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//////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2009-2012. Distributed under the Boost
// Software License, Version 1.0. (See accompanying file
// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// See http://www.boost.org/libs/interprocess for documentation.
//
//////////////////////////////////////////////////////////////////////////////
#ifndef BOOST_INTERPROCESS_XSI_SHARED_MEMORY_DEVICE_HPP
#define BOOST_INTERPROCESS_XSI_SHARED_MEMORY_DEVICE_HPP
#include <boost/interprocess/detail/config_begin.hpp>
#include <boost/interprocess/detail/workaround.hpp>
#include <boost/detail/workaround.hpp>
#if defined(BOOST_INTERPROCESS_WINDOWS)
#error "This header can't be used in Windows operating systems"
#endif
#include <boost/interprocess/creation_tags.hpp>
#include <boost/interprocess/exceptions.hpp>
#include <boost/interprocess/detail/utilities.hpp>
#include <boost/interprocess/detail/os_file_functions.hpp>
#include <boost/interprocess/detail/tmp_dir_helpers.hpp>
#include <boost/interprocess/interprocess_fwd.hpp>
#include <boost/interprocess/exceptions.hpp>
#include <boost/interprocess/xsi_shared_memory.hpp>
#include <boost/interprocess/sync/xsi/xsi_named_mutex.hpp>
#include <boost/interprocess/mapped_region.hpp>
#include <boost/interprocess/sync/scoped_lock.hpp>
#include <cstddef>
#include <boost/cstdint.hpp>
#include <string>
#include <cstring>
//!\file
//!Describes a class representing a native xsi shared memory.
namespace boost {
namespace interprocess {
class xsi_shared_memory_device
{
/// @cond
BOOST_MOVABLE_BUT_NOT_COPYABLE(xsi_shared_memory_file_wrapper)
/// @endcond
public:
xsi_shared_memory_device();
xsi_shared_memory_device(create_only_t, const char *name, mode_t mode, std::size_t size)
{ this->priv_open_or_create_name_only(ipcdetail::DoCreate, name, mode, size); }
xsi_shared_memory_device(open_or_create_t, const char *name, mode_t mode, std::size_t size)
{ this->priv_open_or_create_name_only(ipcdetail::DoOpenOrCreate, name, mode, size); }
xsi_shared_memory_device(open_only_t, const char *name, mode_t mode)
{ this->priv_open_or_create_name_only(ipcdetail::DoOpen, name, mode, 0); }
xsi_shared_memory_device(create_only_t, const char *filepath, boost::uint8_t id, mode_t mode, std::size_t size)
{ this->priv_open_or_create_name_id(ipcdetail::DoCreate, name, id, mode, size); }
xsi_shared_memory_device(open_or_create_t, const char *filepath, boost::uint8_t id, mode_t mode, std::size_t size)
{ this->priv_open_or_create_name_id(ipcdetail::DoOpenOrCreate, id, name, mode, size); }
xsi_shared_memory_device(open_only_t, const char *filepath, boost::uint8_t id, mode_t mode)
{ this->priv_open_or_create_name_id(ipcdetail::DoOpen, name, id, mode, 0); }
xsi_shared_memory_device(BOOST_RV_REF(xsi_shared_memory_device) moved)
{ this->swap(moved); }
xsi_shared_memory_device &operator=(BOOST_RV_REF(xsi_shared_memory_device) moved)
{
xsi_shared_memory_device tmp(boost::move(moved));
this->swap(tmp);
return *this;
}
//!Swaps two xsi_shared_memory_device. Does not throw
void swap(xsi_shared_memory_device &other);
//!Destroys *this. The shared memory won't be destroyed, just
//!this connection to it. Use remove() to destroy the shared memory.
~xsi_shared_memory_device();
//!Returns the name of the
//!shared memory.
const char *get_name() const;
//!Returns the shared memory ID that
//!identifies the shared memory
int get_shmid() const;
//!Returns access
//!permissions
mode_t get_mode() const;
//!Returns the mapping handle.
//!Never throws
mapping_handle_t get_mapping_handle() const;
//!Erases a XSI shared memory object identified by shmname
//!from the system.
//!Returns false on error. Never throws
static bool remove(const char *shmname);
//!Erases the XSI shared memory object identified by shmid
//!from the system.
