Commit 77d2ad8c929680ed35fcfe6646f940518a07e7e4 | zig

author	Andrew Kelley <andrew@ziglang.org> 2025-12-19 20:15:50-08:00
committer	Andrew Kelley <andrew@ziglang.org> 2025-12-23 22:15:11-08:00
log	77d2ad8c929680ed35fcfe6646f940518a07e7e4
tree	f07cbefcc9b20049369188bfac27734a3c37c655
parent	50c585227ed2a57a4c1cf3f3b44914881999559d

std: consolidate all instances of std.Io.Threaded into a singleton

It's better to avoid references to this global variable, but, in the
cases where it's needed, such as in std.debug.print and collecting stack
traces, better to share the same instance.

20 files changed, 56 insertions(+), 53 deletions(-)

lib
- compiler
  - test_runner.zig
- std
  - Io
    Threaded.zig
  - Thread.zig
  - debug.zig
  - debug
    SelfInfo
    Windows.zig
  - dynamic_library.zig
  - process
    Child.zig
test
- incremental
  - no_change_preserves_tag_names
- standalone
  - cmakedefine
    check.zig
  - dirname
    exists_in.zig
    touch.zig
  - entry_point
    check_differ.zig
  - install_headers
    check_exists.zig
  - posix
    relpaths.zig
  - run_cwd
    check_file_exists.zig
  - run_output_caching
    main.zig
  - run_output_paths
    create_file.zig
  - self_exe_symlink
    create-symlink.zig
  - simple
    hello_world
    hello.zig
  - windows_paths
    test.zig

lib/compiler/test_runner.zig+5-5

lib/std/Io/Threaded.zig+13

...	@@ -626,6 +626,19 @@ pub const init_single_threaded: Threaded = .{	...	@@ -626,6 +626,19 @@ pub const init_single_threaded: Threaded = .{
626	},	626	},
627	};	627	};
628		628
		629	var global_single_threaded_instance: Threaded = .init_single_threaded;
		630
		631	/// In general, the application is responsible for choosing the `Io`
		632	/// implementation and library code should accept an `Io` parameter rather than
		633	/// accessing this declaration. Most code should avoid referencing this
		634	/// declaration entirely.
		635	///
		636	/// However, in some cases such as debugging, it is desirable to hardcode a
		637	/// reference to this `Io` implementation.
		638	///
		639	/// This instance does not support concurrency or cancelation.
		640	pub const global_single_threaded: *Threaded = &global_single_threaded_instance;
		641
629	pub fn setAsyncLimit(t: *Threaded, new_limit: Io.Limit) void {	642	pub fn setAsyncLimit(t: *Threaded, new_limit: Io.Limit) void {
630	t.mutex.lock();	643	t.mutex.lock();
631	defer t.mutex.unlock();	644	defer t.mutex.unlock();

lib/std/Thread.zig+1-2

...	@@ -322,8 +322,7 @@ pub fn getName(self: Thread, buffer_ptr: *[max_name_len:0]u8) GetNameError!?[]co	...	@@ -322,8 +322,7 @@ pub fn getName(self: Thread, buffer_ptr: *[max_name_len:0]u8) GetNameError!?[]co
322	var buf: [32]u8 = undefined;	322	var buf: [32]u8 = undefined;
323	const path = try std.fmt.bufPrint(&buf, "/proc/self/task/{d}/comm", .{self.getHandle()});	323	const path = try std.fmt.bufPrint(&buf, "/proc/self/task/{d}/comm", .{self.getHandle()});
324		324
325	var threaded: std.Io.Threaded = .init_single_threaded;	325	const io = Io.Threaded.global_single_threaded.ioBasic();
326	const io = threaded.ioBasic();
327		326
328	const file = try Io.Dir.cwd().openFile(io, path, .{});	327	const file = try Io.Dir.cwd().openFile(io, path, .{});
329	defer file.close(io);	328	defer file.close(io);

