
Chris@16:       return -1;
Chris@16:    }
Chris@16:    return fd;
Chris@16: }
Chris@16: 
Chris@16: inline void close_lock_file(int fd)
Chris@16: {  _close(fd); }
Chris@16: 
Chris@16: inline bool is_valid_fd(int fd)
Chris@16: {
Chris@16:    struct _stat s;
Chris@16:    return EBADF != _fstat(fd, &s);
Chris@16: }
Chris@16: 
Chris@16: inline bool is_normal_file(int fd)
Chris@16: {
Chris@16:    if(_isatty(fd))
Chris@16:       return false;
Chris@16:    struct _stat s;
Chris@16:    if(0 != _fstat(fd, &s))
Chris@16:       return false;
Chris@16:    return 0 != (s.st_mode & _S_IFREG);
Chris@16: }
Chris@16: 
Chris@16: inline std::size_t get_size(int fd)
Chris@16: {
Chris@16:    struct _stat s;
Chris@16:    if(0 != _fstat(fd, &s))
Chris@16:       return 0u;
Chris@16:    return (std::size_t)s.st_size;
Chris@16: }
Chris@16: 
Chris@16: inline bool fill_file_serial_id(int fd, locking_file_serial_id &id)
Chris@16: {
Chris@16:    winapi::interprocess_by_handle_file_information info;
Chris@16:    if(!winapi::get_file_information_by_handle((void*)_get_osfhandle(fd), &info))
Chris@16:       return false;
Chris@16:    id.fd = fd;
Chris@16:    id.dwVolumeSerialNumber = info.dwVolumeSerialNumber;
Chris@16:    id.nFileIndexHigh = info.nFileIndexHigh;
Chris@16:    id.nFileIndexLow = info.nFileIndexLow;
Chris@16:    id.modules_attached_to_gmem_count = 1; //Initialize attached count
Chris@16:    return true;
Chris@16: }
Chris@16: 
Chris@16: inline bool compare_file_serial(int fd, const locking_file_serial_id &id)
Chris@16: {
Chris@16:    winapi::interprocess_by_handle_file_information info;
Chris@16:    if(!winapi::get_file_information_by_handle((void*)_get_osfhandle(fd), &info))
Chris@16:       return false;
Chris@16: 
Chris@16:    return   id.dwVolumeSerialNumber == info.dwVolumeSerialNumber  &&
Chris@16:             id.nFileIndexHigh       == info.nFileIndexHigh        &&
Chris@16:             id.nFileIndexLow        == info.nFileIndexLow;
Chris@16: }
Chris@16: 
Chris@16: #else //UNIX
Chris@16: 
Chris@16: struct locking_file_serial_id
Chris@16: {
Chris@16:    int fd;
Chris@16:    dev_t st_dev;
Chris@16:    ino_t st_ino;
Chris@16:    //This reference count counts the number of modules attached
Chris@16:    //to the shared memory and lock file. This serves to unlink
Chris@16:    //the locking file and shared memory when all modules are
Chris@16:    //done with the global memory (shared memory)
Chris@16:    volatile boost::uint32_t modules_attached_to_gmem_count;
Chris@16: };
Chris@16: 
Chris@16: inline bool lock_locking_file(int fd)
Chris@16: {
Chris@16:    int ret = 0;
Chris@16:    while(ret != 0 && errno != EINTR){
Chris@16:       struct flock lock;
Chris@16:       lock.l_type = F_WRLCK;
Chris@16:       lock.l_whence = SEEK_SET;
Chris@16:       lock.l_start = 0;
Chris@16:       lock.l_len = 1;
Chris@16:       ret = fcntl (fd, F_SETLKW, &lock);
Chris@16:    }
Chris@16:    return 0 == ret;
Chris@16: }
Chris@16: 
Chris@16: inline bool try_lock_locking_file(int fd)
