zig/lib/std/event/loop.zig
LemonBoy 566adc2510 std: Swap arguments in Thread.spawn
Beside the new order being consistent with the ThreadPool API and making
more sense, this shuffling allows to write the context argument type in
terms of the startFn arguments, reducing the use of anytype (eg. less
explicit casts when using comptime_int parameters, yay).

Sorry for the breakage.

Closes #8082
2021-02-28 14:03:19 +01:00

1714 lines
64 KiB
Zig

// SPDX-License-Identifier: MIT
// Copyright (c) 2015-2021 Zig Contributors
// This file is part of [zig](https://ziglang.org/), which is MIT licensed.
// The MIT license requires this copyright notice to be included in all copies
// and substantial portions of the software.
const std = @import("../std.zig");
const builtin = @import("builtin");
const root = @import("root");
const assert = std.debug.assert;
const testing = std.testing;
const mem = std.mem;
const os = std.os;
const windows = os.windows;
const maxInt = std.math.maxInt;
const Thread = std.Thread;
const is_windows = std.Target.current.os.tag == .windows;
pub const Loop = struct {
next_tick_queue: std.atomic.Queue(anyframe),
os_data: OsData,
final_resume_node: ResumeNode,
pending_event_count: usize,
extra_threads: []*Thread,
/// TODO change this to a pool of configurable number of threads
/// and rename it to be not file-system-specific. it will become
/// a thread pool for turning non-CPU-bound blocking things into
/// async things. A fallback for any missing OS-specific API.
fs_thread: *Thread,
fs_queue: std.atomic.Queue(Request),
fs_end_request: Request.Node,
fs_thread_wakeup: std.Thread.ResetEvent,
/// For resources that have the same lifetime as the `Loop`.
/// This is only used by `Loop` for the thread pool and associated resources.
arena: std.heap.ArenaAllocator,
/// State which manages frames that are sleeping on timers
delay_queue: DelayQueue,
/// Pre-allocated eventfds. All permanently active.
/// This is how `Loop` sends promises to be resumed on other threads.
available_eventfd_resume_nodes: std.atomic.Stack(ResumeNode.EventFd),
eventfd_resume_nodes: []std.atomic.Stack(ResumeNode.EventFd).Node,
pub const NextTickNode = std.atomic.Queue(anyframe).Node;
pub const ResumeNode = struct {
id: Id,
handle: anyframe,
overlapped: Overlapped,
pub const overlapped_init = switch (builtin.os.tag) {
.windows => windows.OVERLAPPED{
.Internal = 0,
.InternalHigh = 0,
.Offset = 0,
.OffsetHigh = 0,
.hEvent = null,
},
else => {},
};
pub const Overlapped = @TypeOf(overlapped_init);
pub const Id = enum {
Basic,
Stop,
EventFd,
};
pub const EventFd = switch (builtin.os.tag) {
.macos, .freebsd, .netbsd, .dragonfly, .openbsd => KEventFd,
.linux => struct {
base: ResumeNode,
epoll_op: u32,
eventfd: i32,
},
.windows => struct {
base: ResumeNode,
completion_key: usize,
},
else => struct {},
};
const KEventFd = struct {
base: ResumeNode,
kevent: os.Kevent,
};
pub const Basic = switch (builtin.os.tag) {
.macos, .freebsd, .netbsd, .dragonfly, .openbsd => KEventBasic,
.linux => struct {
base: ResumeNode,
},
.windows => struct {
base: ResumeNode,
},
else => @compileError("unsupported OS"),
};
const KEventBasic = struct {
base: ResumeNode,
kev: os.Kevent,
};
};
var global_instance_state: Loop = undefined;
const default_instance: ?*Loop = switch (std.io.mode) {
.blocking => null,
.evented => &global_instance_state,
};
pub const instance: ?*Loop = if (@hasDecl(root, "event_loop")) root.event_loop else default_instance;
/// TODO copy elision / named return values so that the threads referencing *Loop
/// have the correct pointer value.
/// https://github.com/ziglang/zig/issues/2761 and https://github.com/ziglang/zig/issues/2765
pub fn init(self: *Loop) !void {
if (builtin.single_threaded or
(@hasDecl(root, "event_loop_mode") and root.event_loop_mode == .single_threaded))
{
return self.initSingleThreaded();
} else {
return self.initMultiThreaded();
}
}
/// After initialization, call run().
/// TODO copy elision / named return values so that the threads referencing *Loop
/// have the correct pointer value.
/// https://github.com/ziglang/zig/issues/2761 and https://github.com/ziglang/zig/issues/2765
pub fn initSingleThreaded(self: *Loop) !void {
return self.initThreadPool(1);
}
/// After initialization, call run().
/// This is the same as `initThreadPool` using `Thread.cpuCount` to determine the thread
/// pool size.
/// TODO copy elision / named return values so that the threads referencing *Loop
/// have the correct pointer value.