//!Returns false on error. Never throws
static bool remove(int shmid);
/// @cond
private:
template<int Dummy>
struct info_constants_t
{
static const std::size_t MaxName = 32;
static const std::size_t FirstID = 2;
static const std::size_t LastID = 256;
static const std::size_t NumID = LastID - FirstID;
};
struct info_t
{
struct names_t
{
char buf[info_constants_t<0>::MaxName];
} names[info_constants_t<0>::NumID];
};
static void priv_obtain_index(mapped_region &m, xsi_named_mutex &m, std::string &path);
static bool priv_remove_dead_memory(info_t *info, const char *path);
bool priv_open_or_create_name_only( ipcdetail::create_enum_t type
, const char *shmname
, mode_t mode
, std::size_t size);
bool priv_open_or_create_name_id( ipcdetail::create_enum_t type
, const char *shmname
, boost::uint8_t id
, mode_t mode
, std::size_t size);
xsi_shared_memory m_shm;
mode_t m_mode;
std::string m_name;
/// @endcond
};
template<int Dummy>
const std::size_t xsi_shared_memory_device::info_constants_t<Dummy>::MaxName;
template<int Dummy>
const std::size_t xsi_shared_memory_device::info_constants_t<Dummy>::FirstID;
template<int Dummy>
const std::size_t xsi_shared_memory_device::info_constants_t<Dummy>::LastID;
template<int Dummy>
const std::size_t xsi_shared_memory_device::info_constants_t<Dummy>::NumID;
/// @cond
inline xsi_shared_memory_device::xsi_shared_memory_device()
: m_shm(), m_mode(invalid_mode), m_name()
{}
inline xsi_shared_memory_device::~xsi_shared_memory_device()
{}
inline const char *xsi_shared_memory_device::get_name() const
{ return m_name.c_str(); }
inline void xsi_shared_memory_device::swap(xsi_shared_memory_device &other)
{
m_shm.swap(other.m_shm);
std::swap(m_mode, other.m_mode);
m_name.swap(other.m_name);
}
inline mapping_handle_t xsi_shared_memory_device::get_mapping_handle() const
{ return m_shm.get_mapping_handle(); }
inline mode_t xsi_shared_memory_device::get_mode() const
{ return m_mode; }
inline int xsi_shared_memory::get_shmid() const
{ return m_shm.get_shmid(); }
inline void xsi_shared_memory_device::priv_obtain_index
(mapped_region ®, xsi_named_mutex &mut, std::string &path)
{
const char *const filename = "xsi_shm_emulation_file";
permissions p;
p.set_unrestricted();
std::string xsi_shm_emulation_file_path;
ipcdetail::create_tmp_and_clean_old_and_get_filename(filename, xsi_shm_emulation_file_path);
ipcdetail::create_or_open_file(xsi_shm_emulation_file_path.c_str(), read_write, p);
const std::size_t MemSize = sizeof(info_t);
xsi_shared_memory index_shm(open_or_create, xsi_shm_emulation_file_path.c_str(), 1, MemSize, 0666);
mapped_region r(index_shm, read_write, 0, MemSize, 0);
xsi_named_mutex m(open_or_create, xsi_shm_emulation_file_path.c_str(), 2, 0666);
reg = boost::move(r);
mut = boost::move(m);
path.swap(xsi_shm_emulation_file_path);
}
inline bool xsi_shared_memory_device::priv_remove_dead_memory
(xsi_shared_memory_device::info_t *info, const char *path)
{
bool removed = false;
for(std::size_t i = 0; i != info_constants_t<0>::NumID; ++i){
if(info->names[i].buf[0]){
try{
xsi_shared_memory temp( open_only, path, i+info_constants_t<0>::FirstID, 0600);
}
catch(interprocess_exception &e){
if(e.get_error_code() == not_found_error){
std::memset(info->names[i].buf, 0, info_constants_t<0>::MaxName);
removed = true;
}
}
}
}
return removed;
}
inline bool xsi_shared_memory_device::priv_open_or_create_name_id
(ipcdetail::create_enum_t type, const char *filepath, mode_t mode, std::size_t size)
{
//Set accesses
if (mode != read_write && mode != read_only){
error_info err = other_error;
throw interprocess_exception(err);
}
int perm = (mode == read_only) ? (0444) : (0666);
if(type == ipcdetail::DoOpen){
if(!found){
error_info err = not_found_error;
throw interprocess_exception(err);
}
xsi_shared_memory temp(open_only, filepath, id, perm);
m_shm = boost::move(temp);
