serenity/Kernel/Devices/NullDevice.h

#pragma once

#include "CharacterDevice.h"

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

    static NullDevice& the();

private:
    // ^CharacterDevice
    virtual ssize_t read(FileDescription&, u8*, ssize_t) override;
    virtual ssize_t write(FileDescription&, const u8*, ssize_t) override;
    virtual bool can_write(FileDescription&) const override { return true; }
    virtual bool can_read(FileDescription&) const override;
    virtual const char* class_name() const override { return "NullDevice"; }
};
Add basic character device support. Start with null and zero. 2018-10-14 02:59:22 +02:00			`#pragma once`

			`#include "CharacterDevice.h"`

			`class NullDevice 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:`
			`NullDevice();`
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 ~NullDevice() override;`
Add basic character device support. Start with null and zero. 2018-10-14 02:59:22 +02:00
Kernel: Make sure processes always start out with fds 0, 1 and 2 open. If we don't have a TTY for the process, fall back to /dev/null. 2019-02-12 11:25:25 +01:00			`static NullDevice& the();`

Kernel: Make /proc/PID/fds display something useful for character devices. 2019-01-21 02:33:01 +01:00			`private:`
			`// ^CharacterDevice`
AK: Rename the common integer typedefs to make it obvious what they are. These types can be picked up by including <AK/Types.h>: * u8, u16, u32, u64 (unsigned) * i8, i16, i32, i64 (signed) 2019-07-03 21:17:35 +02:00			`virtual ssize_t read(FileDescription&, u8*, ssize_t) override;`
			`virtual ssize_t write(FileDescription&, const u8*, ssize_t) override;`
Kernel: Rename FileDescriptor to FileDescription. After reading a bunch of POSIX specs, I've learned that a file descriptor is the number that refers to a file description, not the description itself. So this patch renames FileDescriptor to FileDescription, and Process now has FileDescription* file_description(int fd). 2019-06-07 09:36:51 +02:00			`virtual bool can_write(FileDescription&) const override { return true; }`
			`virtual bool can_read(FileDescription&) const override;`
Kernel: Report the correct name for NullDevice. 2019-02-17 09:40:19 +01:00			`virtual const char* class_name() const override { return "NullDevice"; }`
Add basic character device support. Start with null and zero. 2018-10-14 02:59:22 +02:00			`};`