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/*
* Copyright (c) 2020, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/IntrusiveList.h>
#include <Kernel/Library/NonnullLockRefPtr.h>
#include <Kernel/Memory/ScopedAddressSpaceSwitcher.h>
#include <Kernel/Process.h>
#include <Kernel/Thread.h>
#include <Kernel/UserOrKernelBuffer.h>
#include <Kernel/WaitQueue.h>
namespace Kernel {
class Device;
extern WorkQueue* g_io_work;
class AsyncDeviceRequest : public AtomicRefCounted<AsyncDeviceRequest> {
AK_MAKE_NONCOPYABLE(AsyncDeviceRequest);
AK_MAKE_NONMOVABLE(AsyncDeviceRequest);
public:
enum [[nodiscard]] RequestResult {
Pending = 0,
Started,
Success,
Failure,
MemoryFault,
OutOfMemory,
Cancelled
};
class RequestWaitResult {
friend class AsyncDeviceRequest;
public:
RequestResult request_result() const { return m_request_result; }
Thread::BlockResult wait_result() const { return m_wait_result; }
private:
RequestWaitResult(RequestResult request_result, Thread::BlockResult wait_result)
: m_request_result(request_result)
, m_wait_result(wait_result)
{
}
RequestResult m_request_result;
Thread::BlockResult m_wait_result;
};
virtual ~AsyncDeviceRequest();
virtual StringView name() const = 0;
virtual void start() = 0;
void add_sub_request(NonnullLockRefPtr<AsyncDeviceRequest>);
[[nodiscard]] RequestWaitResult wait(Time* = nullptr);
void do_start(SpinlockLocker<Spinlock<LockRank::None>>&& requests_lock)
{
if (is_completed_result(m_result))
return;
m_result = Started;
requests_lock.unlock();
start();
}
void complete(RequestResult result);
void set_private(void* priv)
{
VERIFY(!m_private || !priv);
m_private = priv;
}
void* get_private() const { return m_private; }
template<typename... Args>
ErrorOr<void> write_to_buffer(UserOrKernelBuffer& buffer, Args... args)
{
if (in_target_context(buffer))
return buffer.write(forward<Args>(args)...);
ScopedAddressSpaceSwitcher switcher(m_process);
return buffer.write(forward<Args>(args)...);
}
template<size_t BUFFER_BYTES, typename... Args>
ErrorOr<size_t> write_to_buffer_buffered(UserOrKernelBuffer& buffer, Args... args)
{
if (in_target_context(buffer))
return buffer.write_buffered<BUFFER_BYTES>(forward<Args>(args)...);
ScopedAddressSpaceSwitcher switcher(m_process);
return buffer.write_buffered<BUFFER_BYTES>(forward<Args>(args)...);
}
template<typename... Args>
ErrorOr<void> read_from_buffer(UserOrKernelBuffer const& buffer, Args... args)
{
if (in_target_context(buffer))
return buffer.read(forward<Args>(args)...);
ScopedAddressSpaceSwitcher switcher(m_process);
return buffer.read(forward<Args>(args)...);
}
template<size_t BUFFER_BYTES, typename... Args>
ErrorOr<size_t> read_from_buffer_buffered(UserOrKernelBuffer const& buffer, Args... args)
{
if (in_target_context(buffer))
return buffer.read_buffered<BUFFER_BYTES>(forward<Args>(args)...);
ScopedAddressSpaceSwitcher switcher(m_process);
return buffer.read_buffered<BUFFER_BYTES>(forward<Args>(args)...);
}
protected:
AsyncDeviceRequest(Device&);
RequestResult get_request_result() const;
private:
void sub_request_finished(AsyncDeviceRequest&);
void request_finished();
[[nodiscard]] bool in_target_context(UserOrKernelBuffer const& buffer) const
{
if (buffer.is_kernel_buffer())
return true;
return m_process == &Process::current();
}
[[nodiscard]] static bool is_completed_result(RequestResult result)
{
return result > Started;
}
Device& m_device;
AsyncDeviceRequest* m_parent_request { nullptr };
RequestResult m_result { Pending };
IntrusiveListNode<AsyncDeviceRequest, LockRefPtr<AsyncDeviceRequest>> m_list_node;
using AsyncDeviceSubRequestList = IntrusiveList<&AsyncDeviceRequest::m_list_node>;
AsyncDeviceSubRequestList m_sub_requests_pending;
AsyncDeviceSubRequestList m_sub_requests_complete;
WaitQueue m_queue;
NonnullLockRefPtr<Process> m_process;
void* m_private { nullptr };
mutable Spinlock<LockRank::None> m_lock {};
};
}
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