lib/std/debug.zig+6-6

lib/std/debug/SelfInfo/Windows.zig+2-2

...	@@ -315,8 +315,8 @@ const Module = struct {	...	@@ -315,8 +315,8 @@ const Module = struct {
315	);	315	);
316	if (len == 0) return error.MissingDebugInfo;	316	if (len == 0) return error.MissingDebugInfo;
317	const name_w = name_buffer[0 .. len + 4 :0];	317	const name_w = name_buffer[0 .. len + 4 :0];
318	var threaded: Io.Threaded = .init_single_threaded;	318	// TODO eliminate the reference to Io.Threaded.global_single_threaded here
319	const coff_file = threaded.dirOpenFileWtf16(null, name_w, .{}) catch \|err\| switch (err) {	319	const coff_file = Io.Threaded.global_single_threaded.dirOpenFileWtf16(null, name_w, .{}) catch \|err\| switch (err) {
320	error.Canceled => \|e\| return e,	320	error.Canceled => \|e\| return e,
321	error.Unexpected => \|e\| return e,	321	error.Unexpected => \|e\| return e,
322	error.FileNotFound => return error.MissingDebugInfo,	322	error.FileNotFound => return error.MissingDebugInfo,

lib/std/dynamic_library.zig+1-3

...	@@ -142,8 +142,6 @@ const ElfDynLibError = error{	...	@@ -142,8 +142,6 @@ const ElfDynLibError = error{
142	Streaming,	142	Streaming,
143	} \|\| posix.OpenError \|\| posix.MMapError;	143	} \|\| posix.OpenError \|\| posix.MMapError;
144		144
145	var static_single_threaded_io: Io.Threaded = .init_single_threaded;
146
147	pub const ElfDynLib = struct {	145	pub const ElfDynLib = struct {
148	strings: [*:0]u8,	146	strings: [*:0]u8,
149	syms: [*]elf.Sym,	147	syms: [*]elf.Sym,
...	@@ -224,7 +222,7 @@ pub const ElfDynLib = struct {	...	@@ -224,7 +222,7 @@ pub const ElfDynLib = struct {
224		222
225	/// Trusts the file. Malicious file will be able to execute arbitrary code.	223	/// Trusts the file. Malicious file will be able to execute arbitrary code.
226	pub fn open(path: []const u8) Error!ElfDynLib {	224	pub fn open(path: []const u8) Error!ElfDynLib {
227	const io = static_single_threaded_io.ioBasic();	225	const io = Io.Threaded.global_single_threaded.ioBasic();
228		226
229	const fd = try resolveFromName(io, path);	227	const fd = try resolveFromName(io, path);
230	defer posix.close(fd);	228	defer posix.close(fd);

lib/std/process/Child.zig+7-8

test/incremental/no_change_preserves_tag_names+2-2

...	@@ -8,7 +8,7 @@	...	@@ -8,7 +8,7 @@
8	const std = @import("std");	8	const std = @import("std");
9	var some_enum: enum { first, second } = .first;	9	var some_enum: enum { first, second } = .first;
10	pub fn main() !void {	10	pub fn main() !void {
11	try std.Io.File.stdout().writeAll(@tagName(some_enum));	11	try std.Io.File.stdout().writeStreamingAll(std.Io.Threaded.global_single_threaded.ioBasic(), @tagName(some_enum));
12	}	12	}
13	#expect_stdout="first"	13	#expect_stdout="first"
14	#update=no change	14	#update=no change
...	@@ -16,6 +16,6 @@ pub fn main() !void {	...	@@ -16,6 +16,6 @@ pub fn main() !void {
16	const std = @import("std");	16	const std = @import("std");
17	var some_enum: enum { first, second } = .first;	17	var some_enum: enum { first, second } = .first;
18	pub fn main() !void {	18	pub fn main() !void {
19	try std.Io.File.stdout().writeAll(@tagName(some_enum));	19	try std.Io.File.stdout().writeStreamingAll(std.Io.Threaded.global_single_threaded.ioBasic(), @tagName(some_enum));
20	}	20	}
21	#expect_stdout="first"	21	#expect_stdout="first"

