Files
rust/src/libcore/task.rs
2012-09-13 20:48:33 +02:00

2435 lines
79 KiB
Rust

// NB: transitionary, de-mode-ing.
#[forbid(deprecated_mode)];
#[forbid(deprecated_pattern)];
/*!
* Task management.
*
* An executing Rust program consists of a tree of tasks, each with their own
* stack, and sole ownership of their allocated heap data. Tasks communicate
* with each other using ports and channels.
*
* When a task fails, that failure will propagate to its parent (the task
* that spawned it) and the parent will fail as well. The reverse is not
* true: when a parent task fails its children will continue executing. When
* the root (main) task fails, all tasks fail, and then so does the entire
* process.
*
* Tasks may execute in parallel and are scheduled automatically by the
* runtime.
*
* # Example
*
* ~~~
* do spawn {
* log(error, "Hello, World!");
* }
* ~~~
*/
use cmp::Eq;
use result::Result;
use pipes::{stream, Chan, Port};
export Task;
export TaskResult;
export Notification;
export SchedMode;
export SchedOpts;
export TaskOpts;
export TaskBuilder;
export task;
export default_task_opts;
export get_opts;
export set_opts;
export set_sched_mode;
export add_wrapper;
export run;
export future_result;
export run_listener;
export run_with;
export spawn;
export spawn_unlinked;
export spawn_supervised;
export spawn_with;
export spawn_listener;
export spawn_conversation;
export spawn_sched;
export try;
export yield;
export failing;
export get_task;
export unkillable, rekillable;
export atomically;
export local_data_key;
export local_data_pop;
export local_data_get;
export local_data_set;
export local_data_modify;
export SingleThreaded;
export ThreadPerCore;
export ThreadPerTask;
export ManualThreads;
export PlatformThread;
macro_rules! move_it (
{ $x:expr } => { unsafe { let y <- *ptr::addr_of($x); move y } }
)
/* Data types */
/// A handle to a task
enum Task {
TaskHandle(task_id)
}
impl Task : cmp::Eq {
pure fn eq(&&other: Task) -> bool { *self == *other }
pure fn ne(&&other: Task) -> bool { !self.eq(other) }
}
/**
* Indicates the manner in which a task exited.
*
* A task that completes without failing is considered to exit successfully.
* Supervised ancestors and linked siblings may yet fail after this task
* succeeds. Also note that in such a case, it may be nondeterministic whether
* linked failure or successful exit happen first.
*
* If you wish for this result's delivery to block until all linked and/or
* children tasks complete, recommend using a result future.
*/
enum TaskResult {
Success,
Failure,
}
impl TaskResult: Eq {
pure fn eq(&&other: TaskResult) -> bool {
match (self, other) {
(Success, Success) | (Failure, Failure) => true,
(Success, _) | (Failure, _) => false
}
}
pure fn ne(&&other: TaskResult) -> bool { !self.eq(other) }
}
/// A message type for notifying of task lifecycle events
enum Notification {
/// Sent when a task exits with the task handle and result
Exit(Task, TaskResult)
}
impl Notification : cmp::Eq {
pure fn eq(&&other: Notification) -> bool {
match self {
Exit(e0a, e1a) => {
match other {
Exit(e0b, e1b) => e0a == e0b && e1a == e1b
}
}
}
}
pure fn ne(&&other: Notification) -> bool { !self.eq(other) }
}
/// Scheduler modes
enum SchedMode {
/// All tasks run in the same OS thread
SingleThreaded,
/// Tasks are distributed among available CPUs
ThreadPerCore,
/// Each task runs in its own OS thread
ThreadPerTask,
/// Tasks are distributed among a fixed number of OS threads
ManualThreads(uint),
/**
* Tasks are scheduled on the main OS thread
*
* The main OS thread is the thread used to launch the runtime which,
* in most cases, is the process's initial thread as created by the OS.
*/
PlatformThread
}
impl SchedMode : cmp::Eq {
pure fn eq(&&other: SchedMode) -> bool {
match self {
SingleThreaded => {
match other {
SingleThreaded => true,
_ => false
}
}
ThreadPerCore => {
match other {
ThreadPerCore => true,
_ => false
}
}
ThreadPerTask => {
match other {
ThreadPerTask => true,
_ => false
}
}
ManualThreads(e0a) => {
match other {
ManualThreads(e0b) => e0a == e0b,
_ => false
}
}
PlatformThread => {
match other {
PlatformThread => true,
_ => false
}
}
}
}
pure fn ne(&&other: SchedMode) -> bool {
!self.eq(other)
}
}
/**
* Scheduler configuration options
*
* # Fields
*
* * sched_mode - The operating mode of the scheduler
*
* * foreign_stack_size - The size of the foreign stack, in bytes
*
* Rust code runs on Rust-specific stacks. When Rust code calls foreign
* code (via functions in foreign modules) it switches to a typical, large
* stack appropriate for running code written in languages like C. By
* default these foreign stacks have unspecified size, but with this
* option their size can be precisely specified.
*/
type SchedOpts = {
mode: SchedMode,
foreign_stack_size: Option<uint>
};
/**
* Task configuration options
*
* # Fields
*
* * linked - Propagate failure bidirectionally between child and parent.
* True by default. If both this and 'supervised' are false, then
* either task's failure will not affect the other ("unlinked").
*
* * supervised - Propagate failure unidirectionally from parent to child,
* but not from child to parent. False by default.
*
* * notify_chan - Enable lifecycle notifications on the given channel
*
* * sched - Specify the configuration of a new scheduler to create the task
* in
*
* By default, every task is created in the same scheduler as its
* parent, where it is scheduled cooperatively with all other tasks
* in that scheduler. Some specialized applications may want more
* control over their scheduling, in which case they can be spawned
* into a new scheduler with the specific properties required.
*
* This is of particular importance for libraries which want to call
* into foreign code that blocks. Without doing so in a different
* scheduler other tasks will be impeded or even blocked indefinitely.
*/
type TaskOpts = {
linked: bool,
supervised: bool,
mut notify_chan: Option<Chan<Notification>>,
sched: Option<SchedOpts>,
};
/**
* The task builder type.
*
* Provides detailed control over the properties and behavior of new tasks.
*/
// NB: Builders are designed to be single-use because they do stateful
// things that get weird when reusing - e.g. if you create a result future
// it only applies to a single task, so then you have to maintain Some
// potentially tricky state to ensure that everything behaves correctly
// when you try to reuse the builder to spawn a new task. We'll just
// sidestep that whole issue by making builders uncopyable and making
// the run function move them in.
// FIXME (#2585): Replace the 'consumed' bit with move mode on self
enum TaskBuilder = {
opts: TaskOpts,
gen_body: fn@(+fn~()) -> fn~(),
can_not_copy: Option<util::NonCopyable>,
mut consumed: bool,
};
/**
* Generate the base configuration for spawning a task, off of which more
* configuration methods can be chained.
* For example, task().unlinked().spawn is equivalent to spawn_unlinked.
*/
fn task() -> TaskBuilder {
TaskBuilder({
opts: default_task_opts(),
gen_body: |body| move body, // Identity function
can_not_copy: None,
mut consumed: false,
})
}
priv impl TaskBuilder {
fn consume() -> TaskBuilder {
if self.consumed {
fail ~"Cannot copy a task_builder"; // Fake move mode on self
}
self.consumed = true;
let notify_chan = if self.opts.notify_chan.is_none() {
None
} else {
Some(option::swap_unwrap(&mut self.opts.notify_chan))
};
TaskBuilder({
opts: {
linked: self.opts.linked,
supervised: self.opts.supervised,
mut notify_chan: move notify_chan,
sched: self.opts.sched
},
gen_body: self.gen_body,
can_not_copy: None,
mut consumed: false
})
}
}
impl TaskBuilder {
/**
* Decouple the child task's failure from the parent's. If either fails,
* the other will not be killed.
*/
fn unlinked() -> TaskBuilder {
let notify_chan = if self.opts.notify_chan.is_none() {
None
} else {
Some(option::swap_unwrap(&mut self.opts.notify_chan))
};
TaskBuilder({
opts: {
linked: false,
supervised: self.opts.supervised,
mut notify_chan: move notify_chan,
sched: self.opts.sched
},
can_not_copy: None,
.. *self.consume()
})
}
/**
* Unidirectionally link the child task's failure with the parent's. The
* child's failure will not kill the parent, but the parent's will kill
* the child.
*/
fn supervised() -> TaskBuilder {
let notify_chan = if self.opts.notify_chan.is_none() {
None
} else {
Some(option::swap_unwrap(&mut self.opts.notify_chan))
};
TaskBuilder({
opts: {
linked: false,
supervised: true,
mut notify_chan: move notify_chan,
sched: self.opts.sched
},
can_not_copy: None,
.. *self.consume()
})
}
/**
* Link the child task's and parent task's failures. If either fails, the
* other will be killed.
*/
fn linked() -> TaskBuilder {
let notify_chan = if self.opts.notify_chan.is_none() {
None
} else {
Some(option::swap_unwrap(&mut self.opts.notify_chan))
};
TaskBuilder({
opts: {
linked: true,
supervised: false,
mut notify_chan: move notify_chan,
sched: self.opts.sched
},
can_not_copy: None,
.. *self.consume()
})
}
/**
* Get a future representing the exit status of the task.