Chris@16: {
Chris@16:    struct flock lock;
Chris@16:    lock.l_type = F_WRLCK;
Chris@16:    lock.l_whence = SEEK_SET;
Chris@16:    lock.l_start = 0;
Chris@16:    lock.l_len = 1;
Chris@16:    return 0 == fcntl (fd, F_SETLK, &lock);
Chris@16: }
Chris@16: 
Chris@16: inline int open_or_create_and_lock_file(const char *name)
Chris@16: {
Chris@16:    permissions p;
Chris@16:    p.set_unrestricted();
Chris@16:    while(1){
Chris@16:       int fd = create_or_open_file(name, read_write, p);
Chris@16:       if(fd < 0){
Chris@16:          return fd;
Chris@16:       }
Chris@16:       if(!try_lock_locking_file(fd)){
Chris@16:          close(fd);
Chris@16:          return -1;
Chris@16:       }
Chris@16:       struct stat s;
Chris@16:       if(0 == stat(name, &s)){
Chris@16:          return fd;
Chris@16:       }
Chris@16:       else{
Chris@16:          close(fd);
Chris@16:       }
Chris@16:    }
Chris@16: }
Chris@16: 
Chris@16: inline int try_open_and_lock_file(const char *name)
Chris@16: {
Chris@16:    int fd = open_existing_file(name, read_write);
Chris@16:    if(fd < 0){
Chris@16:       return fd;
Chris@16:    }
Chris@16:    if(!try_lock_locking_file(fd)){
Chris@16:       close(fd);
Chris@16:       return -1;
Chris@16:    }
Chris@16:    return fd;
Chris@16: }
Chris@16: 
Chris@16: inline void close_lock_file(int fd)
Chris@16: {  close(fd); }
Chris@16: 
Chris@16: inline bool is_valid_fd(int fd)
Chris@16: {
Chris@16:    struct stat s;
Chris@16:    return EBADF != fstat(fd, &s);
Chris@16: }
Chris@16: 
Chris@16: inline bool is_normal_file(int fd)
Chris@16: {
Chris@16:    struct stat s;
Chris@16:    if(0 != fstat(fd, &s))
Chris@16:       return false;
Chris@16:    return 0 != (s.st_mode & S_IFREG);
Chris@16: }
Chris@16: 
Chris@16: inline std::size_t get_size(int fd)
Chris@16: {
Chris@16:    struct stat s;
Chris@16:    if(0 != fstat(fd, &s))
Chris@16:       return 0u;
Chris@16:    return (std::size_t)s.st_size;
Chris@16: }
Chris@16: 
Chris@16: inline bool fill_file_serial_id(int fd, locking_file_serial_id &id)
Chris@16: {
Chris@16:    struct stat s;
Chris@16:    if(0 != fstat(fd, &s))
Chris@16:       return false;
Chris@16:    id.fd = fd;
Chris@16:    id.st_dev = s.st_dev;
Chris@16:    id.st_ino = s.st_ino;
Chris@16:    id.modules_attached_to_gmem_count = 1; //Initialize attached count
Chris@16:    return true;
Chris@16: }
Chris@16: 
Chris@16: inline bool compare_file_serial(int fd, const locking_file_serial_id &id)
Chris@16: {
Chris@16:    struct stat info;
Chris@16:    if(0 != fstat(fd, &info))
Chris@16:       return false;
Chris@16: 
Chris@16:    return   id.st_dev == info.st_dev  &&
Chris@16:             id.st_ino == info.st_ino;
Chris@16: }
Chris@16: 
Chris@101: #endif
Chris@16: 
Chris@16: }  //namespace ipcdetail{
Chris@16: }  //namespace interprocess{
Chris@16: }  //namespace boost{
Chris@16: 
Chris@16: #include <boost/interprocess/detail/config_end.hpp>
Chris@16: 
Chris@16: #endif   //BOOST_INTERPROCESS_FILE_LOCKING_HELPERS_HPP