Struct PowerWakeupCountFile 

pub struct PowerWakeupCountFile { /* private fields */ }

This file allows user space to put the system into a sleep state while taking into account the concurrent arrival of wakeup events.

• Reading from it returns the current number of registered wakeup events and it blocks if some wakeup events are being processed when the file is read from.
• Writing to it will only succeed if the current number of wakeup events is equal to the written value and, if successful, will make the kernel abort a subsequent transition to a sleep state

Implementations

impl PowerWakeupCountFile

pub fn new_node( suspend_resume_manager: Arc<SuspendResumeManager>, ) -> impl FsNodeOps

Trait Implementations

impl FileOps for PowerWakeupCountFile

fn is_seekable(&self) -> bool

Returns whether the file is seekable.

fn seek( &self, locked: &mut Locked<FileOpsCore>, file: &FileObject, current_task: &CurrentTask, current_offset: off_t, target: SeekTarget, ) -> Result<off_t, Errno>

Adjust the current_offset if the file is seekable.

fn sync( &self, file: &FileObject, _current_task: &CurrentTask, ) -> Result<(), Errno>

Syncs cached state associated with the file descriptor to persistent storage.

fn write( &self, _locked: &mut Locked<FileOpsCore>, _file: &FileObject, _current_task: &CurrentTask, _offset: usize, data: &mut dyn InputBuffer, ) -> Result<usize, Errno>

Write to the file with an offset. If the file does not have persistent offsets (either directly, or because it is not seekable), offset will be 0 and can be ignored. Returns the number of bytes written.

fn read( &self, locked: &mut Locked<FileOpsCore>, file: &FileObject, current_task: &CurrentTask, offset: usize, data: &mut dyn OutputBuffer, ) -> Result<usize, Errno>

Read from the file at an offset. If the file does not have persistent offsets (either directly, or because it is not seekable), offset will be 0 and can be ignored. Returns the number of bytes read.

fn wait_async( &self, _locked: &mut Locked<FileOpsCore>, _file: &FileObject, _current_task: &CurrentTask, waiter: &Waiter, events: FdEvents, handler: EventHandler, ) -> Option<WaitCanceler>

Establish a one-shot, edge-triggered, asynchronous wait for the given FdEvents for the given file and task. Returns None if this file does not support blocking waits.

fn query_events( &self, _locked: &mut Locked<FileOpsCore>, _file: &FileObject, _current_task: &CurrentTask, ) -> Result<FdEvents, Errno>

The events currently active on this file.

fn open( &self, _locked: &mut Locked<FileOpsCore>, _file: &FileObject, _current_task: &CurrentTask, ) -> Result<(), Errno>

Called when the FileObject is opened/created

fn close( self: Box<Self>, _locked: &mut Locked<FileOpsCore>, _file: &FileObjectState, _current_task: &CurrentTask, )

Called when the FileObject is destroyed.

fn flush( &self, _locked: &mut Locked<FileOpsCore>, _file: &FileObject, _current_task: &CurrentTask, )

Called every time close() is called on this file, even if the file is not ready to be released.

fn has_persistent_offsets(&self) -> bool

Returns whether the file has meaningful seek offsets. Returning false is only optimization and will makes FileObject never hold the offset lock when calling read and write.

fn writes_update_seek_offset(&self) -> bool

Returns true if write() operations on the file will update the seek offset.

fn data_sync( &self, file: &FileObject, current_task: &CurrentTask, ) -> Result<(), Errno>

Syncs cached data, and only enough metadata to retrieve said data, to persistent storage.

fn get_memory( &self, _locked: &mut Locked<FileOpsCore>, _file: &FileObject, _current_task: &CurrentTask, _length: Option<usize>, _prot: ProtectionFlags, ) -> Result<Arc<MemoryObject>, Errno>

Returns a VMO representing this file. At least the requested protection flags must be set on the VMO. Reading or writing the VMO must read or write the file. If this is not possible given the requested protection, an error must be returned. The length is a hint for the desired size of the VMO. The returned VMO may be larger or smaller than the requested length. This method is typically called by Self::mmap.

fn mmap( &self, locked: &mut Locked<FileOpsCore>, file: &FileObject, current_task: &CurrentTask, addr: DesiredAddress, memory_offset: u64, length: usize, prot_flags: ProtectionFlags, options: MappingOptions, filename: NamespaceNode, ) -> Result<UserAddress, Errno>

Responds to an mmap call. The default implementation calls Self::get_memory to get a VMO and then maps it with [crate::mm::MemoryManager::map]. Only implement this trait method if your file needs to control mapping, or record where a VMO gets mapped.

fn readdir( &self, _locked: &mut Locked<FileOpsCore>, _file: &FileObject, _current_task: &CurrentTask, _sink: &mut dyn DirentSink, ) -> Result<(), Errno>

Respond to a getdents or getdents64 calls.

fn ioctl( &self, locked: &mut Locked<Unlocked>, file: &FileObject, current_task: &CurrentTask, request: u32, arg: SyscallArg, ) -> Result<SyscallResult, Errno>

fn fcntl( &self, _file: &FileObject, _current_task: &CurrentTask, cmd: u32, _arg: u64, ) -> Result<SyscallResult, Errno>

fn to_handle( &self, file: &FileObject, current_task: &CurrentTask, ) -> Result<Option<NullableHandle>, Errno>

Return a handle that allows access to this file descritor through the zxio protocols.

fn as_thread_group_key( &self, _file: &FileObject, ) -> Result<ThreadGroupKey, Errno>

Returns the associated pid_t.

fn readahead( &self, _file: &FileObject, _current_task: &CurrentTask, _offset: usize, _length: usize, ) -> Result<(), Errno>

fn extra_fdinfo( &self, _locked: &mut Locked<FileOpsCore>, _file: &FileHandle, _current_task: &CurrentTask, ) -> Option<FsString>

Extra information that is included in the /proc//fdfino/ entry.