*
* Taking the value of the future will block until the child task
* terminates. The future-receiving callback specified will be called
* *before* the task is spawned; as such, do not invoke .get() within the
* closure; rather, store it in an outer variable/list for later use.
*
* Note that the future returning by this function is only useful for
* obtaining the value of the next task to be spawning with the
* builder. If additional tasks are spawned with the same builder
* then a new result future must be obtained prior to spawning each
* task.
*
* # Failure
* Fails if a future_result was already set for this task.
*/
fn future_result(blk: fn(+future::Future<TaskResult>)) -> TaskBuilder {
// FIXME (#1087, #1857): Once linked failure and notification are
// handled in the library, I can imagine implementing this by just
// registering an arbitrary number of task::on_exit handlers and
// sending out messages.
if self.opts.notify_chan.is_some() {
fail ~"Can't set multiple future_results for one task!";
}
// Construct the future and give it to the caller.
let (notify_pipe_ch, notify_pipe_po) = stream::<Notification>();
blk(do future::from_fn |move notify_pipe_po| {
match notify_pipe_po.recv() {
Exit(_, result) => result
}
});
// Reconfigure self to use a notify channel.
TaskBuilder({
opts: {
linked: self.opts.linked,
supervised: self.opts.supervised,
mut notify_chan: Some(move notify_pipe_ch),
sched: self.opts.sched
},
can_not_copy: None,
.. *self.consume()
})
}
/// Configure a custom scheduler mode for the task.
fn sched_mode(mode: SchedMode) -> TaskBuilder {
let notify_chan = if self.opts.notify_chan.is_none() {
None
} else {
Some(option::swap_unwrap(&mut self.opts.notify_chan))
};
TaskBuilder({
opts: {
linked: self.opts.linked,
supervised: self.opts.supervised,
mut notify_chan: move notify_chan,
sched: Some({ mode: mode, foreign_stack_size: None})
},
can_not_copy: None,
.. *self.consume()
})
}
/**
* Add a wrapper to the body of the spawned task.
*
* Before the task is spawned it is passed through a 'body generator'
* function that may perform local setup operations as well as wrap
* the task body in remote setup operations. With this the behavior
* of tasks can be extended in simple ways.
*
* This function augments the current body generator with a new body
* generator by applying the task body which results from the
* existing body generator to the new body generator.
*/
fn add_wrapper(wrapper: fn@(+fn~()) -> fn~()) -> TaskBuilder {
let prev_gen_body = self.gen_body;
let notify_chan = if self.opts.notify_chan.is_none() {
None
} else {
Some(option::swap_unwrap(&mut self.opts.notify_chan))
};
TaskBuilder({
opts: {
linked: self.opts.linked,
supervised: self.opts.supervised,
mut notify_chan: move notify_chan,
sched: self.opts.sched
},
gen_body: |body| { wrapper(prev_gen_body(move body)) },
can_not_copy: None,
.. *self.consume()
})
}
/**
* Creates and exucutes a new child task
*
* Sets up a new task with its own call stack and schedules it to run
* the provided unique closure. The task has the properties and behavior
* specified by the task_builder.
*
* # Failure
*
* When spawning into a new scheduler, the number of threads requested
* must be greater than zero.
*/
fn spawn(+f: fn~()) {
let notify_chan = if self.opts.notify_chan.is_none() {
None
} else {
let swapped_notify_chan =
option::swap_unwrap(&mut self.opts.notify_chan);
Some(move swapped_notify_chan)
};
let x = self.consume();
let opts = {
linked: x.opts.linked,
supervised: x.opts.supervised,
mut notify_chan: move notify_chan,
sched: x.opts.sched
};
spawn_raw(move opts, x.gen_body(move f));
}
/// Runs a task, while transfering ownership of one argument to the child.
fn spawn_with<A: Send>(+arg: A, +f: fn~(+A)) {
let arg = ~mut Some(move arg);
do self.spawn |move arg, move f|{
f(option::swap_unwrap(arg))
}
}
/**
* Runs a new task while providing a channel from the parent to the child
*
* Sets up a communication channel from the current task to the new
* child task, passes the port to child's body, and returns a channel
* linked to the port to the parent.
*
* This encapsulates Some boilerplate handshaking logic that would
* otherwise be required to establish communication from the parent
* to the child.
*/
fn spawn_listener<A: Send>(+f: fn~(comm::Port<A>)) -> comm::Chan<A> {
let setup_po = comm::Port();
let setup_ch = comm::Chan(setup_po);
do self.spawn |move f| {
let po = comm::Port();
let ch = comm::Chan(po);
comm::send(setup_ch, ch);
f(move po);
}
comm::recv(setup_po)
}
/**
* Runs a new task, setting up communication in both directions
*/
fn spawn_conversation<A: Send, B: Send>
(+f: fn~(comm::Port<A>, comm::Chan<B>))
-> (comm::Port<B>, comm::Chan<A>) {
let from_child = comm::Port();
let to_parent = comm::Chan(from_child);
let to_child = do self.spawn_listener |move f, from_parent| {
f(from_parent, to_parent)
};
(from_child, to_child)
}
/**
* Execute a function in another task and return either the return value
* of the function or result::err.
*
* # Return value
*
* If the function executed successfully then try returns result::ok
* containing the value returned by the function. If the function fails
* then try returns result::err containing nil.
*
* # Failure
* Fails if a future_result was already set for this task.
*/
fn try<T: Send>(+f: fn~() -> T) -> Result<T,()> {
let po = comm::Port();
let ch = comm::Chan(po);
let mut result = None;
let fr_task_builder = self.future_result(|+r| {
result = Some(move r);
});
do fr_task_builder.spawn |move f| {
comm::send(ch, f());
}
match future::get(&option::unwrap(move result)) {
Success => result::Ok(comm::recv(po)),
Failure => result::Err(())
}
}
}
/* Task construction */
fn default_task_opts() -> TaskOpts {
/*!
* The default task options
*
* By default all tasks are supervised by their parent, are spawned
* into the same scheduler, and do not post lifecycle notifications.
*/
{
linked: true,
supervised: false,
mut notify_chan: None,
sched: None
}
}
/* Spawn convenience functions */
fn spawn(+f: fn~()) {
/*!
* Creates and executes a new child task
*
* Sets up a new task with its own call stack and schedules it to run
* the provided unique closure.
*
* This function is equivalent to `task().spawn(f)`.
*/
task().spawn(move f)
}
fn spawn_unlinked(+f: fn~()) {
/*!
* Creates a child task unlinked from the current one. If either this
* task or the child task fails, the other will not be killed.
*/
task().unlinked().spawn(move f)
}
fn spawn_supervised(+f: fn~()) {
/*!
* Creates a child task unlinked from the current one. If either this
* task or the child task fails, the other will not be killed.
*/
task().supervised().spawn(move f)
}
fn spawn_with<A:Send>(+arg: A, +f: fn~(+A)) {
/*!
* Runs a task, while transfering ownership of one argument to the
* child.
*
* This is useful for transfering ownership of noncopyables to
* another task.
*
* This function is equivalent to `task().spawn_with(arg, f)`.
*/
task().spawn_with(move arg, move f)
}
fn spawn_listener<A:Send>(+f: fn~(comm::Port<A>)) -> comm::Chan<A> {
/*!
* Runs a new task while providing a channel from the parent to the child
*
* This function is equivalent to `task().spawn_listener(f)`.
*/
task().spawn_listener(move f)
}
fn spawn_conversation<A: Send, B: Send>
(+f: fn~(comm::Port<A>, comm::Chan<B>))
-> (comm::Port<B>, comm::Chan<A>) {
/*!
* Runs a new task, setting up communication in both directions
*
* This function is equivalent to `task().spawn_conversation(f)`.
*/
task().spawn_conversation(move f)
}
fn spawn_sched(mode: SchedMode, +f: fn~()) {
/*!
* Creates a new scheduler and executes a task on it
*
* Tasks subsequently spawned by that task will also execute on
* the new scheduler. When there are no more tasks to execute the
* scheduler terminates.
*
* # Failure
*
* In manual threads mode the number of threads requested must be
* greater than zero.
*/
task().sched_mode(mode).spawn(move f)
}
fn try<T:Send>(+f: fn~() -> T) -> Result<T,()> {
/*!
* Execute a function in another task and return either the return value
* of the function or result::err.
*
* This is equivalent to task().supervised().try.
