| ... | ... | @@ -9,23 +9,795 @@ const net = std.Io.net; |
| 9 | 9 | const assert = std.debug.assert; |
| 10 | 10 | const Allocator = std.mem.Allocator; |
| 11 | 11 | const Alignment = std.mem.Alignment; |
| 12 | | const posix = std.posix; |
| 13 | 12 | const IpAddress = std.Io.net.IpAddress; |
| 14 | 13 | const errnoBug = std.Io.Threaded.errnoBug; |
| 14 | const posix = std.posix; |
| 15 | 15 | |
| 16 | 16 | /// Must be a thread-safe allocator. |
| 17 | 17 | gpa: Allocator, |
| 18 | mutex: std.Thread.Mutex, |
| 19 | main_fiber_buffer: [@sizeOf(Fiber) + Fiber.max_result_size]u8 align(@alignOf(Fiber)), |
| 20 | threads: Thread.List, |
| 18 | 21 | |
| 19 | | pub fn init(gpa: Allocator) Kqueue { |
| 20 | | return .{ |
| 22 | /// Empirically saw >128KB being used by the self-hosted backend to panic. |
| 23 | const idle_stack_size = 256 * 1024; |
| 24 | |
| 25 | const max_idle_search = 4; |
| 26 | const max_steal_ready_search = 4; |
| 27 | |
| 28 | const changes_buffer_len = 64; |
| 29 | |
| 30 | const Thread = struct { |
| 31 | thread: std.Thread, |
| 32 | idle_context: Context, |
| 33 | current_context: *Context, |
| 34 | ready_queue: ?*Fiber, |
| 35 | kq_fd: posix.fd_t, |
| 36 | idle_search_index: u32, |
| 37 | steal_ready_search_index: u32, |
| 38 | |
| 39 | const canceling: ?*Thread = @ptrFromInt(@alignOf(Thread)); |
| 40 | |
| 41 | threadlocal var self: *Thread = undefined; |
| 42 | |
| 43 | fn current() *Thread { |
| 44 | return self; |
| 45 | } |
| 46 | |
| 47 | fn currentFiber(thread: *Thread) *Fiber { |
| 48 | return @fieldParentPtr("context", thread.current_context); |
| 49 | } |
| 50 | |
| 51 | const List = struct { |
| 52 | allocated: []Thread, |
| 53 | reserved: u32, |
| 54 | active: u32, |
| 55 | }; |
| 56 | }; |
| 57 | |
| 58 | const Fiber = struct { |
| 59 | required_align: void align(4), |
| 60 | context: Context, |
| 61 | awaiter: ?*Fiber, |
| 62 | queue_next: ?*Fiber, |
| 63 | cancel_thread: ?*Thread, |
| 64 | awaiting_completions: std.StaticBitSet(3), |
| 65 | |
| 66 | const finished: ?*Fiber = @ptrFromInt(@alignOf(Thread)); |
| 67 | |
| 68 | const max_result_align: Alignment = .@"16"; |
| 69 | const max_result_size = max_result_align.forward(64); |
| 70 | /// This includes any stack realignments that need to happen, and also the |
| 71 | /// initial frame return address slot and argument frame, depending on target. |
| 72 | const min_stack_size = 4 * 1024 * 1024; |
| 73 | const max_context_align: Alignment = .@"16"; |
| 74 | const max_context_size = max_context_align.forward(1024); |
| 75 | const max_closure_size: usize = @sizeOf(AsyncClosure); |
| 76 | const max_closure_align: Alignment = .of(AsyncClosure); |
| 77 | const allocation_size = std.mem.alignForward( |
| 78 | usize, |
| 79 | max_closure_align.max(max_context_align).forward( |
| 80 | max_result_align.forward(@sizeOf(Fiber)) + max_result_size + min_stack_size, |
| 81 | ) + max_closure_size + max_context_size, |
| 82 | std.heap.page_size_max, |
| 83 | ); |
| 84 | |
| 85 | fn allocate(k: *Kqueue) error{OutOfMemory}!*Fiber { |
| 86 | return @ptrCast(try k.gpa.alignedAlloc(u8, .of(Fiber), allocation_size)); |
| 87 | } |
| 88 | |
| 89 | fn allocatedSlice(f: *Fiber) []align(@alignOf(Fiber)) u8 { |
| 90 | return @as([*]align(@alignOf(Fiber)) u8, @ptrCast(f))[0..allocation_size]; |
| 91 | } |
| 92 | |
| 93 | fn allocatedEnd(f: *Fiber) [*]u8 { |
| 94 | const allocated_slice = f.allocatedSlice(); |
| 95 | return allocated_slice[allocated_slice.len..].ptr; |
| 96 | } |
| 97 | |
| 98 | fn resultPointer(f: *Fiber, comptime Result: type) *Result { |
| 99 | return @ptrCast(@alignCast(f.resultBytes(.of(Result)))); |
| 100 | } |
| 101 | |
| 102 | fn resultBytes(f: *Fiber, alignment: Alignment) [*]u8 { |
| 103 | return @ptrFromInt(alignment.forward(@intFromPtr(f) + @sizeOf(Fiber))); |
| 104 | } |
| 105 | |
| 106 | fn enterCancelRegion(fiber: *Fiber, thread: *Thread) error{Canceled}!void { |
| 107 | if (@cmpxchgStrong( |
| 108 | ?*Thread, |
| 109 | &fiber.cancel_thread, |
| 110 | null, |
| 111 | thread, |
| 112 | .acq_rel, |
| 113 | .acquire, |
| 114 | )) |cancel_thread| { |
