mirror of
https://github.com/genodelabs/genode.git
synced 2025-01-10 06:52:56 +00:00
ca971bbfd8
This patch changes the top-level directory layout as a preparatory step for improving the tools for managing 3rd-party source codes. The rationale is described in the issue referenced below. Issue #1082
78 lines
1.5 KiB
C++
78 lines
1.5 KiB
C++
/*
|
|
* \brief 'pread()' and 'pwrite()' implementations
|
|
* \author Christian Prochaska
|
|
* \date 2012-07-11
|
|
*/
|
|
|
|
/*
|
|
* Copyright (C) 2012-2013 Genode Labs GmbH
|
|
*
|
|
* This file is part of the Genode OS framework, which is distributed
|
|
* under the terms of the GNU General Public License version 2.
|
|
*/
|
|
|
|
/* Genode includes */
|
|
#include <base/lock.h>
|
|
#include <libc-plugin/fd_alloc.h>
|
|
|
|
/* libc includes */
|
|
#include <sys/types.h>
|
|
#include <sys/uio.h>
|
|
#include <unistd.h>
|
|
|
|
|
|
struct Read
|
|
{
|
|
ssize_t operator()(int fd, void *buf, size_t count)
|
|
{
|
|
return read(fd, buf, count);
|
|
}
|
|
};
|
|
|
|
|
|
struct Write
|
|
{
|
|
ssize_t operator()(int fd, const void *buf, size_t count)
|
|
{
|
|
return write(fd, buf, count);
|
|
}
|
|
};
|
|
|
|
|
|
template <typename Rw_func, typename Buf_type>
|
|
static ssize_t pread_pwrite_impl(Rw_func rw_func, int fd, Buf_type buf, ::size_t count, ::off_t offset)
|
|
{
|
|
Libc::File_descriptor *fdesc = Libc::file_descriptor_allocator()->find_by_libc_fd(fd);
|
|
if (fdesc == 0)
|
|
return -1;
|
|
|
|
Genode::Lock_guard<Genode::Lock> rw_lock_guard(fdesc->lock);
|
|
|
|
off_t old_offset = lseek(fd, 0, SEEK_CUR);
|
|
|
|
if (old_offset == -1)
|
|
return -1;
|
|
|
|
if (lseek(fd, offset, SEEK_SET) == -1)
|
|
return -1;
|
|
|
|
ssize_t result = rw_func(fd, buf, count);
|
|
|
|
if (lseek(fd, old_offset, SEEK_SET) == -1)
|
|
return -1;
|
|
|
|
return result;
|
|
}
|
|
|
|
|
|
extern "C" ssize_t pread(int fd, void *buf, ::size_t count, ::off_t offset)
|
|
{
|
|
return pread_pwrite_impl(Read(), fd, buf, count, offset);
|
|
}
|
|
|
|
|
|
extern "C" ssize_t pwrite(int fd, const void *buf, ::size_t count, ::off_t offset)
|
|
{
|
|
return pread_pwrite_impl(Write(), fd, buf, count, offset);
|
|
}
|