*/
task().supervised().try(move f)
}
/* Lifecycle functions */
fn yield() {
//! Yield control to the task scheduler
let task_ = rustrt::rust_get_task();
let killed = rustrt::rust_task_yield(task_);
if killed && !failing() {
fail ~"killed";
}
}
fn failing() -> bool {
//! True if the running task has failed
rustrt::rust_task_is_unwinding(rustrt::rust_get_task())
}
fn get_task() -> Task {
//! Get a handle to the running task
TaskHandle(rustrt::get_task_id())
}
/**
* Temporarily make the task unkillable
*
* # Example
*
* ~~~
* do task::unkillable {
* // detach / yield / destroy must all be called together
* rustrt::rust_port_detach(po);
* // This must not result in the current task being killed
* task::yield();
* rustrt::rust_port_destroy(po);
* }
* ~~~
*/
unsafe fn unkillable<U>(f: fn() -> U) -> U {
struct AllowFailure {
t: *rust_task,
drop { rustrt::rust_task_allow_kill(self.t); }
}
fn AllowFailure(t: *rust_task) -> AllowFailure{
AllowFailure {
t: t
}
}
let t = rustrt::rust_get_task();
let _allow_failure = AllowFailure(t);
rustrt::rust_task_inhibit_kill(t);
f()
}
/// The inverse of unkillable. Only ever to be used nested in unkillable().
unsafe fn rekillable<U>(f: fn() -> U) -> U {
struct DisallowFailure {
t: *rust_task,
drop { rustrt::rust_task_inhibit_kill(self.t); }
}
fn DisallowFailure(t: *rust_task) -> DisallowFailure {
DisallowFailure {
t: t
}
}
let t = rustrt::rust_get_task();
let _allow_failure = DisallowFailure(t);
rustrt::rust_task_allow_kill(t);
f()
}
/**
* A stronger version of unkillable that also inhibits scheduling operations.
* For use with exclusive ARCs, which use pthread mutexes directly.
*/
unsafe fn atomically<U>(f: fn() -> U) -> U {
struct DeferInterrupts {
t: *rust_task,
drop {
rustrt::rust_task_allow_yield(self.t);
rustrt::rust_task_allow_kill(self.t);
}
}
fn DeferInterrupts(t: *rust_task) -> DeferInterrupts {
DeferInterrupts {
t: t
}
}
let t = rustrt::rust_get_task();
let _interrupts = DeferInterrupts(t);
rustrt::rust_task_inhibit_kill(t);
rustrt::rust_task_inhibit_yield(t);
f()
}
/****************************************************************************
* Spawning & linked failure
*
* Several data structures are involved in task management to allow properly
* propagating failure across linked/supervised tasks.
*
* (1) The "taskgroup_arc" is an unsafe::exclusive which contains a hashset of
* all tasks that are part of the group. Some tasks are 'members', which
* means if they fail, they will kill everybody else in the taskgroup.
* Other tasks are 'descendants', which means they will not kill tasks
* from this group, but can be killed by failing members.
*
* A new one of these is created each spawn_linked or spawn_supervised.
*
* (2) The "tcb" is a per-task control structure that tracks a task's spawn
* configuration. It contains a reference to its taskgroup_arc, a
* reference to its node in the ancestor list (below), a flag for
* whether it's part of the 'main'/'root' taskgroup, and an optionally
* configured notification port. These are stored in TLS.
*
* (3) The "ancestor_list" is a cons-style list of unsafe::exclusives which
* tracks 'generations' of taskgroups -- a group's ancestors are groups
* which (directly or transitively) spawn_supervised-ed them. Each task
* is recorded in the 'descendants' of each of its ancestor groups.
*
* Spawning a supervised task is O(n) in the number of generations still
* alive, and exiting (by success or failure) that task is also O(n).
*
* This diagram depicts the references between these data structures:
*
* linked_________________________________
* ___/ _________ \___
* / \ | group X | / \
* ( A ) - - - - - - - > | {A,B} {}|< - - -( B )
* \___/ |_________| \___/
* unlinked
* | __ (nil)
* | //| The following code causes this:
* |__ // /\ _________
* / \ // || | group Y | fn taskA() {
* ( C )- - - ||- - - > |{C} {D,E}| spawn(taskB);
* \___/ / \=====> |_________| spawn_unlinked(taskC);
* supervise /gen \ ...
* | __ \ 00 / }
* | //| \__/ fn taskB() { ... }
* |__ // /\ _________ fn taskC() {
* / \/ || | group Z | spawn_supervised(taskD);
* ( D )- - - ||- - - > | {D} {E} | ...
* \___/ / \=====> |_________| }
* supervise /gen \ fn taskD() {
* | __ \ 01 / spawn_supervised(taskE);
* | //| \__/ ...
* |__ // _________ }
* / \/ | group W | fn taskE() { ... }
* ( E )- - - - - - - > | {E} {} |
* \___/ |_________|
*
* "tcb" "taskgroup_arc"
* "ancestor_list"
*
****************************************************************************/
#[allow(non_camel_case_types)] // runtime type
type sched_id = int;
#[allow(non_camel_case_types)] // runtime type
type task_id = int;
// These are both opaque runtime/compiler types that we don't know the
// structure of and should only deal with via unsafe pointer
#[allow(non_camel_case_types)] // runtime type
type rust_task = libc::c_void;
#[allow(non_camel_case_types)] // runtime type
type rust_closure = libc::c_void;
type TaskSet = send_map::linear::LinearMap<*rust_task,()>;
fn new_taskset() -> TaskSet {
send_map::linear::LinearMap()
}
fn taskset_insert(tasks: &mut TaskSet, task: *rust_task) {
let didnt_overwrite = tasks.insert(task, ());
assert didnt_overwrite;
}
fn taskset_remove(tasks: &mut TaskSet, task: *rust_task) {
let was_present = tasks.remove(&task);
assert was_present;
}
fn taskset_each(tasks: &TaskSet, blk: fn(+*rust_task) -> bool) {
tasks.each_key(blk)
}
// One of these per group of linked-failure tasks.
type TaskGroupData = {
// All tasks which might kill this group. When this is empty, the group
// can be "GC"ed (i.e., its link in the ancestor list can be removed).
mut members: TaskSet,
// All tasks unidirectionally supervised by (directly or transitively)
// tasks in this group.
mut descendants: TaskSet,
};
type TaskGroupArc = unsafe::Exclusive<Option<TaskGroupData>>;
type TaskGroupInner = &mut Option<TaskGroupData>;
// A taskgroup is 'dead' when nothing can cause it to fail; only members can.
pure fn taskgroup_is_dead(tg: &TaskGroupData) -> bool {
(&tg.members).is_empty()
}
// A list-like structure by which taskgroups keep track of all ancestor groups
// which may kill them. Needed for tasks to be able to remove themselves from
// ancestor groups upon exit. The list has a node for each "generation", and
// ends either at the root taskgroup (which has no ancestors) or at a
// taskgroup which was spawned-unlinked. Tasks from intermediate generations
// have references to the middle of the list; when intermediate generations
// die, their node in the list will be collected at a descendant's spawn-time.
type AncestorNode = {
// Since the ancestor list is recursive, we end up with references to
// exclusives within other exclusives. This is dangerous business (if
// circular references arise, deadlock and memory leaks are imminent).
// Hence we assert that this counter monotonically decreases as we
// approach the tail of the list.
// FIXME(#3068): Make the generation counter togglable with #[cfg(debug)].
generation: uint,
// Should really be an immutable non-option. This way appeases borrowck.
mut parent_group: Option<TaskGroupArc>,
// Recursive rest of the list.
mut ancestors: AncestorList,
};
enum AncestorList = Option<unsafe::Exclusive<AncestorNode>>;
// Accessors for taskgroup arcs and ancestor arcs that wrap the unsafety.
#[inline(always)]
fn access_group<U>(x: &TaskGroupArc, blk: fn(TaskGroupInner) -> U) -> U {
unsafe { x.with(blk) }
}
#[inline(always)]
fn access_ancestors<U>(x: &unsafe::Exclusive<AncestorNode>,
blk: fn(x: &mut AncestorNode) -> U) -> U {
unsafe { x.with(blk) }
}
// Iterates over an ancestor list.
// (1) Runs forward_blk on each ancestral taskgroup in the list
// (2) If forward_blk "break"s, runs optional bail_blk on all ancestral
// taskgroups that forward_blk already ran on successfully (Note: bail_blk
// is NOT called on the block that forward_blk broke on!).
// (3) As a bonus, coalesces away all 'dead' taskgroup nodes in the list.
// FIXME(#2190): Change Option<fn@(...)> to Option<fn&(...)>, to save on
// allocations. Once that bug is fixed, changing the sigil should suffice.
fn each_ancestor(list: &mut AncestorList,
bail_opt: Option<fn@(TaskGroupInner)>,
forward_blk: fn(TaskGroupInner) -> bool)
-> bool {
// "Kickoff" call - there was no last generation.
return !coalesce(list, bail_opt, forward_blk, uint::max_value);
// Recursively iterates, and coalesces afterwards if needed. Returns
// whether or not unwinding is needed (i.e., !successful iteration).
fn coalesce(list: &mut AncestorList,
bail_opt: Option<fn@(TaskGroupInner)>,
forward_blk: fn(TaskGroupInner) -> bool,
last_generation: uint) -> bool {
// Need to swap the list out to use it, to appease borrowck.
let tmp_list = util::replace(list, AncestorList(None));
let (coalesce_this, early_break) =
iterate(&tmp_list, bail_opt, forward_blk, last_generation);
// What should our next ancestor end up being?
if coalesce_this.is_some() {
// Needed coalesce. Our next ancestor becomes our old
// ancestor's next ancestor. ("next = old_next->next;")
*list <- option::unwrap(move coalesce_this);
} else {
// No coalesce; restore from tmp. ("next = old_next;")
*list <- tmp_list;
}
return early_break;
}
// Returns an optional list-to-coalesce and whether unwinding is needed.