/// https://github.com/ziglang/zig/issues/2761 and https://github.com/ziglang/zig/issues/2765
pub fn initMultiThreaded(self: *Loop) !void {
if (builtin.single_threaded)
@compileError("initMultiThreaded unavailable when building in single-threaded mode");
const core_count = try Thread.cpuCount();
return self.initThreadPool(core_count);
}
/// Thread count is the total thread count. The thread pool size will be
/// max(thread_count - 1, 0)
pub fn initThreadPool(self: *Loop, thread_count: usize) !void {
self.* = Loop{
.arena = std.heap.ArenaAllocator.init(std.heap.page_allocator),
.pending_event_count = 1,
.os_data = undefined,
.next_tick_queue = std.atomic.Queue(anyframe).init(),
.extra_threads = undefined,
.available_eventfd_resume_nodes = std.atomic.Stack(ResumeNode.EventFd).init(),
.eventfd_resume_nodes = undefined,
.final_resume_node = ResumeNode{
.id = ResumeNode.Id.Stop,
.handle = undefined,
.overlapped = ResumeNode.overlapped_init,
},
.fs_end_request = .{ .data = .{ .msg = .end, .finish = .NoAction } },
.fs_queue = std.atomic.Queue(Request).init(),
.fs_thread = undefined,
.fs_thread_wakeup = undefined,
.delay_queue = undefined,
};
try self.fs_thread_wakeup.init();
errdefer self.fs_thread_wakeup.deinit();
errdefer self.arena.deinit();
// We need at least one of these in case the fs thread wants to use onNextTick
const extra_thread_count = thread_count - 1;
const resume_node_count = std.math.max(extra_thread_count, 1);
self.eventfd_resume_nodes = try self.arena.allocator.alloc(
std.atomic.Stack(ResumeNode.EventFd).Node,
resume_node_count,
);
self.extra_threads = try self.arena.allocator.alloc(*Thread, extra_thread_count);
try self.initOsData(extra_thread_count);
errdefer self.deinitOsData();
if (!builtin.single_threaded) {
self.fs_thread = try Thread.spawn(posixFsRun, self);
}
errdefer if (!builtin.single_threaded) {
self.posixFsRequest(&self.fs_end_request);
self.fs_thread.wait();
};
if (!std.builtin.single_threaded)
try self.delay_queue.init();
}
pub fn deinit(self: *Loop) void {
self.deinitOsData();
self.fs_thread_wakeup.deinit();
self.arena.deinit();
self.* = undefined;
}
const InitOsDataError = os.EpollCreateError || mem.Allocator.Error || os.EventFdError ||
Thread.SpawnError || os.EpollCtlError || os.KEventError ||
windows.CreateIoCompletionPortError;
const wakeup_bytes = [_]u8{0x1} ** 8;
fn initOsData(self: *Loop, extra_thread_count: usize) InitOsDataError!void {
nosuspend switch (builtin.os.tag) {
.linux => {
errdefer {
while (self.available_eventfd_resume_nodes.pop()) |node| os.close(node.data.eventfd);
}
for (self.eventfd_resume_nodes) |*eventfd_node| {
eventfd_node.* = std.atomic.Stack(ResumeNode.EventFd).Node{
.data = ResumeNode.EventFd{
.base = ResumeNode{
.id = .EventFd,
.handle = undefined,
.overlapped = ResumeNode.overlapped_init,
},
.eventfd = try os.eventfd(1, os.EFD_CLOEXEC | os.EFD_NONBLOCK),
.epoll_op = os.EPOLL_CTL_ADD,
},
.next = undefined,
};
self.available_eventfd_resume_nodes.push(eventfd_node);
}
self.os_data.epollfd = try os.epoll_create1(os.EPOLL_CLOEXEC);
errdefer os.close(self.os_data.epollfd);
self.os_data.final_eventfd = try os.eventfd(0, os.EFD_CLOEXEC | os.EFD_NONBLOCK);
errdefer os.close(self.os_data.final_eventfd);
self.os_data.final_eventfd_event = os.epoll_event{
.events = os.EPOLLIN,
.data = os.epoll_data{ .ptr = @ptrToInt(&self.final_resume_node) },
};
try os.epoll_ctl(
self.os_data.epollfd,
os.EPOLL_CTL_ADD,
self.os_data.final_eventfd,
&self.os_data.final_eventfd_event,
);
if (builtin.single_threaded) {
assert(extra_thread_count == 0);
return;
}
var extra_thread_index: usize = 0;
errdefer {
// writing 8 bytes to an eventfd cannot fail
const amt = os.write(self.os_data.final_eventfd, &wakeup_bytes) catch unreachable;
assert(amt == wakeup_bytes.len);
while (extra_thread_index != 0) {
extra_thread_index -= 1;
self.extra_threads[extra_thread_index].wait();
}
}
while (extra_thread_index < extra_thread_count) : (extra_thread_index += 1) {
self.extra_threads[extra_thread_index] = try Thread.spawn(workerRun, self);
}
},
.macos, .freebsd, .netbsd, .dragonfly, .openbsd => {
self.os_data.kqfd = try os.kqueue();
errdefer os.close(self.os_data.kqfd);
const empty_kevs = &[0]os.Kevent{};
for (self.eventfd_resume_nodes) |*eventfd_node, i| {
eventfd_node.* = std.atomic.Stack(ResumeNode.EventFd).Node{
.data = ResumeNode.EventFd{
.base = ResumeNode{
.id = ResumeNode.Id.EventFd,
.handle = undefined,
.overlapped = ResumeNode.overlapped_init,
},
// this one is for sending events
.kevent = os.Kevent{
.ident = i,
.filter = os.EVFILT_USER,
.flags = os.EV_CLEAR | os.EV_ADD | os.EV_DISABLE,
.fflags = 0,
.data = 0,
.udata = @ptrToInt(&eventfd_node.data.base),
},
},
.next = undefined,
};
self.available_eventfd_resume_nodes.push(eventfd_node);
const kevent_array = @as(*const [1]os.Kevent, &eventfd_node.data.kevent);
_ = try os.kevent(self.os_data.kqfd, kevent_array, empty_kevs, null);
eventfd_node.data.kevent.flags = os.EV_CLEAR | os.EV_ENABLE;
eventfd_node.data.kevent.fflags = os.NOTE_TRIGGER;
}
// Pre-add so that we cannot get error.SystemResources
// later when we try to activate it.
self.os_data.final_kevent = os.Kevent{
.ident = extra_thread_count,
.filter = os.EVFILT_USER,
.flags = os.EV_ADD | os.EV_DISABLE,
.fflags = 0,
.data = 0,
.udata = @ptrToInt(&self.final_resume_node),
};
const final_kev_arr = @as(*const [1]os.Kevent, &self.os_data.final_kevent);
_ = try os.kevent(self.os_data.kqfd, final_kev_arr, empty_kevs, null);
self.os_data.final_kevent.flags = os.EV_ENABLE;
self.os_data.final_kevent.fflags = os.NOTE_TRIGGER;
if (builtin.single_threaded) {
assert(extra_thread_count == 0);
return;
}
var extra_thread_index: usize = 0;
errdefer {
_ = os.kevent(self.os_data.kqfd, final_kev_arr, empty_kevs, null) catch unreachable;
while (extra_thread_index != 0) {
extra_thread_index -= 1;
self.extra_threads[extra_thread_index].wait();
}
}
while (extra_thread_index < extra_thread_count) : (extra_thread_index += 1) {
self.extra_threads[extra_thread_index] = try Thread.spawn(workerRun, self);
}
},
.windows => {
self.os_data.io_port = try windows.CreateIoCompletionPort(
windows.INVALID_HANDLE_VALUE,
null,
undefined,
maxInt(windows.DWORD),
);
errdefer windows.CloseHandle(self.os_data.io_port);
for (self.eventfd_resume_nodes) |*eventfd_node, i| {
eventfd_node.* = std.atomic.Stack(ResumeNode.EventFd).Node{
.data = ResumeNode.EventFd{
.base = ResumeNode{
.id = ResumeNode.Id.EventFd,
.handle = undefined,
.overlapped = ResumeNode.overlapped_init,
},
// this one is for sending events
.completion_key = @ptrToInt(&eventfd_node.data.base),
},
.next = undefined,
};
self.available_eventfd_resume_nodes.push(eventfd_node);
}
if (builtin.single_threaded) {
assert(extra_thread_count == 0);
return;
}
var extra_thread_index: usize = 0;
errdefer {
var i: usize = 0;
while (i < extra_thread_index) : (i += 1) {
while (true) {
const overlapped = &self.final_resume_node.overlapped;
windows.PostQueuedCompletionStatus(self.os_data.io_port, undefined, undefined, overlapped) catch continue;
break;
}
}
while (extra_thread_index != 0) {
extra_thread_index -= 1;
self.extra_threads[extra_thread_index].wait();
}
}
while (extra_thread_index < extra_thread_count) : (extra_thread_index += 1) {
self.extra_threads[extra_thread_index] = try Thread.spawn(workerRun, self);
}
},
else => {},
};
}
fn deinitOsData(self: *Loop) void {
nosuspend switch (builtin.os.tag) {
.linux => {
os.close(self.os_data.final_eventfd);
while (self.available_eventfd_resume_nodes.pop()) |node| os.close(node.data.eventfd);
os.close(self.os_data.epollfd);
},
.macos, .freebsd, .netbsd, .dragonfly, .openbsd => {
os.close(self.os_data.kqfd);
},
.windows => {
windows.CloseHandle(self.os_data.io_port);
},
else => {},
};
}
/// resume_node must live longer than the anyframe that it holds a reference to.
