ladybird/Kernel/Devices/RandomDevice.cpp
Liav A f5de4f24b2 Kernel/Devices: Defer creation of SysFS component after the constructor
Instead of doing so in the constructor, let's do immediately after the
constructor, so we can safely pass a reference of a Device, so the
SysFSDeviceComponent constructor can use that object to identify whether
it's a block device or a character device.
This allows to us to not hold a device in SysFSDeviceComponent with a
RefPtr.
Also, we also call the before_removing method in both SlavePTY::unref
and File::unref, so because Device has that method being overrided, it
can ensure the device is removed always cleanly.
2021-09-11 11:41:14 +02:00

50 lines
1.2 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Devices/RandomDevice.h>
#include <Kernel/Random.h>
#include <Kernel/Sections.h>
namespace Kernel {
UNMAP_AFTER_INIT NonnullRefPtr<RandomDevice> RandomDevice::must_create()
{
auto random_device_or_error = try_create_device<RandomDevice>();
// FIXME: Find a way to propagate errors
VERIFY(!random_device_or_error.is_error());
return random_device_or_error.release_value();
}
UNMAP_AFTER_INIT RandomDevice::RandomDevice()
: CharacterDevice(1, 8)
{
}
UNMAP_AFTER_INIT RandomDevice::~RandomDevice()
{
}
bool RandomDevice::can_read(const OpenFileDescription&, size_t) const
{
return true;
}
KResultOr<size_t> RandomDevice::read(OpenFileDescription&, u64, UserOrKernelBuffer& buffer, size_t size)
{
return buffer.write_buffered<256>(size, [&](Bytes bytes) {
get_good_random_bytes(bytes);
return bytes.size();
});
}
KResultOr<size_t> RandomDevice::write(OpenFileDescription&, u64, const UserOrKernelBuffer&, size_t size)
{
// FIXME: Use input for entropy? I guess that could be a neat feature?
return size;
}
}