| 115 | assert(cancel_thread == Thread.canceling); |
| 116 | return error.Canceled; |
| 117 | } |
| 118 | } |
| 119 | |
| 120 | fn exitCancelRegion(fiber: *Fiber, thread: *Thread) void { |
| 121 | if (@cmpxchgStrong( |
| 122 | ?*Thread, |
| 123 | &fiber.cancel_thread, |
| 124 | thread, |
| 125 | null, |
| 126 | .acq_rel, |
| 127 | .acquire, |
| 128 | )) |cancel_thread| assert(cancel_thread == Thread.canceling); |
| 129 | } |
| 130 | |
| 131 | const Queue = struct { head: *Fiber, tail: *Fiber }; |
| 132 | }; |
| 133 | |
| 134 | fn recycle(k: *Kqueue, fiber: *Fiber) void { |
| 135 | std.log.debug("recyling {*}", .{fiber}); |
| 136 | assert(fiber.queue_next == null); |
| 137 | k.gpa.free(fiber.allocatedSlice()); |
| 138 | } |
| 139 | |
| 140 | pub fn init(k: *Kqueue, gpa: Allocator) !void { |
| 141 | const threads_size = @max(std.Thread.getCpuCount() catch 1, 1) * @sizeOf(Thread); |
| 142 | const idle_stack_end_offset = std.mem.alignForward(usize, threads_size + idle_stack_size, std.heap.page_size_max); |
| 143 | const allocated_slice = try gpa.alignedAlloc(u8, .of(Thread), idle_stack_end_offset); |
| 144 | errdefer gpa.free(allocated_slice); |
| 145 | k.* = .{ |
| 21 | 146 | .gpa = gpa, |
| 147 | .mutex = .{}, |
| 148 | .main_fiber_buffer = undefined, |
| 149 | .threads = .{ |
| 150 | .allocated = @ptrCast(allocated_slice[0..threads_size]), |
| 151 | .reserved = 1, |
| 152 | .active = 1, |
| 153 | }, |
| 22 | 154 | }; |
| 155 | const main_fiber: *Fiber = @ptrCast(&k.main_fiber_buffer); |
| 156 | main_fiber.* = .{ |
| 157 | .required_align = {}, |
| 158 | .context = undefined, |
| 159 | .awaiter = null, |
| 160 | .queue_next = null, |
| 161 | .cancel_thread = null, |
| 162 | .awaiting_completions = .initEmpty(), |
| 163 | }; |
| 164 | const main_thread = &k.threads.allocated[0]; |
| 165 | Thread.self = main_thread; |
| 166 | const idle_stack_end: [*]align(16) usize = @ptrCast(@alignCast(allocated_slice[idle_stack_end_offset..].ptr)); |
| 167 | (idle_stack_end - 1)[0..1].* = .{@intFromPtr(k)}; |
| 168 | main_thread.* = .{ |
| 169 | .thread = undefined, |
| 170 | .idle_context = switch (builtin.cpu.arch) { |
| 171 | .aarch64 => .{ |
| 172 | .sp = @intFromPtr(idle_stack_end), |
| 173 | .fp = 0, |
| 174 | .pc = @intFromPtr(&mainIdleEntry), |
| 175 | .x18 = asm ("" |
| 176 | : [x18] "={x18}" (-> u64), |
| 177 | ), |
| 178 | }, |
| 179 | .x86_64 => .{ |
| 180 | .rsp = @intFromPtr(idle_stack_end - 1), |
| 181 | .rbp = 0, |
| 182 | .rip = @intFromPtr(&mainIdleEntry), |
| 183 | }, |
| 184 | else => @compileError("unimplemented architecture"), |
| 185 | }, |
| 186 | .current_context = &main_fiber.context, |
| 187 | .ready_queue = null, |
| 188 | .kq_fd = try posix.kqueue(), |
| 189 | .idle_search_index = 1, |
| 190 | .steal_ready_search_index = 1, |
| 191 | }; |
| 192 | errdefer std.posix.close(main_thread.kq_fd); |
| 193 | std.log.debug("created main idle {*}", .{&main_thread.idle_context}); |
| 194 | std.log.debug("created main {*}", .{main_fiber}); |
| 23 | 195 | } |
| 24 | 196 | |
| 25 | 197 | pub fn deinit(k: *Kqueue) void { |
| 198 | const active_threads = @atomicLoad(u32, &k.threads.active, .acquire); |
| 199 | for (k.threads.allocated[0..active_threads]) |*thread| { |
| 200 | const ready_fiber = @atomicLoad(?*Fiber, &thread.ready_queue, .monotonic); |
| 201 | assert(ready_fiber == null or ready_fiber == Fiber.finished); // pending async |
| 202 | } |
| 203 | k.yield(null, .exit); |
| 204 | const allocated_ptr: [*]align(@alignOf(Thread)) u8 = @ptrCast(@alignCast(k.threads.allocated.ptr)); |
| 205 | const idle_stack_end_offset = std.mem.alignForward(usize, k.threads.allocated.len * @sizeOf(Thread) + idle_stack_size, std.heap.page_size_max); |
| 206 | for (k.threads.allocated[1..active_threads]) |*thread| thread.thread.join(); |
| 207 | k.gpa.free(allocated_ptr[0..idle_stack_end_offset]); |
| 26 | 208 | k.* = undefined; |
| 27 | 209 | } |
| 28 | 210 | |
| 211 | fn findReadyFiber(k: *Kqueue, thread: *Thread) ?*Fiber { |
| 212 | if (@atomicRmw(?*Fiber, &thread.ready_queue, .Xchg, Fiber.finished, .acquire)) |ready_fiber| { |
