Commit 7aa4062f5c
lib/std/Thread/Pool.zig
@@ -335,6 +335,7 @@ pub fn io(pool: *Pool) Io {
.go = go,
.cancel = cancel,
.cancelRequested = cancelRequested,
+ .select = select,
.mutexLock = mutexLock,
.mutexUnlock = mutexUnlock,
@@ -358,10 +359,13 @@ const AsyncClosure = struct {
func: *const fn (context: *anyopaque, result: *anyopaque) void,
runnable: Runnable = .{ .runFn = runFn },
reset_event: std.Thread.ResetEvent,
+ select_condition: ?*std.Thread.ResetEvent,
cancel_tid: std.Thread.Id,
context_offset: usize,
result_offset: usize,
+ const done_reset_event: *std.Thread.ResetEvent = @ptrFromInt(std.mem.alignBackward(usize, std.math.maxInt(usize), @alignOf(std.Thread.ResetEvent)));
+
const canceling_tid: std.Thread.Id = switch (@typeInfo(std.Thread.Id)) {
.int => |int_info| switch (int_info.signedness) {
.signed => -1,
@@ -396,6 +400,17 @@ const AsyncClosure = struct {
.acq_rel,
.acquire,
)) |cancel_tid| assert(cancel_tid == canceling_tid);
+
+ if (@atomicRmw(
+ ?*std.Thread.ResetEvent,
+ &closure.select_condition,
+ .Xchg,
+ done_reset_event,
+ .release,
+ )) |select_reset| {
+ assert(select_reset != done_reset_event);
+ select_reset.set();
+ }
closure.reset_event.set();
}
@@ -455,6 +470,7 @@ fn @"async"(
.result_offset = result_offset,
.reset_event = .{},
.cancel_tid = 0,
+ .select_condition = null,
};
@memcpy(closure.contextPointer()[0..context.len], context);
pool.run_queue.prepend(&closure.runnable.node);
@@ -720,47 +736,54 @@ fn conditionWake(userdata: ?*anyopaque, cond: *Io.Condition, wake: Io.Condition.
fn createFile(
userdata: ?*anyopaque,
- dir: std.fs.Dir,
+ dir: Io.Dir,
sub_path: []const u8,
- flags: std.fs.File.CreateFlags,
-) Io.FileOpenError!std.fs.File {
+ flags: Io.File.CreateFlags,
+) Io.File.OpenError!Io.File {
const pool: *std.Thread.Pool = @alignCast(@ptrCast(userdata));
try pool.checkCancel();
- return dir.createFile(sub_path, flags);
+ const fs_dir: std.fs.Dir = .{ .fd = dir.handle };
+ const fs_file = try fs_dir.createFile(sub_path, flags);
+ return .{ .handle = fs_file.handle };
}
fn openFile(
userdata: ?*anyopaque,
- dir: std.fs.Dir,
+ dir: Io.Dir,
sub_path: []const u8,
- flags: std.fs.File.OpenFlags,
-) Io.FileOpenError!std.fs.File {
+ flags: Io.File.OpenFlags,
+) Io.File.OpenError!Io.File {
const pool: *std.Thread.Pool = @alignCast(@ptrCast(userdata));
try pool.checkCancel();
- return dir.openFile(sub_path, flags);
+ const fs_dir: std.fs.Dir = .{ .fd = dir.handle };
+ const fs_file = try fs_dir.openFile(sub_path, flags);
+ return .{ .handle = fs_file.handle };
}
-fn closeFile(userdata: ?*anyopaque, file: std.fs.File) void {
+fn closeFile(userdata: ?*anyopaque, file: Io.File) void {
const pool: *std.Thread.Pool = @alignCast(@ptrCast(userdata));
_ = pool;
- return file.close();
+ const fs_file: std.fs.File = .{ .handle = file.handle };
+ return fs_file.close();
}
-fn pread(userdata: ?*anyopaque, file: std.fs.File, buffer: []u8, offset: std.posix.off_t) Io.FilePReadError!usize {
+fn pread(userdata: ?*anyopaque, file: Io.File, buffer: []u8, offset: std.posix.off_t) Io.File.PReadError!usize {
const pool: *std.Thread.Pool = @alignCast(@ptrCast(userdata));
try pool.checkCancel();
+ const fs_file: std.fs.File = .{ .handle = file.handle };
return switch (offset) {
- -1 => file.read(buffer),