test/standalone/cmakedefine/check.zig+1-2

...	@@ -9,8 +9,7 @@ pub fn main() !void {	...	@@ -9,8 +9,7 @@ pub fn main() !void {
9	const actual_path = args[1];	9	const actual_path = args[1];
10	const expected_path = args[2];	10	const expected_path = args[2];
11		11
12	var threaded: std.Io.Threaded = .init_single_threaded;	12	const io = std.Io.Threaded.global_single_threaded.ioBasic();
13	const io = threaded.io();
14		13
15	const actual = try std.Io.Dir.cwd().readFileAlloc(io, actual_path, arena, .limited(1024 * 1024));	14	const actual = try std.Io.Dir.cwd().readFileAlloc(io, actual_path, arena, .limited(1024 * 1024));
16	const expected = try std.Io.Dir.cwd().readFileAlloc(io, expected_path, arena, .limited(1024 * 1024));	15	const expected = try std.Io.Dir.cwd().readFileAlloc(io, expected_path, arena, .limited(1024 * 1024));

test/standalone/dirname/exists_in.zig+1-2

...	@@ -34,8 +34,7 @@ fn run(allocator: std.mem.Allocator) !void {	...	@@ -34,8 +34,7 @@ fn run(allocator: std.mem.Allocator) !void {
34	return error.BadUsage;	34	return error.BadUsage;
35	};	35	};
36		36
37	var threaded: std.Io.Threaded = .init_single_threaded;	37	const io = std.Io.Threaded.global_single_threaded.ioBasic();
38	const io = threaded.io();
39		38
40	var dir = try std.Io.Dir.cwd().openDir(io, dir_path, .{});	39	var dir = try std.Io.Dir.cwd().openDir(io, dir_path, .{});
41	defer dir.close(io);	40	defer dir.close(io);

test/standalone/dirname/touch.zig+1-2

...	@@ -29,8 +29,7 @@ fn run(allocator: std.mem.Allocator) !void {	...	@@ -29,8 +29,7 @@ fn run(allocator: std.mem.Allocator) !void {
29	const dir_path = std.Io.Dir.path.dirname(path) orelse unreachable;	29	const dir_path = std.Io.Dir.path.dirname(path) orelse unreachable;
30	const basename = std.Io.Dir.path.basename(path);	30	const basename = std.Io.Dir.path.basename(path);
31		31
32	var threaded: std.Io.Threaded = .init_single_threaded;	32	const io = std.Io.Threaded.global_single_threaded.ioBasic();
33	const io = threaded.io();
34		33
35	var dir = try std.Io.Dir.cwd().openDir(io, dir_path, .{});	34	var dir = try std.Io.Dir.cwd().openDir(io, dir_path, .{});
36	defer dir.close(io);	35	defer dir.close(io);

test/standalone/entry_point/check_differ.zig+1-2

...	@@ -6,8 +6,7 @@ pub fn main() !void {	...	@@ -6,8 +6,7 @@ pub fn main() !void {
6	const args = try std.process.argsAlloc(arena);	6	const args = try std.process.argsAlloc(arena);
7	if (args.len != 3) return error.BadUsage; // usage: 'check_differ <path a> <path b>'	7	if (args.len != 3) return error.BadUsage; // usage: 'check_differ <path a> <path b>'
8		8
9	var threaded: std.Io.Threaded = .init_single_threaded;	9	const io = std.Io.Threaded.global_single_threaded.ioBasic();
10	const io = threaded.io();
11		10
12	const contents_1 = try std.Io.Dir.cwd().readFileAlloc(io, args[1], arena, .limited(1024 * 1024 * 64)); // 64 MiB ought to be plenty	11	const contents_1 = try std.Io.Dir.cwd().readFileAlloc(io, args[1], arena, .limited(1024 * 1024 * 64)); // 64 MiB ought to be plenty
13	const contents_2 = try std.Io.Dir.cwd().readFileAlloc(io, args[2], arena, .limited(1024 * 1024 * 64)); // 64 MiB ought to be plenty	12	const contents_2 = try std.Io.Dir.cwd().readFileAlloc(io, args[2], arena, .limited(1024 * 1024 * 64)); // 64 MiB ought to be plenty

test/standalone/install_headers/check_exists.zig+1-2

...	@@ -11,8 +11,7 @@ pub fn main() !void {	...	@@ -11,8 +11,7 @@ pub fn main() !void {
11	var arg_it = try std.process.argsWithAllocator(arena);	11	var arg_it = try std.process.argsWithAllocator(arena);
12	_ = arg_it.next();	12	_ = arg_it.next();
13		13
14	var threaded: std.Io.Threaded = .init_single_threaded;	14	const io = std.Io.Threaded.global_single_threaded.ioBasic();
15	const io = threaded.io();
16		15
17	const cwd = std.Io.Dir.cwd();	16	const cwd = std.Io.Dir.cwd();
18	const cwd_realpath = try cwd.realPathAlloc(io, arena, ".");	17	const cwd_realpath = try cwd.realPathAlloc(io, arena, ".");

