mirror/zig
1
0
Fork 0
mirror of https://github.com/ziglang/zig.git synced 2026-01-20 14:25:16 +00:00
Code Issues Packages Projects Releases Wiki Activity

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

Browse Source
This commit is contained in:
kprotty 2021-06-30 11:55:52 -05:00
parent 2a6ba41020
commit 2309c81a78
1 changed files with 6 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
lib/std/Thread.zig
View File

@ -497,7 +497,7 @@ const LinuxThreadImpl = struct {
const ThreadCompletion = struct {
completion: Completion = Completion.init(.running),
child_tid: Atomic(i32) = Atomic(i32).init(0),
child_tid: Atomic(i32) = Atomic(i32).init(1),
parent_tid: i32 = undefined,
mapped: []align(std.mem.page_size) u8,
};
@ -510,7 +510,7 @@ const LinuxThreadImpl = struct {
fn entryFn(raw_arg: usize) callconv(.C) u8 {
const self = @intToPtr(*@This(), raw_arg);
defer switch (self.thread.completion.swap(.completed, .Acquire)) {
defer switch (self.thread.completion.swap(.completed, .SeqCst)) {
.running => {},
.completed => unreachable,
.detached => {
@ -600,8 +600,8 @@ const LinuxThreadImpl = struct {
const flags: u32 = os.CLONE_THREAD | os.CLONE_DETACHED |
os.CLONE_VM | os.CLONE_FS | os.CLONE_FILES |
os.CLONE_SIGHAND | os.CLONE_SYSVSEM | os.CLONE_SETTLS |
os.CLONE_PARENT_SETTID | os.CLONE_CHILD_SETTID | os.CLONE_CHILD_CLEARTID;
os.CLONE_PARENT_SETTID | os.CLONE_CHILD_CLEARTID |
os.CLONE_SIGHAND | os.CLONE_SYSVSEM | os.CLONE_SETTLS;
switch (linux.getErrno(linux.clone(
Instance.entryFn,
@ -628,7 +628,7 @@ const LinuxThreadImpl = struct {
}
fn detach(self: Impl) void {
switch (self.thread.completion.swap(.detached, .AcqRel)) {
switch (self.thread.completion.swap(.detached, .SeqCst)) {
.running => {},
.completed => self.join(),
.detached => unreachable,
@ -640,7 +640,7 @@ const LinuxThreadImpl = struct {
var spin: u8 = 10;
while (true) {
const tid = self.thread.child_tid.load(.Acquire);
const tid = self.thread.child_tid.load(.SeqCst);
if (tid == 0) {
break;
}