From aee4786d8e80a2a4b2b2422afc4f8f342433c599 Mon Sep 17 00:00:00 2001 From: Liav A Date: Sat, 11 Sep 2021 09:19:20 +0300 Subject: Kernel: Introduce the DeviceManagement singleton This singleton simplifies many aspects that we struggled with before: 1. There's no need to make derived classes of Device expose the constructor as public anymore. The singleton is a friend of them, so he can call the constructor. This solves the issue with try_create_device helper neatly, hopefully for good. 2. Getting a reference of the NullDevice is now being done from this singleton, which means that NullDevice no longer needs to use its own singleton, and we can apply the try_create_device helper on it too :) 3. We can now defer registration completely after the Device constructor which means the Device constructor is merely assigning the major and minor numbers of the Device, and the try_create_device helper ensures it calls the after_inserting method immediately after construction. This creates a great opportunity to make registration more OOM-safe. --- Kernel/Devices/FullDevice.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'Kernel/Devices/FullDevice.h') diff --git a/Kernel/Devices/FullDevice.h b/Kernel/Devices/FullDevice.h index 3a3f7e09b9..2336e48cff 100644 --- a/Kernel/Devices/FullDevice.h +++ b/Kernel/Devices/FullDevice.h @@ -12,14 +12,15 @@ namespace Kernel { class FullDevice final : public CharacterDevice { AK_MAKE_ETERNAL + friend class DeviceManagement; + public: static NonnullRefPtr must_create(); virtual ~FullDevice() override; - // FIXME: We expose this constructor to make try_create_device helper to work +private: FullDevice(); -private: // ^CharacterDevice virtual KResultOr read(OpenFileDescription&, u64, UserOrKernelBuffer&, size_t) override; virtual KResultOr write(OpenFileDescription&, u64, const UserOrKernelBuffer&, size_t) override; -- cgit v1.2.3