inline file_handle_t create_new_file
(const char *name, mode_t mode, const permissions & perm = permissions(), bool temporary = false)
{
(void)temporary;
int ret = ::open(name, ((int)mode) | O_EXCL | O_CREAT, perm.get_permissions());
if(ret >= 0){
::fchmod(ret, perm.get_permissions());
}
return ret;
}
inline file_handle_t create_or_open_file
(const char *name, mode_t mode, const permissions & perm = permissions(), bool temporary = false)
{
unsigned long attr = temporary ? winapi::file_attribute_temporary : 0;
return winapi::create_file
( name, (unsigned int)mode, winapi::open_always, attr
, (winapi::interprocess_security_attributes*)perm.get_permissions());
}
inline bool semaphore_open
(sem_t *&handle, create_enum_t type, const char *origname,
unsigned int count = 0, const permissions &perm = permissions())
{
std::string name;
#ifndef BOOST_INTERPROCESS_FILESYSTEM_BASED_POSIX_SEMAPHORES
add_leading_slash(origname, name);
#else
create_shared_dir_cleaning_old_and_get_filepath(origname, name);
#endif
//Create new mapping
int oflag = 0;
switch(type){
case DoOpen:
{
//No addition
handle = ::sem_open(name.c_str(), oflag);
}
break;
case DoOpenOrCreate:
case DoCreate:
{
while(1){
oflag = (O_CREAT | O_EXCL);
handle = ::sem_open(name.c_str(), oflag, perm.get_permissions(), count);
if(handle != BOOST_INTERPROCESS_POSIX_SEM_FAILED){
//We can't change semaphore permissions!
//::fchmod(handle, perm.get_permissions());
break;
}
else if(errno == EEXIST && type == DoOpenOrCreate){
oflag = 0;
if( (handle = ::sem_open(name.c_str(), oflag)) != BOOST_INTERPROCESS_POSIX_SEM_FAILED
|| (errno != ENOENT) ){
break;
}
}
else{
break;
}
}
}
break;
default:
{
error_info err(other_error);
throw interprocess_exception(err);
}
}
//Check for error
if(handle == BOOST_INTERPROCESS_POSIX_SEM_FAILED){
throw interprocess_exception(error_info(errno));
}
return true;
}
inline file_handle_t create_or_open_file
(const char *name, mode_t mode, const permissions & perm = permissions(), bool temporary = false)
{
(void)temporary;
int ret = -1;
//We need a loop to change permissions correctly using fchmod, since
//with "O_CREAT only" ::open we don't know if we've created or opened the file.
while(1){
ret = ::open(name, ((int)mode) | O_EXCL | O_CREAT, perm.get_permissions());
if(ret >= 0){
::fchmod(ret, perm.get_permissions());
break;
}
else if(errno == EEXIST){
if((ret = ::open(name, (int)mode)) >= 0 || errno != ENOENT){
break;
}
}
}
return ret;
}
bool open_or_create(const char *name, const permissions &perm)
{
if(m_mtx_hnd == winapi::invalid_handle_value){
m_mtx_hnd = winapi::open_or_create_mutex
( name
, false
, (winapi::interprocess_security_attributes*)perm.get_permissions()
);
return m_mtx_hnd != winapi::invalid_handle_value;
}
else{
return false;
}
}
void interprocess_semaphore::create_or_open(const wchar_t* name, permissions const& perms)
{
#if BOOST_USE_WINAPI_VERSION >= BOOST_WINAPI_VERSION_WIN6
boost::detail::winapi::HANDLE_ h = boost::detail::winapi::CreateSemaphoreExW
(
reinterpret_cast< boost::detail::winapi::SECURITY_ATTRIBUTES_* >(perms.get_native()),
0, // initial count
(std::numeric_limits< boost::detail::winapi::LONG_ >::max)(), // max count
name,
0u, // flags
boost::detail::winapi::SYNCHRONIZE_ | boost::detail::winapi::SEMAPHORE_MODIFY_STATE_ | boost::detail::winapi::SEMAPHORE_QUERY_STATE_
);
#else
boost::detail::winapi::HANDLE_ h = boost::detail::winapi::CreateSemaphoreW
(
reinterpret_cast< boost::detail::winapi::SECURITY_ATTRIBUTES_* >(perms.get_native()),
0, // initial count
(std::numeric_limits< boost::detail::winapi::LONG_ >::max)(), // max count
name
);
#endif
if (h == NULL)
{
boost::detail::winapi::DWORD_ err = boost::detail::winapi::GetLastError();
if (BOOST_LIKELY(err == ERROR_ALREADY_EXISTS))
{
open(name);
return;
}
else
{
BOOST_LOG_THROW_DESCR_PARAMS(boost::log::system_error, "Failed to create an interprocess semaphore object", (err));
}
}
m_sem.init(h);
}
inline bool semaphore_open
(sem_t *&handle, ipcdetail::create_enum_t type, const char *origname,
unsigned int count, const permissions &perm = permissions())
{
std::string name;
#ifndef BOOST_INTERPROCESS_FILESYSTEM_BASED_POSIX_SEMAPHORES
ipcdetail::add_leading_slash(origname, name);
#else
ipcdetail::create_tmp_and_clean_old_and_get_filename(origname, name);
#endif
//Create new mapping
int oflag = 0;
switch(type){
case ipcdetail::DoOpen:
//No addition
break;
case ipcdetail::DoCreate:
oflag |= (O_CREAT | O_EXCL);
break;
case ipcdetail::DoOpenOrCreate:
oflag |= O_CREAT;
break;
default:
{
error_info err = other_error;
throw interprocess_exception(err);
}
}
//Open file using POSIX API
if(oflag & O_CREAT)
handle = sem_open(name.c_str(), oflag, perm.get_permissions(), count);
else
handle = sem_open(name.c_str(), oflag);
//Check for error
if(handle == BOOST_INTERPROCESS_POSIX_SEM_FAILED){
throw interprocess_exception(error_info(errno));
}
return true;
}
bool open_or_create( const char *name
, long sem_count
, long max_count
, const permissions &perm
, bool &created)
{
if(m_sem_hnd == winapi::invalid_handle_value){
m_sem_hnd = winapi::open_or_create_semaphore
( name
, sem_count
, max_count
, (winapi::interprocess_security_attributes*)perm.get_permissions()
);
created = winapi::get_last_error() != winapi::error_already_exists;
return m_sem_hnd != winapi::invalid_handle_value;
}
else{
return false;
}
}
inline void windows_named_sync::open_or_create
( create_enum_t creation_type
, const char *name
, const permissions &perm
, windows_named_sync_interface &sync_interface)
{
std::string aux_str(name);
m_file_hnd = winapi::invalid_handle_value;
//Use a file to emulate POSIX lifetime semantics. After this logic
//we'll obtain the ID of the native handle to open in aux_str
{
create_shared_dir_cleaning_old_and_get_filepath(name, aux_str);
//Create a file with required permissions.
m_file_hnd = winapi::create_file
( aux_str.c_str()
, winapi::generic_read | winapi::generic_write
, creation_type == DoOpen ? winapi::open_existing :
(creation_type == DoCreate ? winapi::create_new : winapi::open_always)
, 0
, (winapi::interprocess_security_attributes*)perm.get_permissions());
//Obtain OS error in case something has failed
error_info err;
bool success = false;
if(m_file_hnd != winapi::invalid_handle_value){
//Now lock the file
const std::size_t buflen = sync_interface.get_data_size();
typedef __int64 unique_id_type;
const std::size_t sizeof_file_info = sizeof(unique_id_type) + buflen;
winapi::interprocess_overlapped overlapped;
if(winapi::lock_file_ex
(m_file_hnd, winapi::lockfile_exclusive_lock, 0, sizeof_file_info, 0, &overlapped)){
__int64 filesize = 0;
//Obtain the unique id to open the native semaphore.
//If file size was created
if(winapi::get_file_size(m_file_hnd, filesize)){
unsigned long written_or_read = 0;
unique_id_type unique_id_val;
if(static_cast<std::size_t>(filesize) != sizeof_file_info){
winapi::set_end_of_file(m_file_hnd);
winapi::query_performance_counter(&unique_id_val);
const void *buf = sync_interface.buffer_with_init_data_to_file();
//Write unique ID in file. This ID will be used to calculate the semaphore name
if(winapi::write_file(m_file_hnd, &unique_id_val, sizeof(unique_id_val), &written_or_read, 0) &&
written_or_read == sizeof(unique_id_val) &&
winapi::write_file(m_file_hnd, buf, buflen, &written_or_read, 0) &&
written_or_read == buflen ){
success = true;
}
winapi::get_file_size(m_file_hnd, filesize);
BOOST_ASSERT(std::size_t(filesize) == sizeof_file_info);
}
else{
void *buf = sync_interface.buffer_to_store_init_data_from_file();
if(winapi::read_file(m_file_hnd, &unique_id_val, sizeof(unique_id_val), &written_or_read, 0) &&
written_or_read == sizeof(unique_id_val) &&
winapi::read_file(m_file_hnd, buf, buflen, &written_or_read, 0) &&
written_or_read == buflen ){
success = true;
}
}
if(success){
//Now create a global semaphore name based on the unique id
char unique_id_name[sizeof(unique_id_val)*2+1];
std::size_t name_suffix_length = sizeof(unique_id_name);
bytes_to_str(&unique_id_val, sizeof(unique_id_val), &unique_id_name[0], name_suffix_length);
success = sync_interface.open(creation_type, unique_id_name);
}
}
//Obtain OS error in case something has failed
err = system_error_code();
//If this fails we have no possible rollback so don't check the return
if(!winapi::unlock_file_ex(m_file_hnd, 0, sizeof_file_info, 0, &overlapped)){
err = system_error_code();
}
}
else{
//Obtain OS error in case something has failed
err = system_error_code();
}
}
else{
err = system_error_code();
}
if(!success){
if(m_file_hnd != winapi::invalid_handle_value){
winapi::close_handle(m_file_hnd);
m_file_hnd = winapi::invalid_handle_value;
}
//Throw as something went wrong
throw interprocess_exception(err);
}
}
}