test/standalone/posix/relpaths.zig+1-2

...	@@ -14,8 +14,7 @@ pub fn main() !void {	...	@@ -14,8 +14,7 @@ pub fn main() !void {
14	const gpa = debug_allocator.allocator();	14	const gpa = debug_allocator.allocator();
15	defer std.debug.assert(debug_allocator.deinit() == .ok);	15	defer std.debug.assert(debug_allocator.deinit() == .ok);
16		16
17	var threaded: std.Io.Threaded = .init_single_threaded;	17	const io = std.Io.Threaded.global_single_threaded.ioBasic();
18	const io = threaded.io();
19		18
20	// TODO this API isn't supposed to be used outside of unit testing. make it compilation error if used	19	// TODO this API isn't supposed to be used outside of unit testing. make it compilation error if used
21	// outside of unit testing.	20	// outside of unit testing.

test/standalone/run_cwd/check_file_exists.zig+1-2

...	@@ -8,8 +8,7 @@ pub fn main() !void {	...	@@ -8,8 +8,7 @@ pub fn main() !void {
8	if (args.len != 2) return error.BadUsage;	8	if (args.len != 2) return error.BadUsage;
9	const path = args[1];	9	const path = args[1];
10		10
11	var threaded: std.Io.Threaded = .init_single_threaded;	11	const io = std.Io.Threaded.global_single_threaded.ioBasic();
12	const io = threaded.io();
13		12
14	std.Io.Dir.cwd().access(io, path, .{}) catch return error.AccessFailed;	13	std.Io.Dir.cwd().access(io, path, .{}) catch return error.AccessFailed;
15	}	14	}

test/standalone/run_output_caching/main.zig+1-2

...	@@ -1,8 +1,7 @@	...	@@ -1,8 +1,7 @@
1	const std = @import("std");	1	const std = @import("std");
2		2
3	pub fn main() !void {	3	pub fn main() !void {
4	var threaded: std.Io.Threaded = .init_single_threaded;	4	const io = std.Io.Threaded.global_single_threaded.ioBasic();
5	const io = threaded.io();
6	var args = try std.process.argsWithAllocator(std.heap.page_allocator);	5	var args = try std.process.argsWithAllocator(std.heap.page_allocator);
7	_ = args.skip();	6	_ = args.skip();
8	const filename = args.next().?;	7	const filename = args.next().?;

test/standalone/run_output_paths/create_file.zig+1-2

...	@@ -1,8 +1,7 @@	...	@@ -1,8 +1,7 @@
1	const std = @import("std");	1	const std = @import("std");
2		2
3	pub fn main() !void {	3	pub fn main() !void {
4	var threaded: std.Io.Threaded = .init_single_threaded;	4	const io = std.Io.Threaded.global_single_threaded.ioBasic();
5	const io = threaded.io();
6	var args = try std.process.argsWithAllocator(std.heap.page_allocator);	5	var args = try std.process.argsWithAllocator(std.heap.page_allocator);
7	_ = args.skip();	6	_ = args.skip();
8	const dir_name = args.next().?;	7	const dir_name = args.next().?;

test/standalone/self_exe_symlink/create-symlink.zig+1-2

...	@@ -15,8 +15,7 @@ pub fn main() anyerror!void {	...	@@ -15,8 +15,7 @@ pub fn main() anyerror!void {
15	const exe_rel_path = try std.fs.path.relative(allocator, std.fs.path.dirname(symlink_path) orelse ".", exe_path);	15	const exe_rel_path = try std.fs.path.relative(allocator, std.fs.path.dirname(symlink_path) orelse ".", exe_path);
16	defer allocator.free(exe_rel_path);	16	defer allocator.free(exe_rel_path);
17		17
18	var threaded: std.Io.Threaded = .init_single_threaded;	18	const io = std.Io.Threaded.global_single_threaded.ioBasic();
19	const io = threaded.io();
20		19
21	try std.Io.Dir.cwd().symLink(io, exe_rel_path, symlink_path, .{});	20	try std.Io.Dir.cwd().symLink(io, exe_rel_path, symlink_path, .{});
22	}	21	}