/// flags must contain EPOLLET
pub fn linuxAddFd(self: *Loop, fd: i32, resume_node: *ResumeNode, flags: u32) !void {
assert(flags & os.EPOLLET == os.EPOLLET);
self.beginOneEvent();
errdefer self.finishOneEvent();
try self.linuxModFd(
fd,
os.EPOLL_CTL_ADD,
flags,
resume_node,
);
}
pub fn linuxModFd(self: *Loop, fd: i32, op: u32, flags: u32, resume_node: *ResumeNode) !void {
assert(flags & os.EPOLLET == os.EPOLLET);
var ev = os.linux.epoll_event{
.events = flags,
.data = os.linux.epoll_data{ .ptr = @ptrToInt(resume_node) },
};
try os.epoll_ctl(self.os_data.epollfd, op, fd, &ev);
}
pub fn linuxRemoveFd(self: *Loop, fd: i32) void {
os.epoll_ctl(self.os_data.epollfd, os.linux.EPOLL_CTL_DEL, fd, null) catch {};
self.finishOneEvent();
}
pub fn linuxWaitFd(self: *Loop, fd: i32, flags: u32) void {
assert(flags & os.EPOLLET == os.EPOLLET);
assert(flags & os.EPOLLONESHOT == os.EPOLLONESHOT);
var resume_node = ResumeNode.Basic{
.base = ResumeNode{
.id = .Basic,
.handle = @frame(),
.overlapped = ResumeNode.overlapped_init,
},
};
var need_to_delete = true;
defer if (need_to_delete) self.linuxRemoveFd(fd);
suspend {
self.linuxAddFd(fd, &resume_node.base, flags) catch |err| switch (err) {
error.FileDescriptorNotRegistered => unreachable,
error.OperationCausesCircularLoop => unreachable,
error.FileDescriptorIncompatibleWithEpoll => unreachable,
error.FileDescriptorAlreadyPresentInSet => unreachable, // evented writes to the same fd is not thread-safe
error.SystemResources,
error.UserResourceLimitReached,
error.Unexpected,
=> {
need_to_delete = false;
// Fall back to a blocking poll(). Ideally this codepath is never hit, since
// epoll should be just fine. But this is better than incorrect behavior.
var poll_flags: i16 = 0;
if ((flags & os.EPOLLIN) != 0) poll_flags |= os.POLLIN;
if ((flags & os.EPOLLOUT) != 0) poll_flags |= os.POLLOUT;
var pfd = [1]os.pollfd{os.pollfd{
.fd = fd,
.events = poll_flags,
.revents = undefined,
}};
_ = os.poll(&pfd, -1) catch |poll_err| switch (poll_err) {
error.NetworkSubsystemFailed => unreachable, // only possible on windows
error.SystemResources,
error.Unexpected,
=> {
// Even poll() didn't work. The best we can do now is sleep for a
// small duration and then hope that something changed.
std.time.sleep(1 * std.time.ns_per_ms);
},
};
resume @frame();
},
};
}
}
pub fn waitUntilFdReadable(self: *Loop, fd: os.fd_t) void {
switch (builtin.os.tag) {
.linux => {
self.linuxWaitFd(fd, os.EPOLLET | os.EPOLLONESHOT | os.EPOLLIN);
},
.macos, .freebsd, .netbsd, .dragonfly, .openbsd => {
self.bsdWaitKev(@intCast(usize, fd), os.EVFILT_READ, os.EV_ONESHOT);
},
else => @compileError("Unsupported OS"),
}
}
pub fn waitUntilFdWritable(self: *Loop, fd: os.fd_t) void {
switch (builtin.os.tag) {
.linux => {
self.linuxWaitFd(fd, os.EPOLLET | os.EPOLLONESHOT | os.EPOLLOUT);
},
.macos, .freebsd, .netbsd, .dragonfly, .openbsd => {
self.bsdWaitKev(@intCast(usize, fd), os.EVFILT_WRITE, os.EV_ONESHOT);
},
else => @compileError("Unsupported OS"),
}
}
pub fn waitUntilFdWritableOrReadable(self: *Loop, fd: os.fd_t) void {
switch (builtin.os.tag) {
.linux => {
self.linuxWaitFd(fd, os.EPOLLET | os.EPOLLONESHOT | os.EPOLLOUT | os.EPOLLIN);
},
.macos, .freebsd, .netbsd, .dragonfly, .openbsd => {
self.bsdWaitKev(@intCast(usize, fd), os.EVFILT_READ, os.EV_ONESHOT);
self.bsdWaitKev(@intCast(usize, fd), os.EVFILT_WRITE, os.EV_ONESHOT);
},
else => @compileError("Unsupported OS"),
}
}
pub fn bsdWaitKev(self: *Loop, ident: usize, filter: i16, flags: u16) void {
var resume_node = ResumeNode.Basic{
.base = ResumeNode{
.id = ResumeNode.Id.Basic,
.handle = @frame(),
.overlapped = ResumeNode.overlapped_init,
},
.kev = undefined,
};
defer {
// If the kevent was set to be ONESHOT, it doesn't need to be deleted manually.
if (flags & os.EV_ONESHOT != 0) {
self.bsdRemoveKev(ident, filter);
}
}
suspend {
self.bsdAddKev(&resume_node, ident, filter, flags) catch unreachable;
}
}
/// resume_node must live longer than the anyframe that it holds a reference to.
