648bcd1505
This patch unifies the patterns of using the 'Genode' and 'Libc' namespaces. Types defined in the 'internal/' headers reside in the 'Libc' namespace. The code in the headers does not need to use the 'Libc::' prefix. Compilation units import the 'Libc' namespace after the definition of local types. Local types reside in the 'Libc' namespace (and should eventually move to an 'internal/' header). Since the 'Libc' namespace imports the 'Genode' namespace, there is no need to use the 'Genode::' prefix. Consequently, code in the compilation units rarely need to qualify the 'Genode' or 'Libc' namespaces. There are a few cases where the 'Libc', the 'Genode', and the global (libc) namespaces are ambigious. In these cases, an explicit clarification is needed: - 'Genode::Allocator' differs from 'Libc::Allocator'. - 'Genode::Env' differs from 'Libc::Env'. - Genode's string functions (strcmp, memcpy, strcpy) conflict with the names of the (global) libc functions. - There exist both 'Genode::uint64_t' and the libc'c 'uint64_t'. Issue #3497
90 lines
1.8 KiB
C++
90 lines
1.8 KiB
C++
/*
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* \brief 'pread()' and 'pwrite()' implementations
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* \author Christian Prochaska
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* \date 2012-07-11
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*/
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/*
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* Copyright (C) 2012-2017 Genode Labs GmbH
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*
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* This file is part of the Genode OS framework, which is distributed
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* under the terms of the GNU Affero General Public License version 3.
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*/
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/* Genode includes */
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#include <base/lock.h>
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#include <libc-plugin/fd_alloc.h>
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/* libc includes */
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#include <sys/types.h>
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#include <sys/uio.h>
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#include <unistd.h>
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/* libc-internal includes */
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#include <internal/types.h>
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struct Read
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{
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ssize_t operator()(int fd, void *buf, size_t count)
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{
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return read(fd, buf, count);
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}
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};
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struct Write
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{
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ssize_t operator()(int fd, const void *buf, size_t count)
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{
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return write(fd, buf, count);
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}
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};
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using namespace Libc;
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template <typename Rw_func, typename Buf_type>
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static ssize_t pread_pwrite_impl(Rw_func rw_func, int fd, Buf_type buf, ::size_t count, ::off_t offset)
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{
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File_descriptor *fdesc = file_descriptor_allocator()->find_by_libc_fd(fd);
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if (fdesc == 0)
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return -1;
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Lock_guard<Lock> rw_lock_guard(fdesc->lock);
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::off_t old_offset = lseek(fd, 0, SEEK_CUR);
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if (old_offset == -1)
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return -1;
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if (lseek(fd, offset, SEEK_SET) == -1)
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return -1;
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ssize_t result = rw_func(fd, buf, count);
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if (lseek(fd, old_offset, SEEK_SET) == -1)
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return -1;
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return result;
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}
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extern "C" ssize_t pread(int fd, void *buf, ::size_t count, ::off_t offset)
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{
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return pread_pwrite_impl(Read(), fd, buf, count, offset);
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}
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extern "C" __attribute__((alias("pread")))
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ssize_t __sys_pread(int fd, void *buf, ::size_t count, ::off_t offset);
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extern "C" ssize_t pwrite(int fd, const void *buf, ::size_t count, ::off_t offset)
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{
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return pread_pwrite_impl(Write(), fd, buf, count, offset);
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}
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extern "C" __attribute__((alias("pwrite")))
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ssize_t __sys_pwrite(int fd, const void *buf, ::size_t count, ::off_t offset);
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