- else => file.pread(buffer, @bitCast(offset)),
+ -1 => fs_file.read(buffer),
+ else => fs_file.pread(buffer, @bitCast(offset)),
};
}
-fn pwrite(userdata: ?*anyopaque, file: std.fs.File, buffer: []const u8, offset: std.posix.off_t) Io.FilePWriteError!usize {
+fn pwrite(userdata: ?*anyopaque, file: Io.File, buffer: []const u8, offset: std.posix.off_t) Io.File.PWriteError!usize {
const pool: *std.Thread.Pool = @alignCast(@ptrCast(userdata));
try pool.checkCancel();
+ const fs_file: std.fs.File = .{ .handle = file.handle };
return switch (offset) {
- -1 => file.write(buffer),
- else => file.pwrite(buffer, @bitCast(offset)),
+ -1 => fs_file.write(buffer),
+ else => fs_file.pwrite(buffer, @bitCast(offset)),
};
}
@@ -774,7 +797,7 @@ fn now(userdata: ?*anyopaque, clockid: std.posix.clockid_t) Io.ClockGetTimeError
fn sleep(userdata: ?*anyopaque, clockid: std.posix.clockid_t, deadline: Io.Deadline) Io.SleepError!void {
const pool: *std.Thread.Pool = @alignCast(@ptrCast(userdata));
const deadline_nanoseconds: i96 = switch (deadline) {
- .nanoseconds => |nanoseconds| nanoseconds,
+ .duration => |duration| duration.nanoseconds,
.timestamp => |timestamp| @intFromEnum(timestamp),
};
var timespec: std.posix.timespec = .{
@@ -784,7 +807,7 @@ fn sleep(userdata: ?*anyopaque, clockid: std.posix.clockid_t, deadline: Io.Deadl
while (true) {
try pool.checkCancel();
switch (std.os.linux.E.init(std.os.linux.clock_nanosleep(clockid, .{ .ABSTIME = switch (deadline) {
- .nanoseconds => false,
+ .duration => false,
.timestamp => true,
} }, ×pec, ×pec))) {
.SUCCESS => return,
@@ -795,3 +818,35 @@ fn sleep(userdata: ?*anyopaque, clockid: std.posix.clockid_t, deadline: Io.Deadl
}
}
}
+
+fn select(userdata: ?*anyopaque, futures: []const *Io.AnyFuture) usize {
+ const pool: *std.Thread.Pool = @alignCast(@ptrCast(userdata));
+ _ = pool;
+
+ var reset_event: std.Thread.ResetEvent = .{};
+
+ for (futures, 0..) |future, i| {
+ const closure: *AsyncClosure = @ptrCast(@alignCast(future));
+ if (@atomicRmw(?*std.Thread.ResetEvent, &closure.select_condition, .Xchg, &reset_event, .seq_cst) == AsyncClosure.done_reset_event) {
+ for (futures[0..i]) |cleanup_future| {
+ const cleanup_closure: *AsyncClosure = @ptrCast(@alignCast(cleanup_future));
+ if (@atomicRmw(?*std.Thread.ResetEvent, &cleanup_closure.select_condition, .Xchg, null, .seq_cst) == AsyncClosure.done_reset_event) {
+ cleanup_closure.reset_event.wait(); // Ensure no reference to our stack-allocated reset_event.
+ }
+ }
+ return i;
+ }
+ }
+
+ reset_event.wait();
+
+ var result: ?usize = null;
+ for (futures, 0..) |future, i| {
+ const closure: *AsyncClosure = @ptrCast(@alignCast(future));
+ if (@atomicRmw(?*std.Thread.ResetEvent, &closure.select_condition, .Xchg, null, .seq_cst) == AsyncClosure.done_reset_event) {
+ closure.reset_event.wait(); // Ensure no reference to our stack-allocated reset_event.
+ if (result == null) result = i; // In case multiple are ready, return first.
+ }
+ }
+ return result.?;
+}
lib/std/Io.zig
@@ -626,17 +626,21 @@ pub const VTable = struct {
/// Thread-safe.
cancelRequested: *const fn (?*anyopaque) bool,
+ /// Blocks until one of the futures from the list has a result ready, such
+ /// that awaiting it will not block. Returns that index.