| 213 | @atomicStore(?*Fiber, &thread.ready_queue, ready_fiber.queue_next, .release); |
| 214 | ready_fiber.queue_next = null; |
| 215 | return ready_fiber; |
| 216 | } |
| 217 | const active_threads = @atomicLoad(u32, &k.threads.active, .acquire); |
| 218 | for (0..@min(max_steal_ready_search, active_threads)) |_| { |
| 219 | defer thread.steal_ready_search_index += 1; |
| 220 | if (thread.steal_ready_search_index == active_threads) thread.steal_ready_search_index = 0; |
| 221 | const steal_ready_search_thread = &k.threads.allocated[0..active_threads][thread.steal_ready_search_index]; |
| 222 | if (steal_ready_search_thread == thread) continue; |
| 223 | const ready_fiber = @atomicLoad(?*Fiber, &steal_ready_search_thread.ready_queue, .acquire) orelse continue; |
| 224 | if (ready_fiber == Fiber.finished) continue; |
| 225 | if (@cmpxchgWeak( |
| 226 | ?*Fiber, |
| 227 | &steal_ready_search_thread.ready_queue, |
| 228 | ready_fiber, |
| 229 | null, |
| 230 | .acquire, |
| 231 | .monotonic, |
| 232 | )) |_| continue; |
| 233 | @atomicStore(?*Fiber, &thread.ready_queue, ready_fiber.queue_next, .release); |
| 234 | ready_fiber.queue_next = null; |
| 235 | return ready_fiber; |
| 236 | } |
| 237 | // couldn't find anything to do, so we are now open for business |
| 238 | @atomicStore(?*Fiber, &thread.ready_queue, null, .monotonic); |
| 239 | return null; |
| 240 | } |
| 241 | |
| 242 | fn yield(k: *Kqueue, maybe_ready_fiber: ?*Fiber, pending_task: SwitchMessage.PendingTask) void { |
| 243 | const thread: *Thread = .current(); |
| 244 | const ready_context = if (maybe_ready_fiber orelse k.findReadyFiber(thread)) |ready_fiber| |
| 245 | &ready_fiber.context |
| 246 | else |
| 247 | &thread.idle_context; |
| 248 | const message: SwitchMessage = .{ |
| 249 | .contexts = .{ |
| 250 | .prev = thread.current_context, |
| 251 | .ready = ready_context, |
| 252 | }, |
| 253 | .pending_task = pending_task, |
| 254 | }; |
| 255 | std.log.debug("switching from {*} to {*}", .{ message.contexts.prev, message.contexts.ready }); |
| 256 | contextSwitch(&message).handle(k); |
| 257 | } |
| 258 | |
| 259 | fn schedule(k: *Kqueue, thread: *Thread, ready_queue: Fiber.Queue) void { |
| 260 | { |
| 261 | var fiber = ready_queue.head; |
| 262 | while (true) { |
| 263 | std.log.debug("scheduling {*}", .{fiber}); |
| 264 | fiber = fiber.queue_next orelse break; |
| 265 | } |
| 266 | assert(fiber == ready_queue.tail); |
| 267 | } |
| 268 | // shared fields of previous `Thread` must be initialized before later ones are marked as active |
| 269 | const new_thread_index = @atomicLoad(u32, &k.threads.active, .acquire); |
| 270 | for (0..@min(max_idle_search, new_thread_index)) |_| { |
| 271 | defer thread.idle_search_index += 1; |
| 272 | if (thread.idle_search_index == new_thread_index) thread.idle_search_index = 0; |
| 273 | const idle_search_thread = &k.threads.allocated[0..new_thread_index][thread.idle_search_index]; |
| 274 | if (idle_search_thread == thread) continue; |
| 275 | if (@cmpxchgWeak( |
| 276 | ?*Fiber, |
| 277 | &idle_search_thread.ready_queue, |
| 278 | null, |
| 279 | ready_queue.head, |
| 280 | .release, |
| 281 | .monotonic, |
| 282 | )) |_| continue; |
| 283 | const changes = [_]posix.Kevent{ |
| 284 | .{ |
| 285 | .ident = 0, |
| 286 | .filter = std.c.EVFILT.USER, |
| 287 | .flags = std.c.EV.ADD | std.c.EV.ONESHOT, |
| 288 | .fflags = std.c.NOTE.TRIGGER, |
| 289 | .data = 0, |
| 290 | .udata = @intFromEnum(Completion.UserData.wakeup), |
| 291 | }, |
| 292 | }; |
| 293 | // If an error occurs it only pessimises scheduling. |
| 294 | _ = posix.kevent(idle_search_thread.kq_fd, &changes, &.{}, null) catch {}; |
| 295 | return; |
| 296 | } |
| 297 | spawn_thread: { |
| 298 | // previous failed reservations must have completed before retrying |
| 299 | if (new_thread_index == k.threads.allocated.len or @cmpxchgWeak( |
| 300 | u32, |
| 301 | &k.threads.reserved, |
| 302 | new_thread_index, |
| 303 | new_thread_index + 1, |
| 304 | .acquire, |
| 305 | .monotonic, |
| 306 | ) != null) break :spawn_thread; |
| 307 | const new_thread = &k.threads.allocated[new_thread_index]; |