// Option<ancestor_list>:
// Whether or not the ancestor taskgroup being iterated over is
// dead or not; i.e., it has no more tasks left in it, whether or not
// it has descendants. If dead, the caller shall coalesce it away.
// bool:
// True if the supplied block did 'break', here or in any recursive
// calls. If so, must call the unwinder on all previous nodes.
fn iterate(ancestors: &AncestorList,
bail_opt: Option<fn@(TaskGroupInner)>,
forward_blk: fn(TaskGroupInner) -> bool,
last_generation: uint) -> (Option<AncestorList>, bool) {
// At each step of iteration, three booleans are at play which govern
// how the iteration should behave.
// 'nobe_is_dead' - Should the list should be coalesced at this point?
// Largely unrelated to the other two.
// 'need_unwind' - Should we run the bail_blk at this point? (i.e.,
// do_continue was false not here, but down the line)
// 'do_continue' - Did the forward_blk succeed at this point? (i.e.,
// should we recurse? or should our callers unwind?)
// The map defaults to None, because if ancestors is None, we're at
// the end of the list, which doesn't make sense to coalesce.
return do (**ancestors).map_default((None,false)) |ancestor_arc| {
// NB: Takes a lock! (this ancestor node)
do access_ancestors(&ancestor_arc) |nobe| {
// Check monotonicity
assert last_generation > nobe.generation;
/*##########################################################*
* Step 1: Look at this ancestor group (call iterator block).
*##########################################################*/
let mut nobe_is_dead = false;
let do_continue =
// NB: Takes a lock! (this ancestor node's parent group)
do with_parent_tg(&mut nobe.parent_group) |tg_opt| {
// Decide whether this group is dead. Note that the
// group being *dead* is disjoint from it *failing*.
nobe_is_dead = match *tg_opt {
Some(ref tg) => taskgroup_is_dead(tg),
None => nobe_is_dead
};
// Call iterator block. (If the group is dead, it's
// safe to skip it. This will leave our *rust_task
// hanging around in the group even after it's freed,
// but that's ok because, by virtue of the group being
// dead, nobody will ever kill-all (foreach) over it.)
if nobe_is_dead { true } else { forward_blk(tg_opt) }
};
/*##########################################################*
* Step 2: Recurse on the rest of the list; maybe coalescing.
*##########################################################*/
// 'need_unwind' is only set if blk returned true above, *and*
// the recursive call early-broke.
let mut need_unwind = false;
if do_continue {
// NB: Takes many locks! (ancestor nodes & parent groups)
need_unwind = coalesce(&mut nobe.ancestors, bail_opt,
forward_blk, nobe.generation);
}
/*##########################################################*
* Step 3: Maybe unwind; compute return info for our caller.
*##########################################################*/
if need_unwind && !nobe_is_dead {
do bail_opt.iter |bail_blk| {
do with_parent_tg(&mut nobe.parent_group) |tg_opt| {
bail_blk(tg_opt)
}
}
}
// Decide whether our caller should unwind.
need_unwind = need_unwind || !do_continue;
// Tell caller whether or not to coalesce and/or unwind
if nobe_is_dead {
// Swap the list out here; the caller replaces us with it.
let rest = util::replace(&mut nobe.ancestors,
AncestorList(None));
(Some(move rest), need_unwind)
} else {
(None, need_unwind)
}
}
};
// Wrapper around exclusive::with that appeases borrowck.
fn with_parent_tg<U>(parent_group: &mut Option<TaskGroupArc>,
blk: fn(TaskGroupInner) -> U) -> U {
// If this trips, more likely the problem is 'blk' failed inside.
let tmp_arc = option::swap_unwrap(parent_group);
let result = do access_group(&tmp_arc) |tg_opt| { blk(tg_opt) };
*parent_group <- Some(move tmp_arc);
move result
}
}
}
// One of these per task.
struct TCB {
me: *rust_task,
// List of tasks with whose fates this one's is intertwined.
tasks: TaskGroupArc, // 'none' means the group has failed.
// Lists of tasks who will kill us if they fail, but whom we won't kill.
mut ancestors: AncestorList,
is_main: bool,
notifier: Option<AutoNotify>,
// Runs on task exit.
drop {
// If we are failing, the whole taskgroup needs to die.
if rustrt::rust_task_is_unwinding(self.me) {
self.notifier.iter(|x| { x.failed = true; });
// Take everybody down with us.
do access_group(&self.tasks) |tg| {
kill_taskgroup(tg, self.me, self.is_main);
}
} else {
// Remove ourselves from the group(s).
do access_group(&self.tasks) |tg| {
leave_taskgroup(tg, self.me, true);
}
}
// It doesn't matter whether this happens before or after dealing with
// our own taskgroup, so long as both happen before we die. We need to
// remove ourself from every ancestor we can, so no cleanup; no break.
for each_ancestor(&mut self.ancestors, None) |ancestor_group| {
leave_taskgroup(ancestor_group, self.me, false);
};
}
}
fn TCB(me: *rust_task, +tasks: TaskGroupArc, +ancestors: AncestorList,
is_main: bool, +notifier: Option<AutoNotify>) -> TCB {
let notifier = move notifier;
notifier.iter(|x| { x.failed = false; });
TCB {
me: me,
tasks: tasks,
ancestors: ancestors,
is_main: is_main,
notifier: move notifier
}
}
struct AutoNotify {
notify_chan: Chan<Notification>,
mut failed: bool,
drop {
let result = if self.failed { Failure } else { Success };
self.notify_chan.send(Exit(get_task(), result));
}
}
fn AutoNotify(+chan: Chan<Notification>) -> AutoNotify {
AutoNotify {
notify_chan: chan,
failed: true // Un-set above when taskgroup successfully made.
}
}
fn enlist_in_taskgroup(state: TaskGroupInner, me: *rust_task,
is_member: bool) -> bool {
let newstate = util::replace(state, None);
// If 'None', the group was failing. Can't enlist.
if newstate.is_some() {
let group = option::unwrap(move newstate);
taskset_insert(if is_member { &mut group.members }
else { &mut group.descendants }, me);
*state = Some(move group);
true
} else {
false
}
}
// NB: Runs in destructor/post-exit context. Can't 'fail'.
fn leave_taskgroup(state: TaskGroupInner, me: *rust_task, is_member: bool) {
let newstate = util::replace(state, None);
// If 'None', already failing and we've already gotten a kill signal.
if newstate.is_some() {
let group = option::unwrap(move newstate);
taskset_remove(if is_member { &mut group.members }
else { &mut group.descendants }, me);
*state = Some(move group);
}
}
// NB: Runs in destructor/post-exit context. Can't 'fail'.
fn kill_taskgroup(state: TaskGroupInner, me: *rust_task, is_main: bool) {
// NB: We could do the killing iteration outside of the group arc, by
// having "let mut newstate" here, swapping inside, and iterating after.
// But that would let other exiting tasks fall-through and exit while we
// were trying to kill them, causing potential use-after-free. A task's
// presence in the arc guarantees it's alive only while we hold the lock,
// so if we're failing, all concurrently exiting tasks must wait for us.
// To do it differently, we'd have to use the runtime's task refcounting,
// but that could leave task structs around long after their task exited.
let newstate = util::replace(state, None);
// Might already be None, if Somebody is failing simultaneously.
// That's ok; only one task needs to do the dirty work. (Might also
// see 'None' if Somebody already failed and we got a kill signal.)
if newstate.is_some() {
let group = option::unwrap(move newstate);
for taskset_each(&group.members) |+sibling| {
// Skip self - killing ourself won't do much good.
if sibling != me {
rustrt::rust_task_kill_other(sibling);
}
}
for taskset_each(&group.descendants) |+child| {
assert child != me;
rustrt::rust_task_kill_other(child);
}
// Only one task should ever do this.
if is_main {
rustrt::rust_task_kill_all(me);
}
// Do NOT restore state to Some(..)! It stays None to indicate
// that the whole taskgroup is failing, to forbid new spawns.
}
// (note: multiple tasks may reach this point)
}
// FIXME (#2912): Work around core-vs-coretest function duplication. Can't use
// a proper closure because the #[test]s won't understand. Have to fake it.
macro_rules! taskgroup_key (
// Use a "code pointer" value that will never be a real code pointer.
() => (unsafe::transmute((-2 as uint, 0u)))
)
fn gen_child_taskgroup(linked: bool, supervised: bool)
-> (TaskGroupArc, AncestorList, bool) {
let spawner = rustrt::rust_get_task();
/*######################################################################*
* Step 1. Get spawner's taskgroup info.