+ select: *const fn (?*anyopaque, futures: []const *AnyFuture) usize,
+
mutexLock: *const fn (?*anyopaque, prev_state: Mutex.State, mutex: *Mutex) Cancelable!void,
mutexUnlock: *const fn (?*anyopaque, prev_state: Mutex.State, mutex: *Mutex) void,
conditionWait: *const fn (?*anyopaque, cond: *Condition, mutex: *Mutex) Cancelable!void,
conditionWake: *const fn (?*anyopaque, cond: *Condition, wake: Condition.Wake) void,
- createFile: *const fn (?*anyopaque, dir: fs.Dir, sub_path: []const u8, flags: fs.File.CreateFlags) FileOpenError!fs.File,
- openFile: *const fn (?*anyopaque, dir: fs.Dir, sub_path: []const u8, flags: fs.File.OpenFlags) FileOpenError!fs.File,
- closeFile: *const fn (?*anyopaque, fs.File) void,
- pread: *const fn (?*anyopaque, file: fs.File, buffer: []u8, offset: std.posix.off_t) FilePReadError!usize,
- pwrite: *const fn (?*anyopaque, file: fs.File, buffer: []const u8, offset: std.posix.off_t) FilePWriteError!usize,
+ createFile: *const fn (?*anyopaque, dir: Dir, sub_path: []const u8, flags: File.CreateFlags) File.OpenError!File,
+ openFile: *const fn (?*anyopaque, dir: Dir, sub_path: []const u8, flags: File.OpenFlags) File.OpenError!File,
+ closeFile: *const fn (?*anyopaque, File) void,
+ pread: *const fn (?*anyopaque, file: File, buffer: []u8, offset: std.posix.off_t) File.PReadError!usize,
+ pwrite: *const fn (?*anyopaque, file: File, buffer: []const u8, offset: std.posix.off_t) File.PWriteError!usize,
now: *const fn (?*anyopaque, clockid: std.posix.clockid_t) ClockGetTimeError!Timestamp,
sleep: *const fn (?*anyopaque, clockid: std.posix.clockid_t, deadline: Deadline) SleepError!void,
@@ -647,28 +651,118 @@ pub const Cancelable = error{
Canceled,
};
-pub const OpenFlags = fs.File.OpenFlags;
-pub const CreateFlags = fs.File.CreateFlags;
+pub const Dir = struct {
+ handle: Handle,
+
+ pub fn cwd() Dir {
+ return .{ .handle = std.fs.cwd().fd };
+ }
+
+ pub const Handle = std.posix.fd_t;
+
+ pub fn openFile(dir: Dir, io: Io, sub_path: []const u8, flags: File.OpenFlags) File.OpenError!File {
+ return io.vtable.openFile(io.userdata, dir, sub_path, flags);
+ }
+
+ pub fn createFile(dir: Dir, io: Io, sub_path: []const u8, flags: File.CreateFlags) File.OpenError!File {
+ return io.vtable.createFile(io.userdata, dir, sub_path, flags);
+ }
+
+ pub const WriteFileOptions = struct {
+ /// On Windows, `sub_path` should be encoded as [WTF-8](https://simonsapin.github.io/wtf-8/).
+ /// On WASI, `sub_path` should be encoded as valid UTF-8.
+ /// On other platforms, `sub_path` is an opaque sequence of bytes with no particular encoding.
+ sub_path: []const u8,
+ data: []const u8,
+ flags: File.CreateFlags = .{},
+ };
+
+ pub const WriteFileError = File.WriteError || File.OpenError || Cancelable;
+
+ /// Writes content to the file system, using the file creation flags provided.