| 308 | const next_thread_index = new_thread_index + 1; |
| 309 | new_thread.* = .{ |
| 310 | .thread = undefined, |
| 311 | .idle_context = undefined, |
| 312 | .current_context = &new_thread.idle_context, |
| 313 | .ready_queue = ready_queue.head, |
| 314 | .kq_fd = posix.kqueue() catch |err| { |
| 315 | @atomicStore(u32, &k.threads.reserved, new_thread_index, .release); |
| 316 | // no more access to `thread` after giving up reservation |
| 317 | std.log.warn("unable to create worker thread due to kqueue init failure: {t}", .{err}); |
| 318 | break :spawn_thread; |
| 319 | }, |
| 320 | .idle_search_index = 0, |
| 321 | .steal_ready_search_index = 0, |
| 322 | }; |
| 323 | new_thread.thread = std.Thread.spawn(.{ |
| 324 | .stack_size = idle_stack_size, |
| 325 | .allocator = k.gpa, |
| 326 | }, threadEntry, .{ k, new_thread_index }) catch |err| { |
| 327 | posix.close(new_thread.kq_fd); |
| 328 | @atomicStore(u32, &k.threads.reserved, new_thread_index, .release); |
| 329 | // no more access to `thread` after giving up reservation |
| 330 | std.log.warn("unable to create worker thread due spawn failure: {s}", .{@errorName(err)}); |
| 331 | break :spawn_thread; |
| 332 | }; |
| 333 | // shared fields of `Thread` must be initialized before being marked active |
| 334 | @atomicStore(u32, &k.threads.active, next_thread_index, .release); |
| 335 | return; |
| 336 | } |
| 337 | // nobody wanted it, so just queue it on ourselves |
| 338 | while (@cmpxchgWeak( |
| 339 | ?*Fiber, |
| 340 | &thread.ready_queue, |
| 341 | ready_queue.tail.queue_next, |
| 342 | ready_queue.head, |
| 343 | .acq_rel, |
| 344 | .acquire, |
| 345 | )) |old_head| ready_queue.tail.queue_next = old_head; |
| 346 | } |
| 347 | |
| 348 | fn mainIdle(k: *Kqueue, message: *const SwitchMessage) callconv(.withStackAlign(.c, @max(@alignOf(Thread), @alignOf(Context)))) noreturn { |
| 349 | message.handle(k); |
| 350 | k.idle(&k.threads.allocated[0]); |
| 351 | k.yield(@ptrCast(&k.main_fiber_buffer), .nothing); |
| 352 | unreachable; // switched to dead fiber |
| 353 | } |
| 354 | |
| 355 | fn threadEntry(k: *Kqueue, index: u32) void { |
| 356 | const thread: *Thread = &k.threads.allocated[index]; |
| 357 | Thread.self = thread; |
| 358 | std.log.debug("created thread idle {*}", .{&thread.idle_context}); |
| 359 | k.idle(thread); |
| 360 | } |
| 361 | |
| 362 | const Completion = struct { |
| 363 | const UserData = enum(usize) { |
| 364 | unused, |
| 365 | wakeup, |
| 366 | cleanup, |
| 367 | exit, |
| 368 | /// *Fiber |
| 369 | _, |
| 370 | }; |
| 371 | /// Corresponds to Kevent field. |
| 372 | flags: u16, |
| 373 | /// Corresponds to Kevent field. |
| 374 | fflags: u32, |
| 375 | /// Corresponds to Kevent field. |
| 376 | data: isize, |
| 377 | }; |
| 378 | |
| 379 | fn idle(k: *Kqueue, thread: *Thread) void { |
| 380 | var events_buffer: [changes_buffer_len]posix.Kevent = undefined; |
| 381 | var maybe_ready_fiber: ?*Fiber = null; |
| 382 | while (true) { |
| 383 | while (maybe_ready_fiber orelse k.findReadyFiber(thread)) |ready_fiber| { |
| 384 | k.yield(ready_fiber, .nothing); |
| 385 | maybe_ready_fiber = null; |
| 386 | } |
| 387 | const n = posix.kevent(thread.kq_fd, &.{}, &events_buffer, null) catch |err| { |
| 388 | // TODO handle EINTR for cancellation purposes |
| 389 | @panic(@errorName(err)); |
| 390 | }; |
| 391 | var maybe_ready_queue: ?Fiber.Queue = null; |
| 392 | for (events_buffer[0..n]) |event| switch (@as(Completion.UserData, @enumFromInt(event.udata))) { |
| 393 | .unused => unreachable, // bad submission queued? |
| 394 | .wakeup => {}, |
| 395 | .cleanup => @panic("failed to notify other threads that we are exiting"), |
| 396 | .exit => { |
| 397 | assert(maybe_ready_fiber == null and maybe_ready_queue == null); // pending async |
| 398 | return; |
| 399 | }, |
| 400 | _ => { |
| 401 | const fiber: *Fiber = @ptrFromInt(event.udata); |
| 402 | assert(fiber.queue_next == null); |
| 403 | fiber.resultPointer(Completion).* = .{ |
| 404 | .flags = event.flags, |
| 405 | .fflags = event.fflags, |
| 406 | .data = event.data, |
| 407 | }; |