pub fn bsdAddKev(self: *Loop, resume_node: *ResumeNode.Basic, ident: usize, filter: i16, flags: u16) !void {
self.beginOneEvent();
errdefer self.finishOneEvent();
var kev = [1]os.Kevent{os.Kevent{
.ident = ident,
.filter = filter,
.flags = os.EV_ADD | os.EV_ENABLE | os.EV_CLEAR | flags,
.fflags = 0,
.data = 0,
.udata = @ptrToInt(&resume_node.base),
}};
const empty_kevs = &[0]os.Kevent{};
_ = try os.kevent(self.os_data.kqfd, &kev, empty_kevs, null);
}
pub fn bsdRemoveKev(self: *Loop, ident: usize, filter: i16) void {
var kev = [1]os.Kevent{os.Kevent{
.ident = ident,
.filter = filter,
.flags = os.EV_DELETE,
.fflags = 0,
.data = 0,
.udata = 0,
}};
const empty_kevs = &[0]os.Kevent{};
_ = os.kevent(self.os_data.kqfd, &kev, empty_kevs, null) catch undefined;
self.finishOneEvent();
}
fn dispatch(self: *Loop) void {
while (self.available_eventfd_resume_nodes.pop()) |resume_stack_node| {
const next_tick_node = self.next_tick_queue.get() orelse {
self.available_eventfd_resume_nodes.push(resume_stack_node);
return;
};
const eventfd_node = &resume_stack_node.data;
eventfd_node.base.handle = next_tick_node.data;
switch (builtin.os.tag) {
.macos, .freebsd, .netbsd, .dragonfly, .openbsd => {
const kevent_array = @as(*const [1]os.Kevent, &eventfd_node.kevent);
const empty_kevs = &[0]os.Kevent{};
_ = os.kevent(self.os_data.kqfd, kevent_array, empty_kevs, null) catch {
self.next_tick_queue.unget(next_tick_node);
self.available_eventfd_resume_nodes.push(resume_stack_node);
return;
};
},
.linux => {
// the pending count is already accounted for
const epoll_events = os.EPOLLONESHOT | os.linux.EPOLLIN | os.linux.EPOLLOUT |
os.linux.EPOLLET;
self.linuxModFd(
eventfd_node.eventfd,
eventfd_node.epoll_op,
epoll_events,
&eventfd_node.base,
) catch {
self.next_tick_queue.unget(next_tick_node);
self.available_eventfd_resume_nodes.push(resume_stack_node);
return;
};
},
.windows => {
windows.PostQueuedCompletionStatus(
self.os_data.io_port,
undefined,
undefined,
&eventfd_node.base.overlapped,
) catch {
self.next_tick_queue.unget(next_tick_node);
self.available_eventfd_resume_nodes.push(resume_stack_node);
return;
};
},
else => @compileError("unsupported OS"),
}
}
}
/// Bring your own linked list node. This means it can't fail.
pub fn onNextTick(self: *Loop, node: *NextTickNode) void {
self.beginOneEvent(); // finished in dispatch()
self.next_tick_queue.put(node);
self.dispatch();
}
pub fn cancelOnNextTick(self: *Loop, node: *NextTickNode) void {
if (self.next_tick_queue.remove(node)) {
self.finishOneEvent();
}
}
pub fn run(self: *Loop) void {
self.finishOneEvent(); // the reference we start with
self.workerRun();
if (!builtin.single_threaded) {
switch (builtin.os.tag) {
.linux,
.macos,
.freebsd,
.netbsd,
.dragonfly,
.openbsd,
=> self.fs_thread.wait(),
else => {},
}
}
for (self.extra_threads) |extra_thread| {
extra_thread.wait();
}
@atomicStore(bool, &self.delay_queue.is_running, false, .SeqCst);
self.delay_queue.event.set();
self.delay_queue.thread.wait();
}
/// Runs the provided function asynchronously. The function's frame is allocated
/// with `allocator` and freed when the function returns.
/// `func` must return void and it can be an async function.
/// Yields to the event loop, running the function on the next tick.
pub fn runDetached(self: *Loop, alloc: *mem.Allocator, comptime func: anytype, args: anytype) error{OutOfMemory}!void {
if (!std.io.is_async) @compileError("Can't use runDetached in non-async mode!");
if (@TypeOf(@call(.{}, func, args)) != void) {
@compileError("`func` must not have a return value");
}
const Wrapper = struct {
const Args = @TypeOf(args);
fn run(func_args: Args, loop: *Loop, allocator: *mem.Allocator) void {
loop.beginOneEvent();
loop.yield();
const result = @call(.{}, func, func_args);
suspend {
loop.finishOneEvent();
allocator.destroy(@frame());
}
}
};
var run_frame = try alloc.create(@Frame(Wrapper.run));
run_frame.* = async Wrapper.run(args, self, alloc);
}
/// Yielding lets the event loop run, starting any unstarted async operations.
/// Note that async operations automatically start when a function yields for any other reason,
/// for example, when async I/O is performed. This function is intended to be used only when
/// CPU bound tasks would be waiting in the event loop but never get started because no async I/O
/// is performed.
pub fn yield(self: *Loop) void {
suspend {
var my_tick_node = NextTickNode{
.prev = undefined,
.next = undefined,
.data = @frame(),
};
self.onNextTick(&my_tick_node);
}
}
/// If the build is multi-threaded and there is an event loop, then it calls `yield`. Otherwise,
/// does nothing.