test/standalone/simple/hello_world/hello.zig+8-3

...	@@ -1,8 +1,13 @@	...	@@ -1,8 +1,13 @@
1	const std = @import("std");	1	const std = @import("std");
2		2
3	var static_single_threaded_io: std.Io.Threaded = .init_single_threaded;
4	const io = static_single_threaded_io.ioBasic();
5
6	pub fn main() !void {	3	pub fn main() !void {
		4	var debug_allocator: std.heap.DebugAllocator(.{}) = .init;
		5	defer _ = debug_allocator.deinit();
		6	const gpa = debug_allocator.allocator();
		7
		8	var threaded: std.Io.Threaded = .init(gpa);
		9	defer threaded.deinit();
		10	const io = threaded.io();
		11
7	try std.Io.File.stdout().writeStreamingAll(io, "Hello, World!\n");	12	try std.Io.File.stdout().writeStreamingAll(io, "Hello, World!\n");
8	}	13	}

test/standalone/windows_paths/test.zig+1-2

...	@@ -10,8 +10,7 @@ pub fn main() anyerror!void {	...	@@ -10,8 +10,7 @@ pub fn main() anyerror!void {
10		10
11	if (args.len < 2) return error.MissingArgs;	11	if (args.len < 2) return error.MissingArgs;
12		12
13	var threaded: Io.Threaded = .init_single_threaded;	13	const io = std.Io.Threaded.global_single_threaded.ioBasic();
14	const io = threaded.io();
15		14
16	const exe_path = args[1];	15	const exe_path = args[1];
17		16

...	@@ -17,7 +17,7 @@ var fba: std.heap.FixedBufferAllocator = .init(&fba_buffer);	...	@@ -17,7 +17,7 @@ var fba: std.heap.FixedBufferAllocator = .init(&fba_buffer);
17	var fba_buffer: [8192]u8 = undefined;	17	var fba_buffer: [8192]u8 = undefined;
18	var stdin_buffer: [4096]u8 = undefined;	18	var stdin_buffer: [4096]u8 = undefined;
19	var stdout_buffer: [4096]u8 = undefined;	19	var stdout_buffer: [4096]u8 = undefined;
20	var runner_threaded_io: Io.Threaded = .init_single_threaded;	20	const runner_threaded_io: Io = Io.Threaded.global_single_threaded.ioBasic();
21		21
22	/// Keep in sync with logic in `std.Build.addRunArtifact` which decides whether	22	/// Keep in sync with logic in `std.Build.addRunArtifact` which decides whether
23	/// the test runner will communicate with the build runner via `std.zig.Server`.	23	/// the test runner will communicate with the build runner via `std.zig.Server`.
...	@@ -74,8 +74,8 @@ pub fn main() void {	...	@@ -74,8 +74,8 @@ pub fn main() void {
74		74
75	fn mainServer() !void {	75	fn mainServer() !void {
76	@disableInstrumentation();	76	@disableInstrumentation();
77	var stdin_reader = Io.File.stdin().readerStreaming(runner_threaded_io.io(), &stdin_buffer);	77	var stdin_reader = Io.File.stdin().readerStreaming(runner_threaded_io, &stdin_buffer);
78	var stdout_writer = Io.File.stdout().writerStreaming(runner_threaded_io.io(), &stdout_buffer);	78	var stdout_writer = Io.File.stdout().writerStreaming(runner_threaded_io, &stdout_buffer);
79	var server = try std.zig.Server.init(.{	79	var server = try std.zig.Server.init(.{
80	.in = &stdin_reader.interface,	80	.in = &stdin_reader.interface,
81	.out = &stdout_writer.interface,	81	.out = &stdout_writer.interface,
...	@@ -224,11 +224,11 @@ fn mainTerminal() void {	...	@@ -224,11 +224,11 @@ fn mainTerminal() void {
224	var skip_count: usize = 0;	224	var skip_count: usize = 0;
225	var fail_count: usize = 0;	225	var fail_count: usize = 0;
226	var fuzz_count: usize = 0;	226	var fuzz_count: usize = 0;
227	const root_node = if (builtin.fuzz) std.Progress.Node.none else std.Progress.start(runner_threaded_io.io(), .{	227	const root_node = if (builtin.fuzz) std.Progress.Node.none else std.Progress.start(runner_threaded_io, .{
228	.root_name = "Test",	228	.root_name = "Test",
229	.estimated_total_items = test_fn_list.len,	229	.estimated_total_items = test_fn_list.len,
230	});	230	});
231	const have_tty = Io.File.stderr().isTty(runner_threaded_io.io()) catch unreachable;	231	const have_tty = Io.File.stderr().isTty(runner_threaded_io) catch unreachable;
232		232
233	var leaks: usize = 0;	233	var leaks: usize = 0;
234	for (test_fn_list, 0..) \|test_fn, i\| {	234	for (test_fn_list, 0..) \|test_fn, i\| {

