ladybird/Kernel/Locking/LockRank.h
2021-09-08 19:17:07 +03:00

43 lines
1.3 KiB
C++

/*
* Copyright (c) 2021, Brian Gianforcaro <bgianf@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/EnumBits.h>
namespace Kernel {
// To catch bugs where locks are taken out of order, we annotate all locks
// in the kernel with a rank. The rank describes the order in which locks
// are allowed to be taken. If a lock is acquired, and it is of an incompatible
// rank with the lock held by the executing thread then the system can detect
// the lock order violation and respond appropriately (crash with error).
//
// A thread holding a lower ranked lock cannot acquire a lock of a greater or equal rank.
enum class LockRank : int {
// Special marker for locks which haven't been annotated yet.
// Note: This should be removed once all locks are annotated.
None = 0x000,
// We need to be able to handle page faults from anywhere, so
// memory manager locks are our lowest rank lock.
MemoryManager = 0x001,
Interrupts = 0x002,
FileSystem = 0x004,
Thread = 0x008,
// Process locks are the highest rank, as they normally are taken
// first thing when processing syscalls.
Process = 0x010,
};
AK_ENUM_BITWISE_OPERATORS(LockRank);
void track_lock_acquire(LockRank);
void track_lock_release(LockRank);
}