| 408 | if (maybe_ready_fiber == null) maybe_ready_fiber = fiber else if (maybe_ready_queue) |*ready_queue| { |
| 409 | ready_queue.tail.queue_next = fiber; |
| 410 | ready_queue.tail = fiber; |
| 411 | } else maybe_ready_queue = .{ .head = fiber, .tail = fiber }; |
| 412 | }, |
| 413 | }; |
| 414 | if (maybe_ready_queue) |ready_queue| k.schedule(thread, ready_queue); |
| 415 | } |
| 416 | } |
| 417 | |
| 418 | const SwitchMessage = struct { |
| 419 | contexts: extern struct { |
| 420 | prev: *Context, |
| 421 | ready: *Context, |
| 422 | }, |
| 423 | pending_task: PendingTask, |
| 424 | |
| 425 | const PendingTask = union(enum) { |
| 426 | nothing, |
| 427 | reschedule, |
| 428 | recycle: *Fiber, |
| 429 | register_awaiter: *?*Fiber, |
| 430 | register_select: []const *Io.AnyFuture, |
| 431 | mutex_lock: struct { |
| 432 | prev_state: Io.Mutex.State, |
| 433 | mutex: *Io.Mutex, |
| 434 | }, |
| 435 | condition_wait: struct { |
| 436 | cond: *Io.Condition, |
| 437 | mutex: *Io.Mutex, |
| 438 | }, |
| 439 | exit, |
| 440 | }; |
| 441 | |
| 442 | fn handle(message: *const SwitchMessage, k: *Kqueue) void { |
| 443 | const thread: *Thread = .current(); |
| 444 | thread.current_context = message.contexts.ready; |
| 445 | switch (message.pending_task) { |
| 446 | .nothing => {}, |
| 447 | .reschedule => if (message.contexts.prev != &thread.idle_context) { |
| 448 | const prev_fiber: *Fiber = @alignCast(@fieldParentPtr("context", message.contexts.prev)); |
| 449 | assert(prev_fiber.queue_next == null); |
| 450 | k.schedule(thread, .{ .head = prev_fiber, .tail = prev_fiber }); |
| 451 | }, |
| 452 | .recycle => |fiber| { |
| 453 | k.recycle(fiber); |
| 454 | }, |
| 455 | .register_awaiter => |awaiter| { |
| 456 | const prev_fiber: *Fiber = @alignCast(@fieldParentPtr("context", message.contexts.prev)); |
| 457 | assert(prev_fiber.queue_next == null); |
| 458 | if (@atomicRmw(?*Fiber, awaiter, .Xchg, prev_fiber, .acq_rel) == Fiber.finished) |
| 459 | k.schedule(thread, .{ .head = prev_fiber, .tail = prev_fiber }); |
| 460 | }, |
| 461 | .register_select => |futures| { |
| 462 | const prev_fiber: *Fiber = @alignCast(@fieldParentPtr("context", message.contexts.prev)); |
| 463 | assert(prev_fiber.queue_next == null); |
| 464 | for (futures) |any_future| { |
| 465 | const future_fiber: *Fiber = @ptrCast(@alignCast(any_future)); |
| 466 | if (@atomicRmw(?*Fiber, &future_fiber.awaiter, .Xchg, prev_fiber, .acq_rel) == Fiber.finished) { |
| 467 | const closure: *AsyncClosure = .fromFiber(future_fiber); |
| 468 | if (!@atomicRmw(bool, &closure.already_awaited, .Xchg, true, .seq_cst)) { |
| 469 | k.schedule(thread, .{ .head = prev_fiber, .tail = prev_fiber }); |
| 470 | } |
| 471 | } |
| 472 | } |
| 473 | }, |
| 474 | .mutex_lock => |mutex_lock| { |
| 475 | const prev_fiber: *Fiber = @alignCast(@fieldParentPtr("context", message.contexts.prev)); |
| 476 | assert(prev_fiber.queue_next == null); |
| 477 | var prev_state = mutex_lock.prev_state; |
| 478 | while (switch (prev_state) { |
| 479 | else => next_state: { |
| 480 | prev_fiber.queue_next = @ptrFromInt(@intFromEnum(prev_state)); |
| 481 | break :next_state @cmpxchgWeak( |
| 482 | Io.Mutex.State, |
| 483 | &mutex_lock.mutex.state, |
| 484 | prev_state, |
| 485 | @enumFromInt(@intFromPtr(prev_fiber)), |
| 486 | .release, |
| 487 | .acquire, |
| 488 | ); |
| 489 | }, |
| 490 | .unlocked => @cmpxchgWeak( |
| 491 | Io.Mutex.State, |
| 492 | &mutex_lock.mutex.state, |
| 493 | .unlocked, |
| 494 | .locked_once, |
| 495 | .acquire, |
| 496 | .acquire, |
| 497 | ) orelse { |
| 498 | prev_fiber.queue_next = null; |
| 499 | k.schedule(thread, .{ .head = prev_fiber, .tail = prev_fiber }); |
| 500 | return; |
| 501 | }, |
| 502 | }) |next_state| prev_state = next_state; |
| 503 | }, |
| 504 | .condition_wait => |condition_wait| { |
| 505 | const prev_fiber: *Fiber = @alignCast(@fieldParentPtr("context", message.contexts.prev)); |
| 506 | assert(prev_fiber.queue_next == null); |
| 507 | const cond_impl = prev_fiber.resultPointer(Condition); |
| 508 | cond_impl.* = .{ |
| 509 | .tail = prev_fiber, |
| 510 | .event = .queued, |
| 511 | }; |
