genode/repos/libports/include/libc-plugin/fd_alloc.h
2017-08-28 16:49:42 +02:00

103 lines
2.2 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_
#include <base/allocator_avl.h>
#include <base/lock.h>
#include <base/log.h>
#include <os/path.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
{
int libc_fd = -1;
char const *fd_path = 0; /* for 'fchdir', 'fstat' */
Plugin *plugin = 0;
Plugin_context *context = 0;
int flags = 0; /* for 'fcntl' */
bool cloexec = 0; /* for 'fcntl' */
Genode::Lock lock;
void path(char const *newpath)
{
if (fd_path) { Genode::warning("may leak former FD path memory"); }
if (newpath) {
Genode::size_t const path_size = ::strlen(newpath) + 1;
char *buf = (char*)malloc(path_size);
if (!buf) {
Genode::error("could not allocate path buffer for libc_fd ",
libc_fd, libc_fd == ANY_FD ? " (any)" : "");
return;
}
::memcpy(buf, newpath, path_size);
fd_path = buf;
} else
fd_path = 0;
}
};
class File_descriptor_allocator : Allocator_avl_tpl<File_descriptor>
{
private:
Genode::Lock _lock;
public:
/**
* Constructor
*/
File_descriptor_allocator(Genode::Allocator &md_alloc);
/**
* Allocate file descriptor
*/
File_descriptor *alloc(Plugin *plugin, Plugin_context *context, int libc_fd = -1);
/**
* Release file descriptor
*/
void free(File_descriptor *fdo);
File_descriptor *find_by_libc_fd(int libc_fd);
};
/**
* Return singleton instance of file-descriptor allocator
*/
extern File_descriptor_allocator *file_descriptor_allocator();
}
#endif /* _LIBC_PLUGIN__FD_ALLOC_H_ */