...	@@ -263,7 +263,7 @@ pub const sys_can_stack_trace = switch (builtin.cpu.arch) {	...	@@ -263,7 +263,7 @@ pub const sys_can_stack_trace = switch (builtin.cpu.arch) {
263		263
264	/// This is used for debug information and debug printing. It is intentionally	264	/// This is used for debug information and debug printing. It is intentionally
265	/// separate from the application's `Io` instance.	265	/// separate from the application's `Io` instance.
266	var static_single_threaded_io: Io.Threaded = .init_single_threaded;	266	const static_single_threaded_io = Io.Threaded.global_single_threaded.ioBasic();
267		267
268	/// Allows the caller to freely write to stderr until `unlockStderr` is called.	268	/// Allows the caller to freely write to stderr until `unlockStderr` is called.
269	///	269	///
...	@@ -284,7 +284,7 @@ var static_single_threaded_io: Io.Threaded = .init_single_threaded;	...	@@ -284,7 +284,7 @@ var static_single_threaded_io: Io.Threaded = .init_single_threaded;
284	/// Alternatively, use the higher-level `Io.lockStderr` to integrate with the	284	/// Alternatively, use the higher-level `Io.lockStderr` to integrate with the
285	/// application's chosen `Io` implementation.	285	/// application's chosen `Io` implementation.
286	pub fn lockStderr(buffer: []u8) Io.LockedStderr {	286	pub fn lockStderr(buffer: []u8) Io.LockedStderr {
287	return static_single_threaded_io.ioBasic().lockStderr(buffer, null) catch \|err\| switch (err) {	287	return static_single_threaded_io.lockStderr(buffer, null) catch \|err\| switch (err) {
288	// Impossible to cancel because no calls to cancel using	288	// Impossible to cancel because no calls to cancel using
289	// `static_single_threaded_io` exist.	289	// `static_single_threaded_io` exist.
290	error.Canceled => unreachable,	290	error.Canceled => unreachable,
...	@@ -292,7 +292,7 @@ pub fn lockStderr(buffer: []u8) Io.LockedStderr {	...	@@ -292,7 +292,7 @@ pub fn lockStderr(buffer: []u8) Io.LockedStderr {
292	}	292	}
293		293
294	pub fn unlockStderr() void {	294	pub fn unlockStderr() void {
295	static_single_threaded_io.ioBasic().unlockStderr();	295	static_single_threaded_io.unlockStderr();
296	}	296	}
297		297
298	/// Writes to stderr, ignoring errors.	298	/// Writes to stderr, ignoring errors.
...	@@ -630,7 +630,7 @@ pub noinline fn captureCurrentStackTrace(options: StackUnwindOptions, addr_buf:	...	@@ -630,7 +630,7 @@ pub noinline fn captureCurrentStackTrace(options: StackUnwindOptions, addr_buf:
630	defer it.deinit();	630	defer it.deinit();
631	if (!it.stratOk(options.allow_unsafe_unwind)) return empty_trace;	631	if (!it.stratOk(options.allow_unsafe_unwind)) return empty_trace;
632		632
633	const io = static_single_threaded_io.ioBasic();	633	const io = static_single_threaded_io;
634		634
635	var total_frames: usize = 0;	635	var total_frames: usize = 0;
636	var index: usize = 0;	636	var index: usize = 0;
...	@@ -692,7 +692,7 @@ pub noinline fn writeCurrentStackTrace(options: StackUnwindOptions, t: Io.Termin	...	@@ -692,7 +692,7 @@ pub noinline fn writeCurrentStackTrace(options: StackUnwindOptions, t: Io.Termin
692	var total_frames: usize = 0;	692	var total_frames: usize = 0;
693	var wait_for = options.first_address;	693	var wait_for = options.first_address;
694	var printed_any_frame = false;	694	var printed_any_frame = false;
695	const io = static_single_threaded_io.ioBasic();	695	const io = static_single_threaded_io;
696	while (true) switch (it.next(io)) {	696	while (true) switch (it.next(io)) {
697	.switch_to_fp => \|unwind_error\| {	697	.switch_to_fp => \|unwind_error\| {
698	switch (StackIterator.fp_usability) {	698	switch (StackIterator.fp_usability) {
...	@@ -800,7 +800,7 @@ pub fn writeStackTrace(st: *const StackTrace, t: Io.Terminal) Writer.Error!void	...	@@ -800,7 +800,7 @@ pub fn writeStackTrace(st: *const StackTrace, t: Io.Terminal) Writer.Error!void
800	return;	800	return;
801	},	801	},
802	};	802	};
803	const io = static_single_threaded_io.ioBasic();	803	const io = static_single_threaded_io;
804	const captured_frames = @min(n_frames, st.instruction_addresses.len);	804	const captured_frames = @min(n_frames, st.instruction_addresses.len);
805	for (st.instruction_addresses[0..captured_frames]) \|ret_addr\| {	805	for (st.instruction_addresses[0..captured_frames]) \|ret_addr\| {
806	// `ret_addr` is the return address, which is after the function call.	806	// `ret_addr` is the return address, which is after the function call.

