Struct task::JoinableTaskRef
source · pub struct JoinableTaskRef { /* private fields */ }Expand description
A reference to a Task that can be joined; auto-derefs into TaskRef.
This allows another task to join this task, i.e., wait for this task
to finish executing, and to obtain its ExitValue thereafter.
Drop-based Behavior
The contained Task is joinable until this object is dropped.
When dropped, this task will be marked as non-joinable and treated as an “orphan” task.
This means that there is no way for another task to wait for it to complete
or obtain its exit value.
As such, this task will be auto-reaped after it exits (in order to avoid zombie tasks).
Not Clone-able
Due to the above drop-based behavior, this type does not implement Clone
because it assumes there is only ever one JoinableTaskRef per task.
However, this type auto-derefs into an inner TaskRef,
which can be cloned, so you can easily call .clone() on it.
Implementations§
source§impl JoinableTaskRef
impl JoinableTaskRef
sourcepub fn join(&self) -> Result<ExitValue, &'static str>
pub fn join(&self) -> Result<ExitValue, &'static str>
Blocks the current task until this task has exited.
Synchronizes memory with respect to the joined task.
Return
Okcontaining thisTask’sExitValueonce this task has exited.- This includes cases where this
Taskfailed or was killed.
- This includes cases where this
Errif there was a problem while waiting for this task to exit.- This does not include cases where this
Taskfailed or was killed, rather only cases where thejoinoperation itself failed.
- This does not include cases where this
Methods from Deref<Target = TaskRef>§
sourcepub fn downgrade(&self) -> WeakTaskRef
pub fn downgrade(&self) -> WeakTaskRef
Creates a new weak reference to this Task, similar to Weak.
sourcepub fn is_joinable(&self) -> bool
pub fn is_joinable(&self) -> bool
Returns true if this task is joinable, false if not.
- If
true, another task holds theJoinableTaskRefobject that was created byTaskRef::create(), which indicates that that other task is able to wait for this task to exit and thus be able to obtain this task’s exit value. - If
false, theJoinableTaskRefobject was dropped, and therefore no other task can join this task or obtain its exit value.
When a task is not joinable, it is considered to be an orphan and will thus be automatically reaped and cleaned up once it exits because no other task is waiting on it to exit.
sourcepub fn kill(&self, reason: KillReason) -> Result<(), &'static str>
pub fn kill(&self, reason: KillReason) -> Result<(), &'static str>
Kills this Task (not a clean exit) without allowing it to run to completion.
The provided KillReason indicates why it was killed.
** Currently this immediately kills the task without performing any unwinding cleanup. In the near future, the task will be unwound such that its resources are freed/dropped to ensure proper cleanup before the task is actually fully killed. **
Locking / Deadlock
This method obtains a writable lock on the underlying Task’s inner state.
Return
- Returns
Okif the exit status was successfully set to the givenKillReason. - Returns
Errif thisTaskwas already exited, and does not overwrite the existing exit status.
Note
The Task will not be halted immediately –
it will finish running its current timeslice, and then never be run again.
Methods from Deref<Target = Task>§
pub fn set_env(&self, new_env: Arc<Mutex<Environment, Spin>, Global>)
pub fn set_env(&self, new_env: Arc<Mutex<Environment, Spin>, Global>)
Sets the Environment of this Task.
Locking / Deadlock
Obtains the lock on this Task’s inner state in order to mutate it.
pub fn get_env(&self) -> Arc<Mutex<Environment, Spin>, Global>
pub fn get_env(&self) -> Arc<Mutex<Environment, Spin>, Global>
Gets a reference to this task’s Environment.