pub fn startCpuBoundOperation() void {
if (builtin.single_threaded) {
return;
} else if (instance) |event_loop| {
event_loop.yield();
}
}
/// call finishOneEvent when done
pub fn beginOneEvent(self: *Loop) void {
_ = @atomicRmw(usize, &self.pending_event_count, .Add, 1, .SeqCst);
}
pub fn finishOneEvent(self: *Loop) void {
nosuspend {
const prev = @atomicRmw(usize, &self.pending_event_count, .Sub, 1, .SeqCst);
if (prev != 1) return;
// cause all the threads to stop
self.posixFsRequest(&self.fs_end_request);
switch (builtin.os.tag) {
.linux => {
// writing to the eventfd will only wake up one thread, thus multiple writes
// are needed to wakeup all the threads
var i: usize = 0;
while (i < self.extra_threads.len + 1) : (i += 1) {
// writing 8 bytes to an eventfd cannot fail
const amt = os.write(self.os_data.final_eventfd, &wakeup_bytes) catch unreachable;
assert(amt == wakeup_bytes.len);
}
return;
},
.macos, .freebsd, .netbsd, .dragonfly, .openbsd => {
const final_kevent = @as(*const [1]os.Kevent, &self.os_data.final_kevent);
const empty_kevs = &[0]os.Kevent{};
// cannot fail because we already added it and this just enables it
_ = os.kevent(self.os_data.kqfd, final_kevent, empty_kevs, null) catch unreachable;
return;
},
.windows => {
var i: usize = 0;
while (i < self.extra_threads.len + 1) : (i += 1) {
while (true) {
const overlapped = &self.final_resume_node.overlapped;
windows.PostQueuedCompletionStatus(self.os_data.io_port, undefined, undefined, overlapped) catch continue;
break;
}
}
return;
},
else => @compileError("unsupported OS"),
}
}
}
pub fn sleep(self: *Loop, nanoseconds: u64) void {
if (std.builtin.single_threaded)
@compileError("TODO: integrate timers with epoll/kevent/iocp for single-threaded");
suspend {
const now = self.delay_queue.timer.read();
var entry: DelayQueue.Waiters.Entry = undefined;
entry.init(@frame(), now + nanoseconds);
self.delay_queue.waiters.insert(&entry);
// Speculatively wake up the timer thread when we add a new entry.
// If the timer thread is sleeping on a longer entry, we need to
// interrupt it so that our entry can be expired in time.
self.delay_queue.event.set();
}
}
const DelayQueue = struct {
timer: std.time.Timer,
waiters: Waiters,
thread: *std.Thread,
event: std.Thread.AutoResetEvent,
is_running: bool,
/// Initialize the delay queue by spawning the timer thread
/// and starting any timer resources.
fn init(self: *DelayQueue) !void {
self.* = DelayQueue{
.timer = try std.time.Timer.start(),
.waiters = DelayQueue.Waiters{
.entries = std.atomic.Queue(anyframe).init(),
},
.event = std.Thread.AutoResetEvent{},
.is_running = true,
// Must be last so that it can read the other state, such as `is_running`.
.thread = try std.Thread.spawn(DelayQueue.run, self),
};
}
/// Entry point for the timer thread
/// which waits for timer entries to expire and reschedules them.
fn run(self: *DelayQueue) void {
const loop = @fieldParentPtr(Loop, "delay_queue", self);
while (@atomicLoad(bool, &self.is_running, .SeqCst)) {
const now = self.timer.read();
if (self.waiters.popExpired(now)) |entry| {
loop.onNextTick(&entry.node);
continue;
}
if (self.waiters.nextExpire()) |expires| {
if (now >= expires)
continue;
self.event.timedWait(expires - now) catch {};
} else {
self.event.wait();
}
}
}
// TODO: use a tickless heirarchical timer wheel:
// https://github.com/wahern/timeout/
const Waiters = struct {
entries: std.atomic.Queue(anyframe),
const Entry = struct {
node: NextTickNode,
expires: u64,
fn init(self: *Entry, frame: anyframe, expires: u64) void {
self.node.data = frame;
self.expires = expires;
}
};
/// Registers the entry into the queue of waiting frames
fn insert(self: *Waiters, entry: *Entry) void {
self.entries.put(&entry.node);
}
/// Dequeues one expired event relative to `now`
fn popExpired(self: *Waiters, now: u64) ?*Entry {
const entry = self.peekExpiringEntry() orelse return null;
if (entry.expires > now)
return null;
assert(self.entries.remove(&entry.node));
return entry;
}
/// Returns an estimate for the amount of time
/// to wait until the next waiting entry expires.
fn nextExpire(self: *Waiters) ?u64 {
const entry = self.peekExpiringEntry() orelse return null;
return entry.expires;
}
fn peekExpiringEntry(self: *Waiters) ?*Entry {
const held = self.entries.mutex.acquire();
defer held.release();
// starting from the head
var head = self.entries.head orelse return null;
// traverse the list of waiting entires to
// find the Node with the smallest `expires` field
var min = head;
while (head.next) |node| {
const minEntry = @fieldParentPtr(Entry, "node", min);
const nodeEntry = @fieldParentPtr(Entry, "node", node);
if (nodeEntry.expires < minEntry.expires)
min = node;
head = node;
}
return @fieldParentPtr(Entry, "node", min);
}
};
};
/// ------- I/0 APIs -------
pub fn accept(
self: *Loop,
/// This argument is a socket that has been created with `socket`, bound to a local address
/// with `bind`, and is listening for connections after a `listen`.
sockfd: os.fd_t,
/// This argument is a pointer to a sockaddr structure. This structure is filled in with the
/// address of the peer socket, as known to the communications layer. The exact format of the
/// address returned addr is determined by the socket's address family (see `socket` and the
/// respective protocol man pages).
addr: *os.sockaddr,
/// This argument is a value-result argument: the caller must initialize it to contain the
/// size (in bytes) of the structure pointed to by addr; on return it will contain the actual size
/// of the peer address.
///
/// The returned address is truncated if the buffer provided is too small; in this case, `addr_size`
/// will return a value greater than was supplied to the call.
addr_size: *os.socklen_t,
/// The following values can be bitwise ORed in flags to obtain different behavior:
/// * `SOCK_CLOEXEC` - Set the close-on-exec (`FD_CLOEXEC`) flag on the new file descriptor. See the
/// description of the `O_CLOEXEC` flag in `open` for reasons why this may be useful.
flags: u32,
) os.AcceptError!os.fd_t {
while (true) {
return os.accept(sockfd, addr, addr_size, flags | os.SOCK_NONBLOCK) catch |err| switch (err) {
error.WouldBlock => {
self.waitUntilFdReadable(sockfd);
continue;
},
else => return err,
};
}
}
pub fn connect(self: *Loop, sockfd: os.socket_t, sock_addr: *const os.sockaddr, len: os.socklen_t) os.ConnectError!void {
os.connect(sockfd, sock_addr, len) catch |err| switch (err) {
error.WouldBlock => {
self.waitUntilFdWritable(sockfd);
return os.getsockoptError(sockfd);
},
else => return err,
};
}
/// Performs an async `os.open` using a separate thread.
pub fn openZ(self: *Loop, file_path: [*:0]const u8, flags: u32, mode: os.mode_t) os.OpenError!os.fd_t {
var req_node = Request.Node{
.data = .{
.msg = .{
.open = .{
.path = file_path,
.flags = flags,
.mode = mode,
.result = undefined,
},
},
.finish = .{ .TickNode = .{ .data = @frame() } },
},
};
suspend {
self.posixFsRequest(&req_node);
}
return req_node.data.msg.open.result;
}
/// Performs an async `os.opent` using a separate thread.
pub fn openatZ(self: *Loop, fd: os.fd_t, file_path: [*:0]const u8, flags: u32, mode: os.mode_t) os.OpenError!os.fd_t {
var req_node = Request.Node{
.data = .{
.msg = .{
.openat = .{
.fd = fd,
.path = file_path,
.flags = flags,
.mode = mode,
.result = undefined,
},
},
.finish = .{ .TickNode = .{ .data = @frame() } },
},
};
suspend {
self.posixFsRequest(&req_node);
}
return req_node.data.msg.openat.result;
}
/// Performs an async `os.close` using a separate thread.
pub fn close(self: *Loop, fd: os.fd_t) void {
var req_node = Request.Node{
.data = .{
.msg = .{ .close = .{ .fd = fd } },
.finish = .{ .TickNode = .{ .data = @frame() } },
},
};
suspend {
self.posixFsRequest(&req_node);
}
}
/// Performs an async `os.read` using a separate thread.