| 512 | if (@cmpxchgStrong( |
| 513 | ?*Fiber, |
| 514 | @as(*?*Fiber, @ptrCast(&condition_wait.cond.state)), |
| 515 | null, |
| 516 | prev_fiber, |
| 517 | .release, |
| 518 | .acquire, |
| 519 | )) |waiting_fiber| { |
| 520 | const waiting_cond_impl = waiting_fiber.?.resultPointer(Condition); |
| 521 | assert(waiting_cond_impl.tail.queue_next == null); |
| 522 | waiting_cond_impl.tail.queue_next = prev_fiber; |
| 523 | waiting_cond_impl.tail = prev_fiber; |
| 524 | } |
| 525 | condition_wait.mutex.unlock(k.io()); |
| 526 | }, |
| 527 | .exit => for (k.threads.allocated[0..@atomicLoad(u32, &k.threads.active, .acquire)]) |*each_thread| { |
| 528 | const changes = [_]posix.Kevent{ |
| 529 | .{ |
| 530 | .ident = 0, |
| 531 | .filter = std.c.EVFILT.USER, |
| 532 | .flags = std.c.EV.ADD | std.c.EV.ONESHOT, |
| 533 | .fflags = std.c.NOTE.TRIGGER, |
| 534 | .data = 0, |
| 535 | .udata = @intFromEnum(Completion.UserData.exit), |
| 536 | }, |
| 537 | }; |
| 538 | _ = posix.kevent(each_thread.kq_fd, &changes, &.{}, null) catch |err| { |
| 539 | @panic(@errorName(err)); |
| 540 | }; |
| 541 | }, |
| 542 | } |
| 543 | } |
| 544 | }; |
| 545 | |
| 546 | const Context = switch (builtin.cpu.arch) { |
| 547 | .aarch64 => extern struct { |
| 548 | sp: u64, |
| 549 | fp: u64, |
| 550 | pc: u64, |
| 551 | x18: u64, |
| 552 | }, |
| 553 | .x86_64 => extern struct { |
| 554 | rsp: u64, |
| 555 | rbp: u64, |
| 556 | rip: u64, |
| 557 | }, |
| 558 | else => |arch| @compileError("unimplemented architecture: " ++ @tagName(arch)), |
| 559 | }; |
| 560 | |
| 561 | inline fn contextSwitch(message: *const SwitchMessage) *const SwitchMessage { |
| 562 | return @fieldParentPtr("contexts", switch (builtin.cpu.arch) { |
| 563 | .aarch64 => asm volatile ( |
| 564 | \\ ldp x0, x2, [x1] |
| 565 | \\ ldp x3, x18, [x2, #16] |
| 566 | \\ mov x4, sp |
| 567 | \\ stp x4, fp, [x0] |
| 568 | \\ adr x5, 0f |
| 569 | \\ ldp x4, fp, [x2] |
| 570 | \\ stp x5, x18, [x0, #16] |
| 571 | \\ mov sp, x4 |
| 572 | \\ br x3 |
| 573 | \\0: |
| 574 | : [received_message] "={x1}" (-> *const @FieldType(SwitchMessage, "contexts")), |
| 575 | : [message_to_send] "{x1}" (&message.contexts), |
| 576 | : .{ |
| 577 | .x0 = true, |
| 578 | .x1 = true, |
| 579 | .x2 = true, |
| 580 | .x3 = true, |
| 581 | .x4 = true, |
| 582 | .x5 = true, |
| 583 | .x6 = true, |
| 584 | .x7 = true, |
| 585 | .x8 = true, |
| 586 | .x9 = true, |
| 587 | .x10 = true, |
| 588 | .x11 = true, |
| 589 | .x12 = true, |
| 590 | .x13 = true, |
| 591 | .x14 = true, |
| 592 | .x15 = true, |
| 593 | .x16 = true, |
| 594 | .x17 = true, |
| 595 | .x19 = true, |
| 596 | .x20 = true, |
| 597 | .x21 = true, |
| 598 | .x22 = true, |
| 599 | .x23 = true, |
| 600 | .x24 = true, |
| 601 | .x25 = true, |
| 602 | .x26 = true, |
| 603 | .x27 = true, |
| 604 | .x28 = true, |
| 605 | .x30 = true, |
| 606 | .z0 = true, |
| 607 | .z1 = true, |
| 608 | .z2 = true, |
| 609 | .z3 = true, |
| 610 | .z4 = true, |
| 611 | .z5 = true, |
| 612 | .z6 = true, |
| 613 | .z7 = true, |
| 614 | .z8 = true, |
| 615 | .z9 = true, |
| 616 | .z10 = true, |
| 617 | .z11 = true, |
| 618 | .z12 = true, |
| 619 | .z13 = true, |
| 620 | .z14 = true, |
| 621 | .z15 = true, |
| 622 | .z16 = true, |
| 623 | .z17 = true, |
| 624 | .z18 = true, |
| 625 | .z19 = true, |
| 626 | .z20 = true, |
| 627 | .z21 = true, |
| 628 | .z22 = true, |
| 629 | .z23 = true, |
| 630 | .z24 = true, |
| 631 | .z25 = true, |
| 632 | .z26 = true, |
| 633 | .z27 = true, |
| 634 | .z28 = true, |
| 635 | .z29 = true, |
| 636 | .z30 = true, |
| 637 | .z31 = true, |
| 638 | .p0 = true, |
| 639 | .p1 = true, |
| 640 | .p2 = true, |
| 641 | .p3 = true, |
| 642 | .p4 = true, |
| 643 | .p5 = true, |
| 644 | .p6 = true, |
| 645 | .p7 = true, |
| 646 | .p8 = true, |
| 647 | .p9 = true, |
| 648 | .p10 = true, |
| 649 | .p11 = true, |
| 650 | .p12 = true, |
| 651 | .p13 = true, |
| 652 | .p14 = true, |
| 653 | .p15 = true, |
| 654 | .fpcr = true, |
| 655 | .fpsr = true, |
| 656 | .ffr = true, |
| 657 | .memory = true, |
| 658 | }), |
| 659 | .x86_64 => asm volatile ( |
| 660 | \\ movq 0(%%rsi), %%rax |