+ pub fn writeFile(dir: Dir, io: Io, options: WriteFileOptions) WriteFileError!void {
+ var file = try dir.createFile(io, options.sub_path, options.flags);
+ defer file.close(io);
+ try file.writeAll(io, options.data);
+ }
+};
+
+pub const File = struct {
+ handle: Handle,
+
+ pub const Handle = std.posix.fd_t;
+
+ pub const OpenFlags = fs.File.OpenFlags;
+ pub const CreateFlags = fs.File.CreateFlags;
+
+ pub const OpenError = fs.File.OpenError || Cancelable;
+
+ pub fn close(file: File, io: Io) void {
+ return io.vtable.closeFile(io.userdata, file);
+ }
+
+ pub const ReadError = fs.File.ReadError || Cancelable;
+
+ pub fn read(file: File, io: Io, buffer: []u8) ReadError!usize {
+ return @errorCast(file.pread(io, buffer, -1));
+ }
+
+ pub const PReadError = fs.File.PReadError || Cancelable;
+
+ pub fn pread(file: File, io: Io, buffer: []u8, offset: std.posix.off_t) PReadError!usize {
+ return io.vtable.pread(io.userdata, file, buffer, offset);
+ }
+
+ pub const WriteError = fs.File.WriteError || Cancelable;
+
+ pub fn write(file: File, io: Io, buffer: []const u8) WriteError!usize {
+ return @errorCast(file.pwrite(io, buffer, -1));
+ }
+
+ pub const PWriteError = fs.File.PWriteError || Cancelable;
+
+ pub fn pwrite(file: File, io: Io, buffer: []const u8, offset: std.posix.off_t) PWriteError!usize {
+ return io.vtable.pwrite(io.userdata, file, buffer, offset);
+ }
+
+ pub fn writeAll(file: File, io: Io, bytes: []const u8) WriteError!void {
+ var index: usize = 0;
+ while (index < bytes.len) {
+ index += try file.write(io, bytes[index..]);
+ }
+ }
-pub const FileOpenError = fs.File.OpenError || Cancelable;
-pub const FileReadError = fs.File.ReadError || Cancelable;
-pub const FilePReadError = fs.File.PReadError || Cancelable;
-pub const FileWriteError = fs.File.WriteError || Cancelable;
-pub const FilePWriteError = fs.File.PWriteError || Cancelable;
+ pub fn readAll(file: File, io: Io, buffer: []u8) ReadError!usize {
+ var index: usize = 0;
+ while (index != buffer.len) {
+ const amt = try file.read(io, buffer[index..]);
+ if (amt == 0) break;
+ index += amt;
+ }
+ return index;
+ }
+};
pub const Timestamp = enum(i96) {
_,
- pub fn durationTo(from: Timestamp, to: Timestamp) i96 {
- return @intFromEnum(to) - @intFromEnum(from);
+ pub fn durationTo(from: Timestamp, to: Timestamp) Duration {
+ return .{ .nanoseconds = @intFromEnum(to) - @intFromEnum(from) };
}
- pub fn addDuration(from: Timestamp, duration: i96) Timestamp {
- return @enumFromInt(@intFromEnum(from) + duration);
+ pub fn addDuration(from: Timestamp, duration: Duration) Timestamp {
+ return @enumFromInt(@intFromEnum(from) + duration.nanoseconds);
}
};
-pub const Deadline = union(enum) {
+pub const Duration = struct {
nanoseconds: i96,
+
+ pub fn ms(x: u64) Duration {
+ return .{ .nanoseconds = @as(i96, x) * std.time.ns_per_ms };
+ }
+};
+pub const Deadline = union(enum) {
+ duration: Duration,
timestamp: Timestamp,
};
pub const ClockGetTimeError = std.posix.ClockGetTimeError || Cancelable;
@@ -1055,7 +1149,7 @@ pub fn Queue(Elem: type) type {
/// Calls `function` with `args`, such that the return value of the function is
/// not guaranteed to be available until `await` is called.
-pub fn async(io: Io, function: anytype, args: anytype) Future(@typeInfo(@TypeOf(function)).@"fn".return_type.?) {
+pub fn async(io: Io, function: anytype, args: std.meta.ArgsTuple(@TypeOf(function))) Future(@typeInfo(@TypeOf(function)).@"fn".return_type.?) {
const Result = @typeInfo(@TypeOf(function)).@"fn".return_type.?;
const Args = @TypeOf(args);
const TypeErased = struct {
@@ -1079,7 +1173,7 @@ pub fn async(io: Io, function: anytype, args: anytype) Future(@typeInfo(@TypeOf(
/// Calls `function` with `args` asynchronously. The resource cleans itself up
/// when the function returns. Does not support await, cancel, or a return value.