...	@@ -266,7 +266,7 @@ pub fn spawn(self: *Child, io: Io) SpawnError!void {	...	@@ -266,7 +266,7 @@ pub fn spawn(self: *Child, io: Io) SpawnError!void {
266	}	266	}
267		267
268	if (native_os == .windows) {	268	if (native_os == .windows) {
269	return self.spawnWindows();	269	return self.spawnWindows(io);
270	} else {	270	} else {
271	return self.spawnPosix(io);	271	return self.spawnPosix(io);
272	}	272	}
...	@@ -750,7 +750,7 @@ fn spawnPosix(self: *Child, io: Io) SpawnError!void {	...	@@ -750,7 +750,7 @@ fn spawnPosix(self: *Child, io: Io) SpawnError!void {
750	self.progress_node.setIpcFd(prog_pipe[0]);	750	self.progress_node.setIpcFd(prog_pipe[0]);
751	}	751	}
752		752
753	fn spawnWindows(self: *Child) SpawnError!void {	753	fn spawnWindows(self: *Child, io: Io) SpawnError!void {
754	var saAttr = windows.SECURITY_ATTRIBUTES{	754	var saAttr = windows.SECURITY_ATTRIBUTES{
755	.nLength = @sizeOf(windows.SECURITY_ATTRIBUTES),	755	.nLength = @sizeOf(windows.SECURITY_ATTRIBUTES),
756	.bInheritHandle = windows.TRUE,	756	.bInheritHandle = windows.TRUE,
...	@@ -953,7 +953,7 @@ fn spawnWindows(self: *Child) SpawnError!void {	...	@@ -953,7 +953,7 @@ fn spawnWindows(self: *Child) SpawnError!void {
953	try dir_buf.appendSlice(self.allocator, app_dir);	953	try dir_buf.appendSlice(self.allocator, app_dir);
954	}	954	}
955		955
956	windowsCreateProcessPathExt(self.allocator, &dir_buf, &app_buf, PATHEXT, &cmd_line_cache, envp_ptr, cwd_w_ptr, flags, &siStartInfo, &piProcInfo) catch \|no_path_err\| {	956	windowsCreateProcessPathExt(self.allocator, io, &dir_buf, &app_buf, PATHEXT, &cmd_line_cache, envp_ptr, cwd_w_ptr, flags, &siStartInfo, &piProcInfo) catch \|no_path_err\| {
957	const original_err = switch (no_path_err) {	957	const original_err = switch (no_path_err) {
958	// argv[0] contains unsupported characters that will never resolve to a valid exe.	958	// argv[0] contains unsupported characters that will never resolve to a valid exe.
959	error.InvalidArg0 => return error.FileNotFound,	959	error.InvalidArg0 => return error.FileNotFound,
...	@@ -977,7 +977,7 @@ fn spawnWindows(self: *Child) SpawnError!void {	...	@@ -977,7 +977,7 @@ fn spawnWindows(self: *Child) SpawnError!void {
977	dir_buf.clearRetainingCapacity();	977	dir_buf.clearRetainingCapacity();
978	try dir_buf.appendSlice(self.allocator, search_path);	978	try dir_buf.appendSlice(self.allocator, search_path);
979		979
980	if (windowsCreateProcessPathExt(self.allocator, &dir_buf, &app_buf, PATHEXT, &cmd_line_cache, envp_ptr, cwd_w_ptr, flags, &siStartInfo, &piProcInfo)) {	980	if (windowsCreateProcessPathExt(self.allocator, io, &dir_buf, &app_buf, PATHEXT, &cmd_line_cache, envp_ptr, cwd_w_ptr, flags, &siStartInfo, &piProcInfo)) {