| 661 | \\ movq 8(%%rsi), %%rcx |
| 662 | \\ leaq 0f(%%rip), %%rdx |
| 663 | \\ movq %%rsp, 0(%%rax) |
| 664 | \\ movq %%rbp, 8(%%rax) |
| 665 | \\ movq %%rdx, 16(%%rax) |
| 666 | \\ movq 0(%%rcx), %%rsp |
| 667 | \\ movq 8(%%rcx), %%rbp |
| 668 | \\ jmpq *16(%%rcx) |
| 669 | \\0: |
| 670 | : [received_message] "={rsi}" (-> *const @FieldType(SwitchMessage, "contexts")), |
| 671 | : [message_to_send] "{rsi}" (&message.contexts), |
| 672 | : .{ |
| 673 | .rax = true, |
| 674 | .rcx = true, |
| 675 | .rdx = true, |
| 676 | .rbx = true, |
| 677 | .rsi = true, |
| 678 | .rdi = true, |
| 679 | .r8 = true, |
| 680 | .r9 = true, |
| 681 | .r10 = true, |
| 682 | .r11 = true, |
| 683 | .r12 = true, |
| 684 | .r13 = true, |
| 685 | .r14 = true, |
| 686 | .r15 = true, |
| 687 | .mm0 = true, |
| 688 | .mm1 = true, |
| 689 | .mm2 = true, |
| 690 | .mm3 = true, |
| 691 | .mm4 = true, |
| 692 | .mm5 = true, |
| 693 | .mm6 = true, |
| 694 | .mm7 = true, |
| 695 | .zmm0 = true, |
| 696 | .zmm1 = true, |
| 697 | .zmm2 = true, |
| 698 | .zmm3 = true, |
| 699 | .zmm4 = true, |
| 700 | .zmm5 = true, |
| 701 | .zmm6 = true, |
| 702 | .zmm7 = true, |
| 703 | .zmm8 = true, |
| 704 | .zmm9 = true, |
| 705 | .zmm10 = true, |
| 706 | .zmm11 = true, |
| 707 | .zmm12 = true, |
| 708 | .zmm13 = true, |
| 709 | .zmm14 = true, |
| 710 | .zmm15 = true, |
| 711 | .zmm16 = true, |
| 712 | .zmm17 = true, |
| 713 | .zmm18 = true, |
| 714 | .zmm19 = true, |
| 715 | .zmm20 = true, |
| 716 | .zmm21 = true, |
| 717 | .zmm22 = true, |
| 718 | .zmm23 = true, |
| 719 | .zmm24 = true, |
| 720 | .zmm25 = true, |
| 721 | .zmm26 = true, |
| 722 | .zmm27 = true, |
| 723 | .zmm28 = true, |
| 724 | .zmm29 = true, |
| 725 | .zmm30 = true, |
| 726 | .zmm31 = true, |
| 727 | .fpsr = true, |
| 728 | .fpcr = true, |
| 729 | .mxcsr = true, |
| 730 | .rflags = true, |
| 731 | .dirflag = true, |
| 732 | .memory = true, |
| 733 | }), |
| 734 | else => |arch| @compileError("unimplemented architecture: " ++ @tagName(arch)), |
| 735 | }); |
| 736 | } |
| 737 | |
| 738 | fn mainIdleEntry() callconv(.naked) void { |
| 739 | switch (builtin.cpu.arch) { |
| 740 | .x86_64 => asm volatile ( |
| 741 | \\ movq (%%rsp), %%rdi |
| 742 | \\ jmp %[mainIdle:P] |
| 743 | : |
| 744 | : [mainIdle] "X" (&mainIdle), |
| 745 | ), |
| 746 | .aarch64 => asm volatile ( |
| 747 | \\ ldr x0, [sp, #-8] |
| 748 | \\ b %[mainIdle] |
| 749 | : |
| 750 | : [mainIdle] "X" (&mainIdle), |
| 751 | ), |
| 752 | else => |arch| @compileError("unimplemented architecture: " ++ @tagName(arch)), |
| 753 | } |
| 754 | } |
| 755 | |
| 756 | fn fiberEntry() callconv(.naked) void { |
| 757 | switch (builtin.cpu.arch) { |
| 758 | .x86_64 => asm volatile ( |
| 759 | \\ leaq 8(%%rsp), %%rdi |
| 760 | \\ jmp %[AsyncClosure_call:P] |
| 761 | : |
| 762 | : [AsyncClosure_call] "X" (&AsyncClosure.call), |
| 763 | ), |
| 764 | else => |arch| @compileError("unimplemented architecture: " ++ @tagName(arch)), |
| 765 | } |
| 766 | } |
| 767 | |
| 768 | const AsyncClosure = struct { |
| 769 | event_loop: *Kqueue, |
| 770 | fiber: *Fiber, |
| 771 | start: *const fn (context: *const anyopaque, result: *anyopaque) void, |
| 772 | result_align: Alignment, |
| 773 | already_awaited: bool, |
| 774 | |
| 775 | fn contextPointer(closure: *AsyncClosure) [*]align(Fiber.max_context_align.toByteUnits()) u8 { |
| 776 | return @alignCast(@as([*]u8, @ptrCast(closure)) + @sizeOf(AsyncClosure)); |
| 777 | } |
| 778 | |
| 779 | fn call(closure: *AsyncClosure, message: *const SwitchMessage) callconv(.withStackAlign(.c, @alignOf(AsyncClosure))) noreturn { |
| 780 | message.handle(closure.event_loop); |
| 781 | const fiber = closure.fiber; |
| 782 | std.log.debug("{*} performing async", .{fiber}); |
| 783 | closure.start(closure.contextPointer(), fiber.resultBytes(closure.result_align)); |
| 784 | const awaiter = @atomicRmw(?*Fiber, &fiber.awaiter, .Xchg, Fiber.finished, .acq_rel); |
| 785 | const ready_awaiter = r: { |
| 786 | const a = awaiter orelse break :r null; |
| 787 | if (@atomicRmw(bool, &closure.already_awaited, .Xchg, true, .acq_rel)) break :r null; |
| 788 | break :r a; |
| 789 | }; |