/// `fd` must block and not return EAGAIN.
pub fn read(self: *Loop, fd: os.fd_t, buf: []u8, simulate_evented: bool) os.ReadError!usize {
if (simulate_evented) {
var req_node = Request.Node{
.data = .{
.msg = .{
.read = .{
.fd = fd,
.buf = buf,
.result = undefined,
},
},
.finish = .{ .TickNode = .{ .data = @frame() } },
},
};
suspend {
self.posixFsRequest(&req_node);
}
return req_node.data.msg.read.result;
} else {
while (true) {
return os.read(fd, buf) catch |err| switch (err) {
error.WouldBlock => {
self.waitUntilFdReadable(fd);
continue;
},
else => return err,
};
}
}
}
/// Performs an async `os.readv` using a separate thread.
/// `fd` must block and not return EAGAIN.
pub fn readv(self: *Loop, fd: os.fd_t, iov: []const os.iovec, simulate_evented: bool) os.ReadError!usize {
if (simulate_evented) {
var req_node = Request.Node{
.data = .{
.msg = .{
.readv = .{
.fd = fd,
.iov = iov,
.result = undefined,
},
},
.finish = .{ .TickNode = .{ .data = @frame() } },
},
};
suspend {
self.posixFsRequest(&req_node);
}
return req_node.data.msg.readv.result;
} else {
while (true) {
return os.readv(fd, iov) catch |err| switch (err) {
error.WouldBlock => {
self.waitUntilFdReadable(fd);
continue;
},
else => return err,
};
}
}
}
/// Performs an async `os.pread` using a separate thread.
/// `fd` must block and not return EAGAIN.
pub fn pread(self: *Loop, fd: os.fd_t, buf: []u8, offset: u64, simulate_evented: bool) os.PReadError!usize {
if (simulate_evented) {
var req_node = Request.Node{
.data = .{
.msg = .{
.pread = .{
.fd = fd,
.buf = buf,
.offset = offset,
.result = undefined,
},
},
.finish = .{ .TickNode = .{ .data = @frame() } },
},
};
suspend {
self.posixFsRequest(&req_node);
}
return req_node.data.msg.pread.result;
} else {
while (true) {
return os.pread(fd, buf, offset) catch |err| switch (err) {
error.WouldBlock => {
self.waitUntilFdReadable(fd);
continue;
},
else => return err,
};
}
}
}
/// Performs an async `os.preadv` using a separate thread.
/// `fd` must block and not return EAGAIN.
pub fn preadv(self: *Loop, fd: os.fd_t, iov: []const os.iovec, offset: u64, simulate_evented: bool) os.ReadError!usize {
if (simulate_evented) {
var req_node = Request.Node{
.data = .{
.msg = .{
.preadv = .{
.fd = fd,
.iov = iov,
.offset = offset,
.result = undefined,
},
},
.finish = .{ .TickNode = .{ .data = @frame() } },
},
};
suspend {
self.posixFsRequest(&req_node);
}
return req_node.data.msg.preadv.result;
} else {
while (true) {
return os.preadv(fd, iov, offset) catch |err| switch (err) {
error.WouldBlock => {
self.waitUntilFdReadable(fd);
continue;
},
else => return err,
};
}
}
}
/// Performs an async `os.write` using a separate thread.
/// `fd` must block and not return EAGAIN.
pub fn write(self: *Loop, fd: os.fd_t, bytes: []const u8, simulate_evented: bool) os.WriteError!usize {
if (simulate_evented) {
var req_node = Request.Node{
.data = .{
.msg = .{
.write = .{
.fd = fd,
.bytes = bytes,
.result = undefined,
},
},
.finish = .{ .TickNode = .{ .data = @frame() } },
},
};
suspend {
self.posixFsRequest(&req_node);
}
return req_node.data.msg.write.result;
} else {
while (true) {
return os.write(fd, bytes) catch |err| switch (err) {
error.WouldBlock => {
self.waitUntilFdWritable(fd);
continue;
},
else => return err,
};
}
}
}
/// Performs an async `os.writev` using a separate thread.
/// `fd` must block and not return EAGAIN.
pub fn writev(self: *Loop, fd: os.fd_t, iov: []const os.iovec_const, simulate_evented: bool) os.WriteError!usize {
if (simulate_evented) {
var req_node = Request.Node{
.data = .{
.msg = .{
.writev = .{
.fd = fd,
.iov = iov,
.result = undefined,
},
},
.finish = .{ .TickNode = .{ .data = @frame() } },
},
};
suspend {
self.posixFsRequest(&req_node);
}
return req_node.data.msg.writev.result;
} else {
while (true) {
return os.writev(fd, iov) catch |err| switch (err) {
error.WouldBlock => {
self.waitUntilFdWritable(fd);
continue;
},
else => return err,
};
}
}
}
/// Performs an async `os.pwrite` using a separate thread.
/// `fd` must block and not return EAGAIN.
pub fn pwrite(self: *Loop, fd: os.fd_t, bytes: []const u8, offset: u64, simulate_evented: bool) os.PerformsWriteError!usize {
if (simulate_evented) {
var req_node = Request.Node{
.data = .{
.msg = .{
.pwrite = .{
.fd = fd,
.bytes = bytes,
.offset = offset,
.result = undefined,
},
},
.finish = .{ .TickNode = .{ .data = @frame() } },
},
};
suspend {
self.posixFsRequest(&req_node);
}
return req_node.data.msg.pwrite.result;
} else {
while (true) {
return os.pwrite(fd, bytes, offset) catch |err| switch (err) {
error.WouldBlock => {
self.waitUntilFdWritable(fd);
continue;
},
else => return err,
};
}
}
}
/// Performs an async `os.pwritev` using a separate thread.
