Commit 2309c81a7812fab071fd2994bb3074edf748de63 | zig

author	kprotty <kbutcher6200@gmail.com> 2021-06-30 11:55:52-05:00
committer	kprotty <kbutcher6200@gmail.com> 2021-06-30 21:49:00-05:00
log	2309c81a7812fab071fd2994bb3074edf748de63
tree	36fc9d8a47b44d0ef9862d76a925d337e3652b5f
parent	2a6ba410209e867ced3b82cf7326960137995853

std.Thread: non-zero child_tid to avoid racy join()

1 files changed, 6 insertions(+), 6 deletions(-)

lib
- std
  - Thread.zig

lib/std/Thread.zig+6-6

...	...	@@ -497,7 +497,7 @@ const LinuxThreadImpl = struct {
497	497
498	498	const ThreadCompletion = struct {
499	499	completion: Completion = Completion.init(.running),
500		child_tid: Atomic(i32) = Atomic(i32).init(0),
	500	child_tid: Atomic(i32) = Atomic(i32).init(1),
501	501	parent_tid: i32 = undefined,
502	502	mapped: []align(std.mem.page_size) u8,
503	503	};
...	...	@@ -510,7 +510,7 @@ const LinuxThreadImpl = struct {
510	510
511	511	fn entryFn(raw_arg: usize) callconv(.C) u8 {
512	512	const self = @intToPtr(*@This(), raw_arg);
513		defer switch (self.thread.completion.swap(.completed, .Acquire)) {
	513	defer switch (self.thread.completion.swap(.completed, .SeqCst)) {
514	514	.running => {},
515	515	.completed => unreachable,
516	516	.detached => {
...	...	@@ -600,8 +600,8 @@ const LinuxThreadImpl = struct {
600	600
601	601	const flags: u32 = os.CLONE_THREAD \| os.CLONE_DETACHED \|
602	602	os.CLONE_VM \| os.CLONE_FS \| os.CLONE_FILES \|
603		os.CLONE_SIGHAND \| os.CLONE_SYSVSEM \| os.CLONE_SETTLS \|
604		os.CLONE_PARENT_SETTID \| os.CLONE_CHILD_SETTID \| os.CLONE_CHILD_CLEARTID;
	603	os.CLONE_PARENT_SETTID \| os.CLONE_CHILD_CLEARTID \|
	604	os.CLONE_SIGHAND \| os.CLONE_SYSVSEM \| os.CLONE_SETTLS;
605	605
606	606	switch (linux.getErrno(linux.clone(
607	607	Instance.entryFn,
...	...	@@ -628,7 +628,7 @@ const LinuxThreadImpl = struct {
628	628	}
629	629
630	630	fn detach(self: Impl) void {
631		switch (self.thread.completion.swap(.detached, .AcqRel)) {
	631	switch (self.thread.completion.swap(.detached, .SeqCst)) {
632	632	.running => {},
633	633	.completed => self.join(),
634	634	.detached => unreachable,
...	...	@@ -640,7 +640,7 @@ const LinuxThreadImpl = struct {
640	640
641	641	var spin: u8 = 10;
642	642	while (true) {
643		const tid = self.thread.child_tid.load(.Acquire);
	643	const tid = self.thread.child_tid.load(.SeqCst);
644	644	if (tid == 0) {
645	645	break;
646	646	}