diff --git a/src/libgreen/sched.rs b/src/libgreen/sched.rs index 38bb6e355a77..b9144047df5c 100644 --- a/src/libgreen/sched.rs +++ b/src/libgreen/sched.rs @@ -219,7 +219,7 @@ impl Scheduler { let message = stask.sched.get_mut_ref().message_queue.pop(); rtassert!(match message { msgq::Empty => true, _ => false }); - stask.task.get_mut_ref().destroyed = true; + stask.task.take().unwrap().drop(); } // This does not return a scheduler, as the scheduler is placed diff --git a/src/librustrt/local.rs b/src/librustrt/local.rs index bdb1c60b6d6f..e2a5eef0d99e 100644 --- a/src/librustrt/local.rs +++ b/src/librustrt/local.rs @@ -125,8 +125,8 @@ mod test { }).join(); } - fn cleanup_task(mut t: Box) { - t.destroyed = true; + fn cleanup_task(t: Box) { + t.drop(); } } diff --git a/src/librustrt/task.rs b/src/librustrt/task.rs index d27a4f25b4e7..0f4d72c9b326 100644 --- a/src/librustrt/task.rs +++ b/src/librustrt/task.rs @@ -100,12 +100,21 @@ pub struct Task { pub storage: LocalStorage, pub unwinder: Unwinder, pub death: Death, - pub destroyed: bool, pub name: Option, + state: TaskState, imp: Option>, } +// Once a task has entered the `Armed` state it must be destroyed via `drop`, +// and no other method. This state is used to track this transition. +#[deriving(PartialEq)] +enum TaskState { + New, + Armed, + Destroyed, +} + pub struct TaskOpts { /// Invoke this procedure with the result of the task when it finishes. pub on_exit: Option, @@ -159,7 +168,7 @@ impl Task { storage: LocalStorage(None), unwinder: Unwinder::new(), death: Death::new(), - destroyed: false, + state: New, name: None, imp: None, } @@ -203,7 +212,7 @@ impl Task { /// }).destroy(); /// # } /// ``` - pub fn run(self: Box, f: ||) -> Box { + pub fn run(mut self: Box, f: ||) -> Box { assert!(!self.is_destroyed(), "cannot re-use a destroyed task"); // First, make sure that no one else is in TLS. This does not allow @@ -212,6 +221,7 @@ impl Task { if Local::exists(None::) { fail!("cannot run a task recursively inside another"); } + self.state = Armed; Local::put(self); // There are two primary reasons that general try/catch is unsafe. The @@ -333,12 +343,12 @@ impl Task { // Now that we're done, we remove the task from TLS and flag it for // destruction. let mut task: Box = Local::take(); - task.destroyed = true; + task.state = Destroyed; return task; } /// Queries whether this can be destroyed or not. - pub fn is_destroyed(&self) -> bool { self.destroyed } + pub fn is_destroyed(&self) -> bool { self.state == Destroyed } /// Inserts a runtime object into this task, transferring ownership to the /// task. It is illegal to replace a previous runtime object in this task @@ -453,12 +463,20 @@ impl Task { pub fn can_block(&self) -> bool { self.imp.get_ref().can_block() } + + /// Consume this task, flagging it as a candidate for destruction. + /// + /// This function is required to be invoked to destroy a task. A task + /// destroyed through a normal drop will abort. + pub fn drop(mut self) { + self.state = Destroyed; + } } impl Drop for Task { fn drop(&mut self) { rtdebug!("called drop for a task: {}", self as *mut Task as uint); - rtassert!(self.destroyed); + rtassert!(self.state != Armed); } } @@ -634,12 +652,17 @@ mod test { begin_unwind("cause", file!(), line!()) } + #[test] + fn drop_new_task_ok() { + drop(Task::new()); + } + // Task blocking tests #[test] fn block_and_wake() { let task = box Task::new(); let mut task = BlockedTask::block(task).wake().unwrap(); - task.destroyed = true; + task.destroy(); } }