/// `fd` must block and not return EAGAIN.
pub fn pwritev(self: *Loop, fd: os.fd_t, iov: []const os.iovec_const, offset: u64, simulate_evented: bool) os.PWriteError!usize {
if (simulate_evented) {
var req_node = Request.Node{
.data = .{
.msg = .{
.pwritev = .{
.fd = fd,
.iov = iov,
.offset = offset,
.result = undefined,
},
},
.finish = .{ .TickNode = .{ .data = @frame() } },
},
};
suspend {
self.posixFsRequest(&req_node);
}
return req_node.data.msg.pwritev.result;
} else {
while (true) {
return os.pwritev(fd, iov, offset) catch |err| switch (err) {
error.WouldBlock => {
self.waitUntilFdWritable(fd);
continue;
},
else => return err,
};
}
}
}
pub fn sendto(
self: *Loop,
/// The file descriptor of the sending socket.
sockfd: os.fd_t,
/// Message to send.
buf: []const u8,
flags: u32,
dest_addr: ?*const os.sockaddr,
addrlen: os.socklen_t,
) os.SendToError!usize {
while (true) {
return os.sendto(sockfd, buf, flags, dest_addr, addrlen) catch |err| switch (err) {
error.WouldBlock => {
self.waitUntilFdWritable(sockfd);
continue;
},
else => return err,
};
}
}
pub fn recvfrom(
self: *Loop,
sockfd: os.fd_t,
buf: []u8,
flags: u32,
src_addr: ?*os.sockaddr,
addrlen: ?*os.socklen_t,
) os.RecvFromError!usize {
while (true) {
return os.recvfrom(sockfd, buf, flags, src_addr, addrlen) catch |err| switch (err) {
error.WouldBlock => {
self.waitUntilFdReadable(sockfd);
continue;
},
else => return err,
};
}
}
/// Performs an async `os.faccessatZ` using a separate thread.
/// `fd` must block and not return EAGAIN.
pub fn faccessatZ(
self: *Loop,
dirfd: os.fd_t,
path_z: [*:0]const u8,
mode: u32,
flags: u32,
) os.AccessError!void {
var req_node = Request.Node{
.data = .{
.msg = .{
.faccessat = .{
.dirfd = dirfd,
.path = path_z,
.mode = mode,
.flags = flags,
.result = undefined,
},
},
.finish = .{ .TickNode = .{ .data = @frame() } },
},
};
suspend {
self.posixFsRequest(&req_node);
}
return req_node.data.msg.faccessat.result;
}
fn workerRun(self: *Loop) void {
while (true) {
while (true) {
const next_tick_node = self.next_tick_queue.get() orelse break;
self.dispatch();
resume next_tick_node.data;
self.finishOneEvent();
}
switch (builtin.os.tag) {
.linux => {
// only process 1 event so we don't steal from other threads
var events: [1]os.linux.epoll_event = undefined;
const count = os.epoll_wait(self.os_data.epollfd, events[0..], -1);
for (events[0..count]) |ev| {
const resume_node = @intToPtr(*ResumeNode, ev.data.ptr);
const handle = resume_node.handle;
const resume_node_id = resume_node.id;
switch (resume_node_id) {
.Basic => {},
.Stop => return,
.EventFd => {
const event_fd_node = @fieldParentPtr(ResumeNode.EventFd, "base", resume_node);
event_fd_node.epoll_op = os.EPOLL_CTL_MOD;
const stack_node = @fieldParentPtr(std.atomic.Stack(ResumeNode.EventFd).Node, "data", event_fd_node);
self.available_eventfd_resume_nodes.push(stack_node);
},
}
resume handle;
if (resume_node_id == ResumeNode.Id.EventFd) {
self.finishOneEvent();
}
}
},
.macos, .freebsd, .netbsd, .dragonfly, .openbsd => {
var eventlist: [1]os.Kevent = undefined;
const empty_kevs = &[0]os.Kevent{};
const count = os.kevent(self.os_data.kqfd, empty_kevs, eventlist[0..], null) catch unreachable;
for (eventlist[0..count]) |ev| {
const resume_node = @intToPtr(*ResumeNode, ev.udata);
const handle = resume_node.handle;
const resume_node_id = resume_node.id;
switch (resume_node_id) {
.Basic => {
const basic_node = @fieldParentPtr(ResumeNode.Basic, "base", resume_node);
basic_node.kev = ev;
},
.Stop => return,
.EventFd => {
const event_fd_node = @fieldParentPtr(ResumeNode.EventFd, "base", resume_node);
const stack_node = @fieldParentPtr(std.atomic.Stack(ResumeNode.EventFd).Node, "data", event_fd_node);
self.available_eventfd_resume_nodes.push(stack_node);
},
}
resume handle;
if (resume_node_id == ResumeNode.Id.EventFd) {
self.finishOneEvent();
}
}
},
.windows => {
var completion_key: usize = undefined;
const overlapped = while (true) {
var nbytes: windows.DWORD = undefined;
var overlapped: ?*windows.OVERLAPPED = undefined;
switch (windows.GetQueuedCompletionStatus(self.os_data.io_port, &nbytes, &completion_key, &overlapped, windows.INFINITE)) {
.Aborted => return,
.Normal => {},
.EOF => {},
.Cancelled => continue,
}
if (overlapped) |o| break o;
} else unreachable; // TODO else unreachable should not be necessary
const resume_node = @fieldParentPtr(ResumeNode, "overlapped", overlapped);
const handle = resume_node.handle;
const resume_node_id = resume_node.id;
switch (resume_node_id) {
.Basic => {},
.Stop => return,
.EventFd => {
const event_fd_node = @fieldParentPtr(ResumeNode.EventFd, "base", resume_node);
const stack_node = @fieldParentPtr(std.atomic.Stack(ResumeNode.EventFd).Node, "data", event_fd_node);
self.available_eventfd_resume_nodes.push(stack_node);
},
}
resume handle;
self.finishOneEvent();
},
else => @compileError("unsupported OS"),
}
}
}
fn posixFsRequest(self: *Loop, request_node: *Request.Node) void {
self.beginOneEvent(); // finished in posixFsRun after processing the msg
self.fs_queue.put(request_node);
self.fs_thread_wakeup.set();
}
fn posixFsCancel(self: *Loop, request_node: *Request.Node) void {
if (self.fs_queue.remove(request_node)) {
self.finishOneEvent();
}
}
fn posixFsRun(self: *Loop) void {
nosuspend while (true) {
self.fs_thread_wakeup.reset();
while (self.fs_queue.get()) |node| {
switch (node.data.msg) {
.end => return,
