Commit fd74c5742d3c8343868516c03a6a0695280744d1 | zig

author	hubidubi <hubidubi@noreply.codeberg.org> 2026-02-13 20:39:38+01:00
committer	Andrew Kelley <andrew@ziglang.org> 2026-02-13 20:39:38+01:00
log	fd74c5742d3c8343868516c03a6a0695280744d1
tree	0988ebfa90fe3da65d12be7d682a7dc797c925a8
parent	dbfe34167de6b2a3a46ee4aff8f016c5afda7ccf

std.Io.Threaded: fix FreeBSD Futex max_waiters (#30094)

On FreeBSD, the maximum waiters should be Cs INT_MAX instead of the maximum of a u32. Waiting for the Io.Event in the broadcast test triggers this bug.

Resolves #30715

Co-authored-by: Simon Galli <hubi@hubidubi.net>
Reviewed-on: https://codeberg.org/ziglang/zig/pulls/30094
Reviewed-by: Andrew Kelley <andrew@ziglang.org>
Co-authored-by: hubidubi <hubidubi@noreply.codeberg.org>
Co-committed-by: hubidubi <hubidubi@noreply.codeberg.org>

2 files changed, 7 insertions(+), 6 deletions(-)

lib
- std
  - Io
    Threaded.zig
    test.zig

lib/std/Io/Threaded.zig+1-1

...	...	@@ -1104,7 +1104,7 @@ const Thread = struct {
1104	1104	const rc = std.c._umtx_op(
1105	1105	@intFromPtr(ptr),
1106	1106	@intFromEnum(std.c.UMTX_OP.WAKE_PRIVATE),
1107		@as(c_ulong, max_waiters),
	1107	@as(c_ulong, @min(max_waiters, std.math.maxInt(c_int))),
1108	1108	0, // there is no timeout struct
1109	1109	0, // there is no timeout struct pointer
1110	1110	);

lib/std/Io/test.zig+6-5

...	...	@@ -818,10 +818,11 @@ test "Event broadcast" {
818	818	event: Io.Event = .unset,
819	819	counter: std.atomic.Value(usize) = std.atomic.Value(usize).init(num_threads),
820	820
821		fn wait(self: *@This()) void {
	821	fn wait(self: *@This()) !void {
822	822	if (self.counter.fetchSub(1, .acq_rel) == 1) {
823	823	self.event.set(io);
824	824	}
	825	try self.event.wait(io);
825	826	}
826	827	};
827	828
...	...	@@ -829,9 +830,9 @@ test "Event broadcast" {
829	830	start_barrier: Barrier = .{},
830	831	finish_barrier: Barrier = .{},
831	832
832		fn run(self: *@This()) void {
833		self.start_barrier.wait();
834		self.finish_barrier.wait();
	833	fn run(self: *@This()) !void {
	834	try self.start_barrier.wait();
	835	try self.finish_barrier.wait();
835	836	}
836	837	};
837	838
...	...	@@ -841,5 +842,5 @@ test "Event broadcast" {
841	842	for (&threads) \|t\| t. = try std.Thread.spawn(.{}, Context.run, .{&ctx});
842	843	defer for (threads) \|t\| t.join();
843	844
844		ctx.run();
	845	try ctx.run();
845	846	}