*######################################################################*/
let spawner_group = match unsafe { local_get(spawner,
taskgroup_key!()) } {
None => {
// Main task, doing first spawn ever. Lazily initialise here.
let mut members = new_taskset();
taskset_insert(&mut members, spawner);
let tasks =
unsafe::exclusive(Some({ mut members: move members,
mut descendants: new_taskset() }));
// Main task/group has no ancestors, no notifier, etc.
let group =
@TCB(spawner, move tasks, AncestorList(None), true, None);
unsafe { local_set(spawner, taskgroup_key!(), group); }
group
}
Some(group) => group
};
/*######################################################################*
* Step 2. Process spawn options for child.
*######################################################################*/
return if linked {
// Child is in the same group as spawner.
let g = spawner_group.tasks.clone();
// Child's ancestors are spawner's ancestors.
let a = share_ancestors(&mut spawner_group.ancestors);
// Propagate main-ness.
(move g, move a, spawner_group.is_main)
} else {
// Child is in a separate group from spawner.
let g = unsafe::exclusive(Some({ mut members: new_taskset(),
mut descendants: new_taskset() }));
let a = if supervised {
// Child's ancestors start with the spawner.
let old_ancestors = share_ancestors(&mut spawner_group.ancestors);
// FIXME(#3068) - The generation counter is only used for a debug
// assertion, but initialising it requires locking a mutex. Hence
// it should be enabled only in debug builds.
let new_generation =
match *old_ancestors {
Some(arc) => access_ancestors(&arc, |a| a.generation+1),
None => 0 // the actual value doesn't really matter.
};
assert new_generation < uint::max_value;
// Build a new node in the ancestor list.
AncestorList(Some(unsafe::exclusive(
{ generation: new_generation,
mut parent_group: Some(spawner_group.tasks.clone()),
mut ancestors: move old_ancestors })))
} else {
// Child has no ancestors.
AncestorList(None)
};
(move g, move a, false)
};
fn share_ancestors(ancestors: &mut AncestorList) -> AncestorList {
// Appease the borrow-checker. Really this wants to be written as:
// match ancestors
// Some(ancestor_arc) { ancestor_list(Some(ancestor_arc.clone())) }
// None { ancestor_list(None) }
let tmp = util::replace(&mut **ancestors, None);
if tmp.is_some() {
let ancestor_arc = option::unwrap(move tmp);
let result = ancestor_arc.clone();
**ancestors <- Some(move ancestor_arc);
AncestorList(Some(move result))
} else {
AncestorList(None)
}
}
}
fn spawn_raw(+opts: TaskOpts, +f: fn~()) {
let (child_tg, ancestors, is_main) =
gen_child_taskgroup(opts.linked, opts.supervised);
unsafe {
let child_data = ~mut Some((move child_tg, move ancestors, move f));
// Being killed with the unsafe task/closure pointers would leak them.
do unkillable {
// Agh. Get move-mode items into the closure. FIXME (#2829)
let (child_tg, ancestors, f) = option::swap_unwrap(child_data);
// Create child task.
let new_task = match opts.sched {
None => rustrt::new_task(),
Some(sched_opts) => new_task_in_new_sched(sched_opts)
};
assert !new_task.is_null();
// Getting killed after here would leak the task.
let mut notify_chan = if opts.notify_chan.is_none() {
None
} else {
Some(option::swap_unwrap(&mut opts.notify_chan))
};
let child_wrapper = make_child_wrapper(new_task, move child_tg,
move ancestors, is_main, move notify_chan, move f);
let fptr = ptr::addr_of(child_wrapper);
let closure: *rust_closure = unsafe::reinterpret_cast(&fptr);
// Getting killed between these two calls would free the child's
// closure. (Reordering them wouldn't help - then getting killed
// between them would leak.)
rustrt::start_task(new_task, closure);
unsafe::forget(move child_wrapper);
}
}
// This function returns a closure-wrapper that we pass to the child task.
// (1) It sets up the notification channel.
// (2) It attempts to enlist in the child's group and all ancestor groups.
// (3a) If any of those fails, it leaves all groups, and does nothing.
// (3b) Otherwise it builds a task control structure and puts it in TLS,
// (4) ...and runs the provided body function.
fn make_child_wrapper(child: *rust_task, +child_arc: TaskGroupArc,
+ancestors: AncestorList, is_main: bool,
+notify_chan: Option<Chan<Notification>>,
+f: fn~()) -> fn~() {
let child_data = ~mut Some((move child_arc, move ancestors));
return fn~(move notify_chan, move child_data, move f) {
// Agh. Get move-mode items into the closure. FIXME (#2829)
let mut (child_arc, ancestors) = option::swap_unwrap(child_data);
// Child task runs this code.
// Even if the below code fails to kick the child off, we must
// send Something on the notify channel.
//let mut notifier = None;//notify_chan.map(|c| AutoNotify(c));
let notifier = match notify_chan {
Some(notify_chan_value) => {
let moved_ncv = move_it!(notify_chan_value);
Some(AutoNotify(move moved_ncv))
}
_ => None
};
if enlist_many(child, &child_arc, &mut ancestors) {
let group = @TCB(child, move child_arc, move ancestors,
is_main, move notifier);
unsafe { local_set(child, taskgroup_key!(), group); }
// Run the child's body.
f();
// TLS cleanup code will exit the taskgroup.
}
};
// Set up membership in taskgroup and descendantship in all ancestor
// groups. If any enlistment fails, Some task was already failing, so
// don't let the child task run, and undo every successful enlistment.
fn enlist_many(child: *rust_task, child_arc: &TaskGroupArc,
ancestors: &mut AncestorList) -> bool {
// Join this taskgroup.
let mut result =
do access_group(child_arc) |child_tg| {
enlist_in_taskgroup(child_tg, child, true) // member
};
if result {
// Unwinding function in case any ancestral enlisting fails
let bail = |tg: TaskGroupInner| {
leave_taskgroup(tg, child, false)
};
// Attempt to join every ancestor group.
result =
for each_ancestor(ancestors, Some(bail)) |ancestor_tg| {
// Enlist as a descendant, not as an actual member.
// Descendants don't kill ancestor groups on failure.
if !enlist_in_taskgroup(ancestor_tg, child, false) {
break;
}
};
// If any ancestor group fails, need to exit this group too.
if !result {
do access_group(child_arc) |child_tg| {
leave_taskgroup(child_tg, child, true); // member
}
}
}
result
}
}
fn new_task_in_new_sched(opts: SchedOpts) -> *rust_task {
if opts.foreign_stack_size != None {
fail ~"foreign_stack_size scheduler option unimplemented";
}
let num_threads = match opts.mode {
SingleThreaded => 1u,
ThreadPerCore => rustrt::rust_num_threads(),
ThreadPerTask => {
fail ~"ThreadPerTask scheduling mode unimplemented"
}
ManualThreads(threads) => {
if threads == 0u {
fail ~"can not create a scheduler with no threads";
}
threads
}
PlatformThread => 0u /* Won't be used */
};
let sched_id = if opts.mode != PlatformThread {
rustrt::rust_new_sched(num_threads)
} else {
rustrt::rust_osmain_sched_id()
};
rustrt::rust_new_task_in_sched(sched_id)
}
}
/****************************************************************************
* Task local data management
*
* Allows storing boxes with arbitrary types inside, to be accessed anywhere
* within a task, keyed by a pointer to a global finaliser function. Useful
* for task-spawning metadata (tracking linked failure state), dynamic
* variables, and interfacing with foreign code with bad callback interfaces.
*
* To use, declare a monomorphic global function at the type to store, and use
* it as the 'key' when accessing. See the 'tls' tests below for examples.
*
* Casting 'Arcane Sight' reveals an overwhelming aura of Transmutation magic.
****************************************************************************/
/**
* Indexes a task-local data slot. The function's code pointer is used for
* comparison. Recommended use is to write an empty function for each desired
* task-local data slot (and use class destructors, not code inside the
* function, if specific teardown is needed). DO NOT use multiple
* instantiations of a single polymorphic function to index data of different
* types; arbitrary type coercion is possible this way.
*
* One other exception is that this global state can be used in a destructor
* context to create a circular @-box reference, which will crash during task
* failure (see issue #3039).
*
* These two cases aside, the interface is safe.
*/
type LocalDataKey<T: Owned> = &fn(+@T);
trait LocalData { }
impl<T: Owned> @T: LocalData { }
impl LocalData: Eq {
pure fn eq(&&other: LocalData) -> bool unsafe {
let ptr_a: (uint, uint) = unsafe::reinterpret_cast(&self);
let ptr_b: (uint, uint) = unsafe::reinterpret_cast(&other);
return ptr_a == ptr_b;
}
pure fn ne(&&other: LocalData) -> bool { !self.eq(other) }
}
// We use dvec because it's the best data structure in core. If TLS is used
// heavily in future, this could be made more efficient with a proper map.
type TaskLocalElement = (*libc::c_void, *libc::c_void, LocalData);
// Has to be a pointer at outermost layer; the foreign call returns void *.
type TaskLocalMap = @dvec::DVec<Option<TaskLocalElement>>;
extern fn cleanup_task_local_map(map_ptr: *libc::c_void) unsafe {
assert !map_ptr.is_null();
// Get and keep the single reference that was created at the beginning.
let _map: TaskLocalMap = unsafe::reinterpret_cast(&map_ptr);
// All local_data will be destroyed along with the map.