}
else if(type == ipcdetail::DoCreate){
//Try to reuse slot
xsi_shared_memory temp(create_only, filepath, id, size, perm);
std::strcpy(info->names[target_entry].buf, shmname);
m_shm = boost::move(temp);
}
else{ // if(type == ipcdetail::DoOpenOrCreate){
xsi_shared_memory temp(open_or_create, filepath, id, size, perm);
m_shm = boost::move(temp);
}
m_mode = mode;
m_name.clear();
return true;
}
inline bool xsi_shared_memory_device::priv_open_or_create_name_only
(ipcdetail::create_enum_t type, const char *shmname, mode_t mode, std::size_t size)
{
//Set accesses
if (mode != read_write && mode != read_only){
error_info err = other_error;
throw interprocess_exception(err);
}
if (std::strlen(shmname) >= (info_constants_t<0>::MaxName)){
error_info err = other_error;
throw interprocess_exception(err);
}
{
//Obtain index and index lock
mapped_region region;
xsi_named_mutex mut;
std::string xsi_shm_emulation_file_path;
priv_obtain_index(region, mut, xsi_shm_emulation_file_path);
info_t *info = static_cast<info_t *>(region.get_address());
scoped_lock<xsi_named_mutex> lock(mut);
//Find the correct entry or the first empty index
bool found = false;
int target_entry = -1;
int tries = 2;
while(tries--){
for(std::size_t i = 0; i != info_constants_t<0>::NumID; ++i){
if(target_entry < 0 && !info->names[i].buf[0]){
target_entry = static_cast<int>(i);
}
else if(0 == std::strcmp(info->names[i].buf, shmname)){
found = true;
target_entry = static_cast<int>(i);
break;
}
}
if(target_entry < 0){
if(!tries || !priv_remove_dead_memory(info, xsi_shm_emulation_file_path.c_str())){
error_info err = out_of_resource_error;
throw interprocess_exception(err);
}
}
}
//Now handle the result
int perm = (mode == read_only) ? (0444) : (0666);
if(type == ipcdetail::DoOpen){
if(!found){
error_info err = not_found_error;
throw interprocess_exception(err);
}
xsi_shared_memory temp( open_only, xsi_shm_emulation_file_path.c_str()
, target_entry+info_constants_t<0>::FirstID, perm);
m_shm = boost::move(temp);
}
else{
if(type == ipcdetail::DoCreate){
//Try to reuse slot
xsi_shared_memory temp( create_only, xsi_shm_emulation_file_path.c_str()
, target_entry+info_constants_t<0>::FirstID, size, perm);
std::strcpy(info->names[target_entry].buf, shmname);
m_shm = boost::move(temp);
}
else{ // if(type == ipcdetail::DoOpenOrCreate){
xsi_shared_memory temp( open_or_create, xsi_shm_emulation_file_path.c_str()
, target_entry+info_constants_t<0>::FirstID, size, perm);
if(!found){
std::memset(info->names[target_entry].buf, 0, info_constants_t<0>::MaxName);
std::strcpy(info->names[target_entry].buf, shmname);
}
m_shm = boost::move(temp);
}
}
}
m_mode = mode;
m_name = shmname;
return true;
}
inline bool xsi_shared_memory_device::remove(const char *shmname)
{
try{
//Obtain index and index lockss
mapped_region region;
xsi_named_mutex mut;
std::string xsi_shm_emulation_file_path;
priv_obtain_index(region, mut, xsi_shm_emulation_file_path);
scoped_lock<xsi_named_mutex> lock(mut);
info_t *info = static_cast<info_t *>(region.get_address());
//Now check and remove
bool removed = false;
for(std::size_t i = 0; i != info_constants_t<0>::NumID; ++i){
if(0 == std::strcmp(info->names[i].buf, name)){
xsi_shared_memory temp( open_only, xsi_shm_emulation_file_path.c_str()
, i+info_constants_t<0>::FirstID);
if(!xsi_shared_memory::remove(temp.get_shmid()) && (system_error_code() != invalid_argument)){
return false;
}
std::memset(info->names[i].buf, 0, info_constants_t<0>::MaxName);
removed = true;
break;
}
}
return removed;
}
catch(...){
return false;
}
}
inline bool xsi_shared_memory_device::remove(int shmid)
{ return xsi_shared_memory::remove(shmid); }
///@endcond
} //namespace interprocess {
} //namespace boost {
#include <boost/interprocess/detail/config_end.hpp>
#endif //BOOST_INTERPROCESS_XSI_SHARED_MEMORY_DEVICE_HPP