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//
// SharedMemoryImpl.cpp
//
// Library: Foundation
// Package: Processes
// Module: SharedMemoryImpl
//
// Copyright (c) 2007, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#include "Poco/SharedMemory_POSIX.h"
#include "Poco/Exception.h"
#include "Poco/File.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <unistd.h>
namespace Poco {
SharedMemoryImpl::SharedMemoryImpl(const std::string& name, std::size_t size, SharedMemory::AccessMode mode, const void* addrHint, bool server):
_size(size),
_fd(-1),
_address(0),
_access(mode),
_name("/"),
_fileMapped(false),
_server(server)
{
#if POCO_OS == POCO_OS_HPUX
_name.append("tmp/");
#endif
_name.append(name);
int flags = _server ? O_CREAT : 0;
if (_access == SharedMemory::AM_WRITE)
flags |= O_RDWR;
else
flags |= O_RDONLY;
// open the shared memory segment
_fd = ::shm_open(_name.c_str(), flags, S_IRUSR | S_IWUSR);
if (_fd == -1)
throw SystemException("Cannot create shared memory object", _name);
// now set the correct size for the segment
if (_server && -1 == ::ftruncate(_fd, size))
{
::close(_fd);
_fd = -1;
::shm_unlink(_name.c_str());
throw SystemException("Cannot resize shared memory object", _name);
}
map(addrHint);
}
SharedMemoryImpl::SharedMemoryImpl(const Poco::File& file, SharedMemory::AccessMode mode, const void* addrHint):
_size(0),
_fd(-1),
_address(0),
_access(mode),
_name(file.path()),
_fileMapped(true),
_server(false)
{
if (!file.exists() || !file.isFile())
throw FileNotFoundException(file.path());
_size = file.getSize();
int flag = O_RDONLY;
if (mode == SharedMemory::AM_WRITE)
flag = O_RDWR;
_fd = ::open(_name.c_str(), flag);
if (-1 == _fd)
throw OpenFileException("Cannot open memory mapped file", _name);
map(addrHint);
}
SharedMemoryImpl::~SharedMemoryImpl()
{
unmap();
close();
}
void SharedMemoryImpl::map(const void* addrHint)
{
int access = PROT_READ;
if (_access == SharedMemory::AM_WRITE)
access |= PROT_WRITE;
void* addr = ::mmap(const_cast<void*>(addrHint), _size, access, MAP_SHARED, _fd, 0);
if (addr == MAP_FAILED)
throw SystemException("Cannot map file into shared memory", _name);
_address = static_cast<char*>(addr);
}
void SharedMemoryImpl::unmap()
{
if (_address)
{
::munmap(_address, _size);
}
}
void SharedMemoryImpl::close()
{
if (_fd != -1)
{
::close(_fd);
_fd = -1;
}
if (!_fileMapped && _server)
{
::shm_unlink(_name.c_str());
}
}
} // namespace Poco
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