}
// Gets the map from the runtime. Lazily initialises if not done so already.
unsafe fn get_task_local_map(task: *rust_task) -> TaskLocalMap {
// Relies on the runtime initialising the pointer to null.
// NOTE: The map's box lives in TLS invisibly referenced once. Each time
// we retrieve it for get/set, we make another reference, which get/set
// drop when they finish. No "re-storing after modifying" is needed.
let map_ptr = rustrt::rust_get_task_local_data(task);
if map_ptr.is_null() {
let map: TaskLocalMap = @dvec::DVec();
// Use reinterpret_cast -- transmute would take map away from us also.
rustrt::rust_set_task_local_data(
task, unsafe::reinterpret_cast(&map));
rustrt::rust_task_local_data_atexit(task, cleanup_task_local_map);
// Also need to reference it an extra time to keep it for now.
unsafe::bump_box_refcount(map);
map
} else {
let map = unsafe::transmute(move map_ptr);
unsafe::bump_box_refcount(map);
map
}
}
unsafe fn key_to_key_value<T: Owned>(
key: LocalDataKey<T>) -> *libc::c_void {
// Keys are closures, which are (fnptr,envptr) pairs. Use fnptr.
// Use reintepret_cast -- transmute would leak (forget) the closure.
let pair: (*libc::c_void, *libc::c_void) = unsafe::reinterpret_cast(&key);
pair.first()
}
// If returning Some(..), returns with @T with the map's reference. Careful!
unsafe fn local_data_lookup<T: Owned>(
map: TaskLocalMap, key: LocalDataKey<T>)
-> Option<(uint, *libc::c_void)> {
let key_value = key_to_key_value(key);
let map_pos = (*map).position(|entry|
match entry {
Some((k,_,_)) => k == key_value,
None => false
}
);
do map_pos.map |index| {
// .get() is guaranteed because of "None { false }" above.
let (_, data_ptr, _) = (*map)[index].get();
(index, data_ptr)
}
}
unsafe fn local_get_helper<T: Owned>(
task: *rust_task, key: LocalDataKey<T>,
do_pop: bool) -> Option<@T> {
let map = get_task_local_map(task);
// Interpreturn our findings from the map
do local_data_lookup(map, key).map |result| {
// A reference count magically appears on 'data' out of thin air. It
// was referenced in the local_data box, though, not here, so before
// overwriting the local_data_box we need to give an extra reference.
// We must also give an extra reference when not removing.
let (index, data_ptr) = result;
let data: @T = unsafe::transmute(move data_ptr);
unsafe::bump_box_refcount(data);
if do_pop {
(*map).set_elt(index, None);
}
data
}
}
unsafe fn local_pop<T: Owned>(
task: *rust_task,
key: LocalDataKey<T>) -> Option<@T> {
local_get_helper(task, key, true)
}
unsafe fn local_get<T: Owned>(
task: *rust_task,
key: LocalDataKey<T>) -> Option<@T> {
local_get_helper(task, key, false)
}
unsafe fn local_set<T: Owned>(
task: *rust_task, key: LocalDataKey<T>, +data: @T) {
let map = get_task_local_map(task);
// Store key+data as *voids. Data is invisibly referenced once; key isn't.
let keyval = key_to_key_value(key);
// We keep the data in two forms: one as an unsafe pointer, so we can get
// it back by casting; another in an existential box, so the reference we
// own on it can be dropped when the box is destroyed. The unsafe pointer
// does not have a reference associated with it, so it may become invalid
// when the box is destroyed.
let data_ptr = unsafe::reinterpret_cast(&data);
let data_box = data as LocalData;
// Construct new entry to store in the map.
let new_entry = Some((keyval, data_ptr, data_box));
// Find a place to put it.
match local_data_lookup(map, key) {
Some((index, _old_data_ptr)) => {
// Key already had a value set, _old_data_ptr, whose reference
// will get dropped when the local_data box is overwritten.
(*map).set_elt(index, new_entry);
}
None => {
// Find an empty slot. If not, grow the vector.
match (*map).position(|x| x.is_none()) {
Some(empty_index) => (*map).set_elt(empty_index, new_entry),
None => (*map).push(new_entry)
}
}
}
}
unsafe fn local_modify<T: Owned>(
task: *rust_task, key: LocalDataKey<T>,
modify_fn: fn(Option<@T>) -> Option<@T>) {
// Could be more efficient by doing the lookup work, but this is easy.
let newdata = modify_fn(local_pop(task, key));
if newdata.is_some() {
local_set(task, key, option::unwrap(move newdata));
}
}
/* Exported interface for task-local data (plus local_data_key above). */
/**
* Remove a task-local data value from the table, returning the
* reference that was originally created to insert it.
*/
unsafe fn local_data_pop<T: Owned>(
key: LocalDataKey<T>) -> Option<@T> {
local_pop(rustrt::rust_get_task(), key)
}
/**
* Retrieve a task-local data value. It will also be kept alive in the
* table until explicitly removed.
*/
unsafe fn local_data_get<T: Owned>(
key: LocalDataKey<T>) -> Option<@T> {
local_get(rustrt::rust_get_task(), key)
}
/**
* Store a value in task-local data. If this key already has a value,
* that value is overwritten (and its destructor is run).
*/
unsafe fn local_data_set<T: Owned>(
key: LocalDataKey<T>, +data: @T) {
local_set(rustrt::rust_get_task(), key, data)
}
/**
* Modify a task-local data value. If the function returns 'None', the
* data is removed (and its reference dropped).
*/
unsafe fn local_data_modify<T: Owned>(
key: LocalDataKey<T>,
modify_fn: fn(Option<@T>) -> Option<@T>) {
local_modify(rustrt::rust_get_task(), key, modify_fn)
}
extern mod rustrt {
#[rust_stack]
fn rust_task_yield(task: *rust_task) -> bool;
fn rust_get_sched_id() -> sched_id;
fn rust_new_sched(num_threads: libc::uintptr_t) -> sched_id;
fn sched_threads() -> libc::size_t;
fn rust_num_threads() -> libc::uintptr_t;
fn get_task_id() -> task_id;
#[rust_stack]
fn rust_get_task() -> *rust_task;
fn new_task() -> *rust_task;
fn rust_new_task_in_sched(id: sched_id) -> *rust_task;
fn start_task(task: *rust_task, closure: *rust_closure);
fn rust_task_is_unwinding(task: *rust_task) -> bool;
fn rust_osmain_sched_id() -> sched_id;
#[rust_stack]
fn rust_task_inhibit_kill(t: *rust_task);
#[rust_stack]
fn rust_task_allow_kill(t: *rust_task);
#[rust_stack]
fn rust_task_inhibit_yield(t: *rust_task);
#[rust_stack]
fn rust_task_allow_yield(t: *rust_task);
fn rust_task_kill_other(task: *rust_task);
fn rust_task_kill_all(task: *rust_task);
#[rust_stack]
fn rust_get_task_local_data(task: *rust_task) -> *libc::c_void;
#[rust_stack]
fn rust_set_task_local_data(task: *rust_task, map: *libc::c_void);
#[rust_stack]
fn rust_task_local_data_atexit(task: *rust_task, cleanup_fn: *u8);
}
#[test]
fn test_spawn_raw_simple() {
let po = comm::Port();
let ch = comm::Chan(po);
do spawn_raw(default_task_opts()) {
comm::send(ch, ());
}
comm::recv(po);
}
#[test]
#[ignore(cfg(windows))]
fn test_spawn_raw_unsupervise() {
let opts = {
linked: false,
mut notify_chan: None,
.. default_task_opts()
};
do spawn_raw(opts) {
fail;
}
}
#[test] #[should_fail] #[ignore(cfg(windows))]
fn test_cant_dup_task_builder() {
let b = task().unlinked();
do b.spawn { }
// FIXME(#2585): For now, this is a -runtime- failure, because we haven't
// got modes on self. When 2585 is fixed, this test should fail to compile
// instead, and should go in tests/compile-fail.
do b.spawn { } // b should have been consumed by the previous call
}
// The following 8 tests test the following 2^3 combinations:
// {un,}linked {un,}supervised failure propagation {up,down}wards.
// !!! These tests are dangerous. If Something is buggy, they will hang, !!!
// !!! instead of exiting cleanly. This might wedge the buildbots. !!!
#[test] #[ignore(cfg(windows))]
fn test_spawn_unlinked_unsup_no_fail_down() { // grandchild sends on a port
let po = comm::Port();
let ch = comm::Chan(po);
do spawn_unlinked {
do spawn_unlinked {
// Give middle task a chance to fail-but-not-kill-us.
for iter::repeat(16) { task::yield(); }
comm::send(ch, ()); // If killed first, grandparent hangs.
}
fail; // Shouldn't kill either (grand)parent or (grand)child.