981	break :run;	981	break :run;
982	} else \|err\| switch (err) {	982	} else \|err\| switch (err) {
983	// argv[0] contains unsupported characters that will never resolve to a valid exe.	983	// argv[0] contains unsupported characters that will never resolve to a valid exe.
...	@@ -1079,6 +1079,7 @@ const ErrInt = std.meta.Int(.unsigned, @sizeOf(anyerror) * 8);	...	@@ -1079,6 +1079,7 @@ const ErrInt = std.meta.Int(.unsigned, @sizeOf(anyerror) * 8);
1079	/// Note: If the dir is the cwd, dir_buf should be empty (len = 0).	1079	/// Note: If the dir is the cwd, dir_buf should be empty (len = 0).
1080	fn windowsCreateProcessPathExt(	1080	fn windowsCreateProcessPathExt(
1081	allocator: Allocator,	1081	allocator: Allocator,
		1082	io: Io,
1082	dir_buf: *ArrayList(u16),	1083	dir_buf: *ArrayList(u16),
1083	app_buf: *ArrayList(u16),	1084	app_buf: *ArrayList(u16),
1084	pathext: [:0]const u16,	1085	pathext: [:0]const u16,
...	@@ -1122,16 +1123,14 @@ fn windowsCreateProcessPathExt(	...	@@ -1122,16 +1123,14 @@ fn windowsCreateProcessPathExt(
1122	// Under those conditions, here we will have access to lower level directory	1123	// Under those conditions, here we will have access to lower level directory
1123	// opening function knowing which implementation we are in. Here, we imitate	1124	// opening function knowing which implementation we are in. Here, we imitate
1124	// that scenario.	1125	// that scenario.
1125	var threaded: std.Io.Threaded = .init_single_threaded;
1126	const io = threaded.ioBasic();
1127
1128	var dir = dir: {	1126	var dir = dir: {
1129	// needs to be null-terminated	1127	// needs to be null-terminated
1130	try dir_buf.append(allocator, 0);	1128	try dir_buf.append(allocator, 0);
1131	defer dir_buf.shrinkRetainingCapacity(dir_path_len);	1129	defer dir_buf.shrinkRetainingCapacity(dir_path_len);
1132	const dir_path_z = dir_buf.items[0 .. dir_buf.items.len - 1 :0];	1130	const dir_path_z = dir_buf.items[0 .. dir_buf.items.len - 1 :0];
1133	const prefixed_path = try windows.wToPrefixedFileW(null, dir_path_z);	1131	const prefixed_path = try windows.wToPrefixedFileW(null, dir_path_z);
1134	break :dir threaded.dirOpenDirWindows(.cwd(), prefixed_path.span(), .{	1132	// TODO eliminate this reference
		1133	break :dir Io.Threaded.global_single_threaded.dirOpenDirWindows(.cwd(), prefixed_path.span(), .{
1135	.iterate = true,	1134	.iterate = true,
1136	}) catch return error.FileNotFound;	1135	}) catch return error.FileNotFound;
1137	};	1136	};