Struct TimerFile 

pub struct TimerFile { /* private fields */ }

A TimerFile represents a file created by timerfd_create.

Clients can read the number of times the timer has triggered from the file. The file supports blocking reads, waiting for the timer to trigger.

Implementations

impl TimerFile

pub fn new_file<L>( locked: &mut Locked<L>, current_task: &CurrentTask, wakeup_type: TimerWakeup, timeline: Timeline, flags: OpenFlags, ) -> Result<FileHandle, Errno>

where L: LockEqualOrBefore<FileOpsCore>,

Creates a new anonymous TimerFile in kernel.

Returns an error if the zx::Timer could not be created.

pub fn current_timer_spec(&self) -> itimerspec

Returns the current itimerspec for the file.

The returned itimerspec.it_value contains the amount of time remaining until the next timer trigger.

pub fn set_timer_spec( &self, current_task: &CurrentTask, file_object: &FileObject, timer_spec: itimerspec, flags: u32, ) -> Result<itimerspec, Errno>

Sets the itimerspec for the timer, which will either update the associated zx::Timer’s scheduled trigger or cancel the timer.

Returns the previous itimerspec on success.

Trait Implementations

impl FileOps for TimerFile

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

Called when the FileObject is destroyed.

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, event_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 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.