mirror of
https://github.com/genodelabs/genode.git
synced 2024-12-30 10:38:55 +00:00
5fa91c573b
The fds in O_APPEND state may have changed by the child. The local seek state needs to be valid/current for the next to be forked child, which seek state is set by File_descriptor_allocator::generate_info(). Issue #3991
138 lines
2.8 KiB
C++
138 lines
2.8 KiB
C++
/*
|
|
* \brief file descriptor allocator interface
|
|
* \author Christian Prochaska
|
|
* \date 2010-01-21
|
|
*
|
|
*/
|
|
|
|
/*
|
|
* Copyright (C) 2010-2017 Genode Labs GmbH
|
|
*
|
|
* This file is part of the Genode OS framework, which is distributed
|
|
* under the terms of the GNU Affero General Public License version 3.
|
|
*/
|
|
|
|
#ifndef _LIBC_PLUGIN__FD_ALLOC_H_
|
|
#define _LIBC_PLUGIN__FD_ALLOC_H_
|
|
|
|
/* Genode includes */
|
|
#include <base/mutex.h>
|
|
#include <base/log.h>
|
|
#include <os/path.h>
|
|
#include <base/allocator.h>
|
|
#include <base/id_space.h>
|
|
#include <util/bit_allocator.h>
|
|
#include <util/xml_generator.h>
|
|
|
|
/* libc includes */
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
|
|
#include <libc-plugin/plugin.h>
|
|
|
|
enum { MAX_NUM_FDS = 1024 };
|
|
|
|
namespace Libc {
|
|
|
|
/**
|
|
* Plugin-specific file-descriptor context
|
|
*/
|
|
struct Plugin_context { virtual ~Plugin_context() { } };
|
|
|
|
enum { ANY_FD = -1 };
|
|
|
|
struct File_descriptor
|
|
{
|
|
Genode::Mutex mutex { };
|
|
|
|
typedef Genode::Id_space<File_descriptor> Id_space;
|
|
Id_space::Element _elem;
|
|
|
|
int const libc_fd = _elem.id().value;
|
|
|
|
char const *fd_path = nullptr; /* for 'fchdir', 'fstat' */
|
|
|
|
Plugin *plugin;
|
|
Plugin_context *context;
|
|
|
|
int flags = 0; /* for 'fcntl' */
|
|
bool cloexec = 0; /* for 'fcntl' */
|
|
bool modified = false;
|
|
|
|
File_descriptor(Id_space &id_space, Plugin &plugin, Plugin_context &context,
|
|
Id_space::Id id)
|
|
: _elem(*this, id_space, id), plugin(&plugin), context(&context) { }
|
|
|
|
void path(char const *newpath);
|
|
};
|
|
|
|
|
|
class File_descriptor_allocator
|
|
{
|
|
private:
|
|
|
|
Genode::Mutex _mutex;
|
|
|
|
Genode::Allocator &_alloc;
|
|
|
|
typedef File_descriptor::Id_space Id_space;
|
|
|
|
Id_space _id_space;
|
|
|
|
Genode::Bit_allocator<MAX_NUM_FDS> _id_allocator;
|
|
|
|
public:
|
|
|
|
/**
|
|
* Constructor
|
|
*/
|
|
File_descriptor_allocator(Genode::Allocator &_alloc);
|
|
|
|
/**
|
|
* Allocate file descriptor
|
|
*/
|
|
File_descriptor *alloc(Plugin *plugin, Plugin_context *context, int libc_fd = -1);
|
|
|
|
/**
|
|
* Release file descriptor
|
|
*/
|
|
void free(File_descriptor *fdo);
|
|
|
|
/**
|
|
* Prevent the use of the specified file descriptor
|
|
*/
|
|
void preserve(int libc_fd);
|
|
|
|
File_descriptor *find_by_libc_fd(int libc_fd);
|
|
|
|
/**
|
|
* Return any file descriptor with close-on-execve flag set
|
|
*
|
|
* \return pointer to file descriptor, or
|
|
* nullptr is no such file descriptor exists
|
|
*/
|
|
File_descriptor *any_cloexec_libc_fd();
|
|
|
|
/**
|
|
* Update seek state of file descriptor with append flag set.
|
|
*/
|
|
void update_append_libc_fds();
|
|
|
|
/**
|
|
* Return file-descriptor ID of any open file, or -1 if no file is
|
|
* open
|
|
*/
|
|
int any_open_fd();
|
|
|
|
void generate_info(Genode::Xml_generator &);
|
|
};
|
|
|
|
|
|
/**
|
|
* Return singleton instance of file-descriptor allocator
|
|
*/
|
|
extern File_descriptor_allocator *file_descriptor_allocator();
|
|
}
|
|
|
|
#endif /* _LIBC_PLUGIN__FD_ALLOC_H_ */
|