ladybird/Kernel/Syscalls/anon_create.cpp
Andreas Kling b56646e293 Kernel: Switch process file descriptor table from spinlock to mutex
There's no reason for this to use a spinlock. Instead, let's allow
threads to block if someone else is using the descriptor table.
2022-01-29 02:17:09 +01:00

45 lines
1.2 KiB
C++

/*
* Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/FileSystem/AnonymousFile.h>
#include <Kernel/FileSystem/OpenFileDescription.h>
#include <Kernel/Memory/AnonymousVMObject.h>
#include <Kernel/Process.h>
namespace Kernel {
ErrorOr<FlatPtr> Process::sys$anon_create(size_t size, int options)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this);
TRY(require_promise(Pledge::stdio));
if (!size)
return EINVAL;
if (size % PAGE_SIZE)
return EINVAL;
if (size > NumericLimits<ssize_t>::max())
return EINVAL;
auto new_fd = TRY(allocate_fd());
auto vmobject = TRY(Memory::AnonymousVMObject::try_create_purgeable_with_size(size, AllocationStrategy::Reserve));
auto anon_file = TRY(AnonymousFile::try_create(move(vmobject)));
auto description = TRY(OpenFileDescription::try_create(move(anon_file)));
description->set_writable(true);
description->set_readable(true);
u32 fd_flags = 0;
if (options & O_CLOEXEC)
fd_flags |= FD_CLOEXEC;
m_fds.with_exclusive([&](auto& fds) { fds[new_fd.fd].set(move(description), fd_flags); });
return new_fd.fd;
}
}