| 790 | closure.event_loop.yield(ready_awaiter, .nothing); |
| 791 | unreachable; // switched to dead fiber |
| 792 | } |
| 793 | |
| 794 | fn fromFiber(fiber: *Fiber) *AsyncClosure { |
| 795 | return @ptrFromInt(Fiber.max_context_align.max(.of(AsyncClosure)).backward( |
| 796 | @intFromPtr(fiber.allocatedEnd()) - Fiber.max_context_size, |
| 797 | ) - @sizeOf(AsyncClosure)); |
| 798 | } |
| 799 | }; |
| 800 | |
| 29 | 801 | pub fn io(k: *Kqueue) Io { |
| 30 | 802 | return .{ |
| 31 | 803 | .userdata = k, |
| ... | ... | @@ -229,11 +1001,33 @@ fn mutexUnlock(userdata: ?*anyopaque, prev_state: Io.Mutex.State, mutex: *Io.Mut |
| 229 | 1001 | |
| 230 | 1002 | fn conditionWait(userdata: ?*anyopaque, cond: *Io.Condition, mutex: *Io.Mutex) Io.Cancelable!void { |
| 231 | 1003 | const k: *Kqueue = @ptrCast(@alignCast(userdata)); |
| 232 | | _ = k; |
| 233 | | _ = cond; |
| 234 | | _ = mutex; |
| 235 | | @panic("TODO"); |
| 1004 | k.yield(null, .{ .condition_wait = .{ .cond = cond, .mutex = mutex } }); |
| 1005 | const thread = Thread.current(); |
| 1006 | const fiber = thread.currentFiber(); |
| 1007 | const cond_impl = fiber.resultPointer(Condition); |
| 1008 | try mutex.lock(k.io()); |
| 1009 | switch (cond_impl.event) { |
| 1010 | .queued => {}, |
| 1011 | .wake => |wake| if (fiber.queue_next) |next_fiber| switch (wake) { |
| 1012 | .one => if (@cmpxchgStrong( |
| 1013 | ?*Fiber, |
| 1014 | @as(*?*Fiber, @ptrCast(&cond.state)), |
| 1015 | null, |
| 1016 | next_fiber, |
| 1017 | .release, |
| 1018 | .acquire, |
| 1019 | )) |old_fiber| { |
| 1020 | const old_cond_impl = old_fiber.?.resultPointer(Condition); |
| 1021 | assert(old_cond_impl.tail.queue_next == null); |
| 1022 | old_cond_impl.tail.queue_next = next_fiber; |
| 1023 | old_cond_impl.tail = cond_impl.tail; |
| 1024 | }, |
| 1025 | .all => k.schedule(thread, .{ .head = next_fiber, .tail = cond_impl.tail }), |
| 1026 | }, |
| 1027 | } |
| 1028 | fiber.queue_next = null; |
| 236 | 1029 | } |
| 1030 | |
| 237 | 1031 | fn conditionWaitUncancelable(userdata: ?*anyopaque, cond: *Io.Condition, mutex: *Io.Mutex) void { |
| 238 | 1032 | const k: *Kqueue = @ptrCast(@alignCast(userdata)); |
| 239 | 1033 | _ = k; |
| ... | ... | @@ -243,10 +1037,9 @@ fn conditionWaitUncancelable(userdata: ?*anyopaque, cond: *Io.Condition, mutex: |
| 243 | 1037 | } |
| 244 | 1038 | fn conditionWake(userdata: ?*anyopaque, cond: *Io.Condition, wake: Io.Condition.Wake) void { |
| 245 | 1039 | const k: *Kqueue = @ptrCast(@alignCast(userdata)); |
| 246 | | _ = k; |
| 247 | | _ = cond; |
| 248 | | _ = wake; |
| 249 | | @panic("TODO"); |
| 1040 | const waiting_fiber = @atomicRmw(?*Fiber, @as(*?*Fiber, @ptrCast(&cond.state)), .Xchg, null, .acquire) orelse return; |
| 1041 | waiting_fiber.resultPointer(Condition).event = .{ .wake = wake }; |
| 1042 | k.yield(waiting_fiber, .reschedule); |
| 250 | 1043 | } |
| 251 | 1044 | |
| 252 | 1045 | fn dirMake(userdata: ?*anyopaque, dir: Dir, sub_path: []const u8, mode: Dir.Mode) Dir.MakeError!void { |
| ... | ... | @@ -426,7 +1219,7 @@ fn netBindIp( |
| 426 | 1219 | const k: *Kqueue = @ptrCast(@alignCast(userdata)); |
| 427 | 1220 | const family = Io.Threaded.posixAddressFamily(address); |
| 428 | 1221 | const socket_fd = try openSocketPosix(k, family, options); |
| 429 | | errdefer posix.close(socket_fd); |
| 1222 | errdefer std.posix.close(socket_fd); |
| 430 | 1223 | var storage: Io.Threaded.PosixAddress = undefined; |
| 431 | 1224 | var addr_len = Io.Threaded.addressToPosix(address, &storage); |
| 432 | 1225 | try posixBind(k, socket_fd, &storage.any, addr_len); |
| ... | ... | @@ -704,3 +1497,11 @@ fn setSocketOption(k: *Kqueue, fd: posix.fd_t, level: i32, opt_name: u32, option |
| 704 | 1497 | fn checkCancel(k: *Kqueue) error{Canceled}!void { |
| 705 | 1498 | if (cancelRequested(k)) return error.Canceled; |
| 706 | 1499 | } |
| 1500 | |
| 1501 | const Condition = struct { |
| 1502 | tail: *Fiber, |
| 1503 | event: union(enum) { |
| 1504 | queued, |
| 1505 | wake: Io.Condition.Wake, |
| 1506 | }, |
| 1507 | }; |
Andrew Kelley <andrew@ziglang.org> 2025-10-23 03:21:32-07:00
lib