ladybird/Kernel/ZeroDevice.h

#pragma once

#include "CharacterDevice.h"

class ZeroDevice final : public CharacterDevice {
    AK_MAKE_ETERNAL
public:
    ZeroDevice();
    virtual ~ZeroDevice() override;

private:
    // ^CharacterDevice
    virtual ssize_t read(Process&, byte*, ssize_t) override;
    virtual ssize_t write(Process&, const byte*, ssize_t) override;
    virtual bool can_read(Process&) const override;
    virtual bool can_write(Process&) const override { return true; }
    virtual const char* class_name() const override { return "ZeroDevice"; }
};
Add basic character device support. Start with null and zero. 2018-10-14 02:59:22 +02:00			`#pragma once`

			`#include "CharacterDevice.h"`

			`class ZeroDevice final : public CharacterDevice {`
Add a kmalloc_eternal() for things that will never be destroyed. 2018-10-31 23:19:15 +01:00			`AK_MAKE_ETERNAL`
Add basic character device support. Start with null and zero. 2018-10-14 02:59:22 +02:00			`public:`
			`ZeroDevice();`
Implement a basic way for read() to block. FileHandle gets a hasDataAvailableForRead() getter. If this returns true in sys$read(), the task will block(BlockedRead) + yield. The fd blocked on is stored in Task::m_fdBlockedOnRead. The scheduler then looks at the state of that fd during the unblock phase. This makes "sh" restful. :^) There's still some problem with the kernel not surviving the colonel task getting scheduled. I need to figure that out and fix it. 2018-10-25 13:07:59 +02:00			`virtual ~ZeroDevice() override;`
Add basic character device support. Start with null and zero. 2018-10-14 02:59:22 +02:00
Kernel: Make /proc/PID/fds display something useful for character devices. 2019-01-21 02:33:01 +01:00			`private:`
			`// ^CharacterDevice`
Kernel: Make syscalls that take a buffer size use ssize_t instead of size_t. Dealing with the unsigned overflow propagation here just seems unreasonably error prone. Let's limit ourselves to 2GB buffer sizes instead. 2019-02-25 21:19:57 +01:00			`virtual ssize_t read(Process&, byte*, ssize_t) override;`
			`virtual ssize_t write(Process&, const byte*, ssize_t) override;`
Rename CharacterDevice::has_data_available_for_reading() -> can_read(). 2019-01-16 00:10:13 +01:00			`virtual bool can_read(Process&) const override;`
Allow character devices to block write attempts until there is more space. 2019-01-15 09:17:22 +01:00			`virtual bool can_write(Process&) const override { return true; }`
Kernel: Make /proc/PID/fds display something useful for character devices. 2019-01-21 02:33:01 +01:00			`virtual const char* class_name() const override { return "ZeroDevice"; }`
Add basic character device support. Start with null and zero. 2018-10-14 02:59:22 +02:00			`};`