}
comm::recv(po);
}
#[test] #[ignore(cfg(windows))]
fn test_spawn_unlinked_unsup_no_fail_up() { // child unlinked fails
do spawn_unlinked { fail; }
}
#[test] #[ignore(cfg(windows))]
fn test_spawn_unlinked_sup_no_fail_up() { // child unlinked fails
do spawn_supervised { fail; }
// Give child a chance to fail-but-not-kill-us.
for iter::repeat(16) { task::yield(); }
}
#[test] #[should_fail] #[ignore(cfg(windows))]
fn test_spawn_unlinked_sup_fail_down() {
do spawn_supervised { loop { task::yield(); } }
fail; // Shouldn't leave a child hanging around.
}
#[test] #[should_fail] #[ignore(cfg(windows))]
fn test_spawn_linked_sup_fail_up() { // child fails; parent fails
let po = comm::Port::<()>();
let _ch = comm::Chan(po);
// Unidirectional "parenting" shouldn't override bidirectional linked.
// We have to cheat with opts - the interface doesn't support them because
// they don't make sense (redundant with task().supervised()).
let opts = {
let mut opts = default_task_opts();
opts.linked = true;
opts.supervised = true;
move opts
};
let b0 = task();
let b1 = TaskBuilder({
opts: move opts,
can_not_copy: None,
.. *b0
});
do b1.spawn { fail; }
comm::recv(po); // We should get punted awake
}
#[test] #[should_fail] #[ignore(cfg(windows))]
fn test_spawn_linked_sup_fail_down() { // parent fails; child fails
// We have to cheat with opts - the interface doesn't support them because
// they don't make sense (redundant with task().supervised()).
let opts = {
let mut opts = default_task_opts();
opts.linked = true;
opts.supervised = true;
move opts
};
let b0 = task();
let b1 = TaskBuilder({
opts: move opts,
can_not_copy: None,
.. *b0
});
do b1.spawn { loop { task::yield(); } }
fail; // *both* mechanisms would be wrong if this didn't kill the child...
}
#[test] #[should_fail] #[ignore(cfg(windows))]
fn test_spawn_linked_unsup_fail_up() { // child fails; parent fails
let po = comm::Port::<()>();
let _ch = comm::Chan(po);
// Default options are to spawn linked & unsupervised.
do spawn { fail; }
comm::recv(po); // We should get punted awake
}
#[test] #[should_fail] #[ignore(cfg(windows))]
fn test_spawn_linked_unsup_fail_down() { // parent fails; child fails
// Default options are to spawn linked & unsupervised.
do spawn { loop { task::yield(); } }
fail;
}
#[test] #[should_fail] #[ignore(cfg(windows))]
fn test_spawn_linked_unsup_default_opts() { // parent fails; child fails
// Make sure the above test is the same as this one.
do task().linked().spawn { loop { task::yield(); } }
fail;
}
// A couple bonus linked failure tests - testing for failure propagation even
// when the middle task exits successfully early before kill signals are sent.
#[test] #[should_fail] #[ignore(cfg(windows))]
fn test_spawn_failure_propagate_grandchild() {
// Middle task exits; does grandparent's failure propagate across the gap?
do spawn_supervised {
do spawn_supervised {
loop { task::yield(); }
}
}
for iter::repeat(16) { task::yield(); }
fail;
}
#[test] #[should_fail] #[ignore(cfg(windows))]
fn test_spawn_failure_propagate_secondborn() {
// First-born child exits; does parent's failure propagate to sibling?
do spawn_supervised {
do spawn { // linked
loop { task::yield(); }
}
}
for iter::repeat(16) { task::yield(); }
fail;
}
#[test] #[should_fail] #[ignore(cfg(windows))]
fn test_spawn_failure_propagate_nephew_or_niece() {
// Our sibling exits; does our failure propagate to sibling's child?
do spawn { // linked
do spawn_supervised {
loop { task::yield(); }
}
}
for iter::repeat(16) { task::yield(); }
fail;
}
#[test] #[should_fail] #[ignore(cfg(windows))]
fn test_spawn_linked_sup_propagate_sibling() {
// Middle sibling exits - does eldest's failure propagate to youngest?
do spawn { // linked
do spawn { // linked
loop { task::yield(); }
}
}
for iter::repeat(16) { task::yield(); }
fail;
}
#[test]
#[ignore(cfg(windows))]
fn test_spawn_raw_notify_success() {
let (task_ch, task_po) = pipes::stream();
let (notify_ch, notify_po) = pipes::stream();
let opts = {
notify_chan: Some(move notify_ch),
.. default_task_opts()
};
do spawn_raw(opts) |move task_ch| {
task_ch.send(get_task());
}
let task_ = task_po.recv();
assert notify_po.recv() == Exit(task_, Success);
}
#[test]
#[ignore(cfg(windows))]
fn test_spawn_raw_notify_failure() {
// New bindings for these
let (task_ch, task_po) = pipes::stream();
let (notify_ch, notify_po) = pipes::stream();
let opts = {
linked: false,
notify_chan: Some(notify_ch),
.. default_task_opts()
};
do spawn_raw(opts) {
task_ch.send(get_task());
fail;
}
let task_ = task_po.recv();
assert notify_po.recv() == Exit(task_, Failure);
}
#[test]
fn test_run_basic() {
let po = comm::Port();
let ch = comm::Chan(po);
do task().spawn {
comm::send(ch, ());
}
comm::recv(po);
}
#[test]
fn test_add_wrapper() {
let po = comm::Port();
let ch = comm::Chan(po);
let b0 = task();
let b1 = do b0.add_wrapper |body| {
fn~() {
body();
comm::send(ch, ());
}
};
do b1.spawn { }
comm::recv(po);
}
#[test]
#[ignore(cfg(windows))]
fn test_future_result() {
let mut result = None;
do task().future_result(|+r| { result = Some(r); }).spawn { }
assert future::get(&option::unwrap(result)) == Success;
result = None;
do task().future_result(|+r| { result = Some(r); }).unlinked().spawn {
fail;
}
assert future::get(&option::unwrap(result)) == Failure;
}
#[test] #[should_fail] #[ignore(cfg(windows))]
fn test_back_to_the_future_result() {
let _ = task().future_result(util::ignore).future_result(util::ignore);
}
#[test]
fn test_spawn_listiner_bidi() {
let po = comm::Port();
let ch = comm::Chan(po);
let ch = do spawn_listener |po| {
// Now the child has a port called 'po' to read from and
// an environment-captured channel called 'ch'.
let res: ~str = comm::recv(po);
assert res == ~"ping";
comm::send(ch, ~"pong");
};
// Likewise, the parent has both a 'po' and 'ch'
comm::send(ch, ~"ping");
let res: ~str = comm::recv(po);
assert res == ~"pong";
}
#[test]
fn test_spawn_conversation() {
let (recv_str, send_int) = do spawn_conversation |recv_int, send_str| {
let input = comm::recv(recv_int);
let output = int::str(input);
comm::send(send_str, output);
};
comm::send(send_int, 1);
assert comm::recv(recv_str) == ~"1";
}
#[test]
fn test_try_success() {
match do try {
~"Success!"