-pub fn go(io: Io, function: anytype, args: anytype) void {
+pub fn go(io: Io, function: anytype, args: std.meta.ArgsTuple(@TypeOf(function))) void {
const Args = @TypeOf(args);
const TypeErased = struct {
fn start(context: *const anyopaque) void {
@@ -1095,55 +1189,56 @@ pub fn go(io: Io, function: anytype, args: anytype) void {
);
}
-pub fn openFile(io: Io, dir: fs.Dir, sub_path: []const u8, flags: fs.File.OpenFlags) FileOpenError!fs.File {
- return io.vtable.openFile(io.userdata, dir, sub_path, flags);
-}
-
-pub fn createFile(io: Io, dir: fs.Dir, sub_path: []const u8, flags: fs.File.CreateFlags) FileOpenError!fs.File {
- return io.vtable.createFile(io.userdata, dir, sub_path, flags);
-}
-
-pub fn closeFile(io: Io, file: fs.File) void {
- return io.vtable.closeFile(io.userdata, file);
-}
-
-pub fn read(io: Io, file: fs.File, buffer: []u8) FileReadError!usize {
- return @errorCast(io.pread(file, buffer, -1));
-}
-
-pub fn pread(io: Io, file: fs.File, buffer: []u8, offset: std.posix.off_t) FilePReadError!usize {
- return io.vtable.pread(io.userdata, file, buffer, offset);
+pub fn now(io: Io, clockid: std.posix.clockid_t) ClockGetTimeError!Timestamp {
+ return io.vtable.now(io.userdata, clockid);
}
-pub fn write(io: Io, file: fs.File, buffer: []const u8) FileWriteError!usize {
- return @errorCast(io.pwrite(file, buffer, -1));
+pub fn sleep(io: Io, clockid: std.posix.clockid_t, deadline: Deadline) SleepError!void {
+ return io.vtable.sleep(io.userdata, clockid, deadline);
}
-pub fn pwrite(io: Io, file: fs.File, buffer: []const u8, offset: std.posix.off_t) FilePWriteError!usize {
- return io.vtable.pwrite(io.userdata, file, buffer, offset);
+pub fn sleepDuration(io: Io, duration: Duration) SleepError!void {
+ return io.vtable.sleep(io.userdata, .MONOTONIC, .{ .duration = duration });
}
-pub fn writeAll(io: Io, file: fs.File, bytes: []const u8) FileWriteError!void {
- var index: usize = 0;
- while (index < bytes.len) {
- index += try io.write(file, bytes[index..]);
+/// Given a struct with each field a `*Future`, returns a union with the same
+/// fields, each field type the future's result.
+pub fn SelectUnion(S: type) type {
+ const struct_fields = @typeInfo(S).@"struct".fields;
+ var fields: [struct_fields.len]std.builtin.Type.UnionField = undefined;
+ for (&fields, struct_fields) |*union_field, struct_field| {
+ const F = @typeInfo(struct_field.type).pointer.child;
+ const Result = @TypeOf(@as(F, undefined).result);
+ union_field.* = .{
+ .name = struct_field.name,
+ .type = Result,
+ .alignment = struct_field.alignment,
+ };
}
+ return @Type(.{ .@"union" = .{
+ .layout = .auto,
+ .tag_type = std.meta.FieldEnum(S),
+ .fields = &fields,
+ .decls = &.{},
+ } });
}
-pub fn readAll(io: Io, file: fs.File, buffer: []u8) FileReadError!usize {
- var index: usize = 0;
- while (index != buffer.len) {
- const amt = try io.read(file, buffer[index..]);
- if (amt == 0) break;
- index += amt;
+/// `s` is a struct with every field a `*Future(T)`, where `T` can be any type,
+/// and can be different for each field.
+pub fn select(io: Io, s: anytype) SelectUnion(@TypeOf(s)) {
+ const U = SelectUnion(@TypeOf(s));
+ const S = @TypeOf(s);
+ const fields = @typeInfo(S).@"struct".fields;
+ var futures: [fields.len]*AnyFuture = undefined;
+ inline for (fields, &futures) |field, *any_future| {
+ const future = @field(s, field.name);
+ any_future.* = future.any_future orelse return @unionInit(U, field.name, future.result);
+ }
+ switch (io.vtable.select(io.userdata, &futures)) {
+ inline 0...(fields.len - 1) => |selected_index| {
+ const field_name = fields[selected_index].name;
+ return @unionInit(U, field_name, @field(s, field_name).await(io));
+ },
+ else => unreachable,
}
- return index;
-}
-
-pub fn now(io: Io, clockid: std.posix.clockid_t) ClockGetTimeError!Timestamp {
- return io.vtable.now(io.userdata, clockid);
-}
-
-pub fn sleep(io: Io, clockid: std.posix.clockid_t, deadline: Deadline) SleepError!void {
- return io.vtable.sleep(io.userdata, clockid, deadline);
}