Locking / Deadlock
Obtains the lock on this Task’s inner state in order to access it.
pub fn is_running(&self) -> bool
pub fn is_running(&self) -> bool
Returns true if this Task is currently running.
pub fn running_on_cpu(&self) -> Option<CpuId>
pub fn running_on_cpu(&self) -> Option<CpuId>
Returns the ID of the CPU this Task is currently running on.
pub fn pinned_cpu(&self) -> Option<CpuId>
pub fn pinned_cpu(&self) -> Option<CpuId>
Returns the ID of the CPU this Task is pinned on,
or None if it is not pinned.
pub fn is_runnable(&self) -> bool
pub fn is_runnable(&self) -> bool
pub fn get_namespace(&self) -> &Arc<CrateNamespace, Global>
pub fn get_namespace(&self) -> &Arc<CrateNamespace, Global>
Returns the namespace that this Task is loaded/linked into and runs within.
pub fn with_kstack<R, F>(&self, func: F) -> Rwhere
F: FnOnce(&Stack) -> R,
pub fn with_kstack<R, F>(&self, func: F) -> Rwhere F: FnOnce(&Stack) -> R,
Exposes read-only access to this Task’s [Stack] by invoking
the given func with a reference to its kernel stack.
Locking / Deadlock
Obtains the lock on this Task’s inner state for the duration of func
in order to access its stack.
The given func must not attempt to obtain that same inner lock.
pub fn with_restart_info<R, F>(&self, func: F) -> Rwhere
F: FnOnce(Option<&RestartInfo>) -> R,
pub fn with_restart_info<R, F>(&self, func: F) -> Rwhere F: FnOnce(Option<&RestartInfo>) -> R,
Invokes func with immutable access to this Task’s RestartInfo.
Locking / Deadlock
Obtains the lock on this Task’s inner state for the duration of func
in order to access its stack.
The given func must not attempt to obtain that same inner lock.
pub fn has_exited(&self) -> bool
pub fn has_exited(&self) -> bool
Returns true if this Task has been exited, i.e.,
if its RunState is either Exited or Reaped.
pub fn is_application(&self) -> bool
pub fn is_application(&self) -> bool
Returns true if this is an application Task.
This will also return true if this task was spawned by an application task,
since a task inherits the “application crate” field from its “parent” that spawned it.
pub fn is_restartable(&self) -> bool
pub fn is_restartable(&self) -> bool
Returns true if this Task was spawned as a restartable task.
Locking / Deadlock
Obtains the lock on this Task’s inner state in order to access it.
pub fn block(&self) -> Result<RunState, RunState>
pub fn block(&self) -> Result<RunState, RunState>
Blocks this Task by setting its runstate to RunState::Blocked.
Returns the previous runstate on success, and the current runstate on error. This will only succeed if the task is runnable or already blocked.
pub fn block_initing_task(&self) -> Result<RunState, RunState>
pub fn block_initing_task(&self) -> Result<RunState, RunState>
Blocks this Task if it is a newly-spawned task currently being initialized.
This is a special case only to be used when spawning a new task that should not be immediately scheduled in; it will fail for all other cases.
Returns the previous runstate (i.e. RunState::Initing) on success,
or the current runstate on error.
pub fn unblock(&self) -> Result<RunState, RunState>
pub fn unblock(&self) -> Result<RunState, RunState>
Unblocks this Task by setting its runstate to RunState::Runnable.
Returns the previous runstate on success, and the current runstate on error. Will only succed if the task is blocked or already runnable.
pub fn make_inited_task_runnable(&self) -> Result<RunState, RunState>
pub fn make_inited_task_runnable(&self) -> Result<RunState, RunState>
Makes this Task Runnable if it is a newly-spawned and fully initialized task.
This is a special case only to be used when spawning a new task that is ready to be scheduled in; it will fail for all other cases.
Returns the previous runstate (i.e. RunState::Initing) on success, and
the current runstate on error.
pub fn suspend(&self)
pub fn suspend(&self)
Suspends this Task.
pub fn unsuspend(&self)
pub fn unsuspend(&self)
Unsuspends this Task.
pub fn is_suspended(&self) -> bool
pub fn is_suspended(&self) -> bool
Returns true if this Task is suspended.
Note that a task being suspended is independent from its RunState.