} {
result::Ok(~"Success!") => (),
_ => fail
}
}
#[test]
#[ignore(cfg(windows))]
fn test_try_fail() {
match do try {
fail
} {
result::Err(()) => (),
result::Ok(()) => fail
}
}
#[test]
#[should_fail]
#[ignore(cfg(windows))]
fn test_spawn_sched_no_threads() {
do spawn_sched(ManualThreads(0u)) { }
}
#[test]
fn test_spawn_sched() {
let po = comm::Port();
let ch = comm::Chan(po);
fn f(i: int, ch: comm::Chan<()>) {
let parent_sched_id = rustrt::rust_get_sched_id();
do spawn_sched(SingleThreaded) {
let child_sched_id = rustrt::rust_get_sched_id();
assert parent_sched_id != child_sched_id;
if (i == 0) {
comm::send(ch, ());
} else {
f(i - 1, ch);
}
};
}
f(10, ch);
comm::recv(po);
}
#[test]
fn test_spawn_sched_childs_on_same_sched() {
let po = comm::Port();
let ch = comm::Chan(po);
do spawn_sched(SingleThreaded) {
let parent_sched_id = rustrt::rust_get_sched_id();
do spawn {
let child_sched_id = rustrt::rust_get_sched_id();
// This should be on the same scheduler
assert parent_sched_id == child_sched_id;
comm::send(ch, ());
};
};
comm::recv(po);
}
#[nolink]
#[cfg(test)]
extern mod testrt {
fn rust_dbg_lock_create() -> *libc::c_void;
fn rust_dbg_lock_destroy(lock: *libc::c_void);
fn rust_dbg_lock_lock(lock: *libc::c_void);
fn rust_dbg_lock_unlock(lock: *libc::c_void);
fn rust_dbg_lock_wait(lock: *libc::c_void);
fn rust_dbg_lock_signal(lock: *libc::c_void);
}
#[test]
fn test_spawn_sched_blocking() {
// Testing that a task in one scheduler can block in foreign code
// without affecting other schedulers
for iter::repeat(20u) {
let start_po = comm::Port();
let start_ch = comm::Chan(start_po);
let fin_po = comm::Port();
let fin_ch = comm::Chan(fin_po);
let lock = testrt::rust_dbg_lock_create();
do spawn_sched(SingleThreaded) {
testrt::rust_dbg_lock_lock(lock);
comm::send(start_ch, ());
// Block the scheduler thread
testrt::rust_dbg_lock_wait(lock);
testrt::rust_dbg_lock_unlock(lock);
comm::send(fin_ch, ());
};
// Wait until the other task has its lock
comm::recv(start_po);
fn pingpong(po: comm::Port<int>, ch: comm::Chan<int>) {
let mut val = 20;
while val > 0 {
val = comm::recv(po);
comm::send(ch, val - 1);
}
}
let setup_po = comm::Port();
let setup_ch = comm::Chan(setup_po);
let parent_po = comm::Port();
let parent_ch = comm::Chan(parent_po);
do spawn {
let child_po = comm::Port();
comm::send(setup_ch, comm::Chan(child_po));
pingpong(child_po, parent_ch);
};
let child_ch = comm::recv(setup_po);
comm::send(child_ch, 20);
pingpong(parent_po, child_ch);
testrt::rust_dbg_lock_lock(lock);
testrt::rust_dbg_lock_signal(lock);
testrt::rust_dbg_lock_unlock(lock);
comm::recv(fin_po);
testrt::rust_dbg_lock_destroy(lock);
}
}
#[cfg(test)]
fn avoid_copying_the_body(spawnfn: fn(+fn~())) {
let p = comm::Port::<uint>();
let ch = comm::Chan(p);
let x = ~1;
let x_in_parent = ptr::addr_of(*x) as uint;
do spawnfn {
let x_in_child = ptr::addr_of(*x) as uint;
comm::send(ch, x_in_child);
}
let x_in_child = comm::recv(p);
assert x_in_parent == x_in_child;
}
#[test]
fn test_avoid_copying_the_body_spawn() {
avoid_copying_the_body(spawn);
}
#[test]
fn test_avoid_copying_the_body_spawn_listener() {
do avoid_copying_the_body |f| {
spawn_listener(fn~(move f, _po: comm::Port<int>) {
f();
});
}
}
#[test]
fn test_avoid_copying_the_body_task_spawn() {
do avoid_copying_the_body |f| {
do task().spawn {
f();
}
}
}
#[test]
fn test_avoid_copying_the_body_spawn_listener_1() {
do avoid_copying_the_body |f| {
task().spawn_listener(fn~(move f, _po: comm::Port<int>) {
f();
});
}
}
#[test]
fn test_avoid_copying_the_body_try() {
do avoid_copying_the_body |f| {
do try {
f()
};
}
}
#[test]
fn test_avoid_copying_the_body_unlinked() {
do avoid_copying_the_body |f| {
do spawn_unlinked {
f();
}
}
}
#[test]
fn test_platform_thread() {
let po = comm::Port();
let ch = comm::Chan(po);
do task().sched_mode(PlatformThread).spawn {
comm::send(ch, ());
}
comm::recv(po);
}
#[test]
#[ignore(cfg(windows))]
#[should_fail]
fn test_unkillable() {
let po = comm::Port();
let ch = po.chan();
let opts = {
let mut opts = default_task_opts();
opts.linked = false;
move opts
};
// We want to do this after failing
do spawn_raw(opts) {
for iter::repeat(10u) { yield() }
ch.send(());
}
do spawn {
yield();
// We want to fail after the unkillable task
// blocks on recv
fail;
}
unsafe {
do unkillable {
let p = ~0;
let pp: *uint = unsafe::transmute(p);
// If we are killed here then the box will leak
po.recv();
let _p: ~int = unsafe::transmute(pp);
}
}
// Now we can be killed
po.recv();
}
#[test]
#[ignore(cfg(windows))]
#[should_fail]
fn test_unkillable_nested() {
let (ch, po) = pipes::stream();
// We want to do this after failing
let opts = {
let mut opts = default_task_opts();
opts.linked = false;
move opts
};
do spawn_raw(opts) {
for iter::repeat(10u) { yield() }
ch.send(());
}
do spawn {
yield();
// We want to fail after the unkillable task
// blocks on recv
fail;
}
unsafe {
do unkillable {
do unkillable {} // Here's the difference from the previous test.
let p = ~0;
let pp: *uint = unsafe::transmute(p);
// If we are killed here then the box will leak
po.recv();
let _p: ~int = unsafe::transmute(pp);
}
}
// Now we can be killed
po.recv();
}
#[test] #[should_fail] #[ignore(cfg(windows))]
fn test_atomically() {
unsafe { do atomically { yield(); } }
}
#[test]
fn test_atomically2() {
unsafe { do atomically { } } yield(); // shouldn't fail
}
#[test] #[should_fail] #[ignore(cfg(windows))]
fn test_atomically_nested() {
unsafe { do atomically { do atomically { } yield(); } }
}
#[test]
fn test_child_doesnt_ref_parent() {
// If the child refcounts the parent task, this will stack overflow when
// climbing the task tree to dereference each ancestor. (See #1789)
// (well, it would if the constant were 8000+ - I lowered it to be more
// valgrind-friendly. try this at home, instead..!)
const generations: uint = 16;
fn child_no(x: uint) -> fn~() {
return || {
if x < generations {
task::spawn(child_no(x+1));
}
}
}
task::spawn(child_no(0));
}
#[test]
fn test_tls_multitask() unsafe {
fn my_key(+_x: @~str) { }
local_data_set(my_key, @~"parent data");
do task::spawn unsafe {
assert local_data_get(my_key).is_none(); // TLS shouldn't carry over.
local_data_set(my_key, @~"child data");
assert *(local_data_get(my_key).get()) == ~"child data";
// should be cleaned up for us
}
// Must work multiple times
assert *(local_data_get(my_key).get()) == ~"parent data";
assert *(local_data_get(my_key).get()) == ~"parent data";
assert *(local_data_get(my_key).get()) == ~"parent data";
}
#[test]
fn test_tls_overwrite() unsafe {
fn my_key(+_x: @~str) { }
local_data_set(my_key, @~"first data");
local_data_set(my_key, @~"next data"); // Shouldn't leak.
assert *(local_data_get(my_key).get()) == ~"next data";
}
#[test]
fn test_tls_pop() unsafe {
fn my_key(+_x: @~str) { }
local_data_set(my_key, @~"weasel");
assert *(local_data_pop(my_key).get()) == ~"weasel";
// Pop must remove the data from the map.
assert local_data_pop(my_key).is_none();
}
#[test]
fn test_tls_modify() unsafe {
fn my_key(+_x: @~str) { }
local_data_modify(my_key, |data| {
match data {
Some(@val) => fail ~"unwelcome value: " + val,
None => Some(@~"first data")
}
});
local_data_modify(my_key, |data| {
match data {
Some(@~"first data") => Some(@~"next data"),
Some(@val) => fail ~"wrong value: " + val,
None => fail ~"missing value"
}
});
assert *(local_data_pop(my_key).get()) == ~"next data";
}
#[test]
fn test_tls_crust_automorestack_memorial_bug() unsafe {
// This might result in a stack-canary clobber if the runtime fails to set
// sp_limit to 0 when calling the cleanup extern - it might automatically
// jump over to the rust stack, which causes next_c_sp to get recorded as
// Something within a rust stack segment. Then a subsequent upcall (esp.
// for logging, think vsnprintf) would run on a stack smaller than 1 MB.
fn my_key(+_x: @~str) { }
do task::spawn {
unsafe { local_data_set(my_key, @~"hax"); }
}
}
#[test]
fn test_tls_multiple_types() unsafe {
fn str_key(+_x: @~str) { }
fn box_key(+_x: @@()) { }
fn int_key(+_x: @int) { }
do task::spawn unsafe {
local_data_set(str_key, @~"string data");
local_data_set(box_key, @@());
local_data_set(int_key, @42);
}
}
#[test]
fn test_tls_overwrite_multiple_types() {
fn str_key(+_x: @~str) { }
fn box_key(+_x: @@()) { }
fn int_key(+_x: @int) { }
do task::spawn unsafe {
local_data_set(str_key, @~"string data");
local_data_set(int_key, @42);
// This could cause a segfault if overwriting-destruction is done with
// the crazy polymorphic transmute rather than the provided finaliser.
local_data_set(int_key, @31337);
}
}
#[test]
#[should_fail]
#[ignore(cfg(windows))]
fn test_tls_cleanup_on_failure() unsafe {
fn str_key(+_x: @~str) { }
fn box_key(+_x: @@()) { }
fn int_key(+_x: @int) { }
local_data_set(str_key, @~"parent data");
local_data_set(box_key, @@());
do task::spawn unsafe { // spawn_linked
local_data_set(str_key, @~"string data");
local_data_set(box_key, @@());
local_data_set(int_key, @42);
fail;
}
// Not quite nondeterministic.
local_data_set(int_key, @31337);
fail;
}
#[test]
fn test_sched_thread_per_core() {
let cores = rustrt::rust_num_threads();
let mut reported_threads = 0u;
do spawn_sched(ThreadPerCore) {
reported_threads = rustrt::sched_threads();
}
assert(cores == reported_threads);
}