.read => |*msg| {
msg.result = os.read(msg.fd, msg.buf);
},
.readv => |*msg| {
msg.result = os.readv(msg.fd, msg.iov);
},
.write => |*msg| {
msg.result = os.write(msg.fd, msg.bytes);
},
.writev => |*msg| {
msg.result = os.writev(msg.fd, msg.iov);
},
.pwrite => |*msg| {
msg.result = os.pwrite(msg.fd, msg.bytes, msg.offset);
},
.pwritev => |*msg| {
msg.result = os.pwritev(msg.fd, msg.iov, msg.offset);
},
.pread => |*msg| {
msg.result = os.pread(msg.fd, msg.buf, msg.offset);
},
.preadv => |*msg| {
msg.result = os.preadv(msg.fd, msg.iov, msg.offset);
},
.open => |*msg| {
if (is_windows) unreachable; // TODO
msg.result = os.openZ(msg.path, msg.flags, msg.mode);
},
.openat => |*msg| {
if (is_windows) unreachable; // TODO
msg.result = os.openatZ(msg.fd, msg.path, msg.flags, msg.mode);
},
.faccessat => |*msg| {
msg.result = os.faccessatZ(msg.dirfd, msg.path, msg.mode, msg.flags);
},
.close => |*msg| os.close(msg.fd),
}
switch (node.data.finish) {
.TickNode => |*tick_node| self.onNextTick(tick_node),
.NoAction => {},
}
self.finishOneEvent();
}
self.fs_thread_wakeup.wait();
};
}
const OsData = switch (builtin.os.tag) {
.linux => LinuxOsData,
.macos, .freebsd, .netbsd, .dragonfly, .openbsd => KEventData,
.windows => struct {
io_port: windows.HANDLE,
extra_thread_count: usize,
},
else => struct {},
};
const KEventData = struct {
kqfd: i32,
final_kevent: os.Kevent,
};
const LinuxOsData = struct {
epollfd: i32,
final_eventfd: i32,
final_eventfd_event: os.linux.epoll_event,
};
pub const Request = struct {
msg: Msg,
finish: Finish,
pub const Node = std.atomic.Queue(Request).Node;
pub const Finish = union(enum) {
TickNode: Loop.NextTickNode,
NoAction,
};
pub const Msg = union(enum) {
read: Read,
readv: ReadV,
write: Write,
writev: WriteV,
pwrite: PWrite,
pwritev: PWriteV,
pread: PRead,
preadv: PReadV,
open: Open,
openat: OpenAt,
close: Close,
faccessat: FAccessAt,
/// special - means the fs thread should exit
end,
pub const Read = struct {
fd: os.fd_t,
buf: []u8,
result: Error!usize,
pub const Error = os.ReadError;
};
pub const ReadV = struct {
fd: os.fd_t,
iov: []const os.iovec,
result: Error!usize,
pub const Error = os.ReadError;
};
pub const Write = struct {
fd: os.fd_t,
bytes: []const u8,
result: Error!usize,
pub const Error = os.WriteError;
};
pub const WriteV = struct {
fd: os.fd_t,
iov: []const os.iovec_const,
result: Error!usize,
pub const Error = os.WriteError;
};
pub const PWrite = struct {
fd: os.fd_t,
bytes: []const u8,
offset: usize,
result: Error!usize,
pub const Error = os.PWriteError;
};
pub const PWriteV = struct {
fd: os.fd_t,
iov: []const os.iovec_const,
offset: usize,
result: Error!usize,
pub const Error = os.PWriteError;
};
pub const PRead = struct {
fd: os.fd_t,
buf: []u8,
offset: usize,
result: Error!usize,
pub const Error = os.PReadError;
};
pub const PReadV = struct {
fd: os.fd_t,
iov: []const os.iovec,
offset: usize,
result: Error!usize,
pub const Error = os.PReadError;
};
pub const Open = struct {
path: [*:0]const u8,
flags: u32,
mode: os.mode_t,
result: Error!os.fd_t,
pub const Error = os.OpenError;
};
pub const OpenAt = struct {
fd: os.fd_t,
path: [*:0]const u8,
flags: u32,
mode: os.mode_t,
result: Error!os.fd_t,
pub const Error = os.OpenError;
};
pub const Close = struct {
fd: os.fd_t,
};
pub const FAccessAt = struct {
dirfd: os.fd_t,
path: [*:0]const u8,
mode: u32,
flags: u32,
result: Error!void,
pub const Error = os.AccessError;
};
};
};
};
test "std.event.Loop - basic" {
// https://github.com/ziglang/zig/issues/1908
if (builtin.single_threaded) return error.SkipZigTest;
if (true) {
// https://github.com/ziglang/zig/issues/4922
return error.SkipZigTest;
}
var loop: Loop = undefined;
try loop.initMultiThreaded();
defer loop.deinit();
loop.run();
}
fn testEventLoop() i32 {
return 1234;
}
fn testEventLoop2(h: anyframe->i32, did_it: *bool) void {
const value = await h;
testing.expect(value == 1234);
did_it.* = true;
}
var testRunDetachedData: usize = 0;
test "std.event.Loop - runDetached" {
// https://github.com/ziglang/zig/issues/1908
if (builtin.single_threaded) return error.SkipZigTest;
if (!std.io.is_async) return error.SkipZigTest;
if (true) {
// https://github.com/ziglang/zig/issues/4922
return error.SkipZigTest;
}
var loop: Loop = undefined;
try loop.initMultiThreaded();
defer loop.deinit();
// Schedule the execution, won't actually start until we start the
// event loop.
try loop.runDetached(std.testing.allocator, testRunDetached, .{});
// Now we can start the event loop. The function will return only
// after all tasks have been completed, allowing us to synchonize
// with the previous runDetached.
loop.run();
testing.expect(testRunDetachedData == 1);
}
fn testRunDetached() void {
testRunDetachedData += 1;
}
test "std.event.Loop - sleep" {
// https://github.com/ziglang/zig/issues/1908
if (builtin.single_threaded) return error.SkipZigTest;
if (!std.io.is_async) return error.SkipZigTest;
const frames = try testing.allocator.alloc(@Frame(testSleep), 10);
defer testing.allocator.free(frames);
const wait_time = 100 * std.time.ns_per_ms;
var sleep_count: usize = 0;
for (frames) |*frame|
frame.* = async testSleep(wait_time, &sleep_count);
for (frames) |*frame|
await frame;
testing.expect(sleep_count == frames.len);
}
fn testSleep(wait_ns: u64, sleep_count: *usize) void {
Loop.instance.?.sleep(wait_ns);
_ = @atomicRmw(usize, sleep_count, .Add, 1, .SeqCst);
}